Flatworms part 2: Gnathifera, Ectoprocta and Nemertea

Question 1

Which phylum has:
Complete digestive system (mouth to anus), salivary and gastric glands
Dioecious (males smaller than females), some males unknown
Females with paired ovaries, parthenogenic reproduction in some.

Answer 1

Rotifera

Question 2

The rotifer excretory system of has a pair of

Answer 2

protonephridial tubules with flame cells that empty to common bladder

Question 3

Why is osmoregulation important in both freshwater and marine species;

Answer 3

because water enters by the mouth during feeding.

Question 4

What is included in the rotifer nervous system?

Answer 4

A bilobed brain is dorsal to the mastax with paired nerves leading off to the organs.

Sensory organs include eyespots, sensory bristles and papillae, and ciliated pits and dorsal antennae.

Question 5

The mastax is a ____

Answer 5

muscular pharynx equipped with hard jaws, the trophi.

Question 6

What has a funnel-shaped area around the mouth; side lobes fold inward to entrap prey.

Answer 6

Trappers

Question 7

What do hunters do?

Answer 7

project trophi to seize prey.

Question 8

Rotiferous are dioecious this means that

Answer 8

with males being smaller than females which contain combined ovaries and yolk glands.

Question 9

Some rotiferans are ____ which means

Answer 9

are parthenogenetic* and produce diploid (2N) eggs that hatch to diploid (2N) females only (diploid amictic eggs)

Question 10

What type of factors can affect the eggs development of rotifers?

Answer 10

Environmental- in forming diploid or haploid eggs

Question 11

Unfertilized haploid eggs form haploid males but if fertilized can become dormant ______ eggs with thick resistant shell that will hatch as amictic females.

Answer 11

Winter resistant eggs

Question 12

parthenogenesis is

Answer 12

a form of asexual reproduction

Question 13

Ectoprocts are also called _____ and are different because of the location of the anus on _____ ring around the mouth

Answer 13

Bryozoans

outside of the tentacular ring

Question 14

Some key characteristics of Bryozoa

Answer 14

• Complete gut
• no excretory, circulatory or respiratory organs
• Some are monoecious, some dioecious, and some produce sperm first and later eggs
• Trochophore-like larva

Question 15

how many living species are there in Bryozoa

Answer 15

4500

Question 16

Where are Bryozoa found?

Answer 16

Inhabit both shallow freshwater and marine habitats
Some marine colonies form limy encrustations on seaweed, shells, and rocks
Others form fuzzy or shrubby growths or erect branching colonies
Freshwater colonies may form moss-like colonies on stems of plants or on rocks

Question 17

What do the aquatic animals do in Bryozoa?

Answer 17

often encrust hard surfaces

Most are sessile, some slide slowly, and others crawl actively across surfaces

Question 18

What are the colony members called in Bryozoa- Phylum Ectoprocta and how to they feed

Answer 18

colony members are called zooids
feed by extending lophophores into surrounding water to collect tiny particles
also secrete exoskeleton in which they live in called zoecium

Question 19

What is:
may be gelatinous, chitinous, or stiffened with calcium and possibly impregnated with sand that can be boxlike, vaselike, oval, or tubular in shape

Answer 19

Zoecium

Question 20

Zooids pop up to feed but any disturbance they go into a trapdoor called

Answer 20

operculum

Question 21

The lophophore is extended and tentacles spread out into a funnel when needing to ___

Answer 21

feed

Question 22

Digestion begins extracellularly in ___ and is completed in ____

Answer 22

in the stomach and completed intracellularly in the intestine in a complete gut system.

Question 23

How do you differentiate a colonial cnidarian (coral) from a colonial bryozoa?

Answer 23

• Cilia on tentacles of bryozoa.
• Gastrovascular cavity continuous between coral polyps while in some bryozoa through coelomic fluid connections.
• Complete gut in byrozoa. Incomplete in coral.

Question 24

Ectoprocta can have non feeding members called

Answer 24

heterozooids

Question 25

Aviculariums are modified

Answer 25

zooids that resemble bird beaks and can snap at small invading organisms that approach the colony

Question 26

Vibraculum

Answer 26

have long bristles that sweep away foreign particles

Question 27

Ectoprocts are mostly hermaphroditic (monoecious) and brood their eggs

Answer 27

brood their eggs

Question 28

where does brooding occur?

Answer 28

within the coelom and some have an external chamber

Question 29

embryos proliferate asexually from the initial embryo in a process called

Answer 29

polyembryony

Question 30

Larva of _____ have a functional gut and swim for a few months before settling.

Answer 30

nonbrooding species

Question 31

Larva of ______ do not feed and settle after a brief free-swimming existence.

Answer 31

brooding species

Question 32

In Ectoprocta new colonies begin from a single metamorphosed primary zooid, called an

Answer 32

ancestrula

Question 33

Ancestrula undergoes_____ to produce many zooids of a colony

Answer 33

asexual budding

Question 34

Freshwater ectoprocts undergo budding that produces ____ which are hard, resistant capsules containing a mass of germinative cells.

Answer 34

Statoblasts

Question 35

When do statoblasts

Answer 35

occur in the summer and fall that eventually give rise to zooids and later forming new colonies

Question 36

What phylum is also known as ribbon worms?

Answer 36

Phylum Nemertea

Question 37

What is a unique characteristic of the Phylum Nemertea

Answer 37

Eversible proboscis lies in free cavity (rhynchocoel) above alimentary canal

Question 38

Which phylum:
Simplest animal with blood vascular system
Adult has anus, complete digestive system

Answer 38

Phylum Nemertea

Question 39

Nemerteans Feeding+Digestion

Some species detect prey when physically near and use ____ hiding in a cavity called the ____ to seize

Answer 39

use proboscis

called the rhynchocoel

Question 40

Nemerteans:

Adult has an anus, producing a

Answer 40

complete digestive system

Question 41

What has true circulatory system and blood flow is irregular due to contraction of vessels and general body movements

Answer 41

Nemerteans

Question 42

Flame bulb ____ associated with circulatory system to achieve true excretory role of removing wastes

Answer 42

protonephridia