SEASHELLS OF SRI LANKA: A Little Known Bounty

Black-lipped pearl oyster: Pinctada margaritifera.

One of two species of pearl oysters in Sri Lanka. They do not exceed 100mm in this country but grow to nearly three times that size in the Torres Straits.

Mussels: Perna viridis.

Grows to about 100mm in length. The commoner brown mussel is smaller. Both are edible and offered for sale 

Jewel box: Chama lazarus.

One of a number of species in the island and the most spectacular. 

Wing oyster: Pteria brevialata.

The hinge is greatly elongated, hence the shape. Four other species of various sizes, usually attached to branching soft corals, the smallest to a stinging hydroid. Same family as the pearl oysters.

Rock or Bombay oyster: Saccostrea cucullata.

Growing up to about 80mm these gregarious oysters grow crowded on rocks along the beach at the level of the highest tides. Drying out at low tides, they rely on waves splashing on to them for moisture.

Venus clam, hiant clam: Marcia hiantina.

A beautiful golden yellow and very tasty. The shell seen from the side. 45mm

Venus clam, meretrix venus: Meretrix meretrix.

The shell is shown from the top, with left and right valves to either side. The black colour behind (below) is characteristic. 55mm

Scallops: Chlamys spectabilis, Ch. irregularis, Unknown species, Ch. senatorius (clockwise from top). 

Four out of a number of species of scallops in Sri Lankan waters. Mostly small and not commercially fished

Sacred Chank: Turbinella pyrum.

Two varieties of chanks are found around the coast. There is a large organised commercial fishery for these shells that are exported to the sub-continent for the manufacture of jewellery and ornaments. In life they are covered by a thick brown ‘skin’ – at left. In the rare valampuri the shell opening would be on the left of the shell. Up to 170mm.

Eyed cowrie: Cypraea argus.

This has a cylindrical shape with the long, narrow opening on the underside as in all cowries. 80mm.

 Map cowrie: Cypraea mappa.

This cowrie has the bulbous shape common to most species. It gets its name from the pattern on the upper surface, fancifully likened to a geographic map. 80mm.

Abbas cone: Conus abbas.

This and the following striate cone possess potent venom able to harm humans. The abbas cone belongs to the group of textile cones, on account of the closely woven pattern. 50mm.

Striate cone: Conus striatus. 90mm.

Soldier cone: Conus miles.

A pretty non-venomous cone. 50mm.

Cloud cone: Conus nimbosus.

An uncommon cone with fine ridges around the outside making it rough to touch. All cones have long, narrow openings at the side. 40mm.

 Limpets: Cellana rota, Patelloida striata and Clypidina notata. 

These three belong in three different families but often live clustered together in colonies. Some of the images are of the undersides—useful in identifying them. They are small – 10 to 25mm.

 Periwinkles: Littoraria undulata, Echinolittorina millegrana, Nodilittorina trochoides and N. quadricincta. 

These four, out of the six, periwinkle species often cluster together, mostly above the tide line where they dry out at times. They are small, ranging from about 10 to 20mm in size.

Vexillate volute: Voluta (Harpulina) arausiaca.

A volute found off northern Sri Lanka and southern India growing to about 75mm. Rare.

Clover’s lyria: Voluta (Lyria) cloveriana.

A volute found off southern Sri Lanka growing to about 85mm. Rare, but seems to be locally frequent.

Orange mouth spider conch: Lambis crocata.

Two other species are on the protected list. It is rarely that one finds these shells with the spines unbroken, and so strongly coloured. 125mm overall. Bigger shells with pale interior and damaged spines.

Venus comb murex: Murex pecten. 

One of a group of sand bottom-dwelling carnivores that drill holes into bivalves and suck out the flesh, this is the most spectacular. Growing to about 130mm in length it has three rows of sharp, slender spines. Other species have fewer and shorter spines.

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