Chapter 17: Annelids and Allies

annelids and allies classification

coelomate protostomes

annelids and allies coelom formation through

schizocoely

annelids and allies cleavage through

spiral mosaic

phylum annelida roots

annelus (little ring)

metamerism

body divided into segments called metameres

annuli

rings

setae

chitinous bristles

phylum annelida symmetry

bilateral, triploblastic

phylum annelida epithelium secretes

moist cuticle

phylum annelida digestive system

complete, non segmented

phylum annelida asexual reproduction

fission and fragmentation

phylum annelida waste removal via pair of

kidney like organs per segment

phylum annelida circulatory system

closed

phylum annelida head

prostomium, peristomium, pygidium

phylum annelida new segments from

before the pygidium

phylum annelida older segments

at the front

phylum annelida coelom acts as a

hydrostatic skeleton (except in leeches)

class polychaeta roots

polys (many) and chaite (long hair)

class polychaeta importance in marine food chains

feather dusters

class polychaeta habitat

marine underneath rocks

class polychaeta size

3 m/10 ft

differentiated head, paired parapodia, many setae

class polychaeta

class polychaeta prostomium

retractable; holds eyes, tentacles, sensory palps

class polychaeta peristomium

surrounds mouth; holds setae, palps, chitinous jaws

class polychaeta respiratory

parapodia and gills
small use diffusion

class polychaeta mobile forms feeding

scavengers and predators

class polychaeta sedentary form feeding

filter feeders

class polychaeta kidney types

protonephridia, metanephridia, or mixed

class polychaeta nervous system

double ventral nerve cord

class polychaeta sensory structures

eyes, statocysts, nuchal organs

class polychaeta reproduction

dioecious, no permanent sex organs

neresis common name

clam/sand worms

neresis habitat

mucus lined burrows in sediment

neresis behavior

active at night

neresis feeding

seize food with jaws, swallow while retracting pharynx

neresis locomotion

creeps but swim quickly by undualtion

scale worms body

flattened

scale worms feeding

carnivorous

scale worms habitat

commensal (burrows of others)

fireworms defense

hollow, brittle setae that secrete venom

fireworms attack mechanism

setae punctures > breaks off > deposit venom

fireworms feed on

cnidarians

tubeworms habitat

burrow in sand or mud

tubeworms feeding

sedentary, filter feed, deposit feed

tubeworms deposit feed by

extending tentacles to find bigger food

tubeworms featherdusters have ____ for filter feeding

radioles

class siboglinidae common name

beardworms

class siboglinidae formally called

pogonophora (beard)

class siboglinidae dredging

secrete long, chitinous tubes

long, cylindrical body covered with a cuticle

class siboglinidae

class siboglinidae body structure parts

forepart, trunk, opisthosoma

class siboglinidae lack

mouth and digestive system

class siboglinidae feed by

absorbing nutrients from seawater

class siboglinidae mutualistic relationship with

chemoautotrophic bacteria

class siboglinidae cleavage

spiral and schizocoelic

class siboglinidae embyro

worm shaped and ciliated
carried by water currents

clitellum

ring of secretory cells in epidermis

clitellum always visible in

oligochaetes

clitellum seasonal in

hirudinea

clade clitellata lack

parapodia

clade clitellata reproduction and development

monoecious, direct development

class oligochaeta common name

earthworms

class oligochaeta movement

peristalsis

peristalsis

contract/relax circular muscles while using body point as an anchor by contracting longitudinal muscles

class oligochaeta feeding

scavengers

class oligochaeta food processing

pharynx > crop > gizzard > intestine (typhlosole)

class oligochaeta chloragogen tissue

synthesize glycogen and fat

class oligochaeta transport system

double (coelomic and circulatory)

class oligochaeta ___ main body trunks

five (dorsal ventral, aortic arches, single ventral vessel)

class oligochaeta blood contains

hemoglobin

class oligochaeta gas exchange through

moist skin

class oligochaeta excretion

metanephridia in all segments

class oligochaeta excretion flow

nephrostome (ciliated funnel) > nephridial tubule (loops) > nephridiophore (discharges waste outside)

class oligochaeta aquatic species excrete

ammonia

class oligochaeta terrestrial species excrete

urea or mixture of urea and ammonia

class oligochaeta osmoregulation

salt and water exchange across integument

class oligochaeta ___ acts as a brain

pair of cerebral ganglia

class oligochaeta have ___ in nerve cord

giant axons for rapid signal transmission

what class has some learning ability

oligochaeta

class oligochaeta neurosecretory cells perform

endocrine functions

class oligochaeta ___ produces mucus for mating and forms cocoon

clitellum

class oligochaeta fertilization

sperm travel via seminal grooves > cocoon forms > cocoon seals > hatches

order hirudinea common name

leeches

class hirudinea number of segments

34

class hirudinea setae

none

class hirudinea suckers

anterior and posterior

class acanthobdellida number of segments

27

class acanthobdellida setae

first five segments

class acanthobdellida suckers

only posterior

class branchiobdellida number of segments

14/15

class branchiobdellida setae

none

class branchiobdellida suckers

only anterior

class branchiobdellida relationship with crayfish

commensal/parasitic

class hirudinea clitellum visible only during

breeding

class hirudinea segments are marked by

transverse grooves

class hirudinea coelom

septa absent, spaces called lacunae

class hirudinea movement

crawl by pushing loops
swim by undulation

class hirudinea feeding

blood parasites and decaying matter

class hirudinea gas exchange through

skin

class hirudinea excretion

10-17 pairs of nephridia and coelomocytes