A wide variety of creatures inhabit the forests, tundras and bogs of the Lapland reserve.
Each group of animals has its own unique role in a complex hierarchy of ecological relationships.
Special place is hold by the most numerous predators in the microcosm – spiders.
Оrder of spiders (Aranei) belongs to the class of the arachnids (Arachnida), subtype chelicerate arthropods (Chelicerata), type of arthropods (Arthropoda). At the present moment
almost 44 000 species of spiders are known in the world.
In number of terrestrial arthropods species, they are second
only to related order of acarians (Acarina) and five major insect orders (beetles, butterflies, bugs, Diptera and Hymenoptera). Spiders have fully inhabited all natural areas and terranean habitat types. Spiders fauna in Russia has more than
2 500 species, and this is not the final number.
It is not easy to present a complete portrait of these creatures; we will try to tell at least about several features of them.
Unlike millipedes, crustaceans and insects spiders like
all the chelicerate arthropods have quite simply organized
mouthparts – there are two chelicerae (jaws analogue) and
two pedipalps (tentaculites). Chelicerae consist of two segments – a main one and an end one, claw-like embedded
in the main segment stria like a pen knife cutting edge. Clawlike segment by the way it is organized resembles a fang – inside is a channel which is used to conduct poison into a kill or
an enemy body. However, chelicerae are used by spiders not
only to bite an enemy, they also catch and mill kills; it is also
a tool to clean the other extremities, dig soil, cut a web while
constructing it and for other needs. Pedipalps unlike chelicerae
Spiders of the Lapland reserve
Spiders of the Lapland reserve
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Lapland state nature biosphere reserve
Spiders of the Lapland reserve
consist of six segments with claws on the top of the latter and
are mainly used as tactile organs, although this is not their single role. Using pedipalps spiders hold a kill and other objects,
taste and smell, make a web. If fore feet are lost, pedipalps can
partially replace them and help moving. Many species of spiders are able to cast feet. As a lizard’s tail, cast leg continues
moving for a while, distracting potential enemies, and a new
one grows on its place provided that a spider can still shed.
Adult males’ pedipalps convert into a copulatory organ.
The latter function of pedipalps is typical namely for spiders
and is not encountered among the other chelicerate arthropods. Once upon a time ancestors of male spiders used pedipalps to transfer bags with semen – spermatophores – and
passed them to females during a mating ritual. To make carrying spermatophores more convenient pedipalps have been
changing gradually, a claw shifted from the top to the side
surface of the last segment, and then acquired a bizarre shape,
looking like a syringe capable of injecting semen into female
genital pores. Segment itself has increased, acquired a spoon
shape, and an onion-like syringe-claw securely storing sperm
is located inside a “cup” of a “spoon”. The need for a protective bag – spermatophore – disappeared, and the only thing
that reminds about it is that spider’s spermia are not located
in semen one by one, but packed by several pieces together.
Male pedipalps can often have some additional outgrowths,
bristles and deepenings of various shapes that fit together female genitals key to a lock. This mechanism of “a lock and
a key” is an obstacle for interspecific hybridization and therefore is an important generic feature. Drawings of the external sex organs are the basis for description of spider species
in the scientific literature.
Eyes of remote ancestors of spiders were faceted, complex,
consisting of many simple eyes, just as of modern insects.
However, after inhabiting ground ways of two groups of ancestor diverged – if insects preserved faceted eyes, individual
facets of chelicerates were divided and gave start to formation of simple eyes. It should be noted that such eyes often
give to an image of spider a remarkable resemblance to vertebrates, unattainable for other arthropods.
Figure 8 is amusingly repeated manifold in a structure
of spiders. This is known by everyone amount of walking legs,
which distinguishes most arachnids; and a number of eyes
(although some species of spiders, especially those living
in caves can have reduced amount of eyes by one pair or more,
until complete absence of eyes). Even body shape of a spider
resembles an eight, consisting of the anterior part – prosoma
and posterior – abdomen. Prosoma is a half of body that is responsible for interaction with the outside world. For a reason
a head and sense receptor of bilateral animals with a front end
of the body (as opposed to radially symmetrical animals, like
sea stars) have developed namely in the front, in the direction
of movement. This process reached its logical end at spiders:
the front half of the body has not only main sense receptors,
but limbs, and a nervous system inside a prosoma coordinates everything, it is concentrated in a rather complicated
for invertebrate brain, more perfect than, say, insects. Even
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The pair of spiders Microlinyphia pusilla:
differences between pedipalps of male and female are well seen
Look of the spider-wolf Alopecosa aculeata seems quite sensible
The spider-wolf Trochosa spinipalpis, side-view
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Figure 8 is amusingly repeated manifold in
a structure of spiders. This is amount of walking
legs; a number of eyes and even body shape
of a spider resembles an eight.
We will again remember extinct predecessors of spiders.
On rear part of a body they had limbs that were inherited
from the more ancient progenitors of all arthropods – annelid
polychaete worms. It must be said that limbs of animals – are
organs than can in the course of evolution be easily subjected
to amazing modifications and can switch to completely different roles than in the beginning. This happened to abdominal
legs of ancient chelicerates: a part of them, which served for
movement and breathing in water (they settled gill branches)
persistently kept on perform a respiratory function when animals began to inhabit ground. For this purpose, pits and later
nests for respiratory legs were formed in abdomen to protect
them from drying in air. Thus limbs transformed into lungs.
It distinguishes spiders from insects and strangely reminiscent
of terrestrial vertebrates: only they and we have lungs. However, with decrease in body size insect respiratory system –
the trachea – is more suitable and many groups of spiders
switched to it partially or completely, and very small species
generally lost their respiratory organs and breathe through
the whole body surface.
Hind abdominal legs of ancient pre-spiders fulfilled another role. Spinning glands appeared namely here. What was their
initial function is difficult to say; possible for making a shelter or protective canopy for eggs laying. Over time, the main
body of the glands moved to abdomen, only glands outputs
left on shortening legs; number of legs segments was reduced
to two or three, and the legs themselves displaced to the end
of abdomen. Thus spinnerets were formed, by the way an initial number of them was equal to eight (four pairs)! However, amount of spinnerets of modern spiders reduced up to 6,
4 or 2; it is enough to create webs. One pair of spinnerets
of some spiders species is still very elongated and resembles
small legs, often used in addition to creating web as sense
of touch. Position of spinnerets on the end of the body, even
a hind one, has proved to be very successful: they are able to
move as hand fingers, abdomen can also be moved from side
to side, moving the entire “palm with fingers” like a painter’s
brush. Amount of waking legs appeared to be abundant, therefore a rear pair is used, in addition to walking, to pull a web and
make manipulations with it. So it is not a surprise that with
such a set of “tools: and freedom of movement spiders have
developed and improved their web making abilities. Suitable
body structure served as a basis for further evolution.
