CHARACTERISTIC DEEP-SEA TYPES. FISHES. 



27 



to life in the ooze and slime of the bottom. Macrurus Bairdii 

 and Phyds Chesteri (Fig. 204) are the two most common fishes 

 of the continental slope, where they occur in immense numbers, 

 and breed at depths varying from 140 to 500 fathoms. 



The family Breginacerotidae, hitherto known only through a 

 single species, a native of the Indian Ocean, appears adapted to 

 living at considerable depths. The discovery by the " Blake " 

 of a species (the long-finned Breymaceros atlanticus) (Fig. 205) 



Fig. 205. Bregmaceros atlanticus. 



of this old-world genus in the Gulf of Mexico, at a depth of 

 305390 fathoms, is very interesting to ichthyologists. 



Certain groups of the blennies, gobies and the like, often send 

 stragglers down to the lesser abyssal depths. They are forms 

 with more or less elongate bodies, and low, feeble vertical fins, 

 adapted neither to free swimming nor to the pursuit of prey at 

 the surface. They are, in fact, bottom feeders, somewhat slug- 

 gish in habit, and usually live among stones and hide in crevices ; 

 while, as a rule, fishes like the perch, the sea-bream, and the 

 mackerel, belonging to groups with compact, short bodies, pow- 

 erful fins, and boldly predaceous disposition, do not descend to 

 great depths, and do not wander far from the coast waters. The 

 Berycoidea, the first group of bony fishes to appear upon the 

 geological horizon, occurring early in the cretaceous, are repre- 

 sented in the deepest dredgings of the " Albatross " (2,949 fath- 

 oms) by a species of Plectromus. (Fig. 206.) The Norwegian 

 deep-sea expedition found a species of Beryx, and Beryx splen- 

 dens, a magnificent brilliant scarlet species, known hitherto only 

 from Madeira, was one of the most important captures of the 

 " Albatross," in 460 fathoms. 



