10 NEW SOUTH WALES 



CHAPTER II. 



The Fish Fauna of New South Wales. 



In order to understand tlie cliaracteristics of the fish fauna of the 

 coasts and i"ivers, it will be necessary to explain something of the fishes 

 of the Australian region generally. They do not difi'er in any singular 

 or remarkable degree from the fishes of the rest of the world. If there 

 are one or two apparent exceptions to this, it is in the case of some 

 Australian fishes which have representatives, not living, but in remote 

 periods of the world's geological history. Such examples are found in 

 the Ceratoclus, which inhabits the rivers of Queensland, and the 

 CestracioJi, or Port Jackson shark [Heterodontus). The dentition of the 

 last is extremely like fossil teeth of Acrodus, found in mesozoic deposits. 

 Ceratodics is an existing ganoid fish, which is abundantly and almost 

 exclusively represented in the Trias formation. Its anatomy also shows 

 it to be a faint connecting link between a lizard and a fish. 



Except for such rare instances, the families of Australian fishes are 

 only slightly diflferent from those of other seas. Some are absent and 

 some are very poorly represented, but the great mass of them have 

 relations with these of neighbouring seas or those in which the same 

 conditions of temperature and coast line prevail. There are however 

 minor difierences, especially in genera, and these give to Australia 

 whatever distinctive characteristics are possessed by its fish fauna. We 

 find also that these Australian features are more marked on the southern 

 than ill the northern coasts. The more remote oiir coasts are from other 

 lands the more peculiar and distinct are the characters which the coast 

 fishes present, which is just what we might expect. Thus, on the north, 

 north-west, and north-east coasts the fauna is closely connected with 

 that of the Indian and tropical seas, and is in very many species identical 

 with it. The tribes of the colder regions are here wanting and in place 

 we have the fishes of the equatorial zone in all their gorgeous liveries 

 of red, blue, green, and gold, arrayed in those fanciful patterns which 

 awaken the enthusiasm of every naturalist. We find also that as we 

 go southwards on either coast there is a gradual disappearance of the 

 In-opical fauna and a mingling of that of the temperate regions. Now 

 if we cast our eyes on the limits of the coasts of New South Wales, we 

 shall find that they lie in regions where the fishes are most likely to be 

 intermediate in character. No part of the Colony is within the tropics, 

 though its northern boundary is not five degrees from the tropic of 

 Capricorn. Again, no part of the Colony abuts upon the south coast, 

 but its southern limits are just at the entrance of Bass's Straits. Thus 

 it is cut ofi" from the equatorial, and again from the South Australian 

 regions. In such a province we can only expect that what is peculiar 

 in its fish fauna will belong to the Pacific Ocean, and in fact it does 

 possess more of the fishes of that area than any other jaortion of the 

 coasts of Australia. It may be necessary further to mention that these 

 remarks apply to the shore fishes only, that is, fishes which inhabit 

 shallow waters in the neighbourhood of land. Pelagic fishes are those 

 which inhabit the surface or uppermost strata of the open sea and only 

 visit the coasts accidentally iii search of prey or periodically for the 



