The endemic cichlids of the Cuatro Cienegas Basin, Coahuila, Mexico are currently grouped in a single polymorphic species,Cichlasoma minckleyi.Twomorphs ofC.minckleyiwere distinguished largely by features of the trophic apparatus, especially the pharyngeal dentition. Variation in body shape, based upon analysis of a set of linear measures, was continuous and did not allow recognition of discret...

Introduced fishes comprise a substantial fraction of the fish fauna in 2 Bexar County waters: 35% in upper San Antonio River and 43% in Braunig Reservoir. Four species (Astyanax mexicanus, Poecilia latipinna, P. formosa, and Cichlasoma cyanoguttatum) are south Texas fishes displaced northward. Two species (Cyprinodon variegatus and Menidia beryllina) are recent introductions from estuarine wate...

Many characteristics of the South American teleost fish Cichlasoma dimerus (body size, easy breeding, undemanding maintenance) make it amenable to laboratory studies. In the last years, many of the fundamental aspects of its reproductive and developmental biology have been addressed in our laboratory. Rather recently, the immunohistochemical localization of pituitary hormones involved in reprod...

A new cucullanid nematode, Dichelyne mexicanus sp. n., is described from the intestine of three species of fishes, Agonostomus monticola (Bancroft) (Mugilidae, Perciformes) (type host), Ictalurus balsanus (Jordan et Snyder) (Ictaluridae, Siluriformes) and Cichlasoma beani (Jordan) (Cichlidae, Perciformes), from three rivers (La Maquina River, Veracruz; Chontalcoatlán River, Guerrero and Santiag...

The family Rivulidae is one of the largest families of freshwater fishes of the Neotropical region [1]. It is a diverse group of annual fish, most popularly known as “killifish”, which occurs in seasonal freshwater swamps of tropical and subtropical areas of South America [2]. Brazil has the greatest diversity of the family Rivulidae and is represented by 30 genera with approximately 120 fish s...