Prosoma and abdomen of spiders are connected with
a small pedicle which connects all body parts – blood vessels,
nerves and intestines. And that’s basically all that is contained
in the pedicle! It is very thin, so it can be used as a special
“joint” for abdomen movement, at that abdomen itself can
not change its shape and operate easily, being more mobile
than a prosoma. On the other hand, such a narrow pedicle
testifies about a perfect internal structure of spiders allowing
connecting the fore and hind body parts by minimum amount
of “binding yarns.”
The whole spider body is covered with hairs and setae
being more important than it may seem at the first glance.
The fact that unlike us, having soft skin which is direct contact
with the outside environment, arthropods’ body is covered
by a protective carapace – cuticle, which outer layer almost
doesn’t content living cells. There are advantages and disadvantages. For example, a cuticle can be attached muscles and
another organs from inside, and a body retains moisture for
a long time thanks to such a carapace. And on the contrary,
it is impossible to grow within it, so spiders have to shed from
time to time, getting rid of an old “fell”, becoming softer and
defenseless, and body size significantly increases only at that
period. Hard cover restricts mobility, and body with limbs have
to be divided into segments connected by more elastic parts
(hence the name of species is arthropods). We, chordates, were
also originated from annelids, but went the other way – created an internal skeleton and preserved elastic alive external
covers. Each way was good: arthropods successfully occupied
a niche of small animals and chordates – medium and large.
So a protective hard cuticle makes it almost impossible
to feel anything. And the most part of sensations – tactile,
chemical (smell and taste), auditory is transferred through
a cuticle from different types of hairs as if dressing a rigid spider’s body in the second ephemeral sensitive shell. In addition, hairs protect a body from contact and water (the bigger
is a spider, the thicker hair covering it has, the more it resembles wool of mammals), create on its hind legs series for
spinning a web and series in sound bodies, thicken into spikes
for catching preys on the front legs and form tenacious pads
allowing walking on any surface ... and finally, hairs are mainly
responsible for spiders coloring.
Color of an animal is determined either by presence of pigments in tissues or structural features of the latter. For example,
white spots on abdomen of diadem spiders (genus Araneus)
are formed by deposition of guanine, and metallic sheen on
Spiders of the Lapland reserve
digestive system in spider’s prosoma is represented primarily
by departments responsible for interaction with the environment – esophagus and sucking stomach sucking (spiders do
not swallow food using jaws and throat, but gradually suck it in
a liquid form using a “vacuum pump” – sucking stomach).
The rear half of spider’s body, by contrast, has collected
almost all organs responsible for internal processes in a body.
A considerable part of the digestive system, and a chemical
factory: – liver, excretory system, reproductive glands where
ova and sperm are formed are located here; spinning gland
are located here as well, capable of synthesizing unsurpassed
in its quality protein building material. If the main in a prosoma
uniting other organ systems (limbs, senses, etc.) – is a brain,
in abdomen such a center is heart ensuring hemolymph run
and metabolism.
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Lapland state nature biosphere reserve
Spiders of the Lapland reserve
Xerolycosa nemoralis – one of the most
brightly colored spiders-wolves in reserve
Abdomen of Araneus quadratus
has white spots forming quadrangle
body of leaping spiders (Heliophanus) is manifested by refraction of light in lenticular areas in cover hairs. Coloring plays
a protective role, allowing a spider to blend with a surrounding
substrate – the so-called cryptic coloration. Spots and stripes
can conceal an overall silhouette, in this case coloring is disruptive. Sometimes a body shape and color of spider resemble
other creatures – mostly ants – it is mimicry. All mentioned
variations have one main purpose – protection from birds, because namely birds among the other predators that eat spiders, are mostly oriented on vision while hunting a prey.
Sometimes coloration may be physiological – match
the original color of tissues and body cover. Some species are
darker than the others and thus heat up quickly in sunlight,
spiders sitting on their webs “back down”, have a dark color
on the underside of a body, usually facing the sky. Coloration
of spiders with good eyesight also has a signal role. Origin
of a pattern on top of abdomen is interesting – it is often presented by a tapered longitudinal spot in the front half and wide
“herringbone” in the rear part. So, a tapered spot is usually located just above spider’s heart and copies its size and shape.
Perhaps it serves as heart temperature regulation, as differs
in tone from the rest of abdomen coloration. And a tapering
“herringbone” of repetitive elements – this is the only externally visible trace of posterior half of a body segments connection, which once led to formation of abdomen. It should
be noted that segmentation of chelicerates body is determined by genetic mechanisms similar to those of vertebrates
(certainly vertebrates’ body is not segmented externally, but
the skeleton has repeated segments, such as vertebrae) and
it is coded differently at insects comparing to us and spiders.
If you look at the overall body structure, its uniformity
within the order is striking, no step aside. The same can be
said about feed preferences: all spiders, with the minor exception – are certainly predators (only some species can eat pollen
of plants, one lives on protein bodies of tropical acacia intended for ant-trees symbionts).
Heliophanus dubius male
glitters brightly in the sun
These two features are typical for the other groups of arachnids, except acarians. These are namely spiders and acarians
which reached an unprecedented prosperity among the other chelicerates. Acarians have achieved this by switching to
a variety of feed sources, and due to their ability to change
body structure with the course of the evolution; it means due
to a very deep and multidirectional specialization. Spiders,
on the contrary, remain omnivorous predators and the structure of their bodies is the least specialized of all orders
of arachnids. The set of their limbs is slightly abundant, therefore legs easily acquire an additional role in case of minimal
structure changes and are used to hold prey, feel a substrate,
for manipulation during web making, some tropical species –
for throwing spider “lasso” with a drop of glue on the end or
catching insects with an elastic “butterfly net”, for fixing a female during copulation, etc.
Loss of any leg or pedipalp is easily compensated functionally by adjacent limbs. Therefore, lifestyle changes for spiders
became widely possible without a fundamental restructuring of body. But other orders of arachnids, by contrast, even
at the moment of appearance followed the way of narrow
morphological specialization. Let us consider, for example,
scorpions. Their pedipalps turned into claws, abdomen has
a stretched section-“tail” with a poisonous needle on the end,
thin walking legs located in one plane are unable to support
body by weight – scorpions were not able to retreat the structure formed in the aquatic environment. It defines possible
sizes, and lifestyles, imposing strict limits on diversity and limiting the number of emerging species.
