lyo 



ANIMAL LIFE OF THE DEEP SEA BOTTOM 



The semi-transparent brotiilid (Acanthonus) with large giU-cuver spines. From the Gulf of 

 Guinea, 2,3^0 metres deep. Half natural size. 



rated with water and had worms and bivalves boring in the decaying 

 tissues. 



It was always a good sign when there was an abundance of dead 

 vegetation from the land in the trawl. In one such haul in the Mozambique 

 Channel, at a depth of 3,400 metres, we obtained our only specimen of 

 the remarkable Benthosaurus (Fig. p. 173). This belongs to the ray-fin 

 family (Bathypteroidce), which also have representatives in the deep-sea, 

 though most of ours were taken over the continental slope; for example, 

 no fewer than 42 in one trawl at 915 metres in the Gulf of Panama. They 

 are characterized by having some of the fin rays enormously prolonged. 

 Our Benthosaurus was covered in mud, so that it came up almost un- 

 damaged, and, in particular, with the extraordinarily long rays of its tail 

 and ventral fins intact. The fish is quite blind, so that we may infer that 

 it sails over the sea-floor using the three long rays as feelers to report 

 when there is anything worth investigating as possible food. Benthosaurus 

 had previously been known only from the North Atlantic, where the 

 American Blake Expedition caught two specimens, the Norwegian Michael 

 Sars Expedition one, and the Swedish Skagerrak Expedition two. Thus 

 ours was the sixth, and it extended the known area of distribution to the 

 Indian Ocean. 



