ANIMAL LIFE OF THE DEEP SEA BOTTOM 



171 



Typhlonus, showing the distended head and mouth on the underside. Caught in the Celebes Sea, 

 at 5,ogo metres. Half natural size. 



Another typical deep-sea fish, Bathymicrops, which so far has been 

 found only between depths of 4,255 and 6,000 metres, belongs to a family 

 closely related to the ray-fins, but, apart from its blindness, this fish is 

 not remarkable for its structure (Fig. p. 174). But it is an illustrative 

 example both of the wide distribution of certain deep-sea animals and 

 of the relatively great contribution of the Scandinavian countries to deep- 

 sea exploration. It was first caught by the Norwegian Michael Sars Expe- 

 dition in the North Atlantic in 1 9 1 o ; it was found here again by the Swe- 

 dish Albatross Expedition in 1948; and finally we on the Galathea Expe- 

 dition found it both in the Indian Ocean and in the Pacific. Otherwise, 

 only the British Tohn Murray Expedition has found, in the Indian Ocean 

 in 1932, a closely related form, and we found that on the Galathea expe- 

 dition too. 



We have already remarked that the supply of food from the surface 

 phytoplankton and drifting vegetation from the coasts may be an impor- 

 tant factor in the distribution of deep-sea fauna. There is one other factor 

 concerned with natural surface conditions which affects the distribution 

 of deep-sea animals, and that is the water masses themselves: their tempe- 

 rature, salinity, and currents, and the facilities which these offer for the 

 breeding of deep-sea animals. 



