Biodiversity 6 Vodcast 2 Flashcards

These flashcards cover key concepts, characteristics, and feeding behaviors of echinoderms, aiding in the review for the upcoming exam.

What are Echinoderms categorized as in terms of developmental biology?

Echinoderms are deuterostomes.

What is the habitat preference for most echinoderms?

Most echinoderms are marine and benthic.

What are the feeding modes employed by echinoderms?

Filter feeding, scavenging, grazing, and predation.

What type of symmetry do adult echinoderms typically exhibit?

Pentaradial symmetry.

What unique system do echinoderms have for movement?

A water vascular system with tube feet.

How do echinoderm larvae differ from adults?

Echinoderm larvae are ciliated and bilaterally symmetrical.

From what symmetry do echinoderms develop their adult form?

From bilateral symmetry to pentaradial symmetry.

How do starfish use their tube feet?

For locomotion and feeding.

What role do starfish often play in their ecosystems?

They can be keystone predators.

What do brittle stars primarily use their arms for?

Movement and swimming.

What feeding behavior do brittle stars exhibit?

They are scavengers or detritivores.

How do crinoids differ from starfish in terms of mouth location?

Crinoids have their mouths on the dorsal side.

What do sea urchins and sand dollars lack compared to other echinoderms?

They lack arms.

What is the purpose of spines in sea urchins and sand dollars?

For protection and locomotion.

What was Aristotle's contribution to the study of sea urchins?

He described their mouth parts as looking like a lantern.

What is the feeding structure of sea urchins called?

Aristotle's lantern.

How do sea cucumbers differ from other echinoderms?

They are secondarily bilateral.

What type of environment do sea cucumbers typically inhabit?

They crawl along the sea floor.

What adaptation do sea cucumbers exhibit regarding their tube feet?

Modified tube feet near their mouths serve as sensors.

What ecological adaptations do arthropods in dark caves share with sea cucumbers?

Loss of body pigment and increased length of tactile sensors.

What is the main feeding method of sea lilies (crinoids)?

They are filter feeders.

What allows the locomotion of sea cucumbers?

Well-developed tube feet on one side of their bodies.

In what form might crinoids exist as adults?

They may remain sessile or become pelagic swimmers.

What do sea urchins primarily feed on?

They use their rasping teeth to feed on algae.

At what stage is the symmetry of echinoderms classified as bilateral?

In their larval stage.

How many major groups of echinoderms are identified in the notes?

Five major groups.

What type of feeding do sea cucumbers primarily engage in?

They are scavengers.

How do crinoids anchor themselves as juveniles?

Attached to the substrate by a stalk.

What does 'benthic' refer to in terms of echinoderm habitat?

Living on the ocean floor.

What is the significance of the water vascular system in echinoderms?

It aids in movement and feeding.

What is one defining characteristic of all echinoderm larvae?

They possess bilateral symmetry.

How are brittle stars different from starfish in terms of feeding?

Brittle stars mainly use tube feet for feeding rather than movement.

What feature do sand dollars and sea urchins share?

They maintain pentaradial symmetry.

What is the major method through which starfish open bivalves?

Using their tube feet and muscles to evert their stomachs.

What type of symmetry do adult sea cucumbers exhibit?

Secondarily bilateral.

What adaptations allow sea cucumbers to sense food?

Tentacle-like modified tube feet.

In terms of ecological impact, what role do starfish play?

They can be keystone predators.

Which echinoderms are known to be filter feeders?

Sea lilies (crinoids).

What type of animals are echinoderms closely related to?

Chordates.

What does 'pelagic' mean in relation to echinoderm habitat?

Living in the water column.

How do tube feet function in echinoderms?

They aid in locomotion and feeding.

Which echinoderm is described as crawling in dark abyssal depths?

The sea pig (a type of sea cucumber).

Which echinoderm is noted for coming out at night to feed?

Brittle stars.

What adaptation do sea cucumbers possess to withstand environmental pressures?

They have well-developed tube feet on one side.

What type of skeleton do echinoderms possess?

A calcareous internal skeleton.

What distinguishes the locomotion method of brittle stars from that of starfish?

Brittle stars move using their arms.

What is the significance of pentaradial symmetry in echinoderms?

It is a defining characteristic of adult echinoderms.

What type of feeding structures do crinoids utilize for nourishment?

Filter feeding structures.

What notable feature do sea cucumbers possess for sensory purposes?

Tentacle-like structures derived from modified tube feet.

What relationship do echinoderms have with their larval symmetry?

They develop from bilaterally symmetrical larvae to pentaradial adults.

What are the primary methods of locomotion for sea cucumbers?

Using tube feet on one side of their bodies.

Which echinoderm group is known for using muscles to evert their stomachs?

Starfish.

What does 'scavenger' mean in relation to echinoderm feeding habits?

Feeding on dead organic matter.

How do sea urchins use their spines?

For protection and locomotion.

What is a key distinction between the feeding mechanisms of starfish and brittle stars?

Starfish evert their stomachs; brittle stars mainly use tube feet.