CHAPTER XXII 

 CHROMIDES AND PHARYNGOGNATHI 



UBORDER Chromides. The suborder Chromides con- 

 tains spiny-rayed fishes similar to the perch-like 

 forms in most regards, but strikingly distinguished 

 by the complete union of the lower pharyngeal bones, as in the 

 Holconoti and Pharyngognathi, and still more remarkably by 

 the presence of but one nasal opening on each side. In all the 

 perch-like fishes and in nearly all others there are two nasal 

 openings or nostrils on each side, these two entering into the 

 same nasal sac. In all the Chromides the lateral line is incom- 

 plete or interrupted, and the scales are usually large and ctenoid. 



The Cichlidae. The suborder Chromides includes two fami- 

 lies, Cichlida, and Pomacentrida. The Cichlida are fresh-water 

 fishes of the tropics, characterized by the presence of three to 

 ten spines in the anal fin. In size, color, appearance, habits, 

 and food value they bear a striking resemblance to the fresh- 

 water sunfishes, or Centrarchidce, of the eastern United States. 

 This resemblance is one of analogy only, for in structure the 

 Cichlidcs have no more in common with the Centra? -chides than 

 with other families of perch or bass. The numerous species 

 of Cichlidcs are confined to tropical America and to correspond- 

 ing districts in Africa and western Asia. Tilapia nilotica 

 abounds in the Nile. Tilapia galilcea is found in the river 

 Jordan and the Lake of Galilee. This species is supposed to 

 form part of the great draught of fishes recorded in the Gospels, 

 and a black spot on the side is held to commemorate the touch 

 of Simon Peter. Numerous other species of Cichlidcs, large and 

 small, abound in central Africa, even in the salt ditches of the 

 Sahara. 



The species of Cichla, especially Cichla ocellaris, of the rivers 

 of South America, elongate and large-mouthed, bear a strong 



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