276 



WHALES 



False Killers and Pilot Whales live on a mixed diet of fish and cuttle- 

 fish, but the remnants of cuttlefish seem to preponderate in their stomachs. 

 They have fairly short jaws with 8-1 1 well-developed teeth. Risso's 

 Dolphin would seem to have restricted its diet to cuttlefish to an even 

 greater extent, since it has no more than six pairs of weakly developed 

 teeth in the lower jaw, and no teeth at all in the upper jaw. Phocaenoides, 

 a North Pacific relative of our porpoise, which feeds on cuttlefish, has a 

 complete set of teeth, though the teeth have barely broken through. 



The Sperm Whale is a mighty cuttlefish feeder. Not that it scorns other 

 food - for even lo-foot long sharks and also odd seals have been found in 

 its stomach - but cuttlefish is unquestionably its favourite diet. Cuttle- 

 fishes are molluscs with characteristic ink-bags and tentacles. The eight- 

 armed Octopods live mainly at the bottom of the sea, while the ten-armed 

 Decapods generally swim from one depth to another. Although Octopods 

 have been found in the stomachs of Sperm Whales, Decapods form their 

 main diet. It is believed that Sperm Whales do not so much go after this 

 prey as swim about with open mouths, enticing the cuttlefish which seem 

 unable to resist the colourful contrast between the Sperm Whale's purple 

 tongue and white gum of the jaws. While the prey is generally some 

 thirty to forty inches long, the skin of Sperm Whales often bears sucker 

 marks of from one to four inches in diameter, showing that the captors 

 must have fought with giant squids {Architeiithis) . At a whaling station in 

 the Azores, Robert Clarke of the National Institute of Oceanography 

 (England), one the greatest living experts on Sperm Whales, once opened 



Figure 155. Skull of the Beaked Whale Mesoplodon gervaisi (Deslongchamps) with only 

 a single tooth in its lower jaw. A typical cuttle-fish eater. {Van Beneden and Gervais, 1880.) 



