1916.] B.SunDARA Raj: Freshwater Fish of Madras. 263 
tinct species.' Again Day united the two in 1878.? Since then, 
S. singio (H. B.) has been ranked as a synonym of S. /ossilis 
(B1.) by most systematists. Recent anatomical research, however, 
appears to show that the two are probably distinct species. 
Hyrtle * (1853), followed by Hubrecht and Day (1877) *, states that 
in S. stngio the right accessory air-sac is supplied with blood by 
the first afferent branchial artery, the left on the contrary being 
supplied by the fourth afferent artery. Burne in 1894 found that 
in S. fosstlis both air-sacs are supplied by the fourth afferent 
arteries? 
Habitat and Habits—Quite common in ponds and ditches, 
where it frequents the muddy bottom. Its distribution does not 
appear to be limited to fresh water as on the west coast (Cochin) ; 
it is said to occur in backwaters where the fishermen catch it 
at night with a torch, the light of which attracts it. S. fossilis 
is amphibious and consequently lives for a long time out of water. 
‘““ Wounds from the pectoral spines of this fish are dreaded in 
India as they are reputed to be very poisonous.’ 
The breeding season extends from September to December; 
during the rains the fish deposit their eggs in irrigated fields, 
where the young, which are copper-red in colour, are frequently 
caught for stocking tanks. 
Uses.—S. fosstlis attains a length of a foot and a quarter when 
full grown and is highly esteemed as food by Indians.’ 
Wallago attu (Bl. and Schn.) 
Tamil—Valai, Athu Valat. 
Habitat and Habits.—The ‘‘ freshwater shark” inhabits lakes 
and rivers. Col. Tickell® states that it occurs sometimes within 
tidal influence; this is probably the case when it is carried down 
by floods, as the least salinity seems to disagree with this fish and 
to cause death. 
W. attu is a large and powerful fish and predaceousin habits. It 
feeds on both vegetable and animal matter, preferably on the latter, 
and is said to destroy fry and large numbezs of smaller fish in ponds. 
It is sluggish in its movements and lives for the most part at the 
bottom. Thomas attributes the frequent slowness of this fish to 
discover the presence of food to deficient sight. The statement 
that it feeds mostly at night® appears to be incorrect, as I have seen 
it very active and freely take a bait byday. It is usually caught 
in large nets and when handled it makes fierce attempts to bite. 


| Brit. Mus. Cat. Fishes, V, pp. 30 and 31. 
> Fishes of India, p. 480. 
3 Akad Wiss. Wien, XI, p. 302 (1853). 
+ Four. Lin. Soc. Zool., XIII, p. 198 (1877). 
5 Loc. cit.. XV, p, 48 (1894). 
5 and 7 Day, Fishes of India, p. 487. 
* Rod in India, 1881, p. 168. 
* Day, Fauna of Brit. India, Fishes, I, p. 127. 
