50 



MADRAS FISHERIES BULLETIN 



VOL. XI, 



The Five-fingered Chank (Pterocera lambis Linn.). 



Tamil — Aiviral saiigii (gffl?ir-« <9=e)@), Ramnad district. 

 This species of Pterocera, the most common of the genus, is 

 very abundant in the faunistically rich shallows of the south- 

 western angle of Palk Bay. From low water to two fathoms, this 

 shell is often numerous, particularly along the coast between 

 Pamban and Tondi. Some are collected by the shore people 

 wading in the sea at low tide, but the great majority are taken 

 either by the Kadayan and Muhammadan beche-de-mer divers or 

 accidentally in nets set for crabs, whereof many miles length are 



shot daily during the season. 

 The shells serve a variety of 

 purposes ; as food they are 

 broken open and the flesh 

 extracted, and used for cur- 

 ries ; as net sinkers they have 

 the "fingers "broken off, the 

 shell perforated and then are 

 tied at intervals along the 

 ground rope of nets ; by 

 burning, whitewash lime is 

 made ; lastly they are used 

 as octopus traps. To fit 

 them for the last-named use, 

 the apex of each shell is 

 broken off together with the 

 fingers, and are then attach- 

 ed at intervals of 5 or 6 

 feet along a rope to which 

 as many as 30 shells may 

 be thus fastened. A number 

 of ropes are tied end to end and laid in shallow water over- 

 night; when raised next morning a number of small octopus are 

 found sheltering in the cavities of the shells. These are used 

 as bait when lining for such fish as seer, parai, dogfish and 

 rays. Hundreds of these shell-trap lines are in use on the Ramnad 

 coast from Devipatam northwards. In Japan a device on the same 

 principle is used for a similar purpose ; in place of Pterocera shells, 

 the Japanese use narrow-necked vase-shaped earthenware pots, 

 tied at inte-vals by the neck to a strong line. 



Fig. 14. — The Fivr-fingered Chank 

 (Pterocera lambis Linn.). 



