Echinoderms Flashcards

Questions and Answers

What does 'Echinodermata' mean?

spiny skinned

How many classes are within the Phylum Echinodermata?

five classes

Name the classes of Phylum Echinodermata.

Class Asteroidea, Class Ophiuroidea, Class Echinoidea, Class Holothuroidea, Class Crinoidea

What is a characteristic of all echinoderms?

Radial symmetry Signup and view all the answers

Which of the following is not a characteristic of echinoderms?

Presence of a heart Signup and view all the answers

What are photophores?

Light sensitive cells that detect light/dark Signup and view all the answers

What is the ecological range of echinoderms?

Exclusively marine, found in various habitats Signup and view all the answers

What are the feeding habits of some echinoderms?

Carnivorous, detritus foragers, or planktonic feeders Signup and view all the answers

Can echinoderms regenerate missing limbs?

True Signup and view all the answers

Why are echinoderms considered advanced organisms?

Because of their development as Deuterostomes Signup and view all the answers

Match protostomes and deuterostomes with their developmental characteristics:

Protostomes = 1st indentation develops into the mouth Deuterostomes = 1st indentation becomes the anus Signup and view all the answers

What defines Class Asteroidea?

Radial symmetry, several arms radiating from a central body Signup and view all the answers

What are ossicles?

Calcium projections within a sea star Signup and view all the answers

Are massive blooms of sea stars beneficial?

False Signup and view all the answers

Sea stars are voracious predators of bivalves.

True Signup and view all the answers

How do sea stars eat?

They use tube feet to pry open bivalves and release digestive enzymes. Signup and view all the answers

Where does the starfish often live?

Everywhere in coral reefs and on sand or rocks Signup and view all the answers

What defines the majority of sea stars' behavior?

Majority are carnivorous, feed on sponges, bryozoans, and molluscs. Signup and view all the answers

Where is the most diverse coral reef located?

Indonesia Signup and view all the answers

Study Notes

Echinoderms Overview

"Echinodermata" translates to "spiny skinned."
Phylum Echinodermata consists of five classes.

Classes of Echinodermata

Class Asteroidea: Sea stars or starfish.
Class Ophiuroidea: Includes brittle stars, basket stars, and serpent stars.
Class Echinoidea: Comprises sea urchins, heart urchins, and sand dollars.
Class Holothuroidea: Known as holothurians or sea cucumbers.
Class Crinoidea: Includes sea lilies and feather stars.

General Characteristics

Echinoderms exhibit radial symmetry and body structure divided into five segments.
Lack a heart, brain, or eyes; some brittle stars possess light-sensitive parts.
Mouth is located on the underside, anus on top (exceptions exist).
Absence of cephalization and the potential presence of photophores.
Capable of regeneration if a central disk remains intact.
Exclusively found in benthic zones.

Tube Feet and Locomotion

Tube feet are tentacle-like structures with suction pads.
Operate hydraulically via a water vascular system, creating suction.

Ecology and Habitat

Echinoderms are strictly marine and inhabit various environments, including intertidal zones and deep-sea trenches.
Found in diverse habitats, such as coral reefs, sandy bottoms, and rocky substrates.

Behavior and Feeding

Feeding methods vary: carnivorous (sea stars), detritus foragers (sea cucumbers), and planktonic feeders (basket stars).
Reproduction typically involves the release of sperm and eggs into the water, with most species producing planktonic larvae.

Regeneration

Capable of regenerating limbs, arms, spines, and intestines, with some species able to reproduce asexually through fission.

Deuterostomes

Echinoderms are considered advanced organisms as they are classified as deuterostomes, where the first indentation becomes the anus.

Class Asteroidea Characteristics

Exhibit radial symmetry with arms radiating from a central body, usually 5 or multiples of 5.
Mouth and anus are positioned closely, with a madreporite for water intake.
Upper surface is often colorful, while the underside is typically lighter.
Possess minute pincer-like structures called pedicellaria to keep arms free from algae.
Have a hydrostatic skeleton supported by madreporite.

Feeding and Predation

Sea stars are voracious predators of bivalves, gripping and prying them open using tube feet.
Their feeding process involves evisceration where the stomach is pushed outside to digest prey with enzymes.
Ecology includes habitats like coral reefs and rocky environments.

Regeneration in Sea Stars

Ability to regenerate limbs and body parts, with some species reproducing asexually through autotomy and fission.

Biodiversity

The most diverse coral reefs are located in Indonesia.

Environmental Implications

Massive blooms of sea stars are detrimental, indicating ecosystem imbalances.

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Description

Test your knowledge about Echinoderms with this flashcard quiz. Learn key definitions, classifications, and features within the Phylum Echinodermata. Perfect for beginners and biology enthusiasts alike!