Zool 250 Lab 8: Phylum Annelida and Lophophore-bearing Phyla

annelida

segmented worms

polychaeta

paraphyletic grouping of marine segmented worms

siboglinidae

sedentary deep-sea worms

echiurida

spoon worms

errantia

subclass of polychaeta including nereis

sedentaria

subclass of polychaeta including sedentary deep-sea worms and echiurida

clitellata

clade within polychaetes including earthworms and leeches

oligochaeta

earthworms

lumbricus

common earthworm

hirudinea

leeches

sipuncula

clade within annelida with several families of peanut worms

brachiopoda

lamp shells

bryozoa

moss animals

lophophorates

brachiopoda and bryozoa

prostomium

sensory region in front of mouth

peristomium

sensory structure housing mouth

parapodium

notopodium

upper portion of structure

neuropodium

lower portion of structure

acicula

chitinous skeletal rods that manipulate parapodium with extensor and retractor muscles

oblique muscles

attach to base of parapodium, pull down towards substratum, bend anteriorly and posteriorly in locomotion

septa

separate coelomic compartments of segments to allow shape of each segment to be independently adjustable and allow antagonizing of longitudinal muscles

circular muscles

keep coelomic fluid under pressure

dorsal and ventral longitudinal muscles

bend segments in side to side locomotion

dorsal blood vessel

blood flows anteriorly

ventral blood vessel

blood flows posteriorly

clitellum

secrete mucus during copulation and for egg cases

coelomic pores

moistens epidermis for lubrication during burrowing, increases o2 intake

calciferous glands

secrete CaCO3 into gut to improve plant digestion

gizzard

grinds up plant material to improve digestion

seminal receptacles

receives sperm

typhlosole

increase surface area for gut nutrient absorption

lumbricus (class oligochaeta)

dorsal blood vessel

C

typhlosole

D

intestine

E

coelom

F

ventral blood vessel

A

ventral nerve cord

B

pharynx

A

esophagus

B

seminal vesicle

C

seminal receptacle

D

calciferous gland

E

crop

F

gizzard

G

intestine

H

dorsal blood vessel

I

ventral nerve cord

J

metanephridium

K

sedentaria

sedentaria

errantia

errantia

hirudinea

anterior sucker

A

posterior sucker

B

anterior sucker

attachment to host, inch-worm locomotion

posterior sucker

inch-worm locomotion, attaches to substrate when upright and looking for host

sipuncula

brachiopoda

lophophore

filter feeding in brachipoda and bryozoa