( 31 ) 



weirs wliicli span rivers bar llicir upward asceut, aud thus 

 cut tlicm off from Uicir breediug-grouuds. 



Breeding of Fisues in FREsn-WATEUs. 



XLVI. Closely allied, in fact, inseparably connected 



Breeding of n.h in frrsh- ^^ith tUcir migration, is the question 



waicis, Rii-ratow nini noil- of the hrcedliiq of fislics* \\\ tho 



n,ig,ai,o,y ones of u,c phun.. fresh-watcrs, wliicli uiay bc trcai-ed 



of in the following order : — noji-migratory and migra- 

 tory fisli of the plains ; non-migratory and migratory ones 

 of the hills. Apparently, the migratory forms produce the 

 largest number of eggs, 2)robal)ly as a compensation for the 

 increased chances of their destruction. Thus, in a migralorij 

 lierriiig, Chipea pcdasah, there were computed to bc 1,023,G1'5 

 eggs, and in a migratory barbel, 410,500 eggs, whilst carps 

 in the hilly regions appear to have a larger jn-oportion of 

 ova than those in the plains. Amongst the non-vii(jr(dory 

 S2iecics, we likewise observe a difference: the monogamous 

 not depositing so many as i\Mi fohjcjamons, as a general rule, 

 which is probably due to two causes, — -first, in some localilies 

 the former appear to breed more frequently ; ryi\(\, secondly, 

 they ])roteet their offspring. Thus, a " monogamons" Ojj/iio- 

 ccphalus had only 4,700 eggs, Avhilst a "polygamous" non- 

 migratory carp, Cirrhina rcba, had 41,500, and a siluroid, 

 CalUchroHS canio, 47,444. Amongst the shoals of bilsa which 

 1 have seen, more female Dsh were captured than males. 

 The marine fish breeding in rivers usually deposit their ova 

 in the sand : the non-migratory fish of the plains generally 

 amongst the grass at the sides of rivers and at small water- 

 courses, or the margins of tanks, occasionally in the sand. Some 

 of tliese fish, as the hilsa, ap])ear to deposit their eggs at one 

 time : others, as some of the barbels, &c., to do so at intervals. 

 XLVII. Of the non-mujratorxj hill fishes (see para. 



Bimling of migrntnry and XXVIl) in tllC higher raUgCS, tllCrC 



non-niig.atory fish of the hills, ^rc two situatious iu wliicli tlicy may 

 breed : — the first is in water wholly or jiartially obtained from 

 melted snows ; the second is in tributaries or alllucuts of 

 the main streams, as already adverted to (para. VII). It 

 appears as if it were not merely the fact of eleva- 

 tion and difilculiy of ascent Avhich prevents more fish 

 residing in the hill stieams, but because some iulluenco 

 is exerted by the melted snow-water, deleterious at least 

 to the ova, if not to the fry. In the upper ranges of 



• Whether fish, full of Bpnwn, restivntc, nnd conscqncntly nre rendy to deposit tlieir ova 

 ns soon ns the r.iinfl eoinnirnce, is a question not entered upon in this report. Unnhle to 

 prove it by observed facts, I have considered it best to oinit its considerntiou for tlie present 