On the other hand, non-specialized common body structure of spiders is complimented by truly fantastic opportunities for using a web. Different taxons, little changed outwardly,
mastered new variants of hunting spider facilities and took
new ecological niches. Even aquatic spiders surprisingly little
changed comparing to terrestrial spiders, so their appearance
cannot be used to identify their habits; but one glance on sub-
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Technical characteristics of a web transcend any man-made
fibers, that clearly indicates perfection of spider silk chemical
composition, acquired as a result of the evolution. Depending on the purpose the same spider can create multiple spider
threads of different composition and different texture, using
up to seven types of silk glands. So, diadem spiders using ampoule-like glands secrete a thick dry dragline of a radial network
and a thin safety thread when moving outside a web; tree and
flagelliform glands secrete sticky spiral thread of a web: pearshaped glands form bundles of thin adhesive fibers, used to fix
ends of a thick filaments to objects; threads of segment-like
glands are used to mantle prey; threads of tube-like glands
are used to form an egg cocoon, etc. When building a web
a spider carefully calibrates thread tension and acts according
to a complex instinctive action pattern. At that a catching web
Arctosa alpigena –
spider-wolf with “a white heart”
can be modified depending on structural features of a place
where it is being built, weather conditions and other factors,
and sometimes can be modified significantly. Thus, orb-web
spiders in certain conditions may not make a full web, but end
with a small disorderly weaved threads, for example in case
of prey abundance – for example, in a street lamp light. There
is an original way to define some toxic substances – liquid with
admixture of suspicious matter is given to a spider to drink
and then they wait until spider makes a capturing web, change
of its shape is used to determine exactly what kind toxin has
been detected. At the same time webs of orb-web spiders
have such characteristics, that they can be used to identify
species of a host, and some of these features (constant ratio between the sizes of the individual parts of the network)
is on the networks of this spider species at any age.
Except building catching nets, web is used for moving safety (“trace thread”) for mantling a prey and preparing space for
Spiders of the Lapland reserve
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Alopecosa aculeata –
spider-wolf with “a dark heart”
Araneus marmoreus extracts an insect caught into his web
Male and female Nuctenea silvicultrix
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Lapland state nature biosphere reserve
Spiders of the Lapland reserve
its storage and eating, small species and young spiders of large
species – for building shelters, threading burrows, weaving egg
cocoons, for construction of spermatic net by males (which
they use to fill their pedipalps with a seminal fluid from abdomen), to mark territory and leaving odorous marks, hanging
while shedding, to create air domes by water spiders.
Another direction of spiders’ biochemical evolution, where
they also achieved perfection – is production of poison. Spider’s poison consists of mixture of various biologically active
substances – from salt to high molecular proteins – and includes more than a hundred of components, which is a record
among injurious animals. This complex of substances works
in alignment, providing high efficiency of total action; poison
composition is specific for each species of spiders and may also
depend on age, sex, feed, etc. In most cases effect of poison
is directed at main preys of spiders – insects (at that specific
toxins may pose a risk only to a very narrow circle of preys);
mechanism of action is neurotoxic or necrotic. Poisons are often intended also for protection from enemies, therefore there
species of spider dangerous for humans – composition of their
poison is configured to repel vertebrates. In our country, such
spiders inhabit southern semi-desert and called black widows.
Diversity of spiders species makes their poisons inexhaustible
and irreplaceable natural biochemical card index of active substances used in neurobiological research and medicine.
The question arises: why spiders species fauna is so rich
even in the northern territories such as the Lapland reserve?
Spiders almost do not specialize in different feed sources, like
many other animals (for example, snakes of the central Russia: viper hunts small animals, water snake – mainly amphibians, smooth snake – lizards). Hence, separation of ecological
niches of spiders occur on other grounds. First of all this is
a different feeding behavior (which includes use of different
types of catching nets) due to which one habitat can be used
differently. Let us review, for example, a pine forest of the reserve near Chunozero settlement. Between neighboring trees
an orb-web spider Nuctenea silvicultrix is weaving its web, a diadem spider Araneus marmoreus makes its webs on main pine
branches, horizontal webs of long-legged Bolephthyphantes index appear in thickets of small branches, small fine hammocks
of Obscuriphantes obscures are seen among large needles;
simple nets of marked Drapetisca socialis are stretched directly
over cortex, cavity under cortex is densely filled with hunting
nets of Theridion varians, microscopic threads of tiny Savignia
frontata are almost invisible in truck bottom cavities.
Species hunting without nets are inhabiting near artificial
air threads – slow flat crab spiders Coriarachne depressa and
gracious mobile crab spiders Philodromus fuscomarginatus live
in splits, dark-gray twilight hunters Gnaphosa lapponum spend
their time under wide layers of dead bark, bright striped Salticus cingulatus hunt their preys on a sunny side of a trunk,
big colored spiders-wolves Acantholycosa lignaria keep territory near roots. These are the most common inhabitants
of the pines. Firs and birches are inhabited by their own species… Thus spiders can live and hunt on a bark of pine in several different ways, and the same method can be accustomed
Male Bolephthyphantes index
The web of
Obscuriphantes obscurus
Coriarachne depressa
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After fog dew allows to see subtle travel threads of spiders
Eating a fly the female Bolephthyphantes index is a feed for
a larvae of parasitic fly at the same time
Spiders of the Lapland reserve
Salticus cingulatus
to different substrates – bark, stones, ground, and finally spiders are turned out to be dependent on substrates as well as
a method of hunting. So, different methods of hunting, multiplied by structurally different substrates – is one of the main
reasons explaining coexistence of a large number of spiders
species at the same habitat.
Spider population can be very large and close to the number of all the insects of the same size in a given area. If you are
lucky, in a quiet autumn morning when dew is falling or after
a small rain you can see it with your eyes, when usually invisible nets are sparkling silver water droplets systems, and even
one step can disturb at least one of them. Amount of small
spiders in litter fall per 1 m2 can reach more than 200 zooids,
and population of one tree – a few hundred of representatives
from tens of species. It seems that it may not be enough prey
for such hordes of predators and seeming abundance of spiders was noted by researchers more than once.
It is explained by several reasons. First of all, spiders fully digest feed (general ecological rule, stating that only 10 %
of ingested biomass transfers to the next level of a food chain
is not applicable here); Secondly, the vast majority of spiders
is capable to live without feed for a long time not harming
themselves; Thirdly being non-specialized predators when
other feed is absent they can eat their own kind. Therefore
biomass of spiders is safe with respect to adverse and changing environmental conditions, and their population from year
to year remains very stable. It is clear that the role of such
persistent and massive predators in regulating the number
of insects is enormous.
A main enemy of spiders are birds, and in they can
be a basic ration for many insectivorous species such
as tits. Shrews, viviparous lizards, ants, predatory beetles
and many other creatures also readily consume eight-legged
hunter.
At the moment, the Lapland reserve is inhabited by more
than 270 known species of spiders belonging to 17 families. They are found for 4 years of researches, and the fauna
turned to be rich enough for a relatively small northern area.
The reason for this abundance lies in diversity of habitats
in the reserve, and a significant contribution for this is made
by hills – Chunatundra, Monchetundra and Salnye tundras.
Their hillsides are open to different sides of the world and are
illuminated differently by sun; each elevation is characterized
by its vegetation; rock yields in form of boulder streams, cliffs
and rock fall are found on the slopes. All these conditions create a rich mosaic of habitats. Tundra also insulates well watersheds of rivers, which help different species to live in similar
but distant locations.
By hunting strategies spiders are divided into webspinner
spiders and hunters which do not use trapping nets. More differences are found within these groups. Looking at appearance
of a spider one can immediately determine its typical way
of obtaining feed, so its external structure is closely associated with feeding behavior. Active hunting without using a web
is considered to be an initial strategy, however, some modern
hunters have webspinners as their ancestors.
