Key Characteristics of Kingdoms and Domains
Classification of Living Things
DOMAIN
Bacteria
Archaea
KINGDOM
Eubacteria
Archaebacteria
CELL TYPE
Prokaryote
Prokaryote
CELL
Cell walls with
STRUCTURES peptidoglycan
NUMBER OF
CELLS
MODE OF
NUTRITION
Cell walls
without
peptidoglycan
Unicellular
Unicellular
Autotroph or
heterotroph
Autotroph or
heterotroph
Streptococcus, Methanogens,
Escherichia
halophiles
EXAMPLES
coli
Go to
Section:
Eukarya
Protista
Fungi
Plantae
Animalia
Eukaryote
Eukaryote
Eukaryote
Eukaryote
Cell walls of
cellulose in
some; some
have
chloroplasts
Cell walls of
chitin
Cell walls of
cellulose;
chloroplasts
No cell walls
or
chloroplasts
Most
unicellular;
some
colonial;
some
multicellular
Most
multicellular
; some
unicellular
Multicellular
Multicellular
Autotroph
Heterotroph
Autotroph or
heterotroph
Heterotroph
Amoeba,
Paramecium,
slime molds,
giant kelp
Mushrooms
, yeasts
Mosses,
ferns,
flowering
plants
Sponges,
worms,
insects,
fishes,
mammals
CLADOGRAM OF CHORDATE ORIGINS
PROTOCHORDATES
AMPHIOXUS & AGNATHA
Phylum Chordata
Subphylum Urochordata (u'ro-kor-da'ta) (Gr. oura, tail, + L. chorda, cord). (Tunicata). About 2000
species. Tunicates. Only larval forms have all chordate characteristics; adults sessile, without notochord
and dorsal nerve cord; body enclosed in tunic. Example: Molgula, a sea squirt.
Subphylum Cephalochordata (sef'a-Io-kor-da'ta) (Gr. kephalE, head, + L. chorda, cord). About 22
species. Lancelet. Notochord and nerve cord persist throughout life; lance-shaped. Example:
Branchiostoma (amphioxus).
Subphylum Vertebrata (ver'te-bra'ta) (L. vertebratus, backboned). (Craniata). About 50, 900 species.
Vertebrates. Enlarged brain enclosed in cranium; nerve cord surrounded by bony or cartilaginous vertebrae;
notochord in all embryonic stages and persists in adults of some fishes; typical structures include two pairs
of appendages and body plan of head, trunk, and postanal tail.
Subphylum Cephalochordata (lancelets;
Branchiostoma/Amphioxus)
cephalochordates are lancelets: slender, laterally compressed, translucent
animals about 5 to 7 cm in length
inhabit the sandy bottoms of coastal waters around the world
lancelets originally bore the generic name Amphioxus (Gr. amphi, both
ends, + oxys, sharp), later surrendered by priority to Bran. chiostoma (Gr.
branchia, gills, + stoma, mouth). Amphioxus is still used, however, as a
convenient common name for all of approximately 25 species
four species of amphioxus occur in North American coastal waters
Amphioxus is especially interesting because it has the five distinctive
characteristics of chordates in simple form
CLASS MYXINI
•
elongate (eel-like)
•
scaleless
•
Many mucous glands present for antipredator defense.
•
feed on polychaete worms, shrimp, and dead or dying fish
•
anterior nasal opening
Agnatha (Greek, "no jaws") is a superclass of jawless
fish in the phylum Chordata, subphylum Vertebrata.
The group excludes all vertebrates with jaws, known
as gnathostomes.
KEY FEATURES
o Jaws are absent.
o
Paired fins are generally absent.
o
Early species had heavy bony scales and plates in their skin
In most cases the skeleton is cartilaginous. The embryonic
notochord persists in the adult.
Seven or more paired gill pouches are present.
Hagfish sheds slime layer
A light-sensitive pineal eye is present.
The digestive system lacks a stomach.
External fertilization; both ovaries and
testes present in individual but gonads
of only one sex functional in hagfishes,
no larval stage; separate sexes and a
long larval stage in lampreys.
HAGFISH CLASSIFICATION
•
•
•
•
•
•
•
Kingdom Animalia
Phylum Chordata
Class Pteraspidomorphi
Order Myxiniformes
Family Myxinidae
Genus Myxine
Species glutinosa
HAGFISH
Hagfish can be found in chilly waters
They tend to live on and in muddy sea floors in very dense
groups (up to 15,000 in an area).
Because females tend to produce large eggs in small numbers,
their population sizes suggest a low death rate.
HAGFISH ANATOMY
LAMPREY CLASSIFICATION
• Kingdom Animalia
• Phylum Chordata
• Subphylum Vertebrata
• Class Cephalaspidomorphi
• Order Petromyzontiformes
• Family Petromyzontidae
CLASS PETROMYZONTES
•
have a skeleton of cartilage, previously interpreted as descended from the ostracoderms
•
two semicircular canals
•
seven gill pouches open directly to exterior