FISH EGGS AND LARVAE FROM THE JAVA SEA 



by 



Dr. H. C. Delsman, 



Laboratorium voor het Onderzoek der Zee, Batavia. 



2. Chirocentrus dorab (Forsk.) 



with 9 figures. 



One of the easiest recognizable pelagic eggs is the one which proved 

 to belong to Chirocentrus dorab. This is a herring-like fish of a very 

 elongated shape, attaining a length of a meter and more, though as a rule, 

 as far as I could judge from specimens from the Java Sea, it does not 

 exceed some 60 or 70 cm. in length '). To its strongly compressed, sharp 

 belly it owes the Malayan names "golok-golok" or "parang-parang", which 

 both mean "chopping knife". It ranges from the East coast of Africa and 

 the Red Sea to New Britain (Australia), and from Japan to Queensland. 

 In the Java Sea it is a common fish. The eggs may be easily recognized 

 by several peculiarities. In the first place they belong to the large variety, 



measuring from 1590 — 1670 fx when in 

 the living condition. Thus the average 

 diameter is nearly the same as that of 

 the ç^gg of Fistularia (cf. nr. 1 of this 

 series, in Treiibia Vol. II). In the secpnd 

 place the ç^gg membrane is not smooth 

 but has on its surface a network of fine 

 ridges which give it a honey-comb appear- 

 ance. A similar disposition is found in 

 the ç,gg of the european Dragonet (Callio- 

 nymus lyra) and in the Java Sea I met 

 with three or four kinds of eggs showing 

 the same peculiarity, one of them having 

 about the same diameter as that of 

 Chirocentrus. The latter, however, differs 

 from all these in that the network is 

 much finer, too fine, indeed, to be 

 reproduced in fig. 1, the meshes barely having a diameter of 15 fx. They 

 can be illustrated only by increasing the scale of enlargement, as in fig. 2. 



im.M. 



Fig. 1. Egg ol Chirocentrus dorab, 

 the honey-comb-like design of the 

 egg membrane being left out. 



') According to the statements of certain authors it may attain a length of fully 

 12 feet (cf. D. G. Stead, Fishes of Australia, Sydney, 1906). This statement, however, 

 seems hardly reliable. 



