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Related FAQs: Bivalves,
Bivalves 2,
&
Bivalve Identification,
Bivalve Behavior, Bivalve Compatibility,
Bivalve Selection,
Bivalve Systems, Bivalve Feeding,
Bivalve Disease,
Bivalve Reproduction,
Tridacnids,
Tridacnid Clam Business, Tridacnid
Identification, Tridacnid
Selection, Tridacnid Compatibility, Tridacnid
Systems, Tridacnid Lighting, Tridacnid
Placement, Tridacnid Feeding, Tridacnid
Disease, Tridacnid Reproduction,
Flame Scallops,
Related Articles: Mollusks, Giant
Clams/Tridacnids,
/The Conscientious
Marine Aquarist
Bivalves: Clams,
Oysters, Mussels... Class Bivalvia
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By Bob Fenner |
Spondylus varians, Fiji
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Bivalve Mollusks: Shellfish with two opposing shells that
are hinged at one end with an elastic byssal material and brought together with
attached muscles. May be attached to hard substrates, burrowed into same or
wood, buried in sand, mud or free-living, able to jettison about with powerful
discharges of water from their exhalant siphons.
Most bivalves are filter-feeders, sifting food through
their gills, which also function as respiratory organs. Some notable aquarium
species, the giant clams (family Tridacnidae) utilize endosymbiotic algae
(zooxanthellae) to produce food through exposing their mantles to bright light.
About 7,700 species worldwide... Some 129 in Hawaiian
waters of which 66 are endemic.
Ark Shells, Family Archidae: Have a row of fine teeth along the hinge
line of their solid ribbed shells. Some attached, others living in sand. Twelve
Hawaiian species.
| Arca ventricosa Lamarck 1819, the Ventricose Ark
Shell. One of eight species found in HI. Found through-out Indo-Pacific
attached to rocks with straight hinge facing outwards. to eighty feet in
depth, three inches in length. A dead shell and a live, attached animal
off of the Big
Island, Hawai'i. |
 
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Pen Shells, Family Pinnidae: Winglike, triangular in shape, anchored,
pointing with their sharp ends into the soft substrate.
| Atrina pectinata (Linnaeus 1767), the Pen Shell.
India to Australia; Indonesia, Philippines, Japan. There are other species
called Pen Shells, and some of these make their way into the ornamental
trade. Typical appearance in an aquarium, mounted vertically, but the
Seastar is not a friend and image in the wild, Maldives showing the dark
mantle from a view above. |
 
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| Dendostea frons, the Frond Oyster. Tropical West
Atlantic. To two and a half inches in length. A couple off of St. Lucia
attached to an octocoral skeleton, and another off of St. Thomas, U.S.V.I.
Note zig-zag interlocking valves. |
 
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| Hyotissa hyotis (Linnaeus 1758), the Honeycomb
Oyster. South Africa to the Red Sea, out to New Guinea, Indonesia and the
Philippines. This group in Pulau Redang, Malaysia. |
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Flame Scallops that are not. Pen Shells, family Limidae: A popular
item, particularly Lima scabra out of the Caribbean. Most all of these die in
short order from starvation. Need frequent "immersion type"
feedings... daily.
| Lima (Limaria) scabra (Born 1778), sold as "Flame Scallops" in
the aquarium interest, this is aka the Rough Fileclam of the Penshell
family Limidae. Can "swim away" if threatened. A beautiful
animal that generally starves in captivity due to a lack of food. Aquarium
images of not so healthy and healthier specimens, and a real good
specimen... in the wild (St. Thomas, U.S.V.I.) |
| Limaria fragilis Gmelin 1791, the Fragile File Shell.
Indo-Pacific; Red Sea to Japan, Australia. Takes a beating if stocked with
many types of fishes, crustaceans. Needs to be inserted in rock cover.
Queensland, Australian photo. |
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| Limaria orientalis (Adams & Reeves 1850), File
Shell. Uniformly Red with thicker tentacles than other Files. Found in
sand or between rocks (like here). Western Pacific; New Guinea, Indonesia,
Philippines. N. Sulawesi image. |
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Pearl Oysters, Family Pteriidae:
| Lopha cristagalli (Linnaeus 1758), the Cock's Comb
Oyster. Indo-West Pacific; including the Red Sea. Characteristic "zig zag"
shells, and less calcification than Hyotissa above. Can be kept in aquariums
lacking predatory starfishes. Filter feeders that can be serviced by
utilizing timers to shut off filter pumps temporarily. Attach to hard
substrates. Red Sea and N. Sulawesi images. |
 
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| Pinctada margaritifera Linnaeus 1758, the
Black-Lipped Pearl Oyster. THE pearl oyster of the South Pacific.
Indo-Pacific all the way to the Eastern Pacific. To almost a foot in
length. Hawai'i pic. |
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| Pteria aegyptica (Chemnitz 1782), Egyptian Wing-Oyster.
Indo-Pacific; including Red Sea. Found attached to gorgonians (as
here), stony corals, soft corals, hydrozoans. Needs strong current,
moderate light and very small (less than 15 millimicron diameter) for
food. To 8 cm. in length. |
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| Pteria brunnea (Pease 1863), the Winged Pearl Oyster.
Usually found in clusters on whip corals (Cirrhipathes, Stichopathes spp.)
or black coral (Antipathes spp.), with Bryozoans et al. in turn growing on
their shells. Hawai'i pic. (this may be an endemic) |
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| Pteria colymbus, Atlantic Wing-Oyster. Tropical West
Atlantic. 2-3 inches. Found attached to Gorgonians, mostly Sea Plumes.
Often overgrown in turn by other organisms. Turks photo. |
.JPG) |
Family Pinnidae: Penshells
| Pinna carnea, the Amber Penshell.
Found singly in mud, sand, interspersed between rocks on reefs,
fore-reefs. Look like their thin shells were stuck in the sand facing up,
slightly agape. Tropical west Atlantic. Bonaire pic of a view from above. |
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| Pedum spongyloideum (Gmelin 1791), the Iridescent
Scallop. Red Sea, Indo-Pacific. Live embedded in various corals, usually
Porites spp. Grow to a couple of inches across. Not boring organisms, but preclude
growth where they attach. Gili, Lombok, Indo. and Red Sea pix. |
 
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Thorny Oysters, Family Spondylidae: Have sturdy, ribbed shells,
sometimes with continuing projections at their openings. Attached to rocks. When
open have colorful mantles and small bluish eyes. Four Hawaiian species.
| Spondylus americanus Herman 1781, the Atlantic Thorny
Oyster. Caribbean. To four inches across. Here off St. Lucia and the
Bahamas in the
Caribbean. |
 
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| Spondylus linguaefelis Sowerby 1847, Carl's Tongue
Thorny Oyster. Long thin spines that reminded the namer of a "cat's tongue"
in their roughness. This is a tentative ID... This animal photographed in S.
Sulawesi. Range given for this species as Hawai'i and Clipperton Islands. |
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| Spondylus varians Sowerby 1829, the Variable Thorny
Oyster. The most common bivalve in its Western Pacific range. Orange
mantle, blue eyes, white spines (typically overgrown) on overall shell.
This one off the Gilis, Lombok and N. Sulawesi, Indonesia. |
 
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| Spondylus violacescens Lamarck 1819, the Cliff Oyster.
As the common name suggests, this bivalve is found on the undersides and
clefts of rocks. To four inches in diameter. Empty attached shell often
with white middle, purple or orangish ring on inside perimeter. Big
Island, Hawai'i pix. Here attached under rocks. |
 
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