44 BULLETIN 188, UNITED STATES NATIONAL MUSEUM 



16. No distinct notch in middle of upper jaws ; size medium ; not anadromous. 

 2a. Scales marked by transverse grooves that are in pairs and are deficient 

 mediaiily ; last 2 anal rays enlarged ; lovv^er jaw not markedly 



pi-oniinent Sardinella 



26. Scales marked by transverse grooves that are not in pairs and are con- 

 tinuous across middle of scale ; last 2 anal rays not enlarged ; lower jaw 

 more prominent Harengula 



Genus HILSA Regan 



Hilsa Regan, Ann. Mag. Nat. Hist., ser. 8, vol. 19, p. 303, 1917. (Tj'pe, Paralosa 

 durMnensis Regan.) 



HILSA TOLI (Cuvier and Valenciennes) 



Alausa toll Cuviek and Valenciennes, 1847, vol. 20, p. 435 (Coromandel, Pondi- 



cherry ) . 

 Clupea (Alausa) toll von Maetens, 1876, p. 405 (Bangkok). 

 Culpea (Alosa) toll Webek and db Beaufort, 1913, vol. 2, p. 64 (Siam). 

 Hilsa toll HORA, 1923b, p. 174 (Nontaburi). 



From the East Indies the range of this species extends to Malaya, 

 Thailand, and India. 



In Thailand interest in this fish arises from the fact that it is typi- 

 cally anadromous, like the closely related hilsa {Hilsa ilisha (Hamil- 

 ton) ) of India and the shad {Alosa sapidisshna) of the Atlantic coast 

 of North America. The most noteworthy run is in the Menam Chao 

 Phya. Fish usually begin to arrive every year late in November and 

 slowly ascend the flooded river as far as Pakret and Koh Yai. Some 

 years no fish are observed until the first or second week in December. 



There is considerable variation in the size of the fish as they run up 

 the Menam Chao Phya at the spawning time. The males, which aver- 

 age smaller than the females and never reach the size of the largest 

 females, range from 27 to 40 cm. in total length for a large number 

 examined. The females have been 39 to 58 cm. long. For all examples 

 measured during several years, the average length of males was 34.8 cm. 

 and of females 46.7 cm., all these being fully adult fish that had gone 

 into fresh water to spawn. 



When the fish first come in from the sea their sexual organs are 

 in an undeveloped condition. Ripening ensues rapidly in fresh water, 

 and spawning takes place in January and February. The favorite 

 spawning ground is the west channel of the river at Pakret. By the 

 end of February all fish have spawned. Spent fish, very pale and 

 somewhat emaciated, gradually work their way downstream, swim- 

 ming rather deep and being rarely caught in the pongpang (bag) nets, 

 which are set near the surface and are kept distended by the outflow- 

 ing current. 



A special gill-net fishery is conducted for this fish from the village 

 of Ban Po, a part of Bangkok. In an ordinary season there are 30 

 boats engaged, each with a crew of 2 or 3 men or women. The nets 



