GASTROCHAENIDAE
rock-borer clams

  Gastrochaena cymbium
(Spengler, 1783)

Relevant Synonyms
-

Misidentification
-

 photo: P. Pravlis / Coll. L. and R. Enzenross    

SHORT DESCRIPTION
Shells inequilateral, delicate and fragile. Outline ovate, wedge shaped. The dorsal and ventral margins are almost parallel; posterior margin short subtruncate; anterior margin short straight. Gape occupying most of the length of the valves. Sculpture of concentric growth fine lines only, except on anterio-ventral region where few fine raised lines develop. Animal enclosed in a calcareous tube with characteristic constrictions at regular intervals.

color : white.

common size : 5 mm to 12 mm in length, tube 12 x 6.5 mm.

DISTINGUISHING CHARACTERISTICS
The native G. dubia (Pennant, 1777) has a shell which covers more of the soft parts and is well rounded posteriorly; it is also usually totally embedded in the perforated substrate and, when enclosed in a tube, this tube incorporates sediment particles and lacks the constrictions.

BIOLOGY / ECOLOGY
Borer, nestling in hard substrata, immobile, unattached organisms with a suspension feeding trophic mode.

habitat : very common, mostly attached to dead shells, enclosed in calcareous capsules (see detailed photo below), with a preference to bivalves lying on the surface of sands and muds; in deep continental shelf waters (9-91 m depth).


A valve of Gastrochaena, left: in a valve of Anadara (Coll. Spada from Barash, 1961); right: once extracted.
photo: P. Pravlis


1st Mediterranean record
Israel, 1973 [1954].


DISTRIBUTION
Worldwide: Indo-Pacific, including throughout the Red Sea; recorded in the Suez Canal (Moazzo, 1939). Mediterranean: recorded first in 1954 from Israel (Barash and Danin, 1973); successively from Greece, Saronikos (Tenekidis, 1989); southeastern Turkey (Niederhöfer et al., 1991).

ESTABLISHMENT SUCCESS
Very common in far eastern Mediterranean. The flask shell is encountered on numerous species of bivalves and gastropods, on corals, bones and stones.

speculated reasons for success :
-


MODE OF INTRODUCTION
Via the Suez Canal.


IMPORTANCE TO HUMANS
None.


KEY REFERENCES

  • Barash A. and Danin Z., 1973. The Indo-Pacific species of mollusca in the Mediterranean and notes on a collection from the Suez Canal. Israel Journal of Zoology, 21(3-4): 301-374.
  • Mienis H.K., 2002e. Mariene Mollusken uit het Oostelijk deel van de Middellandse Zee. 10. Woorwerpen de door Cucurbitula cymbium gebruikt worden als substraat. Spirula - Correspondentieblad van de Nederlandse Malacologische Vereniging, 327: 75-76.
  • Niederhöfer H., Enzenross L. and Enzenross R., 1991. Neue Erkenntnisse über die Ausbreitung von "Lesseps'schen Einwanderern" (Mollusca) a der türkischen Mittelmeerküste. Club Conchilia Information, 23(3-4): 94-108.

 

  • Tenekides N.S., 1989. On a collection of shells from the Greek Seas. 187 p. (in Greek).

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Last update : January 2005

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