Curled sea hare

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Curled sea hare
Ringed lumpfish (Aplysia dactylomela)

Ringed lumpfish ( Aplysia dactylomela )

Systematics
Order : Opisthobranchia
Subordination : Broad- footed snails (Anaspidea)
Superfamily : Aplysioidea
Family : Aplysiidae
Genre : Aplysia
Type : Curled sea hare
Scientific name
Aplysia dactylomela
S. Rang , 1828

The curled sea hare ( Aplysia dactylomela ) is a sea snail of the genus Aplysia . Characteristic is a leopard look, which is applied by black circular rings on the back on the light beige, brown, yellow-brown, green skin. The specimens of this species are of medium size. They occur in shallow water areas of all subtropical and tropical seas.

Features and way of life

External features

A crawling curled sea hare on the coast of Fuerteventura , Canary Islands.

The structure of Aplysia dactylomela follows that of all sea hares. The head, neck and abdomen are divided into three parts. In the area of ​​the throat, the head has two flat, rolled-up tentacles with mechano and chemoreceptors that extend sideways and react to pressure. Between the head and neck there are rhinophores that can extend out of a pocket under the skin and retract in danger. The rhinophores have notches at their upper end with epithelial skin covered with chemosensors and neurons and serve as an olfactory sense organ. There is an eye under each rhinophore.

The neck widens towards the rear. In this are the reduced mantle cavity with central organs such as the heart and gills covered by an ingrown shell that has atrophied in evolution.

The lateral parapodial lobes are often seen closed to protect the space above the mantle cavity and sometimes give them a dinosaur-like appearance. The lobes have not grown together, but can be opened.

The basic color of the animals ranges from almost colorless beige to strong sandy brown, from light gray to green to dark brown. Characteristic surface patterns are large black rings that give it a kind of leopard look. In some specimens, black, network-like thread lines beginning at the edges of the parapodial lobes are striking. Still other specimens have parapodial lobes with a light-white colored border.

Aplysia dactylomela : opening of the throat
Aplysia dactylomela : throat tentacles, rhinophores, erect parapodial lobes

Habitats

The Aplysia dactylomela are cosmopolitans and occur in various tropical and subtropical seas and areas. One speaks therefore of a circumtropical distribution . Sightings have taken place in the Atlantic, Pacific, Indian Ocean, Caribbean, Red Sea, and since around 2002 also in the Mediterranean.

The Aplysia dactylomela are a benthic species, that is, they live in shallow water areas of different depths or even in tidal waters, that is, areas cut off from the sea at low tide. There they stay in dense vegetation, which serves them as protection and food.

nutrition

There are different statements about nutrition. A strong focus on red algae is reported , including the genera Asparagopsis , Laurencia and the species Acanthophora specifera . But the diet of green algae was also observed.

Reproduction

The Aplysia dactylomela are hermaphrodites and have a hermaphrodite . Since they are not self-fertilizing, they will need a partner. The fertilization takes place alternately in pairs, or in rows in chains. One animal takes on the role of the male, another that of the female. The genital opening is located on the back (dorsal) between the parapodial lobes. The animal acting as a male introduces the sperm with a penis into the sexual opening of the animal acting as a female. After fertilization, the animals leave out spawning lines. The spawning lines are shaped like jelly-like tubes in which the eggs are located. In Aplysia dacylomela , the spawning cords sometimes have unusual colors. Yellow-brown, pink and violet-colored spawning lines were spotted.

protection

Good camouflage offers protection. Circles, grain and surface color are barely noticeable on sand or stony soils. This applies even to sparse, but roughly the same colored vegetation.

Sources and literature

  • S. Gofas, J. Le Renard, P. Bouchet: Mollusca. In: MJ Costello et al. (Ed.) (2001). European register of marine species: a check list of the marine species in Europe and a bibliography of guides to their identification. In: Collection Patrimoines Naturels. 50 2001, pp. 180-213.
  • DD Turgeon, JF Quinn, AE Bogan, EV Coan, FG Hochberg, WG Lyons et al: Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26. American Fisheries Society, Bethesda, Maryland, USA, ISBN 1-888569-01-8 .
  • AE Verrill: The nudibranchs and naked tectibranchs of the Bermudas. In: Transactions of the Connecticut Academy of Arts and Sciences. 10.09-1900; pl. 661, pp. 545-550.

Individual evidence

  1. ↑ S. Rank: Histoire naturelle des Aplysiens, prèmiere famille de l'ordre des Tectibranches. 84pp, plates 1-24; In: D. Férussac: Histoire naturelle generale et particuliere des Mollusques. Firmin Didot, Paris 1828.
  2. ^ WB Rudman: Comment on Re: Aplysia dactylomela from the Canary Islands by Stanley Ramsell. In: Sea Slug Forum. Australian Museum, Sydney March 6, 2008; (on-line)
  3. ↑ P. Chen: Feeding preference of Aplysia dactylomela. In: Sea Slug Forum. Australian Museum, Sydney October 26, 2001. (online)
  4. ^ V. Padula: Re: Aplysia dactylomela and its egg-mass. In: Sea Slug Forum. Australian Museum, Sydney July 10, 2008. (online)
  5. ↑ M. Poddubetskaia: Aplysia dactylomela and its egg-mass. In: Sea Slug Forum. Australian Museum, Sydney March 10, 2004. (online)
  6. ^ A. Greco: Aplysia dactylomela egg masses from the Mediterranean. In: Sea Slug Forum. Australian Museum, Sydney August 12, 2008. (online)

Web links

Commons : Aplysia dactylomela  - Collection of images, videos and audio files