ICHTHYOLOGY OF VENEZTJELA — SCHULTZ 3 



GEOGRAPHY AND CLIMATE OF THE MARACAIBO BASIN 



Lago de Maracaibo has an average depth of about 100 feet (maxi- 

 mum 34 meters, or 11 iK feet) and a soft muddy bottom. From its 

 southern end to the beginning of the channel at Punta de Pahnas, 

 south of the city of Maracaibo, it is 154.5 kilometers, or 95.8 miles, long; 

 the length of the channel from Punta de Palmas to Punta Vigia at 

 entrance into El Tablazo is about 39% kilometers, or 24.3 miles; and 

 from Punta Vigia across El Tablazo to the entrance into the Gulf of 

 Venezuela at Castillo de San Carlos is 20.75 kilometers, or about 12.9 

 miles, making a total length from the Gulf of Venezuela to the southern 

 end of the lake of 214.9 kilometers, or about 133.25 miles. The 

 greatest width of the lake is about 121 kilometers, or 75 miles. The 

 long axis of the lake is almost directly north-south. 



High mountain ranges enclose the T^Iaracaibo Basin on all sides 

 except the north. The Sierra de Perija forms the western divide, 

 whereas the Cordillera Oriental occurs at the southwestern side, and 

 along the southern and southeastern side the lofty Cordillera de Los 

 Andes, with Pico Bolivar reaching to a height of 5,005 meters. Another 

 range of high hills and mountains forms the eastern rim of the basin. 

 The northern end of the l\Iaracaibo Basin is semidesert, contrasting 

 sharply with the tropical jungle at the southwestern and southern ends, 

 where the rainfall is very great along the eastern slopes of the Cordil- 

 leras de Perijd and Oriental even during the dry season. 



During 1941 the Maracaibo Nautical School recorded the following 

 monthly average temperatures and total monthly rainfall at Mara- 

 caibo, as published February 14, 1942, in the Maracaibo Herald: 

 January, 81° F., 4 mm.; February, 83° F., 6 mm.; March, 82° F., no 

 rainfall; April, 84° F., 16 mm.; May, 85° F., 144 mm.; June, 85° F., 

 1 1 mm. ; July, 85° F., 9 mm. ; August, 85° F., 3 mm. ; September, 85° F., 

 38 mm.; October, 83° F., 26 mm.; November, 84° F., 68 mm.; De- 

 cember, 83° F., 5 mm. The rainfall thus totals 330 mm., or 13 inches. 



The average monthly rainfall for the eastern shore at LaguniUas is 

 given below for a period of 14 years (1928-1941), from information 

 furnished by the Lago Petroleum Corp. These records are in inches, 

 with minima and maxima in parentheses. January, 0.22 (0.00 to 

 1.33); February, 0.26 (0.00 to 1.08); March, 0.69 (0.00 to 2.09); April, 

 1.59 (0.11 to 5.41); May, 4.47 (1.49 to 9.21); June, 3.20 (1.07 to 7.72); 

 July, 3.81 (0.87 to 11.71); August, 4.05 (0.76 to 8.91); September, 

 4.89 (0.94 to 11.90); October, 6.21 (2.62 to 11.53); November, 3.52 

 (0.45 to 8.78); December, 0.80 (0.00 to 1.78). Total average rainfall 

 33.98 inches, with a minimum of 18.40 in 1939 and a maximum of 

 51.01 in 1933. These data indicate the increase in amount of rainfall 

 southward in the Maracaibo Basin. Undoubtedly the heaviest rain- 

 fall occurs at the southwestern corner of the Basin where the jungle is 



