Flatworms part 2: Gnathifera, Ectoprocta and Nemertea Flashcards
(42 cards)
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.
Rotifera
The rotifer excretory system of has a pair of
protonephridial tubules with flame cells that empty to common bladder
Why is osmoregulation important in both freshwater and marine species;
because water enters by the mouth during feeding.
What is included in the rotifer nervous system?
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.
The mastax is a ____
muscular pharynx equipped with hard jaws, the trophi.
What has a funnel-shaped area around the mouth; side lobes fold inward to entrap prey.
Trappers
What do hunters do?
project trophi to seize prey.
Rotiferous are dioecious this means that
with males being smaller than females which contain combined ovaries and yolk glands.
Some rotiferans are ____ which means
are parthenogenetic* and produce diploid (2N) eggs that hatch to diploid (2N) females only (diploid amictic eggs)
What type of factors can affect the eggs development of rotifers?
Environmental- in forming diploid or haploid eggs
Unfertilized haploid eggs form haploid males but if fertilized can become dormant ______ eggs with thick resistant shell that will hatch as amictic females.
Winter resistant eggs
parthenogenesis is
a form of asexual reproduction
Ectoprocts are also called _____ and are different because of the location of the anus on _____ ring around the mouth
Bryozoans
outside of the tentacular ring
Some key characteristics of Bryozoa
- Complete gut
- no excretory, circulatory or respiratory organs
- Some are monoecious, some dioecious, and some produce sperm first and later eggs
- Trochophore-like larva
how many living species are there in Bryozoa
4500
Where are Bryozoa found?
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
What do the aquatic animals do in Bryozoa?
often encrust hard surfaces
Most are sessile, some slide slowly, and others crawl actively across surfaces
What are the colony members called in Bryozoa- Phylum Ectoprocta and how to they feed
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
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
Zoecium
Zooids pop up to feed but any disturbance they go into a trapdoor called
operculum
The lophophore is extended and tentacles spread out into a funnel when needing to ___
feed
Digestion begins extracellularly in ___ and is completed in ____
in the stomach and completed intracellularly in the intestine in a complete gut system.
How do you differentiate a colonial cnidarian (coral) from a colonial bryozoa?
- 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.
Ectoprocta can have non feeding members called
heterozooids
