Taxonomy and ecology of the genus Chasmodes (Pisces: Blenniidae) with a discussion of its zoogeography

Abstract

The western Atlantic blenniid fish genus Chasmodes is represented by two species, C. bosquianus and C. saburrae. C. saburrae is the more tropical of the species and is found on Florida's east coast from Edgewater southward around the tip of Florida, northward and westward to the Chandeleur Islands, Louisiana. C. bosquianus is composed of two subspecies, C. b. bosquianus and C. b. longimaxilla new subspecies. C. b. bosquianus is distributed on the Atlantic seaboard from Maryland to Marineland, Florida, and C. b. longimaxilla occurs in the northern Gulf of Mexico from Pensacola, Florida, to Veracruz, Mexico.

Chasmodes bosquianus longimaxilia exhibits character displacement in the zone of sympatry with C. saburrae in the Gulf Increased maxillary length in this area may be contributing to the divergence of the disjunct populations of C. bosquianus.

The zoogeographyof the genus Chasmodes is discussed and recent geological information is used in a consideration of the events leading to its present distribution.

Experimental hybridization experiments were performed with Chasmodes saburrae and C. b. longimaxilla, but lack of adequate facilities prevented rearing the larvae.