''Leptasterias tenera'' is a
species of
starfish
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea (). Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish ...
in the
family Asteriidae. It is found on the eastern coast of North America.
Description
''Leptasterias tenera'' is a small starfish with five arms
and a slow growth rate. It can grow to a diameter of but most adults only reach about half that size.
Distribution and habitat
''Leptasterias tenera'' occurs on the eastern seaboard of Canada and the United States, ranging from
Nova Scotia and
Prince Edward Island southwards to
Cape Hatteras.
[ It is also known from the ]Sargasso Sea
The Sargasso Sea () is a region of the Atlantic Ocean bounded by four currents forming an ocean gyre. Unlike all other regions called seas, it has no land boundaries. It is distinguished from other parts of the Atlantic Ocean by its charac ...
.[ It is found at depths down to about on sandy or muddy seabeds.][
]
Biology
''Leptasterias tenera'' is an ambush predator. It remains stationary on the seabed for long periods, snaring any small crustaceans which come into contact with it, gripping them with its tube feet and pedicellariae and flexing its arms to transfer the prey to its mouth. Large items are pushed as far as they will go into the pyloric stomach but only the portion inside is digested at first.[
A study was undertaken of the breeding behaviour of ''Leptasterias tenera'' at ]Block Island
Block Island is an island in the U.S. state of Rhode Island located in Block Island Sound approximately south of the mainland and east of Montauk Point, Long Island, New York, named after Dutch explorer Adriaen Block. It is part of Washingt ...
near Rhode Island at a site about deep where the sea floor was fine muddy sand. The area was dominated by the presence of tube-building amphipods and there were some bivalve molluscs. ''Leptasterias tenera'' was the most numerous predatory species but also present were other starfish '' Asterias forbesi'' and ''Asterias rubens
The common starfish, common sea star or sugar starfish (''Asterias rubens'') is the most common and familiar starfish in the north-east Atlantic. Belonging to the family Asteriidae, it has five arms and usually grows to between 10–30 ...
'' and the Jonah crab ''Cancer borealis
The Jonah crab (''Cancer borealis'') is a marine brachyuran crab that inhabits waters along the east coast of North America from Newfoundland to Florida. Jonah crabs possess a rounded, rough-edged carapace with small light spots, and robust claws ...
''. Up to twelve ''Leptasterias tenera'' were found per square metre (ten per square yard). Examination of the stomach contents showed that the main items of diet were the numerous amphipods. Breeding took place in the winter.[ The eggs were large and yolky and few in number.][ The fertilised eggs were at first retained within the pyloric stomach of the female where the embryos underwent the first stages of their development.][ Later they emerged and the ]brachiolaria
A brachiolaria is the second stage of larval development in many starfishes. It follows the bipinnaria. Brachiolaria have bilateral symmetry, unlike the adult starfish, which have a pentaradial symmetry. Starfish of the order Paxillosida (''Astrope ...
larvae were brooded underneath the arched disc of the starfish. The breeding season lasted about four months but it was unclear for how long any individual female brooded her young. While brooding, feeding either stopped or was restricted but a few brooding females were found to have prey items in their pyloric stomachs.[
]
References
{{Taxonbar, from=Q3276231
Leptasterias
Animals described in 1862