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Lapland state nature biosphere reserve
Young Dolomedes fimbriatus
The marshland on the lake
Spiders of the Lapland reserve
Close families of spiders-wolves (Lycosiae) and spiders-ramblers (Pisauridae) belong to the group of daytime hunters.
They have a rather large size, long strong legs, well-developed
eyes and protective coloring in the color of ground, stones,
or leaves; they run and jump well.
Most of these spiders spend life in constant motion and
therefore often found underfoot in the woods and swamps.
Inaction is alien to them, except only at the onset of cold
weather; active lifestyle requires constant feeding, therefore
feed absence is more complicated for these spiders comparing
with another.
Dolomedes fimbriatus is the one representative of Pisauridae
in the reserve – the largest species among terrestrial species,
reaches more than 4 cm in legs span. Inhabits grassy marshes
and coasts, sometimes hunts even aquatic animals. In north
conditions for large species of spiders it is very important
to choose a warm habitat and swamps in this regard are very
suitable biotopes for size record-breaking spiders of the local
fauna – protected by forest from the, exposed to sun, storing
heat in wet moss cushion for a long time.
A life cycle of this spider in the reserve is two years, mature
spiders appear in June, after the last shedding. Many species
of spiders when mating period begins in early warm season
(May-June), cannot shed for the last time and become sexually mature, not wintered. Spiders overwinter in leaf litters and
can completely freeze without any threat to life due to natural
antifreeze contained in hemolymph. Throughout the summer
and early autumn spiders of the penultimate stage of development accumulate fed and only hibernation stimulates them
to shed – this is the mechanism of simultaneous mass emergence of adults in early summer.
Male finds a female spider, approaches and performs
a courtship ritual. Often it is waiting for a suitable moment
when a female catches a prey and begins to eat – it is safer.
After mating, a female feeds up and constructs a large spherical cocoon in June that is always carried by her with some
difficulties. In some time it chooses a place and hangs a cocoon on sedge leaves or heather twig, and then it spins around
a large loose shield ball, of a grapefruit size of strong messy
threads and remains in this ball to protect a cocoon. It repels
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Growth stages of dolomedes: kids in the nest, grown up spider before its first hibernation,
young female before its second hibernation, adult female
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insects by itself, rushing at them and hitting with front legs,
and a ball is serving as protection from birds. Several hundreds
of baby spiders leave a cocoon in August, for 2–3 days they
remain as a single bunch inside a ball, and then scatter around
the area. Typical light stria appear at baby spiders pretty early, but the overall coloration is not velvety brown, but olive
or green; they live in grass stand, often encountered quite far
from adults. In September baby spiders of the first and second years of life may acquire a reddish outfit to match colors
of autumn leaves.
In calm sunny autumn days after cold nights babies of the
first year are spread through a flight. To do this, they climb on
top of a high plant, stand on tiptoe and raise abdomen vertically, taking the starting position. Sun-heated air flows them
smoothly up and at this moment spinnerets start evolving finest strong thread. The thread is getting longer and picked up
by the air at some point almost takes a spider from surface.
Then it attaches a thread end next to it, moves to it and bites.
Probably all kinds of spiders found in the reserve are capable
to fly. Autumn journeys in search of new territories are limited
only by aeronauts size, so only baby spiders of large species
and adults as well of small species are flying.
Apart from the main life cycle – growth and reproduction – spiders and dependent on shedding cycles. Dolomedes
undergoes throughout life about 8–10 sheds until it becomes
an adult. During shedding a spider is absolutely helpless and
does not respond to external stimuli, fully concentrating on
what is happening. A usual way to shed is hanging back down.
Number of external and internal factors can disrupt this process and a spider can lose a limb or die. Shedding occurs in
a hidden place, often at night. Immediately after it covers are
very elastic, and a spider is unable to move normally and defend itself, it easily loses and absorbs moisture. After a couple
of hours a cuticle hardens, coloration becomes brighter and
another inter-shedding period begins. Relatives of spiders
(scorpions, amblypygi), and many tropical spiders (though
only female) can shed being adults unlimited number of times.
At the moment the Lapland reserve is inhabited by
more than 270 known species of spiders belonging
to 17 families.
The grass spider-crab before flying
Spiders of the Lapland reserve
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The female under the dome of the ball
Balloon-nest
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Lapland state nature biosphere reserve
Pardosa lugubris: immature May male, adult June, and July female with cocoon
amentata, dark Pardosa paludicola and small Pardosa prativaga)
to the highest tundra peaks (Pardosa eiseni inhabiting stony areas and Pardosa palustris of a color of dried grass). The first two
species are common in the moderate climate and their breeding season there starts very early – in April. Here in the north,
along with the other species they start breeding in summer.
One species from the top of Salnye tundras Pardosa indecora,
should not be found on the Kola peninsula at all, as according to all data it is encountered far to the east, for example,
on Taimyr.
Representatives of the genus Acantholycosa changed free
lifestyle to more sedentary. Close relatives of Pardosa, they
differ by large size and long legs. Each female owns its personal territory of several large stones (acantholycosa norvegica)
or a trunk of a fallen tree (acantholycosa A. lignaria), where
a spider hides in case of danger. If one cautiously approaches
an area inhabited by acantholycosa spiders, he/she can make
good pictures of sitting spiders, observe them hunting.
Among Lycosidae spiders there are also amphibiotic spiders living along banks, marshes, craftily walking by water and
Spiders of the Lapland reserve
So why are our species not capable for that? The main reason – hard external sex organs – a special plate with holes on
abdomen of a female and modified pedipalps claws of a male.
Beneath new covers are not able to be formed, and shedding
would lead to tearing of tissues. Thus, any adult male spiders
are not capable of shedding, but female of species without
abdominal plates can usually do it and live longer. Generally,
such species are spread in countries with a warm climate.
The largest Lycosidae of the reserve Alopecosa pinetorum
together with a short-legged phlegmatic Trochosa spinipalpis, like a fishing spider is encountered on margins of cozy
and warm swamps and is very rare. More common is a smaller Alopecosa aculeata – the most notable and active spider
on a dry fragrant needle bed of sparse coniferous forests
in June. The majority of Lycosidae is represented by Pardosa,
agile and graceful small hunters, each species of them prefers
a different type of soil and a plant litter. Thus, all 13 species
of Pardosa share the territory of the reserve, although often
representatives of 2–3 species can be found together. They
live everywhere, from marshes and shores (colored Pardosa
Common in tundra Pardosa eiseni is basking in the sun
Pardosa paludicola
10
ABCGheritage – Our common arctic heritage
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Female Pirata piraticus
Spiders of the Lapland reserve
Acantholycosa lignaria
diving if necessary. In the Lapland reserve such species of spiders from Pirata genus are represented. They have a slightly
greenish color with a light trident on cephalothorax. The most
common is Pirata piraticus, and its close relative, actually reduced copy of it, Pirata insularis, is met only on a sedge
swamp around a steam at the bottom of the ecological path
“Elnyun-II”.
