COASTAL FISH I37 



(Antennarius) and a sponge in which the fish had taken shelter. Sponge 

 and fish were of exactly the same green colour. Many other remarkable 

 fish live on coral reefs: Murccna, vicious eels with venomous teeth, snake 

 eels (Ophichthys), with alternating light and dark transverse bands like 

 sea snakes, and trigger-fish (Ballistes maculatus). This last has three spikes 

 in the front dorsal fin, the first of them being very powerful and so 

 arranged that it cannot be laid down until the second one has been laid 

 back — a refinement which its enemies probably find difficult to under- 

 stand. 



Let us leave the shallow water and take a look at the animal popula- 

 tion of the continental shelf, down to about 200 metres. 



Although we were able to carry out a fairly large number of trawls 

 in this sphere, they were necessarily rather haphazard and it is too much 

 to expect that they would give a clear picture of the fauna of the conti- 

 nental shelf or result in any important new finds. Quite naturally, this 

 is the best-known sea region, since it is here that all important commercial 

 fishing takes place. A walk through the smelly fish-market of any tropical 

 town will give a fair enough impression of the fish life of adjacent waters, 

 because practically everything caught is brought ashore. We also took 

 every opportunity, when visiting these markets, to buy anything we 

 thought was of interest. But rather than dwell on this material we will 

 consider the bottom fishes which we ourselves caught, in 17 or 18 trawls, 

 at depths ranging from 10 to 100 metres. The available space is totally 

 inadequate to convey any real impression of the great variety of fish 

 represented, as there were 34 orders covering at least 52 genera, some 

 with several species each — altogether about 275 individuals. But at 

 least the figures illustrate the great wealth of forms met with in tropical 

 and subtropical seas. Even then, they do not include the still more nume- 

 rous pelagic fishes taken in the same trawls. 



A closer inspection shows two groups competing for first place — flat- 

 fishes and mail-cheeked fishes. Of flatfishes there are representatives of 



Cynoglossidae, a tropical flatfish from the Indo-Pacific continental shelf. 



