130 



FISH GALLERY. 



Pipe- 

 fishes 

 and Sea- 

 horses. 



water with its sharp ventral edge. The body is protected by 

 a dermal cuirass which is continuous with the internal skeleton j 

 there are about six large, elongated trunk vertebras and fourteen 

 very small caudal. The body ends in the two dorsal fins, the 

 first of which bears a strong spine : the tail fin is reduced and 

 is ventral, not terminal in position. 



The families Solenostomatidse and Syugnathidse agree in having 

 gills which are not comb-like, but reduced to small rounded 

 knobs or lobes borne by the gill-arches (fig. 61) ; they were 

 formerly grouped in a special division known as the Lophobranchii. 

 Not only are the gills reduced but the gill-cover also ; there is 

 no preopercular bone and only a few branchiostegal rays. The 

 skin is strengthened by large, star-shaped, bony plates or by 

 bony rings encircling the body ; there are no scales. The 

 muscular system is feebly developed. The snout is prolonged 

 into a tube, and the mouth is small, terminal and toothless. 



Fig. 60. — Pipe-fish, Syngnathus acus. 



In the Syngnathidse the gill-opening is small and set high up j 

 the anterior dorsal fin and the pelvic fins are wanting. The 

 eo-gs are carried by the male in a brood-pouch situated either on 

 the abdomen or on the tail, and usually formed by two folds 

 of skin, right and left. In Nerophis (434) and Gastrotokeus 

 (437), however, there is no pouch; the eggs are embedded in 

 the soft skin of the abdomen of the male. The Syngnathidae 

 are small and marine, living near the coast in temperate and 

 tropical regions ; they are poor swimmers and are carried about 

 passively by currents. 



The commonest forms are the Pipe-fishes (e. g. the Greater 

 Pipe-fish, Syngnathus acus, 436, and fig. 60, the Ocean Pipe-fish, 

 Nerophis aquoreus, 434), which have a tail that is not prehensile. 



