Ondina diaphana
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Casing of Ondina diaphana , picture by GW Tryon, 1886 |
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| Ondina diaphana | ||||||||||||
| ( Jeffreys , 1848) |
Ondina diaphana ( synonym : Menestho diaphana ) is the name of a small screw from the family of pyramidellidae that in the Atlantic as Ectoparasite on centrifugal spray worm ( Phascolion strombus lives).
features
The white colored, slender, spindle-shaped shell of Ondina diaphana , which reaches up to 3.4 mm in length, consists of three whorls and the protoconch in adult snails. It has a smooth and shiny surface with fine stripes on the side of the body around the body facing away from the tip. The last passage takes up about two thirds of the total length of the house. The elongated housing mouth is thickened, the tooth of the spindle designed differently. The house has a big navel.
Way of life
Ondina diaphana is an obligatory ectoparasite of the gyro splashworm ( Phascolion strombus ), which lives in empty mollusc shells. With its long proboscis, the snail looks for a suitable place on the skin of the syringe worm and pricks it with a stylet at the tip of the proboscis in order to suck in its celomial fluid, which is rich in erythrocytes and granulocytes, by means of the buccal pump.
distribution
Ondina diaphana is widespread at its host's localities in the Atlantic Ocean and Mediterranean .
Life cycle
Ondina diaphana is a hybrid that produces sperm and egg cells at the same time and in which the partners mate each other with their penises . In summer, gelatinous egg clutches are attached to the outside of the mollusc shell inhabited by Phascolion strombus , from which Veliger larvae hatch. An egg clutch is about 2 mm by 3 mm in size and contains about 50 to 150 eggs with a diameter of 0.2 mm, embedded in colorless gelatin. The snail dies after laying eggs.
Ondina diaphana and Ondina perezi
Ondina diaphana was first described in 1848 by the British malacologist John Gwyn Jeffreys as Odostomia diaphana using a bowl from Exmouth on the south-west coast of England. There was no record of the biology of this species. In 1925, Philippe Dautzenberg and Paul-Henri Fischer described a species of snail associated with the splashworm Phascolion strombus under the name Odontostomia perezi , today Ondina perezi , which differs from Ondina diaphana by its matt housing. In his detailed description of the biology of this species from 1970, Jørgen Hylleberg Kristensen regards the two snails as a species, for which he uses the species name Menestho diaphana , and sees Odontostomia perezi as a synonym. The status of these two species as one species is still controversial to this day.
literature
- Paul Chambers: British Seashells: A Guide for Collectors and Beachcombers. Original Victorian Illustrations by George Sowerby. Remember When, Pen & Sword Books, Barnsley (South Yorkshire) 2009. p. 107, no. 187, Ondina diaphana (Jeffreys).
- Peter J. Hayward, John S. Ryland: Handbook of the Marine Fauna of North-West Europe. Oxford University Press, 2017. p. 508.
- Jørgen Hylleberg Kristensen (1970): Fauna associated with the sipunculid Phascolion strombi (Montagu), especially the parasitic gastropod Menestho diaphana (Jeffreys). Ophelia 7 (2), pp. 257-276, here pp. 263-271.
- Philippe Dautzenberg, Paul-Henri Fischer: Les mollusques marins du Finistère et en particulier de la région de Roscoff. Les Presses Universitaires de France, Paris 1925. p. 81.
Web links
- MJ de Kluijver, SS Ingalsuo & RH de Bruyne: Ondina diaphana (Jeffreys, 1848). Marine Species Identification Portal
Individual evidence
- ↑ Tore Høisæter: The Pyramidellidae (Gastropoda, Heterobranchia) of Norway and adjacent waters. A taxonomic review. Fauna Norvegica 34, pp. 7–78, November 2014, here p. 47f. doi : 10.5324 / fn.v34i0.1672