Classification and Anatomy of Sea Stars Quiz

Answer: Echinodermata

In addition to sea stars, brittle stars, sea urchins, sand dollars and sea cucumbers are also a part of this conglomerate. Among the many things they share in common are reproducing asexually and being capable of regenerating tissue within the body.

Answer: Flexible

A flexible skeleton helps the sea star survive in the wild. It allows it to more effectively regrow lost tissue around its body, and also to handle adverse weather conditions more easily. A sea star has an endoskeleton, inside the body like that of humans, enabling it to freely bend and maneuver its limbs at will.

Material found within the sea star is generally thin, silky and, upon death, will decay very quickly.

Answer: Water Vascular

In general, the alignment of a sea star consists of a few different canals that it absorbs nutrients and, in this case, breathes from. Water that it uses to breathe enters from the madreporite, the main 'entrance system' of the water vascular system.

If looking at a sea star right-side up, this would be around the "head" area.

Answer: Regenerate

Sea stars can regenerate entire limbs if given the time to do so. That said, regrowth can take several months and, if a sea star is in a vulnerable position following a conflict or other damaging accident, it could have difficulty doing so.

Answer: Tip

Sea stars often maneuver about by turning the tips of their arms up, to best maintain awareness of their surroundings. These eye spots do not, however, respond very well to light. Sea stars will aim to use them as a means to gain external stimuli, explaining why they may seem to travel in spinning motions.

Answer: Sea Sponges

Sea stars will generally prey on small creatures but, as they themselves are rather small, the list isn't as extensive as they might like. Targets could include bivalves, algae, coral and a few different types of plankton.

Answer: Crabs

Beyond crabs, sea stars could find themselves in peril around the likes of seagulls, tritons, bigger fish in general and sea otters. They do have a little bit of natural defense against predators, as they can briefly make themselves taste very unpleasant by producing toxins against their body walls. They are ultimately at the mercy of a lot of the ecosystem, however.

Answer: Asterias amurensis

After appearing in Tasmania, thought to be in the 1980s, this species grew in number to the point where it became a problem for the local ecosystem. Specifically, this species became a problem in overeating nearby bivalves and causing a shortage.

Answer: True

Whereas most sea stars mature at around two years and survive to ten, the Pisaster Ochraceus generally matures in five years and can survive as long as 34 years of age.

Answer: Robert Paine

Paine came up with the term initially to describe the relationship between the Pisaster ochraceus and a particular species of mussel, the Mytilus californianus.

Paine was an ecologist who graduated from Harvard and spent his career teaching at the University of Washington.