Cardita calyculata

Cardita calyculata
Cardita calyculata (from Reeve, 1843: Cardita plate 1, Fig. 1)
Systematics
Archiheterodonta Order : Carditida Superfamily : Carditoidea Family : Trapezoidal shells (Carditidae) Genre : Cardita Type : Cardita calyculata
Scientific name
Cardita calyculata
( Linnaeus , 1758)

Lock teeth of Cardita calyculata : HZ = main tooth, HSZ = rear posterior tooth, VSZ = anterior posterior tooth (from Lamy, 1922: p. 221, text illustration)

Cardita calyculata : the ventral border is above in this picture! (from Dautzenberg, 1913: Plate 42, Fig. 143)

Cardita calyculata is a shell - type from the family of trapeze shells (Carditidae).

features

The equally flared, strongly expanded housing is up to 30 mm long. It is approximately rectangular in outline. Nordsieck gives a ratio of: length = 30 mm, height = 18 mm and thickness = 19 mm. It is strongly extended backwards and therefore very unequal. Specimens elongated to the rear were also called var.oblonga Requien, 1848. The comparatively small vertebrae, which are rolled up to the front, sit near the front end. The posterior dorsal margin is moderately long and rises. The anterior dorsal margin drops off steeply, it merges directly into the ventral margin. The transition is tightly rounded. The ventral margin is straight to slightly concave. The posterior dorsal margin merges with the wide arched posterior margin at a very flat angle. The transition from the front edge to the ventral edge is not marked. The ligament is external. The lunula is small, egg-shaped and sunken. An area is not developed. In the left valve there is an anterior short main tooth, a rear lamellar main tooth, and a weaker rear posterior tooth. Occasionally a very small anterior posterior tooth appears. In the right valve there are two lamellar main teeth, lengthened to the rear, and a smaller anterior posterior tooth. There are two sphincters. The posterior sphincter impression is slightly larger but flatter than the anterior, raised sphincter impression.

The shell is thick and firm. The ornamentation consists of 17 to 18 radial ribs, which are reinforced in the intersection area with weak growth strips parallel to the edge to form lamellae. They are also much stronger in the long rear part of the housing than in the short front part. The spaces between the ribs are very narrow. The ribs are initially rounded and become wider towards the edge of the housing, the number of lamellas decreases. For this, the lamellas are knotted. In the rear part of the case, the ribs are also slightly angled. The surface is white, there are brown spots and dots in the rear part of the case. The edge of the case is roughly notched, the ribs shine through on the inside. The inside of the shell is white, often with brown spots in the back. In some specimens the ribs can be severely weakened (var. Obsoleta Dautzenberg, 1881).

Geographical distribution and habitat

The distribution area of ​​the species extends from the French Atlantic coast, over the coastal waters around the Iberian Peninsula to the Mediterranean . It is also found in the coastal waters around the Canary Islands , the Azores, and Madeira .

The depth distribution ranges from the tidal range to a depth of 216 meters. A record of the Azores in 1385 meters water depth is completely out of the ordinary. The animals live under or between stones or on the roots or stalks of larger algae attached to byssus threads.

Taxonomy

The species was founded in 1758 by Carl von Linné under the original binomial Chama calyculata . It is the type species of the genus Cardita Bruguière, 1792. Synonyms include: Cardita calyculata . Var imperans de Gregorio, 1885, Cardita calyculata var. Oblonga Requiems, 1848 Cardita calyculata var. Obsoleta Dautzenberg, 1883, Cardita calyculata var. Obtusata Requiems, 1848 , Cardita calyculata var. Pita de Gregorio, 1885, Cardita calyculata var. Tirisa de Gregorio, 1885, Cardita calyculata var. Unicolor Bucquoy, Dautzenberg & Dollfus, 1892,? Cardita elongata Bronn, 1831, Cardita fabula Reeve, 1843, Cardita formosula Locard, 1892, Cardita sinuata Lamarck, 1819 and Mytilicardia elongata Fontannes, 1882.

supporting documents

literature

• Edouard Lamy: Review of the Carditacea vivants du Muséum National d'Histoire Naturelle de Paris. Journal de Conchyliologie , 66: 218–276, 289–368, 1922 Online at www.biodiversitylibrary.org (p. 221)
• 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. 73)
• Guido Poppe, Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 pp., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unv. Reprint), ISBN 3925919104 (p. 89)

Individual evidence

1. ^ Lovell Augustus Reeve: Conchologia iconica, or, Illustrations of the shells of molluscous animals. Vol. 1, Reeve & Brothers, London 1843 Online at www.biodiversitylibrary.org (Plate 1).
2. ^ Philippe Dautzenberg: Atlas de poche des coquilles des côtes de France (Manche, océan, Méditerranée) communes, pittoresques ou comestibles, Paris, Librairie des sciences naturelles, Paul Klincksiek, 1913. Online at www.biodiversitylibrary.org (Plate 42)
3. ^ Carl von Linné: Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. Pp. 1-824, Holmia / Stockholm, Salvius, 1758. Online at www.biodiversitylibrary.org (p. 692).
4. ↑ ^{a b} MolluscaBase: Cardita calyculata (Linnaeus, 1758)

annotation

1. ↑ Some authors state that the distribution area extends along the West African coast to Senegal. However, this refers to Cardita senegalensis (Reeve, 1843), a taxon that was previously considered a subspecies of Cardita calyculata .