TRAWLING FOR CRUSTACEANS AT TORTUGAS, 



FLORIDA 



By WALDO L. SCHMITT, 

 Curator of Marine Invertebrates, U. S. National Museum 



The richness of the crustacean fauna at Tortugas, Florida, and its 

 importance in relation to the food habits and movements of certain 

 fishes, led me to continue investigations at the Carnegie Marine Bio- 

 logical Station from July 9 to August 8, 1930, through the kindness of 

 the Carnegie Institution of Washington. It is planned as a point of 

 departure for further studies on the Crustacea to complete a survey 

 of their kinds and distribution. Judging from the results already 

 obtained, it is anticipated that at least 200 species will be found to occur 

 at Tortugas and vicinity. 



This year was the first in which a preliminary investigation of the 

 deeper waters readily accessible to the laboratory was undertaken. In 

 the course of some 20 hauls made with the 30-foot otter trawl, two 

 hauls between 180 and 2$j fathoms brought to light 16 species of 

 " deep sea " Crustacea. Most noteworthy among these were eight 

 specimens of that giant among isopods, Bathynomus, and a new 

 Portunid crab of the genus Benthocascon, heretofore known only from 

 a single specimen taken between 185 and 440 fathoms in the Andaman 

 Sea. 



Three specimens of Bathynomus were obtained from the first haul 

 in 180 to 220 fathoms, and five specimens in the second haul in 220 

 to 237 fathoms. The largest specimen measures io| inches long by 4^ 

 inches broad. In length it is only an eighth of an inch shorter than the 

 record specimen taken at a depth between 225 and 594 fathoms off 

 the northeast coast of Ceylon. The species is comparatively rare in col- 

 lections. Between 1890 and 1906 nine specimens were taken by the 

 Royal Indian Marine Survey Ship Investigator in Indian Seas in the 

 course of six hauls in from 195 to 740 fathoms, while seventeen speci- 

 mens have been secured by various American vessels. The first speci- 

 men known to science was taken by the Blake in 1878 from 955 

 fathoms in the Caribbean Sea ; two specimens were secured by the 

 Albatross in 1885 and 1888 in the Gulf of Mexico and the Bahamas 

 in 730 and 1,186 fathoms respectively; six specimens were taken by 

 the Bingham Oceanographic Expedition of 1925 off the coast of Brit- 

 ish Honduras north of Glover Reef in 366 fathoms and, finally, the 



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