A welldeveloped circulatory system and complete digestive trac
characteristic feature of higher metazoans
Coelom
body cavity between intestinal wall and body wall
Somites
Bodies composed of series of ring-like segments
Setae
Many annelids have chitinous bristles or hair-like structures called
movement, anchorage, deter predators
uses of setae
Polychaeta and Clitellata
class of Annelida
Parapodium
function as gills and aid in locomotion.
Polychaeta
has many setae
Sandworm, Bispira, Chloea
examples of Polychaeta
Clitellum
pronounced cylindrical glandular regions of the body
Class Clitellata
has permanent gonads
Oligochaeta (earthworms) and Hirudinae (Leeches)
subclass of Clitellata
Annuli
Secondary subdivisions found in segment in SC Hirudinae
34 segments
number of segments of Leeches
only appears during breeding season), like oligochaetes
clitellum of Hirudinae
Phylum Mollusca
Eucoelomate • Well-developed circulatory system and a complete muscular digestive tract • Soft-bodied animals that are usually protected with hard shells made up of calcium carbonate • Internal shells or none at all • Triploblastic, non-segmented, usually dioecious • includes snails and slugs, oysters and clams, and octopuses and squids.
Visceral mass
containing digestive, circulatory, respiratory and reproductive organs.
Mantle
houses the gills and in some secretes a protective shell over the visceral mass
Muscular foot, visceral mass, mantle
3 body plans that Mollusc have
Class Aplacophora
Solenogasters • Worm-like • Live in deep ocean bottoms • Poorly developed head • Lacks mantle, foot, and shell
Neomenia
example of class Aplacophora
Class Monoplacophora
Single cap-like shell • Broad flat foot • Dioecious
Neoplina
example of class Monoplacophora
Polyplacophora
“Chitons” • Elongated with dorso-ventrally flattened body • Head with armor-like eight-plated shell
Radula
to scrape algae off rocks
Ctenidia
gills for breathing