( 31 ) 



weirs which span rivers bar their upward ascent, and thus 

 cut them off from their breeding-grounds. 



Breeding oe Fishes in Eresh-waters. 

 XLVI. Closely allied, in fact, inseparably connected 

 Breeding of fish in fresh- wit]l their migration, is the question 



waters, Migratory and non- of the breeding of fis!l€S* hi the 



migratory ones of the plains. fresh-waters, which may be treated 

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

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

 of the hills. Apparently, the migratory forms produce the 

 largest number of eggs, probably as a compensation for the 

 increased chances of their destruction. Thus, in a migratory 

 herring, Clupea palasah, there were computed to be 1,023,645 

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

 in the hilly regions appear to have a larger proportion of 

 ova than those in the plains. Amongst the non-migratory 

 species, we likewise observe a difference : the monogamous 

 not depositing so many as the polygamous, as a general rule, 

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

 the former appear to breed more frequently ; and, secondly, 

 they protect their offspring. Thus, a "monogamous" Ophio- 

 cephalus had only 4,700 eggs, whilst a "polygamous" non- 

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

 Callichrous canio, 47,444. Amongst the shoals of hilsa which 

 I have seen, more female fish 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 these fish, as the hilsa, appear to deposit their eggs at one 

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

 XLVI I. Of the non-migratory hill fishes (see para. 

 Breeding of migratory and XXVII) in the higher ranges, there 

 non-migratory fish of the hiiis. are t w0 situations in which they may 



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

 melted snows ; the second is in tributaries or affluents of 

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

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

 tion and difficulty of ascent which prevents more fish 

 residing in the hill streams, but because some influence 

 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 spawn, sestivate, and consequently are ready to deposit their ova 

 as soon as the rains commence, is a question not entered upon in this report. Unable to 

 prove it by observed facts, 1 have considered it best to omit its consideration for the present- 



