Clams

from Wikipedia, the free encyclopedia
Clams
Small club clam (Cuspidaria cuspidata)

Small club clam ( Cuspidaria cuspidata )

Systematics
Subclass : Heterodonta
Euheterodonta
Superordinate : Anomalodesmata
Order : Septibranchia
Superfamily : Cuspidarioidea
Family : Clams
Scientific name
Cuspidariidae
Dall , 1886

The leg shells (Cuspidariidae) are a shell - family from the large group of Anomalodesmata .

features

The slightly unevenly hinged , small to medium-sized cases are elongated at the back ("beaked"), the "beak" is often transformed into a tube. The right flap is slightly smaller than the left flap. The body of the case is rounded or ovoid and heavily inflated. In relation to the housing body, the orthogyratic vortices are approximately in the middle. Lock teeth can be present, but are missing in many genera. The ligament is external. The mantle bay is shallow.

The shell is thin and fragile. It is aragonitic with a homogeneous inner layer and a homogeneous outer layer. The periostracum is thin and flakes easily. The ornamentation consists of more or less pronounced, parallel to the edge growth strips or ribs. There can also be radial elements. In some genera, the rear part of the housing is attached by a (rarely two) keel extending from the vertebra. There are two sphincter muscles of approximately the same size.

The siphons are very long and extendable.

Geographical distribution and habitat

The family is spread around the world. They prefer to live in deeper water, for example from the outer shelf to the bathyal and abyssal zones.

nutrition

Similar to the mussels of the Verticordiidae and Poromyidae families , the Cuspidariidae also live as carnivores that catch small crabs in particular . In the class of mussels - the vast majority of strudlers - these families are an exception. The horizontal septum, which divides the mantle cavity into two chambers in the septibranchia of these families , plays a crucial role in catching prey. The siphon with the inflow opening is used as a catching organ that can be quickly stretched out towards the prey after it has been located by mechanoreceptors on the sensory tentacles due to low-frequency movements. The contraction of the septum creates a strong inflow of water and the prey is sucked into the mantle cavity, where it is picked up by the large funnel-shaped mouth. The flap at the base of the Sipho prevents it from escaping. The proteins are digested with the help of a strong protease in the mussel's stomach.

Taxonomy

The taxon was established in 1886 by William Healey Dall . It is widely recognized today. There are uncertainties about the number of genera. According to MolluscaBase, the Cuspidariidae family is divided into the following genera:

The following are considered synonyms : Cardiomyidae Scarlato & Starobogatov, 1983, Myoneridae Scarlato & Starobogatov, 1983 and Neaeridae Hidalgo, 1916.

supporting documents

literature

  • Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, 340 p., Verlag Eugen Ulmer, Stuttgart 1997 ISBN 3-8001-7332-8 (p. 86/87)
  • 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. 153)
  • Guido Poppe. Yoshihiro Goto: European Seashells Volume 2 (Scaphopoda, Bivalvia, Cephalopoda) . 221 p., Verlag Christa Hemmen, Wiesbaden 1993 (2000 unc. Reprint), ISBN 3925919104 (p. 132)
  • Myra Keen: Family Cuspidariidae Dall, 1886. In: Raymond Cecil Moore (Ed.): Treatise on invertebrate paleontology. Mollusca, 6, Bivalvia 2. S.N854 / 55, New York, 1969.

Individual evidence

  1. ↑ 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
  2. ↑ 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: B, Royal Society London, Volume 294, Issue 1073, London 1981.
  3. ^ Robert GB Reid, Alison M. Reid (1974): The carnivorous habit of members of the septibranch genus Cuspidaria (Mollusca: Bivalvia). Sarsia, 56 (1), pp. 47-56, DOI: 10.1080 / 00364827.1974.10411261
  4. ^ William Healey Dall: Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the US Coast Survey Steamer Blake, Lieut. -Commander CD Sigsbee, USN, and Commander JR Bartlett, USN, commanding. XXIX. Report on the Mollusca. Part 1. Brachiopoda and Pelecypoda. Bulletin of the Museum of Comparative Zoology, 12 (6): 171–318, Cambridge, Massachusetts 1886 Online at www.biodiversitylibrary.org (p. 196)
  5. ↑ a b MolluscaBase: Cuspidariidae Dall, 1886