376 Memoir Sears Foundation for Marine Research 



Information as to its food is limited to the facts that one taken in Texas waters 

 contained nereid worms, that Chesapeake Bay specimens had eaten Crustacea, and that 

 amphipods are an important dietary item for them on the east coast of Florida. ^i* 



In Louisiana waters, fully ripe males have been captured in February and females 

 giving birth to young in June, and off the coast of Texas small specimens have been 

 taken in spring, summer, and autumn but not in December, January, or February. 

 Thus it appears that young are produced at all times of year except winter. 



Available information suggests that it is a year-round resident throughout the 

 warmer parts of its geographic range. This is true, at least locally, along the coast of 

 Louisiana."' However, it has been learned recentlyi^" that most of those on the Texas 

 Coast desert the shallow bays late in the autumn, when the water cools there below 

 about 16° C (61° F), to spend the winter outside in the coastal zone of the open Gulf 

 of Mexico where winter chilling is less extreme. It does not seem likely that this Ray 

 carries out any corresponding thermal migration on the Atlantic Coast south of north- 

 ern Florida. But the cycle of temperature, as observed at lighthouses and lightshipSji^^ 

 suggests that specimens penetrating estuarine waters along North and South Carolina 

 may be expected to move either offshore or southward at some time during mid- 

 November or later when the water there usually chills below about 16° C (60-61° F), 

 not returning until some time in April when it warms above that value. Z). sabina 

 appears to reach the northern fringe of its range solely as a warm-season visitor, for 

 it is reported in Chesapeake Bay only in July and October. 



Numerical Abundance. D. sabina has been characterized repeatedly as abundant ; 

 actually, however, the published counts have not been as large as this might suggest. 

 Thus a series of trawlings in Barataria Bay, well within its center of abundance, as 

 well as in the Gulf of Mexico nearby, yielded an average of only about one specimen per 

 three hauls in one month (June) during 1932 and 1933; catches in a more extensive 

 series of experimental trawlings in Texas waters ranged from 0-54. ^^^ 



Relation to Man. This little Sting Ray, while of no commercial value, is at least 

 less dangerous because of its small size than are its larger relatives. 



Range. Coastal waters of the western North Atlantic, often running up into fresh 

 water; Gulf of Mexico and Florida, northward to Chesapeake Bay; reported south to 

 Surinam (Dutch Guiana) and Brazil but probably not on good evidence (p. 377). 



Details of Occurrence. Tht coastal waters of the Gulf of Mexico and of Florida appear 

 to be the center of abundance for D. sabina. Thus it is reported as more plentiful than 

 all other Sting Rays combined in the bays of middle and northern Texas and in the 

 neighboring coastal waters outside; it is caught regularly (if in no great numbers) by 

 the shrimp trawlers in the bays of Louisiana as well as in the Gulf offshore. It has been 



118. Personal communication from Stewart Springer. 



119. They are taken in Barataria Bay at all times of the year. 



120. Gunter, Publ. Inst. mar. Sci. Texas, i, 1945: 23. 



121. Rathbun in Goode, Fish. Fish. Industr. U.S., Sect. 3, Append., 1887: 155-172, 32 charts; Parr, Bull. Bingham 

 oceanogr. Coll., 4 (3), 1933. 



122. Gunter, Publ. Inst. mar. Sci. Texas, 7, 1945: 22, 127, table 7. 



