Atagema osseosa

Atagema osseosa
Live specimen of Atagema osseosa
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Nudibranchia
Family:	Discodorididae
Genus:	Atagema
Species:	A. osseosa
Binomial name
Atagema osseosa (Kelaart, 1859)
Synonyms
Doris osseosa Kelaart, 1859 [1] [2] Trippa osseosa (Kelaart, 1859) [3]

Atagema osseosa is a species of sea slug or dorid nudibranch, a marine gastropod mollusk in the family Discodorididae. ^{[2] [4]}

Description

(Original description) The specimen possesses a body approximately one inch in length (25.4 mm), protected by a mantle that is hard, cartilaginous, and characterized by a granular, pitted texture. These granules are distinguished by a pale, whitish color. Along the median line, a narrow ridge extends from the base of the tentacles to the branchial plumes. These plumes, typically numbering four or five, emerge horizontally from beneath the posterior termination of the dorsal ridge.

In some individuals, a large, pitted protuberance is situated at the center of this ridge. The dorsal tentacles are encased in large, granular sheaths and terminate in conical, lamellated apices of a pale green hue. In contrast, the oral tentacles are a pure white. The foot of the organism is notably small and narrow, while the branchial plumes are small and exhibit a delicate, bipinnated structure. ^[1]

Distribution

This species is found in the tropical Indo-West Pacific Ocean, ^{[3] [4]} with records at least from the coasts of India and eastern Australia. ^[4]

Description

This nudibranch has evolved to mimic closely in appearance the sandy-coloured sponge on which it both lives and feeds off. ^[3]

Ecology

Like many nudibranchs, this species feeds on sponges.

References

1. Kelaart, E. F. (1859). "Descriptions of new and little-known species of Ceylonese nudibranchiate mollusks". Annals and Magazine of Natural History. Series 3. 3 (16): 291–304 [298]. This article incorporates text from this source, which is in the public domain .
2. Bieler R, Bouchet P, Gofas S, Marshall B, Rosenberg G, La Perna R, Neubauer TA, Sartori AF, Schneider S, Vos C, ter Poorten JJ, Taylor J, Dijkstra H, Finn J, Bank R, Neubert E, Moretzsohn F, Faber M, Houart R, Picton B, Garcia-Alvarez O, eds. (2022). "Atagema osseosa (Kelaart, 1859)". MolluscaBase. World Register of Marine Species . Retrieved 20 February 2022.
3. Rudman, W.B. (1998–2010). "Atagema osseosa (Kelaart, 1859)". Sea Slug Forum. Australian Museum. Reference given: Kelaart, E.F. (1858). Description of new and little known species of Ceylon nudibranchiate molluscs and zoophytes. Journal of the Ceylon Branch of the Royal Asiatic Society, Columbo, 3(1): 84–139.
4. "Atagema osseosa (Kelaart, 1859)". Global Biodiversity Information Facility . Retrieved 20 February 2022.