Cocoon of Lycosidae is smaller than the one of Dolomedes.
Usually females attach it to spinnerets and quietly go about
their business, not forgetting to use every opportunity to sit
in the sun, warming their future offspring. After hatching spiders remain protected in a swollen and shed there twice before
to go outside. Baby spiders immediately get on a mother’s
body and hold its hair. At certain times of a year Lycosidae females covered by baies can be found everywhere. This characteristic period for the family of protecting offspring lasts several days, during the period a mother is gradually throwing off
baby spiders in different places it likes. Maternal affairs do not
prevent it from regular hunt, and, if weather allows, the first
cocoon will be replaced by the second one and occasionally
it manages to get the third one.
A peak of evolution among day stray spiders – are jumping spiders (family Salticidae). Their world perception is based
on vision, like human. Central front eyes are very large and
are not spherical but tube-shaped resembling a pair of binoculars, which they are in fact. They really do give a detailed
enlarged image. “Binoculars” field of vision is small, and this
defect is compensated by two mechanisms: main eyes are
able to move and follow an object, and provide all-round view
is ensured by remaining 6 eyes. The front side eyes fall short
of size comparing to central ones. Their function is different:
they are not responsible for enlargement, but for binocular
vision (three-dimensional perception of space) as they are located most widely apart.
Other eyes give a low quality image and serve to expand
a visual field. This function is performed by rear eyes of all spiders, but it is perfect at jumping spiders – only their rare side
pair is pushed back, sometimes behind the middle of prosoma.
Generally speaking, it is difficult to imagine how jumping spider see the world: to usual for us color vision they have additional built-in binoculars and back view eyes and it all works at
the same time!
Vision allowed jumping spiders to master the technique
of jumping, which they use to attack (short rushes creeping up
a prey at the right distance) and movement. These capabilities are particularly useful when moving in the midst of plants:
looking all around and accurately estimating a distance between objects, the spiders jump between leaves and stems,
as they want. Movement in a complex three-dimensional environment requires development of a nervous system, and, like
other animal having similar lifestyle (primates, arboreal amphibians, parrots), jumping spiders are the “smartest” among
their relatives, in this case – among spiders. It is proved that
learning by trial and error can be a mandatory component
of jumping spiders behavior unlike fully programmed instinctive actions of most other spiders.
11
Lapland state nature biosphere reserve
Female Acantholycosa norvegica with cocoon
Female Pardosa prativaga with cocoon
Many jumping spiders acquired bright coloration, because
they are able to see and appreciate it. Dresses of all rainbow
colors are used to recognize zooids of their own species, to distinguish males, females and baby spiders, for refined mating
dances. Jumping spiders are usually quite small, but when looking closer to these living colorful sparks, few can resist the fascination. Thick body with compact limbs covered with thick
hair, and “owl-like” expressive eyes changed a standard spider
appearance beyond recognition, giving the jumping spiders
the appearance of mysterious animals. Getting accustomed to
something, they turn cephalothorax following an object producing a lasting impression of an “intelligent” view.
The Salticidae are abundant in the tropics, where they can
even prevail in number of species among the rest of the spiders. This is the largest family of spiders in the world consisting
of more than five and a half thousand species. To the north of
the equator, their diversity is steadily declining, and the fauna
of the Lapland reserve is represented only by 7 species of jumping spiders. The greatest number of these thermophilic spiders
met is encountered in the western slope of the tract Saidnotlag, in a rocky hollow, closed from all sides except the south.
Good drainage at constant streams fall, heating by direct sun-
light and protection from northern winds create there a very
special microclimate. This unique area is inhabited by a number
of southern species not encountered anywhere else in the reserve. We can assume that such emigrees are periodically
brought here by southerly winds; flying over Chunozero lake and
coming across Chuna tundra mountain slope air waves leave
tens of spiders of different species on a warm slope.
In addition to daytime hunters, there are twilight and night
hunters, having an elongated body and almost equal-sized eyes,
usually located in two rows. Close families of sac spiders (Clubionidae) belong to them: Zoridae, Liocranidae, as well as Gnaphosidae.
Unlike wolf spider running and jumping everywhere, ground
spiders hyenas are secret ramblers with a monotone color and
white, as if lifeless eyes. This color is due to a silvery reflective
mirror, typical for many nocturnal creatures. However, a part
of eye remains dark, day part. Most spiders have mirrored eyes,
but eyes of Gnaphosidae are especially noticeable. Representatives of different genera and species are remarkably similar,
only size and gloomy shade colors vary. During a day they hide
under bark and stones, they also overwinter there and protect
cocoons attached to plane substrates.
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Spiders of the Lapland reserve
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Young female Evarcha arcuata
Immature female Evarcha falcata
Immature male Evarcha falcata
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ABCGheritage – Our common arctic heritage
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Adult female Evarcha falcata
Adult male Evarcha falcata
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Only two species of Micaria genus sharply distinguish from
the total mass which switched to a day lifestyle. However, they
have a capping relation with other ground spiders. Well looked
small micaria run in a day time copying habits and appearance
of small ants and wasps. Their dark body sparkles in the sun
by all rainbow colors as it is covered by hairs refracting light.
The two most common species of this genus divided simply
by their preferences – one lives in the lowland part of the reserve, and the other – on the hills; other species are met only
in Saidnotlag mentioned above.
All males from the Liocranidae and sac spiders, including all
adult females from the first family (genus Agroeca) were found
only in August and September, i.e. their mating season starts
in the very end of the warm season. For medium and large
spiders of the Lapland reserve it is an exception to the rule –
males of other species of this size group mature in early to mid
summer.
Among spiders-hunters not making webs spiders-ambuscaders stand alone – “living traps”. If wolf spiders are adapted
to rush, jumping spider – to jump, spiders hyenas – to “ramble”, a business card of ambuscaders is their agility, ability
to crab movement, turn quickly to sides. Such skills were required for inhabiting limited space, such as a fracture under
Zora spinimana
Spiders of the Lapland reserve
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Slope of the tract Saidnotlag
13
Lapland state nature biosphere reserve
Spiders of the Lapland reserve
Female Gnaphosa
Up: Agroeca proxima, down: Clubiona
Immature male Gnaphosa
Worried female Gnaphosa
tree bark, a flower, a cavity between soil particles. Maneuverability is achieved very simply: by a small rotation of an axis attaching legs to a body, as a result legs are not only bent downwards, but sideways as well. System of spider’s legs reminds
a set of tongs, a front pair is bent forward, and hind legs – often – backwards. Two close families of crabs – ambuscaders
(called spider-crabs because of an appearance and manner of
movement), Philodromidae and Thomisidae differ in a relative
size of front and rear pairs of legs – legs of the first are about
the same, and rear legs of the second one are shorter than
front pairs. Front legs are equipped with numerous thick spikes,
helping to keep even a very large prey. Eyes are only day, they
are directed to different sides and raised above the surface of
prosoma for better viewing, like other ambuscaders – frogs,
chameleons, flounder, mantis. Cryptic coloration of crab spiders is adapted to specific conditions and is much better than,
say, coloration of wolf spiders, which has a generalized character, more or less suitable for other habitats. Floral spider Misumena vatia, found near Lower Chuna, is even capable of changing a color of its body, like chameleons, but slower. Its arsenal
consists of green, yellow and white dresses. Philodromus fuscomarginatus’ color tone is also changeable, it inhabits pines,
spiders of a red and gray colors are encountered. Body of crab
spiders inhabiting tree bark is often flattened which only increases the similarity with some crabs hiding among the rocks
on the bottom.
