seen? These little clams are sometimes seen on some of
ours shores, on sandy areas near seagrasses.
Features: 4-7cm.The circular two-part
shell is thick with ribs and a squarish portion at the hinge. It has
a hinge with a socket-like arrangement between the valves. A single,
fused adductor muscle controls the valves (this is the part that is
eaten in seafood, see below). The foot is greatly reduced and there
is usually no siphon. They have a fringe of tentacles, some long and
many short tentacles, with well developed but tiny eyes along the
Some scallops are free living. A scallop can swim by flapping its
valves and using jet propulsion. It sucks in water and then forces
out a jet of water from either sides of the shell hinge. A scallop
can change the direction of its movement by using the velum. The velum
is a curtain-like fold of the mantle that works like lips to direct
the jet of water and thus control its movement.
Some scallops such as the Chlamys species, attach themselves
to stones, rocks and other hard surfaces with byssus threads. Tiny
coral scallops often settle in living hard corals.
What do they eat? Like most other
bivalves, mussels are filter feeders. When submerged, a scallop opens
its valves slightly and sucks in a current of water. It uses its enlarged
gills to sieve food particles out of this current.
Human uses: Larger scallop species
are harvested for seafood. Usually what is eaten is only the adductor
muscle that holds the two valves together. Our wild scallops are much
too small to yield the kind of scallops you can buy at the supermarket.
The flesh of the adductor muscle is sweet because it contains a high
amount of gylcogen. Like other filter-feeding clams, however, scallops
may be affected by red
tide and other harmful algal blooms when they are then harmful
Status and threats: None of our
scallops are listed among the threatened animals of Singapore. However,
like other creatures of the intertidal zone, they are affected by
human activities such as reclamation and pollution. Trampling by careless
visitors and over-collection can also affect local populations.
Changi, Jul 12
along mantle edge.
'Swimming' backwards with clap of valves
on Singapore shores
*Species are difficult
to positively identify without close examination.
On this website, they are grouped by external features for convenience of
Pectinidae recorded for Singapore
Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist
of The Molluscs of Singapore.
- Tan Siong
Kiat and Henrietta P. M. Woo, 2010 Preliminary
Checklist of The Molluscs of Singapore (pdf), Raffles
Museum of Biodiversity Research, National University of Singapore.
- Tan, K. S.
& L. M. Chou, 2000. A
Guide to the Common Seashells of Singapore. Singapore
Science Centre. 160 pp.
- Chou, L.
M., 1998. A
Guide to the Coral Reef Life of Singapore. Singapore Science
Centre. 128 pages.
- Wee Y.C.
and Peter K. L. Ng. 1994. A First Look at Biodiversity in Singapore.
National Council on the Environment. 163pp.
- Ng, P. K.
L. & Y. C. Wee, 1994. The
Singapore Red Data Book: Threatened Plants and Animals of Singapore.
The Nature Society (Singapore), Singapore. 343 pp.
- Abbott, R.
Tucker, 1991. Seashells
of South East Asia.
Graham Brash, Singapore. 145 pp.
- Chuang, S.
H., 1961. On
Muwu Shosa, Singapore. 225 pp., plates 1-112.