[chthyopsida 



435 



species of Teleostei runs high into the thousands and the group has 

 achieved dominance of the modern aquatic world. Viewing the Order 

 as a whole, its most striking characteristic is the enormous diversity of 

 those anatomic adaptations which have enabled fishes to succeed in 

 every imaginable aquatic habitat and even make temporary excursions 

 into the air (flying fishes) and ashore (the "climbing perch," Anabas, 

 of southern Asia). In connection with these adaptations, the basic plan 

 of the vertebrate body has been more profoundly and variously modi- 

 fied than in any other group of vertebrates. The results in some cases 

 are creatures whose external appearance is such that they are hardly 

 recognizable as fishes or even as vertebrates — e.g., the sea horse (Hip- 

 pocampus) which looks like the "knight" of a set of chess, and a 

 related fish (Phyllopteryx) which resembles nothing more than a 

 scraggy bunch of seaweed (Fig. 337). 



Fig. 337. Some of the more highly specialized teleosts. (1) Acestra. (2) Sacco- 

 pharynx. (3) Chirolophius. (4) Himantolophus. (5) Psettus. (6a) Ogcocephalus (dorsal 

 view). (6b) Ogcocephalus (anterior view). (7) Hippocampus (sea horse). (8) Phyl- 

 lopteryx. (9) Orlhagoriscus mola (headfish). (10) Exocoelus volitans. (11) Ostracion. 



There is wide range in size of these fishes. Approximate lengths are as follows: 

 6 inches or less, numbers 4, 5, 7, 8; 12 inches or less, numbers 1, 3, 6, 10, 11; up to 

 6 feet, number 2; up to 8 or 10 feet and weight of 1800 pounds, number 9. (6a, 6b, 

 and 10, courtesy Jordan and Evermann: "Fishes of North and Middle America," 

 Washington, The Smithsonian Institution. All others from "Cambridge Natural 

 History," Vol. VII. By permission of The Macmillan Company, publishers.) 



