337 



mens with more dorsal spines and more scales in the. L.I. 

 increases from West to East. 



Since the times of DALDORFF (1797) this fish, living 

 in ponds and ditches, is renowned as the "Climbing Perch", 

 according to its supposed ability to ascend trees, the highly 

 mobile suboperculum with its strong spines being the chief 

 organ of climbing. This may happen accidentally, as the fish 

 is able to leave the water and migrate long distance on land 

 in search of other ponds, offering better biological conditions. 



The progress on land by erecting its fins, scales and oper- 

 cles lying flat on one side or by keeping its erect position, is 

 described by DAY (Fishes of Malabar, p. 133). The extra- 

 ordinary air-breathing power by retaining water in the super- 

 branchial organ, to keep its thin laminae wet, and its great 

 tenacity of life enable Anabas to live even for six days out 

 of the water or to be buried in exsiccated mud and to bear 

 transport well, even when exposed for some time to the sun. 



Its development is recorded by B. SUNDARA RAJ (Records 

 Indian Mus. XII. 1916, p. 276). 



2. Polyacanthus (K. v. H.) Cuvier & Valenciennes. 



(CuviER & VALENCIENNES, Hist. Nat. Poissons VII. 1831, p. 353 [p.p.]). 



Polyacanthus Gunther, Cat. Brit. Mus. III. 1859 1861, p. 378 (p. p ). 



Polyacanthus Bleeker, Verh. Akad. Amsterdam XIX. 1879, 



Mem. Poiss. pharyng. labyrinth, p. 12. 



Strongly compressed, oblong. Mouth slightly protractile, its 



Fig. 87. Polyacanthus hasselti C.V. X 5 /8- 



cleft rather small, oblique, not extending beyond vertical through 

 frontmargin of orbit. Maxillary nearly entirely hidden when 

 INDO-AUSTRALIAN FISHES IV. 22 



