riSH AND FISHERIES. 105 



they stretch across the river at night, thereby intercepting fishes passing down 

 the river. If, as mentioned above, these river fishes have their migratory periods, 

 the complete stoppage of the river by nets may be most injurious or even 

 destructive to them. — E.E.C. 



The Freshwater Black-fish. 



A very common fisli in some of our rivers, both of eastern and 

 western waters, is the " Black-fish," Gadopsis marmoratus, Avhich 

 belongs to a genus of the most extraordinary fishes known. It is, 

 according to Professor M'Coy, an intermediate type between the 

 Acanthopterygious fishes, in which the anterior rays of the dorsal fin are 

 simple spines, with the scales usually ctenoid, and the IlalacojHerygious 

 fishes, in which all the rays are soft and branched, and the scales usually 

 cycloid. In Gadopsis the cycloid scales, the general form, the imperfect 

 filamentous jugular ventral fins, and the majority of the characters so 

 nearly agree with Malacopterygions that all the most recent writers with 

 Dr. Giinther class it with the Anacanthini, although the anterior I'ays of 

 the dorsal and anal fins are distinctly spinous. Our species is a mud 

 fish, and attains the length of 16-^- inches, but it is generally caught by 

 emptying the water-holes where the summer heat has made them low. 

 It is good eating, but like all these mud-fishes, very rich and oily. In 

 G. marmoratus, Richardson, the head is one-fourth of the length. 

 Prof. M'Coy has described two species. One, G. gracilis, in which the 

 head is proportionately much shorter. This is found in the river Yarra, 

 and difiers in its habits from the fish of western waters, as it is readily 

 caught with a line. It is also a far better fish for the table, and is 

 much esteemed in Melbourne. 



There is a second species of Gadopsis {G. gihbosus, M'Coy), which is 

 proportionately shorter, deeper, and with a much more convex dorsal 

 outline. It abounds in the Bunyip River, Gippsland, Victoria. Another 

 distinction is that it has twelve instead of ten spines in the dorsal. The 

 colouring of these fishes is very variable. Some are light olive green, 

 becoming yellowish-white towards the belly, the sides, back, and fins being 

 mottled irregularly with dark brown. This marbling varies from brown 

 to olive in smaller or larger patches, and the yellow varies to orange. 

 It is only when the mottling is very dark and thick that the name 

 Black-fish is at all applicable. Sometimes the brown marbling is slight 

 and distinct, and the general colour yellowish olive. The scales vary 

 also from truly cycloid to an indented margin, and undulating lines of 

 growth approaching the ctenoid type. An excellent figure of G. gracilis 

 is given in M'Coy's " Prodromus of the Zoology of Victoria," decade 

 3, plate 27, fig. 2. The name Gadopsis is meant to mean like the cod 

 or Gadus. 



The Freshwater Cat-fish. 



The ''cat-fish" [Copkloglanus tandanm) is very abundant in the lagoons and 

 back watei's of the western rivers, and is said to be a most excellent fish, but 

 there is a very general prejudice among Europeans against its iise : it is very fat 

 and eel-like in flavour, and averages, when full grown, 2 feet in length. In this 

 species, as in most if not all of the Silurklce, the ova are fertilized by the male 

 fish before leaving the body of the female, and both sexes seem to unite in the 

 subsequent attendance on the nest in which the ova are deposited. — R.K.C. 



