Small clam shell

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Small clam shell
Small club clam (Cuspidaria cuspidata) (from Forbes & Hanley, 1848: Plate 7, Fig. 4–7 [1])

Small club clam ( Cuspidaria cuspidata ) (from Forbes & Hanley, 1848: Plate 7, Fig. 4–7)

Systematics
Order :
Superfamily : Cuspidarioidea
Family : Club clams (Cuspidariidae)
Subfamily : Cuspidariinae
Genre : Cuspidaria
Type : Small clam shell
Scientific name
Cuspidaria cuspidata
( Olivi , 1792)
Animal with siphons and tentacles around the openings of the siphons

The Small leg shell ( Cuspidaria cuspidata ) is a shell -Art from the family of leg shells (Cuspidariidae).

features

The evenly folded, strongly inflated housing is up to 20 mm (north triangle: up to 18 mm) long. The housing body is obliquely egg-shaped or elliptical in outline. At the back it is drawn out into a long, tubular "beak" (rostrum). The end of the rostrum is truncated perpendicular to the longitudinal axis. In relation to the actual case body, the case is almost equilateral, the vertebrae are only a little in front of the center line, and also a little higher than long. Including the beak, the housing is much longer than it is high. The leading edge is straight and sloping steeply. The ventral margin is widely curved. The short dorsal margin to the rostrum The rostrum is comparatively short. The dorsal edge of the rostrum is straight and sloping flat backwards. The ventral edge is clearly concave and continues in a clear sulcus between the housing body and the rostrum. The comparatively inflated vertebrae are strongly developed. The ligament rests on an elliptical chondrophore in both valves. In the right flap the chondrophor protrudes over the lock plate, in the left flap it stands behind the lock plate. In the right flap there is a long, posterior lateral tooth, which in the left flap engages in a longitudinal pit below the lock plate. There is an anterior and a posterior sphincter muscle. The jacket line is clearly visible, but the jacket bay is only flat.

The dirty, whitish skin is thin and fragile. It is aragonitic with a homogeneous inner layer and a homogeneous outer layer. The brownish periostracum is often furrowed with attached sediment. The ornamentation consists of more or less pronounced growth strips parallel to the edge, which are somewhat coarser at the rear end and at the edges of the case. Inside, the skin is whitish, occasionally with a bluish tint. The inner edge of the case is smooth.

The siphons are comparatively short and at least partially protected by the tubular beak. The openings of the siphons have long tentacles, the ends of which divide into finger-shaped appendages. The gills are muscular septa that close the back of the mantle cavity. The septa are permeable through five pairs of pores. The animals are of separate sex.

Similar species

The small beaked mussel ( Cuspidaria cuspidata ) is smaller, shorter and wider than Cuspidaria rostrata . The front edge drops off more steeply and the ventral edge is more rounded. The vertebrae are smaller but more distended.

Geographical distribution and habitat

The distribution area in the Eastern Atlantic extends from Norway to Angola . It is also found in the waters around Madeira and the Mediterranean .

The animals live half-buried in muddy and sandy-muddy soils in water depths of around 20 meters to the upper shelf. Nordsieck (1969) gave a depth distribution of 30 to 1650 meters, Allen & Morgan (1981) even from 20 to 1850 meters.

The animals are relatively common in suitable habitats.

nutrition

Like other club clams , Cuspidaria cuspidata feeds on small crustaceans and worms as a carnivore . In adaptation to this diet, like other septibranchia, it has a muscular septum that divides the mantle cavity into two chambers. If the sensory tentacles report a corresponding movement, the prey is sucked into the mantle cavity by contraction of the septum with a powerful stream of water through the influx siphon extended towards the prey, where it is taken up by the large funnel-shaped mouth.

Taxonomy

The taxon was first described by Giuseppe Olivi in 1792 in the form of Tellina cuspidata . It is de facto the type species of the genus Cuspidaria Nardo, 1840, which is the formal type species Cuspidaria typus Nardo, 1840 a younger synonym of Tellina cuspidata Olivi, 1792. Other synonyms are: Anatina brevirostris Brown, 1829, Neaera crassa Monterosato, 1880, Neaera cuspidata var. Cinerea Jeffreys, 1865 and Neaera cuspidata var. Curta Jeffreys, 1865.

supporting documents

literature

  • JA Allen, Rhona E. Morgan: The functional morphology of Atlantic deep water species of the families Cuspidariidae and Poromyidae (Bivalvia): an analysis of the evolution of the septibranch condition. Philosophical Transactions of the Royal Society of London Series B, 294: 413-546, London 1981 JSTOR .
  • Fritz Nordsieck : The European sea shells (Bivalvia). From the Arctic Ocean to Cape Verde, the Mediterranean Sea and the Black Sea. 256 p., Gustav Fischer Verlag, Stuttgart 1969 (p. 174)
  • Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (138)

On-line

Individual evidence

  1. ^ Edward Forbes, Sylvanus Hanley: A history of British Mollusca and their shells. Volume 1,477 p., J. Van Voorst, London 1848 (Delivery V: pp. 161 to 200 published in May 1848) Online at www.biodiversitylibrary.org (p. 195) plate G , plate 32
  2. ↑ Fritz Gosselck, Alexander Darr, Jürgen HJ Jungbluth, Michael Zettler: Trivial names for mollusks of the sea and brackish water in Germany. Mollusca, 27 (1): 3-32, 2009 PDF
  3. ^ Brian Morton: Feeding and Digestion in Bivalvia. In: ASM Saleuddin, Karl M. Wilbur: The Mollusca: Physiology, Part 2. Academic Press, 2012. pp. 65–148, here pp. 123–125.
  4. ^ Giuseppe Olivi: Zoologia Adriatica, ossia catalogo ragionato degli animali del golfo e della lagune di Venezia Bassano , Venecia. 334pp, 1792 Online at www.biodiversitylibrary.org (p. 101).
  5. ↑ a b MolluscaBase: Cuspidaria cuspidata (Olivi, 1792)