THE FISH FAUNA OF THE TORTUGAS ARCHIPELAGO. 



By DAVID STARR JORDAN and JOSEPH C. THOMPSON. 



The Tortugas Archipelago consists of a group of seven small, sandy islands and 

 a large reef plateau so situated as partially to form a lagoon of about 50 square 

 miles. Two of the islands are inhabited. On Garden Key is Fort Jefferson, now 

 converted into a United States naval station, and on Loggerhead Key is a light-house. 

 Pure deep ocean water surrounds the islands, and there are none of the extensive 

 mud flats and mangrove-covered shores so characteristic of the keys along the main 

 land of Florida. 



The northern edge of the Gulf Stream lies from l ; 5 to 30 miles south of the Tor 

 tugas, but a strong southerly breeze is sufficient to drive the surface waters, unac- 

 companied by the current, upon the islands, and under these conditions quantities of 

 gulf weed are east upon the shores. Vast numbers of floating animals also are borne 

 along upon the surface of the Gulf Stream, drawn into it by winds and currents from 

 the adjacent tropical regions of the Atlantic, and thus pelagic li-^li from all over the 

 Gulf of Mexico and West Indies may be drifted past the Tortugas. The tempera- 

 ture of the surface waters in the immediate vicinity is remarkably high, being about 

 71 to 77 F. in winter and SO to 86° F. in summer, the average for the whole year 

 being about 7* F. 



About ten square miles of shallow reef Hats surround the islands, and these sup- 

 port a fauna which, according to Dr. A. G. Mayer, for variety and abundance, 

 appears to be unsurpassed by that of any locality on the Atlantic coast of the 

 United States. At present 218 species of fishes are known to occur at the Tortugas. 

 All of these have been taken in reef collecting or at moderate depths with the line. 

 When a thorough investigation can be made in the region, a very great number of 

 additional forms will doubtless lie found. Heretofore Tortugas was the type locality 

 for 6 species; the last year's collecting has increased this number to 14, the following 

 new species having been discovered by Dr. Thompson: Helocentrus tortugse, Eviota 

 personata, Rhinogohius tortugce, Gnathol&pu thompsoni, Elacatinus ooeanops, Erich is 

 lcalisht /■;/ , Ext c< stideg < <//•< gius, Gnathypops aurifrons. 



This paper is based on a collection made by the junior author while on duty as 

 surgeon at the United States Naval Station on Garden Key. Duplicate series have 

 been sent to the United States National Museum, to the United States Bureau of 

 Fisheries, and to the Museum of Stanford University. Several species of interest 

 have been treated in a previous paper, sent to press before the receipt of the full 

 collection. Field notes by Dr. Thompson in the present article are signed "T." 



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