THE SHORE FISHES OF PERU 9 



RANGE AND DISTRIBUTION OF SPECIES 



Among the 264 species of fishes described in this catalog, as 

 belonging to the fauna of Peru, 15 may be considered more or less 

 cosmopolitan in their distribution, and are not included in the 

 numbers given subsequently. At least 128 of the species herein 

 recorded from Peru range northward of that country, and only 48 

 rather certainly range southward into Chile.* On the basis of present 

 knowledge 71 species, including most of the new ones herein described, 

 occur only in Peru. 



Among the species known northward of Peru, 3 range only as far 

 as Ecuador, 1 as far as Colombia, 34 apparently range as far north 

 as Central America (mostly only to Panama Bay), and 75 range to, 

 or rarely beyond, Baja California. The last-mentioned group contains 

 8 species to date not taken at localities intermediate of Baja 

 California and Peru. 



The number of species in Peru, according to present information, 

 diminishes rather rapidly southward. For example, 177 species are 

 recorded herein from extreme northern Peru, that is, north of 6°56' S. 

 (including Lobos de Afuera Island); 102 species from the coast, and 

 nearby islands, between latitudes 6°56' S. and 12°04' S. (including 

 Callao) ; and 88 species are listed from the Peruvian coast, and nearby 

 islands, south of latitude 12°04' S. 



The effect of the fishing (collecting) effort along the different sec- 

 tions of the coast on the number of species taken is not well known. 

 It is quite certain, however, that more collectors have taken specimens 

 at Callao than at any other locality along the coast. It may be as- 

 sumed then that the general vicinity of Callao has been sampled 

 more thoroughly than any other along the coast of Peru, Yet the 

 number of species known from there and northward, about to Lobos 

 de Afuera Island, is much smaller than the number known from 

 extreme northern Peru, as shown in the preceding paragraph. It is 

 judged from the literature and the comparatively small collections 

 from southern Peru that the collecting effort along that section of the 

 coast has not been so great as northward. However, sufficient collect- 

 ing seems to have been done to show rather conclusively that the 

 decline in the number of species inhabiting the shores continues into 

 southern Peru. 



Although notably fewer coastal species are known from southern 

 than from northern Peru, they are for the most part the same. In 

 fact, of the 88 species reported in this catalog from southern Peru 

 (south of Callao), only 15 are not yet known also from northern Peru. 

 As indicated in a preceding paragraph, most of the species reported 



1 It is necessary to use indefinite terms in discussing the range, as in some instances definite localities 

 are missing, and in others the species are in doubt. It should be understood, also, that the same species 

 in some instances has been included in two or more of the numbers given. For example, most of the 49 

 Penjvian species occurring in the Oal&pagos also are recorded from Panama Bay, and some of them from 

 Baja California. 



