bivalves text index | photo index
Phylum Mollusca > Class Bivalvia
Scallops
Family Pectinidae
updated Oct 2016

Where 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 mantle edge.

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 to eat.

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


Eyes along mantle edge.


'Swimming' backwards with clap of valves

*Species are difficult to positively identify without close examination.
On this website, they are grouped by external features for convenience of display.

Family Pectinidae recorded for Singapore
from Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist of The Molluscs of Singapore.
^from WORMS
+Other additions (Singapore Biodiversity Record, etc)

  Scallops commonly seen awaiting identification
Species are difficult to positively identify without close examination.
On this website, they are grouped by external features for convenience of display.
  Large scallop

  Family Pectinidae
  Chlamys madreporarum=^Coralichlamys madreporarum

Comptopallium radula=^Decatopecten radula

Decatopecten velutinus

Laevichlamys squamosa

Minnivola pyxidata

Pedum spondyloideum
(Coral scallop)

+Semipallium flavicans
(Tiger scallop)

Volachlamys singaporina
(Singapore scallop)

Links References
  • Tan Siong Kiat & Martyn E. Y. Low. 20 December 2013. New Singapore record of the Tiger scallop, Semipallium flavicans. Singapore Biodiversity Records 2013: 121.
  • 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.
www.flickr.com
FREE photos from wildsingapore tagged with Pectinidae. Make your own badge here.
links | references | about | email Ria
Spot errors? Have a question? Want to share your sightings? email Ria I'll be glad to hear from you!
wildfactsheets website©ria tan 2008