^6.— THE DEVELOPMENT OF SOME SOUTH AFRICAN 



FISHES. 



By J. D. F. GiLCHKisT, M.A., B.Sc. Ph.D., Goveknmknt 

 Biologist to the Coloxv of thk Cape of Good Hope.* 



The necessity for ascertaining information as to tlie develop- 

 ment of fishes has arisen in Cape Colony as it has in other countries, 

 and the want of such information has caused considerable difficulty 

 in legi.slative matters. Thus it is commonly alleged that the prac- 

 tice of netting, as carried on in the Zwartkops, the Buffalo, and other 

 tidal rivers of South Africa, has proved destructive to the eggs and 

 spawn of fish, those of this opinion asserting with confidence that 

 quantities of fish spawn are brought on shore by the net and left 

 to perish. Another occasion on which the same question arose was 

 ■on the commencement of trawling in False Bay. and on the Agulhas 

 Bank, near Mossel Bav. by the Government steamer. It was thought 

 that the dragging of the net along the bottom of the sea caused the 

 destruction of great quantities of the eggs and young of food fishes. 

 The Cape fishermen, an observant and intelligent class of men. were 

 of opinion that the fish supply was being seriously endangered by 

 such operations, and the question was felt to be so serious that a Com- 

 mission of Parliament was appointed to enquire into the matter. The 

 •evidence seemed to indicate that many of the common fishes may 

 deposit their eggs on the bottom of the .sea. Thus one fisherman, 

 who had had an experience of a life time in fishery matters in False 

 Bay, was of opinion that all fish spawn was on the ground, and that 

 the trawl runs across it, and must destroy it {vide Report of Select 

 ■Committee, p. 13). Another equally experienced fisherman thought, 

 however, that the spawn floats on the surface (p. 18). A fisherman 

 of fifteen years, experience at Kalk Bay could not agree with this 

 (p. 21), while another was of opinion that the eggs floated, and could 

 Ije taken up in the hands out of the water. A practical fisherman of 

 forty-three years' experience considered that the spawn is on the 

 ground, and also floats, adding the additional interesting informa- 

 tion : " I have seen the spawn — whether of fish or not I cannot say, 

 but it is alive — little round things like eggs, and they smell very 

 nastly, like rotten pumpkins. I have seen it a foot thick on the 

 water" (p. 24). Yet another witness thought that "the fish breed 

 ■on the ground, but the spawn does not stop at the bottom." Another 

 practical man gave evidence to the effect that the klip-fish deposits 

 Its spawn on the seaweed, and it is there destroyed bv the trawl 

 (P- 37)- On the other hand, in all the instances where the mature 

 •eggs had been procured and successfully fertilized on the Government 

 steamer, the " Pieter Faurc," they were found to float on the surface 

 of the water, and only after the larvae had been hatched out some 



* For the full paper see "Marine Invcstig.ations," Vdl. II. 