All Philodromidae are featured by high speed and maneuverability, but as in other families, each genus prefers a different type of substrate: Philodromus – bark, Thanatus – soil
surface, Tibellus – grass. Grass – a special place to live, and
a body of tibellus is stretched, covered with long longitudinal
stripes; stopped dead in ambuscade missed – a spider looks
like a straw.
Thomisidae on the contrary are slow (but “agile”). Besides
mentioned Coriarachne and flower spiders they include numerous gray-brown “crabs” of the genus Xysticus (7 species)
that live on ground and low plants, and several small species
of Ozyptila, similar to baby Xysticus. Diminutiveness of Ozyp-
14
ABCGheritage – Our common arctic heritage
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Misumena vatia on Dwarf cornel
tila allows them to penetrate deep into a plant litter, shrubs,
moss cushion. Thick hairs on their bodies partially became
claviform – such tiny upraised “cams” that protect a body from
coarse grains.
A main enemy of spiders are birds. Shrews,
viviparous lizards, ants, predatory beetles and
many other creatures also can consume the spider.
Among nearly invisible inhabitants of reserved bed there
are spiders with very primitive prey networks (family Hahnidae). Web apparatus of most of Theridiidae consists of 6 long
segments spinnerets located strictly in a row across abdomen
bottom. Using spinnerets spiders construct a horizontal flat
panel of irregular shape and go over the network. In fact, such
a network – is just a better copy of soil surface, where prey can
Spider-ambuscader in hunting pose
stick, thread tension allows to understand location of a kill.
Externally spiders of genera Hahnia and Antistea resemble
small gray night hunters than “real” Theridiidae. Only Cryphoeca silvicola, living in birch bark is more or less brightly colored.
Its web apparatus is not exotically structured. But this species
does not avoid a litter – in autumn cryphoeca go down there
for hibernation (crab spiders Philodromus do not do it and remain for overwinter under bark).
On the contrary makers of perfect wheel-shaped vertical
webs are not encountered in a litter. These spiders inhabit all sorts of vegetation and rock slides. Their webs consist
of radial threads forming a kind of bicycle spokes and spiral
sticky trapping thread stretched between them. Such an arrangement allows catching an impressive space sector with
minimum material consumption and repairing damages easily
(as tension of each section of a network can be adjusted separately). Working surface is attached to a simple frame, usually
triangular, only three points of support are enough to fix it;
thick threads of a random length drawn on these points. Finally a network can be placed practically everywhere. Usual-
Spiders of the Lapland reserve
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Color options of female Philodromus fuscomarginatus
15
Lapland state nature biosphere reserve
Closely species of Tibellus – maritimus and oblongus
Cryphorca silvicola
Ground crab Xysticus audax has perfect protective coloration
ly orb-web spider (Araneidae) construct webs at night and
in morning when air is quiet, and majority of birds is sleeping.
In soft light of a cool night busy silent constructors scurry between branches, sit in a center of networks, patch holes made
by large moths, mantle preys and carry them into shelter near
a network. Many species build a new web every night which
is suitable for that and leave an old one, while others are able
to collect used webs with small dipterans in them and eat
a lump. Some features of radial networks and their creators
have been already mentioned above. One can tell much about
them; detailed descriptions are found in many books devoted
to spiders. “Economic” effect of using radial webs is manifested by the fact that the largest Theridiidae of the reserve belong
to orb-web spiders. Large terrestrial spiders are in better conditions – soil surface warms up well during a day, and hunters may find vitally required heat. Theridiidae living on air are
harder to do it.
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Spiders of the Lapland reserve
To the left: female Xysticus ulmi, to the right: female Xysticus obscurus
Ozyptila atomaria
Araneus marmoreus on ground
16
ABCGheritage – Our common arctic heritage
A pair of Larinioides patagiatus
However, some orb-web spider find a way out – during day
time they come down to a warm bedding, and representatives
of one species – Nuctenea silvicultrix sit under pine trees bark
and digest feed consumed in night time warmed by sunshine.
Not for nothing large zooids of this species are encountered
throughout a season, they can be found immediately after
melting of snow. In more southern latitudes during breeding
period of different orb-web species is spaced in time. For example, for a genus Larinioides mating season in the midland
is typical in spring, for many diadem spiders (Araneus) – in late
summer, for Araniella – in early summer; but within the Lapland reserve all of them have to move these important stages
of breeding cycles to the hottest time – mid-summer.
Diadem spiders often have a complex pattern of spots
on an abdomen, and this pattern distinguishes the species
from each other. Moreover, Araneus marmoreus has sev-
eral options for coloration – gray, yellow and reddish. This
marking serves for the same goal – protection, it conceals
a silhouette of immovable spider. In case of evident danger
diadem spiders just fall off a network and freeze. Large globular abdomen and thin legs of the Theridiidae simply do not
allow them to escape from danger, and diadem spiders rely
on their assumed non-visibility. Nuctenea is painted in gray
tones of a bark color, Araniella cucurbitina living in shrubs –
is of a clean green color, Araneus saevus amazingly merges with
surface of dark stones on rockslides.
Among small species of orb-web spiders only Cercidia
prominens is common, it has a hard shell on abdomen, protecting it from predators; species of the genus Hypsosinga and
Cyclosa are rare.
Much more elegant are some species close to orb-web spiders from a small family Tetragnathidae. A common feature
Spiders of the Lapland reserve
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Immature females Araneus marmoreus have similar coloring (first photo), but adult females have different one
17
Lapland state nature biosphere reserve
Spiders of the Lapland reserve
Female Araneus saevus
of this family – is elongated lobe-shaped outgrowths of initial pedipalp segment forming a kind of the second jaws under chelicerae (name Tetragnatha is translated as “four jaws”).
Such blades, but shorter, are typical to the other spiders as
well; they limit a perioral area. Structure of a radial network
also differs – at Tetragnathidae its center is empty, at orb-web
spiders it is usually tightened by a little messy mesh. Metellina merianae is so similar to the genus of diadem spiders, that
scientists-taxonomists sometimes make it “jump” from one
family to another. This species lives in caves, boulder stream,
basements, etc., preferring a mountain landscape. Metellina
is so dependent on its habitat that lives in appropriate places everywhere almost regardless of latitude. It can be found
in the mountains of Central Asia and in the Lapland reserve,
in the Carpathians and the Urals. Metellina’s web is asymmetric, its lower half has two times more semicircular trapping
threads than an upper one.
