beak-like jaws and bizarre forms. In our latitudes the modest, thicket-like structures of 

 madreporic corals are not to be compared with the massive coral buildings of the tropical 

 regions ; but sheltering in these thickets are certain special forms. There are Beryx fishes with 

 enormous eyes, looking like red sea-breams, and small, compressed boar-fishes with pointed 

 snouts, and fin spines menacingly erected. 



The coastal fishes can be grouped under the name of " red fishes ". They are indeed 

 brilhantly coloured, with a predominance of scarlets, crimsons and pinks. A few species, such 

 as the groupers, are somewhat camouflaged, this being evident in marblings added to the general 

 body colour typical for their species. They never move very far, having in general rather slight 

 catadromous habits, shown by a descent to the outer continental shelf at the breeding period. 

 On the approach of the transgressions they move coastwards, thus showing a certain tendency 

 to a stenothermal and stenohaline habit. These animals are not particularly voracious, most 

 feeding on small crustaceans and worms, while others, such as the gurnards, seek their food 

 in the mud. But there is no feeding migration. Differences between the sexes are only found 

 in certain wrasses and boar-fishes. They lay pelagic eggs which are not cared for, there being 

 no parental instinct. In the main they are fishes much esteemed for the quality of their flesh, 

 which plays quite an important part in human nutrition. 



Demersal types. — Below coastal fishes sporting in mid-waters come the demersal fishes 

 extending over shingle, sand or mud. Their sedentary life has involved far reaching changes 

 in their shapes. They are flattened so as to make close contact with the ground, the rays, 

 torpedo-rays and monk-fishes (angel-rays) being enlarged into the form of a lozenge. The 

 pectoral fins are fused to the body, while the gill slits and the nostrils have moved to the underside 

 of the head. Other flat-fishes, the pleuronectids, have undergone a very different evolution, 

 for they rest on either the right or left side of the body. When the larva emerges from the egg 

 it is symmetrical, with norniiiliy placed eyes. But when the young Hsii begins to lead a demersal 

 life, the eye of the side which is to rest on the bottom would obviously not be functional, and it 

 therefore travels in a most remarkable way over the top of the head and comes to lie not far 

 from the other eye. In this way the eyes become placed on the same side of the fish ; and very 

 often the pectoral fin of the blind side degenerates or even disappears. 



The rays and the pleuronectids arc camouflaged, but in dilTerent degrees. Each of the 

 ray species has a colour pattern harmonising in a remarkable way with the ground on which it 

 lives, but not in any way changing during the life of the animal. On the other hand, the 

 pleuronectids can change colour according to that of their background. The skin bears large 

 pigment cells or chromatophores ; black, white, yellow or red in colour — cells capable of 

 expanding or retracting, becoming dispersed or concentrated so as to give a perfect match with 

 the colours of the bottom. 



While this harmonising process is rather long and laborious when a fish first moves to 

 shingle, sand or mud, it all happens extremely quickly if the fish returns to the same ground, 

 just as if it knew beforehand what formula of colour-cell arrangement would suit it in this 

 previously discovered place. In addition to these remarkable ways of camouflage, rays and 

 pleuronectids when resting on a loose, light soil can bury themselves in the sand or mud by 

 movements of their fins, so becoming completely invisible. Only their green or golden eyes 

 project above the surface of the bottom. 



Among the demersal fishes there are also angler-fishes, weevers and rats or star-gazers. 

 Motionless on the bottom, they seek their food by suitable guiles. The angler-fish twitches 

 a long ray set in front of the eyes and bearing a tag of skin ; the weever erects its terrible, 

 poisonous dorsal fin, while the star-gazer in addition to this danger has a worm-shaped lure 

 springing from its mouth. Deceived by these lures the fish approach, expecting to seize some 

 appetising worm. At this moment the angler springs and the unwary fish disappears into its 

 capacious mouth. (The weever or star-gazer paralyses it by an injection of venom.) 



Manoeuvring amid all these sedentary species are snake-like, limbless creatures (without 

 pelvic fins) wriggling like reptiles over the mud. These are fierce and voracious conger and 

 moray eels that may reach great lengths. The congers are more or less camouflaged and take 



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