300 FISHES 



(Siluridae) of Africa and India, Clarias, Heterobranchus, and 

 Saccobranchus have accessory respiratory organs, and Clarias at 

 least is known in West Africa to spend the dry season in bur- 

 rows, although it does not appear to be torpid all the time, but 

 crawls about at night in search of food. Among the eel-like 

 Symbranchii, Symbranchus in South America and Monopterus 

 in China and Japan live in marshes or the shallow ditches of 

 rice-fields, and bury themselves in the mud when the water dries 

 up, although they have no accessory organs of respiration : 

 probably they are able to breathe air sufficiently by means of 

 the ordinary gill-chamber, which is large. 



Among the coral reefs off the coast of Thursday Island in 

 the Torres Straits between New Guinea and Cape York Mr. 

 Savile Kent studied a curious case of association between a 

 small fish and a large sea-anemone. The anemone is, when fully 

 expanded, at least two feet in diameter across the disc, and the 

 fish lives within its internal or digestive cavity without being 

 digested, and without being injured by the poisonous stinging 

 cells of the anemone's tentacles, although the latter usually close 

 upon and kill other animals which come into contact with them. 

 The species of fish which has this peculiar habit is Amphiprion 

 percula, and it belongs to the family Pomacentridae, a tropical 

 family allied to the wrasses of our own coasts. The fishes of this 

 family are as before mentioned usually brilliantly coloured, and 

 this particular species is of a bright vermilion-red with three 

 broad transverse bands of white. The same habit was described 

 in Amphiprion percula and another species A. bifasciatum long 

 before the date of Mr. Kent's observations, by Dr. Francis Day, 

 in the Andaman Islands. Mr. Kent suggests that the fish 

 escapes from its enemies by retreating into the cavity of the 

 anemone, where they cannot follow it, and confers in return a 

 benefit on its protector by the fact that its pursuers in their haste 

 come into contact with the anemone's tentacles and are killed 

 and devoured. It is very difficult to understand, however, how 

 the fish can live when the anemone contracts its tentacles and 

 stomach in order to kill and digest its prey, and also how the 

 fish can live within the cavity without causing the anemone to 

 contract and kill it. It is possible that the anemone tolerates 

 the presence of the fish although the contact of any other animal 

 causes it to contract, or on the other hand it may be that the 



