Zoology Ch. 3

How deep are corals able to form reefs?

100 feet (30 meters)

What class, whose name means flower animals, is composed of sea anemones and corals?

Anthozoa

the true beauties of the phylum cnidaria

Class Anthozoa

the creatures most of us think as the Real jellyfish

Class Scyphozoa

The capturing, or stinging polyps of a Man-o-War

Dactylozooids

Characteristics of Phylum Cnidaria

Entirely aquatic; mostly marine Radial symmetry with no definite head Two stages in life cycle: Polyps and Medusae Body containing 2 layers: Epidermis and Gastrodermis Central Gastrovascular Cavity with a single opening that serves as a mouth and an anus Presence of nematocysts within tentacles to capture prey Nerve Net which carries info both ways Asexual reproduction by budding; sexual by sperm and egg No true coelomic cavity, excretory, or respiratory system

the feeding, or digestive polyps of a man-o-war

Gastrozooids

specialized asexual polypoid structures

Gonangia

Corals that have a mutually symbiotic relationship with a special algae called Zooxanthellae, that live inside them

Hermatypic corals

The freshwater member of the class Hydrazoa is called what?

Hydra

free swimming stage which USUALLY has hanging tentacles

Medusa stage

The thin jellylike layer between the two germ layers of cnidarians is called what?

Mesoglea

The sessile polypoid colonial hydrazoan we studied is better known as what?

Obelia

light sensitive organs that help them determine light intensity

Ocelli

The floating polymorphic colonial Hydrazoan is better known as what?

Physaia or Portuguese man-o-war

sexual reproduction in cnidarians is carried out by monoecious or dioecious forms. The resultant larval form is called what?

Planula

act like sensory receptors for touch

Rhopalia

Jellyfish have 2 very important sensory structures called what?

Rhopalia and Ocelli

The true jellyfishes belong to what class?

Scyphozoa

What kind of reef is simply a circular or a semicircular reef with no island in the middle?

atoll reef

What kind of reef has a lagoon between the island and the reef?

barrier reef

most common form of asexual reproduction

budding

sexual reprodcution

carried out by sperm and egg-as hermaphrodites They have both ovaries and testes

The stinging cells of cnidarians are called what?

cnidocytes

very similar to miniature sea anemones except they secrete there own skeletal structures and have no siphonoglyph

corals

The unusual tissue in cnidarians which helps them move are called what?

epitheliomuscular tissue

What kind of reef is found around newer islands, when the reef is found along the shoreline?

fringing reef

The large hollow gut of cnidarians is better known as what?

gastrovascular cavity

produce gonopores, which develop into Medusae

gonangia

The kind of corals that build reefs are called what?

hermatypic corals

What creatures place anemones on their backs?

hermit crabs

has a mouth located above the hypostome, a raised portion inside the ring of tentacles

hydra

only freshwater hydrazoan--also only one with NO medusa stage and is a singular organism rather than colonial

hydra

used for attachment and locomotion in a basal disc

hydra

opens into the gastrovascular cavity

hydra mouth

have the most distinctive and obvious medusa in all of the phylum cnidaria

jellyfish

the sexual free-swimming stage in the life cycle is called what?

medusa

stages of aurelia

medusa, zygote, planula, scyphistoma, strobila, Ephyra

What do clow fishes produce to keep from getting stung by sea anemones?

mucus

What is the Epitheliomuscular tissue made up of?

myofibrils and epitheliomuscular cells

the special stingers on cnidocytes with barbed filaments used to capture and paralyze prey are called what?

nematocysts

a colonial, marine hydrazoan

obelia

2 germinative layers which surround the jellylike mesoglea

outer epidermis and inner gastrodermis

larva

planula

the gas filled sail or float of a man-o-war

pneumatophore

sessile stage which USUALLY has tentacles reaching upward

polyp stage

What does a clown fish get from its anemone?

protection

The sensory structures in Scyphozoans are called what?

rhopalia

exist only in polyp form; do NOT have a medusa stage

sea anemone

clown fish live in a mutually symbiotic relationship with what?

sea anemones

have an oral disc that contains the mouth--which leads in the pharynx

sea anemones

The Nerve Net is made of what?

sensory cells

a grooved structure on either side of the mouth and pharynx; its function is to pull water into gastrovascular cavity

siphonoglyph

The small ciliated grooves on either side of an anemone's mouth are called what?

siphonoglyphs

The long string-like structures used by cnidarians to catch their prey/food are known as what?

tentacles

forms a hydrostatic skeleton for structure and support

water filled gastrovascular cavity

Hermatypic corals have a mutually symbiotic relationship with what kind of algae?

zooxanthellae