CH 17: Annelids and Allies

A coelomate protostome develops its coelom through ______

schizocoely

Coelomate protostomes have ______ _______ cleavage

spiral mosaic

The phylum name Annelida comes from a Latin root annelus meaning ______

little ring

The division of the body into segments is called ______

metamerism

The ring-like divisions on annelids are called ______

annuli

Chitinous bristles found on some annelids are called ______

setae

Annelids exhibit ______ symmetry and are triploblastic

bilateral

The body covering of annelids secretes a moist ______

cuticle

Annelids possess a ______ digestive system that is not segmented

complete

Asexual reproduction in annelids can occur by ______ and fragmentation

fission

Waste removal in annelids is typically handled by paired ______

kidney-like organs

Annelids have a ______ circulatory system

closed

The head of an annelid usually consists of a prostomium and a ______

peristomium

The terminal end of an annelid body is called the ______

pygidium

New segments in annelids are added just in front of the ______

pygidium

Fluid-filled coelom in most annelids functions as a ______

hydrostatic skeleton

The class Polychaeta name comes from the Greek (polys) (chaite) meaning ______

many long hairs

Polychaetes primarily live in ______ environments and are up to

marine

Paired appendages used for movement and gas exchange in polychaetes are ______

parapodia

Polychaetes are often divided into ______ and mobile forms

sedentary

The _________ in polychaetes may contain eyes, tentacles, and sensory palps

prostomium

In predatory polychaetes, the peristomium may contain chitinous ______

jaws

Polychaetes have a digestive tract divided into foregut, midgut, and ______

hindgut

Gas exchange in polychaetes often occurs through parapodia and ______

gills

Polychaetes have three types of kidneys depending on species which include include _______ and ______

protonephridia, metanephridia

The opening of nephridia into the coelom is called a ______

nephrostome

Polychaetes possess a ______ ventral nerve cord

double

Chemoreceptive sensory structures in polychaetes are called ______

nuchal organs

Polychaetes typically have separate sexes and external ______

fertilization

Polychaetas usually have no permanent ____ _____

sex organs

In polychaetes, gonads exhibit _______ _______, where gametes shed into the coelom

temporary swelling

The larval stage of polychaetes is called a ______

trochophore

Nereis worms live in ______-lined burrows

mucus

Representative polychaetes are _______ worms that are carnivorous

scale

Fireworms defend themselves using hollow setae that inject ______

venom

Fireworms feed on ______

cniarians

Tubeworms line their burrows with ______

mucus

Featherduster worms use ______ for filter feeding

radioles

Class Siboglinidae are beardworms that used to be called ________

Pogonophora

Siboglinids (Siboglinidae) lack a mouth and digestive tract and rely on ______ bacteria

chemoautotrophic

Siboglinids (Siboglinidae) absorb nutrients from __________

seawater

The organ housing symbiotic bacteria in siboglinids is called the ______

trophosome

Clitellates possess a reproductive structure called the ______

clitellum

Members of Clitellata lack ______

parapodia

Clitellates are all ______

monoecious

Oligochaetes move using ______ movement

peristaltic

Oligochaeta are sometimes _____

parasitic

Food in oligochaetes is stored in the ______

crop

The structure that grinds food in oligochaetes is the ______

gizzard

Oligochaetes draw food in via the _______ pharynx

muscular

The intestine of oligochaetes contains a fold called the ______

typhlosole

In oligochaetes, yellowish chloragogen tissue synthesizes ______ and ______

glycogen and fat

Circulation and respiration in oligochaetes is a ______ transport system using coelomic fluid and circulatory fluid

double

Oligochaetes have ____ main blood trunks through the body

5

Gas exchange in oligochaetes occurs across the ______

moist skin

Excretory structures in oligochaetes are mainly ______

metanephridia

The funnel-like opening of a nephridium is called the ______

nephrostome

Oligochaetes have a ______ ______ nerve chord

double ventral

The brain of oligochaetes consists of paired ______

cerebral ganglia

Fast signal transmission in oligochaetes is enabled by ______

giant axons

Oligochaetes are typically simultaneous ______

hermaphrodites

Oligochaetes have a clitellum that secretes _____ that hold mating together

mucus

In oligochaetes, sperm travel by _____ ______

seminal grooves

Baby earthworms resemble miniature versions of ______ rather than leech-like larvae

adults

Leeches belong to the class ______

Hirudinea

True leeches have ______ segments

34

Leeches lack setae and possess anterior and posterior ______

suckers

The coelomic spaces in leeches are reduced to ______

lacunae

Many leeches are ______ parasites

blood

Leeches exchange gases through their ______

skin

Leeches have two brains composed of 21 pairs of segmental ______

ganglia

Leeches (Hirudinea) are hermaphroditic cross fertilizers. ______ is transferred by peniic or hypodermic impregnation.

sperm

Echiurans are sometimes called ______ worms

spoon

Echiurans consist of ~140 species of marine worms that _____ in mud, sand, or live in holes and crevices

burrow

The proboscis of echiurans is used for ______

feeding

Echiurans have a ____ groove leading to the mouth

ciliated

Echiurans have a large coelom and a long digestive tract that is coiled and _______

complete

Gas exchange in echiurans occurs mainly in the ______ through cloacal irrigation

hindgut

Sipunculans are commonly called ______ worms (~250 species)

peanut

Sipunculans lack segmentation and ______

setae

The feeding structure in sipunculans is a retractile ______

proboscis

The digestive tract of sipunculans is _______ and U -shaped

complete

Sipunculans lack circulatory and ______ systems

respiratory

Why has the coelom evolved? It is poorly understood but….

hydrostatic skeleton, primitive circulatory fluid, gamete storage for synchronous release