CLIMBING PERCH. 



137 



Tetra- 

 o'onurus. 



Centrolophus niger, 465, of European seas is occasionally, but 

 rarely, caught off Britain, as also is the Rudder-fish, Lirus 

 perciformis. Stromateus fiatola, 464, the ' Fiatola ' of the Italian 

 fishermen, is an excellent food-fish of the Mediterranean. Nomeus 

 gronovii, 466, a little fish about three inches long, widely distri- 

 buted and common in the Gulf of Mexico, is found sheltering 

 from its enemies among the long streamers of the Portuguese 

 Man-of-"\Yar {Physalia), from which it enjoys a remarkable im- 

 munity. As many as ten of these fishes may be found swimming 

 about beneath a large Physalia. 



The remarkable deep-sea fish Tetragonurus (463) is allied to the 

 Stromateidse, as is shown by the structure of the mouth, the 

 dentition, and more particularly the occurrence on each side of the 

 oesophagus of a muscular sac studded internally with rather soft 

 papillae. There is but a single species, Tetragonurus cuvieri, 

 sometimes called the Square-tail. It occurs in the Atlantic, 

 Mediterranean, and the South Pacific, but is rare; it is poisonous 

 as food ; it feeds on jelly-fish, and probably lives in the depths of 

 the sea by day and comes to the surface at night to feed. The 

 young are said to live in the pharyngeal cavity of large Salps. 



The Climbing Perch, Anabas scandens, 468, is so called because Olimbino- 

 it is able to climb a sloping bank, to travel over land, and, it has Perch, 

 been stated, to climb trees, by means of the stout, backwardly 

 sloping spines of the anal and pelvic fins and of the gill-cover, 

 which is very movable. The fish holds on to the ground by the 

 opercular spines, bends its tail and inserts its anal spines ; it then 

 straightens the body and causes the opercular spines to move 

 forward over the ground, and then repeats the whole operation. 

 The fish wriggles along thus on its side at a fairly rapid rate. The 

 Climbing Perch can live a long time out of water; above the gills 

 are a pair of large cavities, opening downwards, and divided up by 

 thin, scroll-like plates of bone covered with delicate and highly 

 vascular mucous membrane, by which air is breathed. The air is 

 taken in through the mouth, and is expired through the mouth, 

 not through the gill-openings. The Climbing Perch is a fresh- 

 water fish of India, Burmah and Malay ; some species of Anabas 

 occur in Africa. 



The Snake-head, Ophiocephalus striatus, 467, of the grassy 

 swamps of China, India and the Philippine Islands, resembles 



Snake- 

 head. 