The genus Tetragnatha giving its name to the family includes only slim long-legged spiders which elongated body
shape means adaptation to live in grass. Small neat meshes of elongated Tetragnatha Tetragnatha extensa, described
by Carl Linne, can be seen on marshes, along river and lake
coasts, among different grasses of the reserve. Adult spiders
are encountered in summer, and baby spiders can be found
at any time; in autumn growing spiders often become reddish, similar to growing Dolomedes spiders. The smallest have
almost spherical abdomen, which is increasingly stretched
while growing. When hunting Tetragnatha are stretched out
in a center of their networks and externally resemble a needle.
In case of danger they run across to a stem or leaf of grass next
to a network, embrace it with shortened legs of the third pairs
and spread out to become almost invisible. As hard to imagine riverbanks without sedges, so hard is to imagine riverbank
sedge without Tetragnatha.
Female Cyclosa conica
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Metellina female
A pair Tetragnatha
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ABCGheritage – Our common arctic heritage
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Orb-web spiders are on the top of the evolution among the
Theridiidae, as jumping spiders among hunters. However, ways
of evolution are fancy, and the last from two genera Tetragnathidae – Pachygnatha found in the reserve includes species
that do not use trapping networks at all and returned to live
on simple hunting.
Pachygnatha clercki is found only in the entry of the river
Verkhnyaya Chuna; spider roams on a surface of soil across
coastal vegetation, using transportation threads to move
among sedge stems sticking out of water, and if there
is a need – it can run fast. Externally pachygnata is not really
similar to its relatives Tetragnatha and Metellina but similar
to them is widely spread, from Central Asia to Taimyr, which
is associated with its choice of habitats – stone deposits and
rocks, water coasts and sedges can be found in almost any
latitude and longitude.
The only predators that could permanently settle in human
residential buildings also belong to the Theridiidae, primarily
from the family of the cobweb spiders (Theridiidae). Species
of Steadoda genus, distant relatives of black widow, are worldwide common in residential buildings. In the wild nature they
live in dry rocks and caves of warm countries, therefore they
are capable of staying without feed and water for extremely
long period, and their web network functions well for many
days with a minimum repair requirement. Real synanthropic
spiders are not encountered in the reserve’s farm – as internal
house temperature in winter is too unstable; but a local steatoda species small Steatoda bipunctata inhabits the surrounding territory, in the woods, under tree bark. It is eager to inhabit the houses inside and outside, and reserve personnel
can often observe brownish spiders descending from somewhere in the ceiling on a web. Usually they are males traveling
in search of females. Their networks are often found behind
furniture, in corners, under wooden panels leaning against
a house – as it shall be for house spiders. But still steatoda
bipunctata remains a “wild” species – it is not encountered
in big cities, and if it is met a residential house, that is because
its habitat is not far from it.
Pachygnatha male
Steatoda bipunctata female
Spiders of the Lapland reserve
A young Tetragnatha extensa female in autumn coloring
Asagena phalerata male
19
Lapland state nature biosphere reserve
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Spiders of the Lapland reserve
Crustullina guttata
For a close genus Asagena wandering males are also very
typical. They are often found on dry open slopes in the forest-tundra belt. Brightly colored spiders with thick covers are
not afraid to run in a day time as they resemble big red ants
very much.
On open slopes of Chuna tundra in Saidnotlag tracts the tiniest species of web spiders from the local fauna are found –
Crustullina guttata. Two millimeter round spiders, brown
in white dots, live in the bottom surface of stones on the edges of stone falls where in the cavities between soil and stones
they are constructing a rare web typical for their family consisting of a pattern raised above a substrate and many short
sticky trapping threads connecting with it intended to catch
small crawling insects. If you turn a stone, sun blinded crustullina will freeze on a stone surface as tiny polka dots, hoping
that they will remain unnoticed, and somehow everything will
return to its initial stage. Female lay only a few (5–8) huge
eggs comparing to its size and its large offspring shall shed several times to grow. Therefore, the breeding cycle of crustullina
is little connected with a certain season, and under one stone
spiders of all ages can be found.
Population of Crustullina guttata in its habitats is large;
Meanwhile, in the reserve crustullina is found only in one place.
This is an example of extreme confinement to a particular type
of a certain biotope, and as a local settlement. It means that
crustullina can not be met at the same habitat simply because
they didn’t get there in sufficient amount and were not able
to stay there. For the majority of spiders in the different situation is common: if there is a certain habitat certainly there
are typical species inhabiting the area. The most abundant
species have even “additional” habitats, where the population can be quite large, but there is a constant migration from
basic habitats where population of a species lives successfully. So the picture of living environment is blurry, such as of
the wolf spider Alopecosa aculeata.
The most numerous Theridiidae in the reserve are inhabitants of mosses and plant litter of the genus Robertus: 7 species of small gray spiders are found in a variety of wet places.
Robertus lividus under old plank
Cryptachaea riparia and Theridion varians
20
ABCGheritage – Our common arctic heritage
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The most common is Robertus lividus, inhabiting somewhere
under decaying trunk or old woods, their webs are coexisting
with white hyphae.
Several colorful species of Theridiidae inhabit also trunks
and branches of trees, preferring thick fir crowns. The most
common is Theridion varians, which network has no expressed
pattern and consists of random loose and sticky threads.
Very similar to theridion is the only one species found in
the reserve from the family Mimetidae – Ero furcata. Only if you
look closely, you will notice unusual rows of thin strong spines
on its front legs. Before us is terrible predator – spider preying
on other spiders. Ero is slowly wandering over surface of soil
and plants, grabbing another spiders with its spiny limbs. If it
finds a spider’s web, it starts to pull it, simulating a trapped insect; intrigued host deathwards rushes eagerly to alleged prey.
In August and September somewhere in a dark corner not far
from soil surface Ero female constructs a cocoon and protects
it. Golden ball covered by a loose shell sits on a long thin stem,
recalling a strange fruit. It contains only 6–10 large eggs.
Some other species from the Linyphiidae family also have
equipped front legs, however, they still hunt for insects. In late
summer Drapetisca socialis abundantly inhabiting tree trunks
closes its spiked limbs cabin around a prey and makes it unable to escape from a “cage”. These spiders often settle near
each other, that is why Drapetisca received its species name –
“social”. Such clusters can be seen, for example, at the summerhouse near Pouce cordon. Tiny Maso sundevalli and Minicia
marginella hunt in the same manner in litter.
