Abstract
Two new endemic forms are added to the growing list of species indigenous to the tropical wet rainforest region of the Pacific versant of Costa Rica. The new species are described from extensive material collected from throughout their respective ranges. In addition to meristic and morphometric data, the colors of live specimens, sexual dimorphism, and ecological aspects are discussed.
Both new species appear to represent Pacific slope cognates of Trans-American geminate pairs: Cichhlasoma sajica and the Atlantic slope C. septemfasciatum, and C. diquis and the principally Atlantic slope C. alfari. It is postulated that these and other geminale pairs with similar distributions arose from common ancestors on the Tertiary Talamanan, and that during the Pliocene the members of each species pair were isolated from each other by the emerging intercontinental land bridge between the Americas.
References
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Copyright (c) 1974 Revista de Biología Tropical