Echinoderms Flashcards
400 million- years ago ________ were among the most prevalent marine creatures in the ocean.
echinoderms
______ (sand, mud, and excrement) at the opening of U-shaped burrows are evidence of worm-like animals that are members of the phylum ________.
Other members of this phylum include equally unfamiliar filter feeders called _______.
Coiled castings; Hemichordata
pterobranchs
Phylum of Echinoderms and Hemichordates are the first members of the clade_________
Second embryonic opening.
Indeterminate development and radial Cleavage.
The echinoderms and hemichordates are covered in one chapter because they comprise the deuterostome clade _______.
Studies of Hox genes, RNA genes, and mitochondrial DNA have led researchers to agree on the common ancestry of members of these two phyla.
Deuterostomia
Ambulacraria
_______ are a major group of only marine animals.
• The name comes from the Greek word for “_______”.
Echinoderms (scientific name Echinodermata)
spiny skin
There are about 7,000 species found usually on the sea floor in every marine habitat from the intertidal zone to the ocean depths.
They have a wide variety of colors.
Echinoderms
Others feed and decaying matter called _____ found the ocean floor.
detritus ( de TRI tus )
All ocean-dweling -Tidal pools, deep ocean, seafloors, near the shore.
• Carnivores and Scavengers -They eat: slow-moving sedentary/ mollusks and dead organisms. - Some eat a live coral, causing major destruction to the coral reefs.
• Wide range of colors and sizes.
CLASS ASTEROIDEA
• Spiny Skin
• Tube feet
• Arms
• Central disk
CLASS ASTEROIDEA
• Slowing
• Feet provide suction
• Rock pools and beaches
• Brackish water
• Camouflage adaptation
CLASS ASTEROIDEA
• Egg and Sperm Cell
• External fertilization free spawning
• Rapid Metamorphose into adult
• Ability to Regenerate
• 5-34 years life spam
CLASS ASTEROIDEA
• The most abundant echinoderms (about 2000 known species worldwide)
•Nocturnal Animals
CLASS OPHIUROIDEA
SKELETON
•Brittle stars have long flexible arms that attach to a _____.
central disk
TWO TYPES OSSICLES
•ARM OSSICLES
•SKELETAL OSSICLES
•Phylum Echinodermata
•Regular and irregular
•Found in all intertidal zones
•1000 known species
CLASS ECHINOIDEA
_______
- 450 million years ago during the ordovician
________
Ancestral duetorostome believed to evolve from the edioasteroids
REGULAR ECHINOIDS
IRREGULAR ECHINOIDS
• Water Vascular system
•Locomotion
•Respiration
•Food an waste transportation
•Aristotle’s lantern
•Bilateral symmetry
•Test (aka the shell)
•Movable spines
•Inhabit ocean floor
•Omnivores
REGULAR ECHINOIDS
•Penta-radial and bilateral symmetry
•Anus on the side rather than apex.
IRREGULAR ECHINOIDS
•About 2 inches in diameter
•Muddy areas, burrowing up to 6 inches
•Most common in depths under 16ft
HEART URCHIN
•Shallow, Sandy areas
•Flattened
•Miniature spines(felt like)
•Aristotle’s lantern (mouth) more flat and grinds sand
•Bury themselves for defense
SAND DOLLAR
______
This class contains approximately 1,500 species. ______, is a group of economically important echinoderms. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad (organ that makes gametes).
CLASS HOLOTHUROIDEA;
SEA CUCUMBERS
_____have no arms, and they are elongate along the oral-aboral axis. Most adults range in length between 10 and 30 cm; play an important role in the recycling of nutrients.
Sea cucumbers
The sea cucumber is capable of ______ (casting off) its internal body organs during times of stress which can later be regenerated.
eviscerating
_______, commonly called sea lilies. Approximately 630 species are living today.
Crinoidea
______ use outstretched arms for feeding. The foot of the tube is attached to any planktonic organism that touches it. The cilia in the ambulacral grooves carry it to the mouth. This method of feeding is different from the feeding of modern echinoderms. But it shows the original function of the water vascular system.
Crinoids
Gametes are formed by _____ in the coelom.
germinal epithelium
