practical lab 3 part 2
most distinctive feature of phylum annelida
the division of their bodies into rings or segments
metamerism
body segmented into rings
annelids common name
segmented worms
most annelids show internal metamerism with
the division of the body into compartments by regularly repeated walls (septa) and the repetitive arrangement of organs and organ systems
____ show evolutionary advancements over ____
annelids and nematodes
annelids have
a true coelom, fully lined with a layer of mesodermal epithilium called the peritoneum
have a more centralized nervous system and a closed circulatory system
annelids
setae
small bristle-like appendages, most annelids have them
four classes of annelids
oligochaeta polychaeta hirudinea archiannelida
excretory organs in annelids
nephridia
nephridia
remove fluids and wastes from both tissue fluids and blood in annelids
one nephridium consists of
septum, tubules, nephrostome, capillaries, and nephridopore
all annelids live in ____ environments
wet
annelids have the respiratory pigment:
hemoglobin
the function of internal transport in annelids respiratory system is performed by
coelomic fluid moved around by musculature contractions by a closed circulatory system
pseudohearts
5 pairs surround the esophagus, look like black rings
annelid circulatory system includes
ventral blood vessel (flows posteriorly), dorsal blood vessel (flows anteriorly), sub neural blood vessel, and nephridia
reproductive process of an earthworm (annelid)
mate by attaching at their citella and exchanging sperm, received sperm cells > sperm receptacles while the clitellum secretes a mucous cocoon > cocoon slides along picking up the eggs from the ovaries and stored sperm, the cocoon slips off the worms head and embryos develop in the cocoon
reproductive structures start at segment __ on an earthworm
9
reproductive components of an earthworm (annelid)
seminal receptacles, seminal vesicles, male genital pore or gonophores, vas defrens, or female genital pore or gonophores, ovaries, and small passageways
clam worm
annelid, nereis sp.
carnivores, have parapodia with setae, jaws, well developed head with tentacles
digestive system of clamworm
jaws, mouth, muscular pharynx, esophagus, next to esophagus is esophageal caeca, stomach-intestine
respiratory and circulatory system of clamworms
parapodia have a large surface area and are vascularized and major sites of gas exchange
primitive gills
closed respiratory system
phylum annelida have what body system
coelomate