534 The Bass and their Relatives 
anal especially large. They are found in tropical America 
only, where they are highly valued as food, the flesh being 
like that of the striped bass, white, flaky, and of fine flavor. 
The common robalo, or snook, Oxylabrax (or Centropomus) un- 
decimalts, reaches a weight of fifteen to twenty pounds. It 
ranges north as far as Texas. In this species the lateral line 
is black. The smaller species, of which several are described, 
are known as Robalito or Constantino. 
The Sea-bass: Serranidz.—The central family of the percoid 
fishes is that of the Serranid@, or sea-bass. Of these about 
400 species are recorded, carnivorous fishes found in all warm 
seas, a few ascending the fresh waters. In general, the species 
are characterized by the presence of twenty-four vertebre and 
three anal spines, never more than three. The fresh-water 
species are all more or less archaic and show traits suggesting 
the Oxylabracide, Percide, or Centrarchide, all of which are 
doubtless derived from ancestors of Serranide. Among the 
connecting forms are the perch-like genera Percichthys and 
Percilia of the rivers of Chile. These species look much like 
perch, but have three anal spines, the number of vertebre 
being thirty-five. Percichthys trucha is the common trucha, or 
trout, of Chilean waters. 
Lateolabrax japonicus, the susuki, or bass, of Japan, is one 
of the most valued food-fishes of the Orient, similar in quality to 
the robalo, which it much resembles. This genus and the 
East Indian Centrogenys waigiensis approach Oxylabrax in 
appearance and structure. Nzphon spinosus, the ara of Japan, 
is a very large sea-bass, also of this type. Close to these bass, 
marine and fresh water, are the Chinese genus Siniperca and 
the Korean genus Coreoperca, several species of which abound 
in Oriental rivers. In southern Japan is the rare Bryttosus 
kawamebari, a bass in structure, but very closely resembling 
the American sunfish, even to the presence of the bright-edged 
black ear-spot. There is reason to believe that from some 
such form the Centrarchide were derived. 
Other bass-like fishes occur in Egypt (Lates), Australia 
(Percalates, etc.), and southern Africa. Oligorus macquartensts 
is the great cod of the Australian rivers and Ctenolates ambiguus 
is the yellow belly, while Percalates colonorum is everywhere 
