Family Mesodesmatidae - wedge clams
|
Order |
: |
|||
Class |
: |
Bivalvia |
||
No. of Genera in Ref. |
: |
|||
No. of Species in Ref. |
: |
|||
Environment |
: |
Fresh : No |
Brackish : Yes |
Marine : Yes |
||
Aquarium |
: |
|||
First Fossil Record |
: |
|||
Remark |
: |
Shell equivalve, usually thick and heavy, more or less compressed laterally, inequilateral, elongate ovate or subtrigonal to wedge-shaped in outline. Umbones opisthogyrate. Outer surface smooth or mostly concentrically sculptured, with a well-developed and often glossy periostracum. External ligament short and not prominent, communicating with a strong internal ligament fitting in each valve in a deep pit of the hinge plate. Hinge with 1 or 2 cardinal teeth and more or less developed lateral teeth in each valve. Interior of shell porcelaneous. Two adductor muscle scars, subequal in size. Pallial line with a rather short sinus. Internal margins smooth. Gills of eulamellibranchiate type, with folded branchial sheets. Foot strong and subtrigonal, without a byssus. Siphons separate, naked, papillate on top. Mantle margins smooth, with an anteroventral gape. Suspension filter-feeding animals, actively burrowing in sandy bottoms; sexes separate; development with a free-swimming larval stage; locally collected as food by coastal people (Ref. 348). |
||
Etymology |
: |
|||
Division |
: |
|||
Reproductive guild |
: |
|||
Typical activity level |
: |
|||
Main Ref. |
: |
|||
Coordinator |
: |