﻿Contribution from the Zoological Laboratory of Indiana University, 



No. 175 



The Fresh-Water Fishes of Panama 1 East of 

 Longitude 8o° W. 



By Carl H. Eigenmann 



The eightieth meridian passes thru the mouth of the Chagres 

 river. East of it lie the entire eastern and southern Panama with 

 the Chagres basin and Panama Canal, the Chepo basin, and the 

 Tuyra basin. The Chagres is the only large river flowing toward 

 the Atlantic; between the Chagres and Colombia the streams 

 flowing toward the Atlantic are small. Nothing is known of the 

 fish contents of those east of the Rio Cascajal at Porto Bello. In 

 the region of the Chagres the continental divide is close to the 

 Pacific ocean. Between the Chagres and Colombia the continen- 

 tal divide lies within a few miles of the Atlantic. The rivers 

 coming from the mountains flowing nearly direct to the sea 

 are short and very probably turbulent. 



On the Pacific side there are numerous rivers longer than those 

 on the Caribbean side, and inasmuch as there is considerable tide 

 on the Pacific side, several of the rivers are navigable, the Tuyra 

 being navigable half-way across the continent. 1 The rivers which 

 have been examined for fishes are : first, the smaller rivers near the 

 canal, the Chame, the Chorrera, the Grande, and the Juan Diaz; 

 second, the Bayano or Chepo emptying about 25 miles east of 

 Panama City; and third, the Tuyra emptying about 80 miles 

 southeast of Panama City. Of these the Tuyra is by far the 

 largest, draining with its tributaries a territory 120 miles north 

 and south. Its basin lies just north of the Darien mountains, 

 south of which the continental divide is again switched to near 

 the Pacific ocean. 



. The natural interest in the faunas on the two sides of the 

 Isthmus of Panama was greatly magnified when the Panama 

 Canal was projected. 



iMiscellaneous information on Panama was published by the War Department in 

 Notes on Panama, by Captain N. C. Hale, Washington, D.C., 1903. The Report of the 

 Isthmian Canal Commission 1899-1901, Washington, 1904, contains excellent maps of 

 the entire region. 



