''Akera bullata'', named the royal flush sea slug, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

(or

sea slug Sea slug is a common name for some Marine biology, marine invertebrates with varying levels of resemblance to terrestrial Slug, slugs. Most creatures known as sea slugs are gastropods, i.e. they are Sea snail, sea snails (marine gastropod moll ...

), a marine

opisthobranch Opisthobranchs () is a now informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping. Euopistho ...

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the family

Akeridae Akeridae is a small taxonomic family of sea snails, marine gastropod molluscs belonging to the superfamily Akeroidea, the sea hares. The family, in its original spelling "Aceridae", has previously been attributed in error to Pilsbry, 1893. Ake ...

, a family that is related to the

sea hare The order Aplysiida, 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 t ...

s. This species is the only

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

an representative of the genus ''

Akera ''Akera'' is a marine (ocean), marine genus of sea hare in the family Akeridae, known from the late Callovian (Jurassic) to the recent periods.Gofas, S. (2012). Akera O.F. Müller, 1776. Accessed through: World Register of Marine Species at http: ...

''.

Distribution

This species occurs from

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

to the Canaries, and also in the

Mediterranean The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...

Ecology

This is a

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

bottom dweller (up to 370 m deep), which feeds on

seagrass Seagrasses are the only flowering plants which grow in marine (ocean), marine environments. There are about 60 species of fully marine seagrasses which belong to four Family (biology), families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and ...

es in the genera ''

Zostera ''Zostera'' is a small genus of widely distributed seagrasses, commonly called marine eelgrass, or simply seagrass or eelgrass. The genus ''Zostera'' contains 15 species. Ecology '' Zostera marina'' is found on sandy substrates or in estuarie ...

'' and ''

Posidonia ''Posidonia'' is a genus of flowering plants. It contains nine species of marine plants ("seagrass"), found in the seas of the Mediterranean and around the south coast of Australia. The APG system (1998) and APG II system (2003) accept this ge ...

''.

Description

The body of this sea hare can reach a maximum length of about 6 cm. Its coloration varies from gray to orange, often with white or dark specks. The shell is fragile, smooth, and can be either white or brown. This sea hare is not an agile swimmer. When disturbed, it uses its broad

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

— fleshy protrusions held together in a funnel shape above the head — to paddle away.

Synonyms

''Acera bullata'' is an orthographic variant with considerable currency. The NLBIF lists a large number of synonyms in addition to the above; including: ''Bulla akera'' (Gmelin, J.F., 1791),Marine Mollusca of the Faroes. p. 95. ''Bulla norwegica'' (Bruguière, J.G., 1789), ''Bulla canaliculata'' (Olivi, 1792), ''Bulla resiliens'' (Donovan, E., 1801), ''Bulla fragilis'' (Lamarck, J.B.P.A. de, 1822), ''Akera flexilis'' (Brown, 1844), ''Bulla hanleyi'' (Adams A. in Sowerby G.B. II, 1850/1855), ''Eucampe donovani'' (Leach, W.E., 1852), ''Bulla elastica'' (Sandri & Danilo, 1856), ''Acera bullata'' var. nana (Jeffreys, 1867), ''Acera elegans'' (Locard, 1886), ''Bulla farrani'' (Norman, 1890), ''Bulla globosa'' (Cantraine, F.J., 1840), ''Akera tenuis'' (Brusina, S., 1866) and ''Akera farrani'' (Winckworth, R., 1932).

References

Müller, O.F. (1776). ''Zoologica Danicae Prodromus seu Animalium Daniae et Norvegiae indigenarum characters, nomine, et synonyma imprimis popularium''. Havniae. XXXII, 274 pp., page(s): 242

Distribution

Ecology

Description

Synonyms

References

Further reading