Generally speaking, the Lapland reserve – is a kingdom
of the Linyphiidae family, there are not less than one hundred and fifty species here – more than a half of the entire
fauna. Such abundance of Linyphiidae is typical for the north
Drapetisca socialis female and male
Portrait of Pityohyphantes phrygianus female (up)
and young Pityohyphantes male (down)
Spiders of the Lapland reserve
Ero furcata female and its cocoon
21
Lapland state nature biosphere reserve
Helophora insignis: web and its hostess
and the midland. They are second best in number of species
(about 4 500) in the world after jumping spiders. Almost
any spiders family can be characterized by a certain direction of evolution, a kind of unifying “idea.” Such an idea for
the Linyphiidae is size reduction, miniaturization. One of
the two subfamilies of Linyphiidae is called like that – spiders
pygmies.
Species of a medium size like, for example, Pityohyphantes
phrygianus and Helophora insignis, make up a small part of the
family. They build dense horizontal trapping nets with often
supporting threads directed upwards and downwards; a spi-
Tenuiphantes alacris: web and its owner
der is walking on the underside with its abdomen up and
catches a fallen insect enough right through it. With decreasing of Linyphiidae size structure of their networks becomes
simpler; many spiders Pygmies can do without traps at all.
Not only construction skills disappear, but also a mating behavior became easier, in contact between the sexes sexual organs structure becomes paramount – mechanism of “a lock
and a key”, which prevents different species from mating. Pedipalps of male Linyphiidae often have a very complex structure.
But this, apparently, was not enough, and spiders – pygmies
invented an additional mechanism of “a lock and a key”. Cou-
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Spiders pygmies Hypselistes jacksoni, Ceratinella brevis, Gonatium rubens
Spiders of the Lapland reserve
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Spiders-Linyphiidae Neriene clathrata, Tenuiphantes alacris, Hilaira herniosa
22
ABCGheritage – Our common arctic heritage
Zornella cultrigera: female and male
ple of spiders-pygmies converges head-on, then male dives
under a female, and she grabs his prosoma by chelicerae, but
not to eat: male cephalothorax is equipped by special grooves
for female “fangs”, those pits have different shapes in different
species. In addition to this groups of bizarre-shaped bristles
and outgrowths can develop; cephalothorax of males can look
absolutely fantastic. Very often eyes area is raised up and looks
like a small turret. Latin names of the species often reflect peculiarities of males’ shapes, for example, Walckenaeria monoceros. However, to describe the structure of Linyphiidae thorax
a separate book would be required. So, if a male has a “key” –
his pedipalps corresponding to female genitals, female “key”
is her chelicerae suitable to male thorax.
Tens of Linyphiidae genera living in the reserve create diversity of species comparable to variety of the rest of the families
all together. Long-legged colorful tiny cob-web spiders from
the genus Tenuiphante (6 species) and casting around rambling
Walckenaeria (15 species); tiny whitish moss inhabitants (Palliduphantes antroniensis) and short-legged black armored Ceratinella, easily surviving drying of a loose leaf litter; beach-lovers
Erigone and resident of ant hills Evansia merens; the smallest of
the spiders living in the reserve – tiny Minyriolus pusillus; colonial Savignia product and Kikimora palustris; ubiquitous Zornella
cultrigera; tundra Gonatium rubens and many others ...
Among them there are spring, early summer, late summer and autumn species; many are encountered throughout the whole season, and zooids of several species become
mature under snow; in early May, when snow starts melting
they are already on the peak of the breeding season. In sunny
weather, males can run directly on snow from one thaw hole
to another; temperature in a few degrees above zero is sufficient for their activity. There are cases when pygmy spiders
built their tiny webs right in the thick of loose spring snow
and trapped migrating springtails.
It is not surprisingly that being so cold resistant the Linyphiidae prevail among the northern spiders; two species even live
in the zone of the Arctic polar deserts. This feature allowed
species from the previous ice age to survive in the population
of the reserve: population which was wide spread at that time
still inhabits the tops of the Salnye tundras. Unlike the other
hills of the reserve the entire range of Salnye tundras is circumcised on the southern side by a sharp almost vertical cliff starting at high altitudes, about 800–900 meters above sea level.
To the north, on the contrary, elevation decreases smoothly,
practically forming a plateau. The plateau is isolated by a southern cliff and from the opposite side – by the distance and poor
heating of northern slopes from massive penetration of forest
spiders. Salnye tundras were the only place where Collinsia
holmgreni, Erigone tirolensis, Meioneta nigripes, Walckenaeria clavicornis and other species were found that are currently
common in lowland tundra far to the north from the reserve.
Many of them have a dark, almost black color, which is intended for more effective warm of spider’s bodies by sun.
As it was mentioned above, the main body of the silk glands
in the course of the evolution of spiders moved from spinnerets to an abdomen. In the most families, the foremost pair
of spinnerets disappeared as unnecessary (for weaving primarily
tip of abdomen, i.e. rear spinnerets are used), but some spiders
have kept remaining silk glands, which plunged into an abdomen completely. Now they open outwards on special sieve-like
surface called cribellum. Thread obtained from these wide sieves
has a loose structure and is used for weaving distinctive lace
catching nets. Earlier, all these spiders were refers to a single
group of cribelliae, but recently an opinion was presented that
unrelated species could keep spider gland. As a result, scientists-taxonomists started another shuffling between the families, which is still in progress – until experts come to a consensus.
Representatives of the two small families in the Lapland
reserve belong to spider with cribellum. Small grayish Dictyna
spiders from the Dictynidae family can be met on tree trunks
(Dictyna uncinata) or branched inflorescences of herbs (Dictyna
major), where they build modest irregular nets with a silver delicate lace. South of the Kola peninsula in April-May population
of dictyna can be huge, dried inflorescences of last year plant
such as yarrow on meadows and steppes are entirely braided
by them.
Spiders of the Lapland reserve
nd
ses
ll.
erck
die.
es
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Lapland state nature biosphere reserve
Walckenaeria unicornis
male looking for female
Dictyna uncinata
before hibernation
Dictyna uncinata
is trying to take wing
Spiders of the Lapland reserve
Arctobius inhabit in the lower belt of Salnye tundra
Fast Mastigusa arietina having no cribellum is absolutely not similar to Dictyna. It has been recently moved into
the family Dictynidae. As well as another unusual Dictynidae outstanding Hackmania prominula, Mastigusa is very rare
in the reserve.
The second cribellum family are Amaurobiidae represented
by the only one species detected in the reserve – Arctobius
agelenoides. This is quite a big and powerful spider looks like
wolf spiders, but only males tend to wander. Females and baby
spiders spend all their life in spinnerules between the stones.
Such spinnerules came from a braid lining holes of Amaurobiidae ancestors; the mouth of the tube is disorderly framed
disorderly by horizontal network, signaling about emergence
of preys (a significant proportion of this family diet is constituted by beetles) – spider jumps out, grabs its prey and
pulls it into the tube. Their hunting method and type of webs
are ancient, many groups of primitive spiders have the same
lifestyle in the tropics. Baby spiders released from a cocoon
remain in the shelter for a while and after death of a female
eat her body, and then they spread; life cycle takes at least
two years. This large species with the most ancient way of life
is found only in the lower part of the tundra nelt in the northern slope of Salnye tundras.
Arctobius male
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ABCGheritage – Our common arctic heritage