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Bivalves
on this site
Family Arcidae
Blood Cockle
Anadara granosa
Family Glauconomidae
Brown or Mud Mussel Glauconome
Family Mytilidae
Green Mussel
Perna viridis
Family Dreissenidae
Mytilopsis
Family Isognomonidae
Mangrove Hammer Shell
Isognomon ephippium
Family Anomiidae
Crust Shell
Enignomia rosea
Family Limidae
File Shell Lima lima
Family Clavagellidae
Waterspout or Watering-pot Shell
Brechites penis
Family Ostreidae
Edible Rock Oyster Saccostrea
FamilyChamidae
Jewel Box Shell Chama
Family Geloinidae
Giant Mud Clam Geloina
Family Tridacnidea
Giant Clam Tridacna squamosa |
Class
Bivalvia
Almost all bivalves are filter feeders and have two shell valves which
hinge on their dorsal margin. Among those living on hard substrates,
some have byssal threads to attach themselves (e.g., Barbatia,
Septifer, Pinctada) while others are free-swimming on sandy areas
of rocky shores and reefs (e.g., Chlamys, Lima), or even embedded
in coral rock (eg. Boring Giant Clam, Tildacna crocea Family
Tridacnidae). |
Clockwise
from top left:
Barbatia, Chlamys, Septifer, Gafrarium, Pinctada |
| Chlamys,
the edible Scallop (F. Pectinidae) swims by closing its two valves
rapidly. Wing oysters, Pinctada (F. Pteridae) prefer more open
waters. Ark shells, Barbatia (F. Arcidae) and Septifer (F.
Mytilidae) are found in crevices on the lower surfaces of rocks. Gafrarium
(F. Veneridae) is found in sand between rocks. |
Bivalve shells are also
common in soft substrates, and since they are filter feeders, some populations
inevitably concentrate toxic chemicals (e.g., PCBs, lead, mercury, zinc),
viruses (e.g., hepatitis), bacteria (e.g., Vibrio, the human gut
bacteria Escherichia coli, those involved in food poisoning and cholera),
and sometimes poisonous algae (e.g., dinoflagellates that cause Red Tide).
Paphia,
Meretrix
and Laternula are mangrove species, living in the soft mud
in the littoral area.
Venus and Tellina prefer the littoral sand, whilst Anomalocardia
inhabits muddy areas facing open waters.
Donax occurs in the sand of the upper parts of the littoral
zone. |
1st
row: Meretrix, Paphia (2 species)
2nd row: Venus, Tellina, Donax
3rd row: Laternula, Anomalocardia |
|
Introduction
Shore environment |
