296 Papers from the Marine Biological Laboratory at Tortugas. 



HABITS. 



FEEDING HABITS. 



Of the spotted sting ray's habits we unfortunately know almost nothing. 

 The fish is too large to be kept in captivity, and its free natural life is such as 

 to preclude anything save scattering observations as to its ways of living. 



It is probable that the anonymous "Portugal of Brazil," whom Purchas 

 (1625) quotes in chapter i of volume vii of "His Pilgrims," had reference 



to our ray when he wrote " these Rayes have in their mouth 



two bones, and break with them the Wilkes" whereon they feed. These 

 were undoubtedly pavement-toothed rays, since of all the rays they only live 

 on such fare. But the "two bones" are certainly much more isolated and 

 distinguishable structures in the mouth of an Aetohatus than in that of a 

 Myliohatis. Further, our A . narinari was common along the coast of Brazil. 

 All these points strengthen the conjecture that A. narinari is referred to. 



But three of the older writers refer to its feeding habits. Most of them 

 simply copied Marcgrave, while the few who were so fortunate as to examine 

 specimens usually had only preserved material. Furthermore they were 

 systematists, concerned with little else than the characters necessary for 

 classification. 



The first of the three is Piso (1648), who in his " De Medicina Brasiliensi," 

 in Book III, bearing the title "De Venenatis & Antidotis," under the 

 sub-heading "Pisces Venenati" writes of Narinari that "They are not 

 captured away from the shore. They feed on fishes, for which they lie in 

 ambush and which they capture with the sting of their tail. When they 

 have removed this, they eat them." Here Piso either got his information at 

 second hand or else made a conjecture. Later it will be shown that they 

 live on mollusks alone. However, Piso is correct as to their being shallow- 

 water forms, and it should be noted that this observation of his is the be- 

 ginning of our knowledge of the habits of the fish. 



Sloane (1697) describes the tongue of a ray of Jamaica (plainly A. 

 narinari) as made up of 19 bones separated by furrows, and adds that this 

 tongue works against the like bones of the upper jaw to cut, tear, or grind 

 the food ; unfortunately he gives no idea of what this food consists. Later, 

 in writing of the same fish, Sloane (1725) says that these rays use their tails 

 "to round their prey to strike them better." In the next paragraph, how- 

 ever, he adds, "They are to be found everywhere in shallow Waters where 

 I was informed they feed on Herbs, Fuci, or Grass." For Sloane's drawing 

 of the teeth of this ray see text-figure 7. 



Blainville (1828), speaking of the genus Raie, of which he gives Raies 

 aigles, Aetobatis, as an example, says: 



The Rays are voracious fishes which feed on other fishes and also on mollusks and 

 crustaceans, which they probably do not catch by swimming, but seize them at the bottom 

 of the seas, in the mud where they have hidden themselves and whence they are able to 

 be dug out by the rays' snouts. 



