''Aplysia morio'', the Atlantic black sea hare or sooty sea hare, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea slug Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary t ...

, a

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family

Aplysiidae Aplysiidae is the only family in the superfamily Aplysioidea, within the clade Anaspidea. These animals are commonly called sea hares because, unlike most sea slugs, they are often quite large, and when they are underwater, their rounded body sh ...

, the

sea hares The clade Anaspidea, commonly known as sea hares (''Aplysia'' species and related genera), are medium-sized to very large opisthobranch gastropod molluscs with a soft internal shell made of protein. These are marine gastropod molluscs in the s ...

. It lives in warm waters in the Caribbean Sea and off the south and southeastern coast of the United States, where it feeds on seaweed.

Description

''Aplysia morio'' is a bulky sea slug that can grow to a length of or more. It is usually dark chocolate brown to blackish in colour, and sometimes dark lines are visible on the head and flanks. The tentacles are curled and shaped rather like rabbit's ears. They are rich in nerve cells and are equipped with receptor organs. The shell is a fragile disc, hidden within the mantle, and the foot has large flaps at the side called

parapodia In invertebrates, the term parapodium ( Gr. ''para'', beyond or beside + ''podia'', feet; plural: parapodia) refers to lateral outgrowths or protrusions from the body. Parapodia are predominantly found in annelids, where they are paired, unjointed ...

which are used for swimming.

Distribution and habitat

This species is found in the semi-tropical western Atlantic Ocean. Its range includes the eastern coast of the United States, Bermuda, the West Indies, Florida, the Caribbean Sea, the Gulf of Mexico and Venezuela. It typically lives in shallow water, down to depths of about in areas where there is little wave action. It is usually found on rocky surfaces among the algae that it feeds on, but is also found on sandy seabeds.

Ecology

''Aplysia morio'' feeds on algae. In Bermuda juveniles seem to feed almost exclusively on species of the red alga ''

Laurencia ''Laurencia'' is a genus of red algae that grow in temperate and tropical shore areas, in littoral to sublittoral habitats, at depths up to . Description ''Laurencia'' species have a thallus that is erect or decumbent with distichous, whorled ...

'', even though there is a wide range of algae to choose from. Adults widen their diet slightly to include ''

Palmaria palmata ''Palmaria palmata'', also called dulse, dillisk or dilsk (from Irish/Scottish Gaelic '/'), red dulse, sea lettuce flakes, or creathnach, is a red alga (Rhodophyta) previously referred to as ''Rhodymenia palmata''. It grows on the northern coast ...

''. The animal either crawls over the seaweed or rears up to grasp the fronds with its

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

and the

odontophore The odontophore is part of the feeding mechanism in molluscs. It is the cartilage which underlies and supports the radula, a ribbon of teeth. The radula is found in every class of molluscs except for the bivalves. The feeding apparatus can be exte ...

(cartilage) that supports it. It may also swim, in a manner reminiscent of a

manta ray Manta rays are large rays belonging to the genus ''Mobula'' (formerly its own genus ''Manta''). The larger species, '' M. birostris'', reaches in width, while the smaller, '' M. alfredi'', reaches . Both have triangular Pectoral fin#AnchPect ...

, when looking for food. An adult is a

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

that can act as a male and a female at the same time. As the penis of one individual is inserted into the genital opening of another, chains or clusters of mating sea hares can form. The initially spawning individual releases chemical signals that can trigger spawning in others, which may culminate in a mass spawning event. Fertilized eggs hatch and develop into

veliger A veliger is the planktonic larva of many kinds of sea snails and freshwater snails, as well as most bivalve molluscs (clams) and tusk shells. Description The veliger is the characteristic larva of the gastropod, bivalve and scaphopod ...

larvae, which drift with the

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

for at least a month and settle onto ''Laurencia'' seaweed.

References

External links

* * {{Taxonbar, from=Q3734807 morio Gastropods described in 1901