LABORATORIO
Annelida
EJERCICIO 12
Goals for today
• Learn to recognized the Phylum Annelida from
other animals
• Learn the main ‘diagnostic’ characteristics
• Learn about some species biology
Annelida
Annelids include earthworms, leeches, and marine polychaetes.
Key characteristics of the phylum:
Lophotrochozoa
Protostomia
Radiata
Parazoa
Bilateria
Eumetazoa
Deuterostomia
Ecdysozoa
Annelida
Mollusca
Lophophorata
Rotifera
Platyhelminthes
Cnidaria and Ctenophora
Esquizocoelomates
Triploblastic
Bilateral symmetry
Cephalization
Protostomates
Segmentation or metamerism
Belong to phylogenetic clade:
Lophotrochozoa
• Complete digestive system
Porifera
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Lophotrochozoa
Mollusks: Your Tasks
Exercise 12A:
– Phylum: Annelida
• Clase Polychaeta
• Genus: Nereis
Nereis is a sandworm strictly
marine. They live in the mud and
debris of shallow coastal waters
often in burrows. Largely
nocturnal. They reach 0.5 m
Annelida: Polychaetes
1. Observe lamina de parapodia. Identify the parts in the figure.
Where is the notopodium and neuropodium?
Annelida: Polychaetes
1. Observe preserved polychaetes. Put one in a petri dish and
observed the following structures in the dissecting scope
Mollusks: Your Tasks
Exercise 12B:
– Phylum: Annelida
• Clase Oligochaeta
• Genus: Lumbricus terrestris
Lumbricus terrestris prefers moist,
rich soil that is not too dry or
sandy. They are primarily nocturnal
and come out of their borrow at
night to forage
Annelida: Lumbricus
1. Observe slide of cross section of an earthworm: look for he
following parts
Annelida: Lumbricus
1. Dissection: of an earthworm and look at the external anatomy
Annelida:
Lumbricus
1. Dissection: of an earthworm
and look at the internal
anatomy
What are the crop and gizzard for?
Is their circulatory system open or close?
Annelida: Lumbricus
Dissection in a ‘fresh’ worm, noticed the location of the typhlosole
Wha is the function of the typhlosole?
Mollusks: Your Tasks
Exercise 12C:
– Phylum: Annelida
• Clase Hirundina
• Genus: Hirudo medicinalis
Medicinal leeches are any of several
species of leeches, but most commonly
Hirudo medicinalis, the European
medicinal leech
Mollusks: Hirudo
Medicinal leeches are now making a
comeback in microsurgery. They provide an
effective means to reduce blood
coagulation, to relieve venous pressure from
pooling blood (venous insufficiency), and in
reconstructive surgery to stimulate
circulation in reattachment operations for
organs with critical blood flow, such as
eyelids, fingers, and ears. The therapeutic
effect is not from the blood taken in the
meal, but from the continued and steady
bleeding from the wound left after the leech
has detached.
Video
http://www.arkive.org/medicinalleech/hirudo-medicinalis/video-00.html
Annelida: Hirudo
1. Observe slide of a leech: identify the oral and caudal suckers,
pharynx, and crop.
Links
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http://en.wikipedia.org/wiki/Hirudo_medicinalis
http://www.arkive.org/medicinal-leech/hirudo-medicinalis/