Chapter 17: Annelids, Class- Polychaeta

Question 1

This is the ____ class in the phylum annelida

Answer 1

largest

Question 2

Mostly live in what habitat?

Answer 2

marine

Question 3

There is ____ in only some of the somites.

Answer 3

differentiated

Question 4

There is more specialization of sensory organs than in the class ____.

Answer 4

clitellates

Question 5

They can tolerate a wide range of what?

Answer 5

salinity

Question 6

Freshwater polychaetes tend to live in ___ regions

Answer 6

warmer

Question 7

They inhabit what ? (3)

Answer 7

• crevices, tubes, or are pelagic

Question 8

They have a well differentiated ___ with ___ organs.

Answer 8

head, sense

Question 9

They have paired appendages called ___ on most segments.

Answer 9

• parapodia

- many setae are bundled on these

Question 10

Do they have a clitellum or not?

Answer 10

not

Question 11

Errant polychaetes travel via ? (3)

Answer 11

free moving, burrowing or crawling

Question 12

Prostomium:

• may or may not be___?
• Often bears what three things?
• It surrounds the ___ and may have what three things?

Answer 12

• retractile
• eyes, tentacles and sensory palps
• mouth, setae, palps, or chitinous jaws

Question 13

Ciliary feeders may bear a _____ that opens like a fan but can be withdrawn into the tube.

Answer 13

tentacular crown

Question 14

Most segments of trunk bear _____ with lobes, cirri, setae and other parts.

Answer 14

parapodia

Question 15

Parapodia explain it !

Answer 15

aid crawling, swimming and anchor worm in a tube

- usually the chief respiratory organ although the worm may also possess gills ( Amphritite and arenicola)

Question 16

Nutrition:

- Polychaetes have what three things that aid in digestion etc?

Answer 16

• foregut, midgut and hindgut

Question 17

Nutrition:

Foregut?

Answer 17

• has a stomodeum, pharynx, anterior esophagus lined with cuticle

Question 18

Nutrition:

Midgut?

Answer 18

• derived from the mesoderm secretes enzymes and leads to anus on the pygidium

Question 19

Nutrition:

Short hindgut ?

Answer 19

• derived from the ectoderm and leads to anus on pygidium

Question 20

Errant polychaetes are what kind of food acquirers?

Answer 20

• predators or scavengers

Question 21

sedentary polychaetes feed on what?

Answer 21

suspended particles or particles in sediment

Question 22

For respiration most have a ___ and ___ for gaseous exchange while others use the ___.

Answer 22

• parapodia , gills, body surface

Question 23

Circulation varies:

In Nereis a ____ carries blood forward and a ___ carries blood posteriorly.

Answer 23

dorsal blood vessel
ventral blood vessel
- blood flows across between these major vessels in networks around the parapodia and intestine

Question 24

Circulation:

In some, ___ are incomplete and _____ serves circulatory function.

Answer 24

• septa

- coelomic fluid

Question 25

Many polychaetes have respiratory pigments. Which can be what? (3)

Answer 25

- Hemoglobin, chlorocruorin or hemerythrin

Question 26

Excretion: - The organs vary from ___ to ____ and some mixed forms - There is ___ per metamere - The inner end also called a _____ opens into the coelomic cavity - Coelomic fluid enters the ___ - Selective reabsorption occurs along what?

Answer 26

- protonephridia, metanephridia - one pair - nephrostome - nephrostome - nephridial duct

Question 27

Reproduction and development ? - Do they have permanent sex organs? - Monoecious or Dioecious? - Gonads appear as what? - Gametes are shed into coelom and exit by____, ____, or ____. - Fertilization is ___ and the early larva is a ___.

Answer 27

- no - monoecious - temporary swellings of peritoneum - gonoducts, metanephridia or rupturing of the body - external, trochophore

Question 28

What are epitokes? Atoke?

Answer 28

- packed with gametes and detach then rise to surface and release gametes. - normal portion of the annelid

Question 29

Instead of transforming a portion of body into epitoke some will ?

Answer 29

- bud off complete worms that become epitokes

Question 30

What are some representatives of the class Polychaeta ? (5)

Answer 30

- Clam worms (Nereis), fire worms, tube worms, fan worms, parchment worms

Question 31

Clam worms (Nereis) : - they are ___ polychaetes - They live in mucus lined burrows near ___ - Prostomium bears what? (3) - Peristomium has what? (3)

Answer 31

- errant - low tide level - a pair of palps sensitive to touch and taste, a pair of short sensory tentacles and two small dorsal eyes sensitive to light - ventral mouth, pair of jaws, four pairs of sensory tentacles

Question 32

``` Clam worms (Nereis) continued: *Parapodia L> contains two lobes what are they? L>acicula are? L>What assits respiration? L>Movement via? (2) L>What kind of muscles are in each somite? L>What movements provide free swimming and burrow pumping actions ? ```

Answer 32

- dorsal notopodium and ventral neuropodium - one or more chitinous spines that support each lobe - abundant blood vessels - oblique - undulatory

Question 33

What do clam worms feed on? | Food is moved through alimentary canal via?

Answer 33

small animals, other worms and larval forms | peristalsis

Question 34

Fireworms: Poisonous secretions are found where? what do they feed on?

Answer 34

- hollow, brittle setae | - cnidarians

Question 35

Tubeworms: - They dwell in? - many line their burrows with what? - They use what to obtain food? (2) - They live in very __ habitats

Answer 35

- tubes - mucus - cilia or mucus - extreme , deep open vents

Question 36

Fanworms: | - have what to aid in feeding?

Answer 36

- unfurl tentacular crowns

Question 37

Parchment worms: - Lives in a ? - What do their modified segments do?

Answer 37

- U-shaped tube | - pump water through tube ( extracting food)