Taxonomic Status of the Lago Coatepeque Endemic Convict Cichlid \u3ci\u3eAmatitlania coatepeque\u3c/i\u3e (Teleostei: Cichlidae)

Abstract

As part of a revision of the cichlid genus Archocentrus, a new genus, Amatitlania, was erected comprising four species: A. nigrofasciata (the type species), A. siquia, A. kanna, and A. coatepeque. Amatitlania coatepeque is an endemic and an eponym of Lago Coatepeque in the interior highlands of western El Salvador. This species was diagnosed by a Y-shaped pattern formed by the ventral fusion of bars four and five on the body; a triple-spined, squarish, or blunt appearance of the dentigerous arm of the dentary; the presence of a posterior projection at the dorsal corner of the lower lip; the presence of a double medial-loop in the gut; sparsely uniform pigmentation of the peritoneum, and 5–5.5 scale rows from the lateral line to the origin of the dorsal fin. Here we examined the taxonomic status of A. coatepeque using molecular and morphological characters. We found that A. coatepeque is phylogenetically nested within the clade of A. nigrofasciata. Additionally, our re-examination of the reported diagnostic morphological characters failed (even in combination) to diagnose A. coatepeque. We instead found that some of those characters were highly variable within A. coatepeque and are sometimes present in members of A. nigrofasciata. Based on our results, we conclude that A. coatepeque is a junior synonym of A. nigrofasciata