Redescription of Vieja hartwegi (Taylor Miller 1980) (Teleostei: Cichlidae) from the Grijalva River basin, Mexico and Guatemala, with description of a rheophilic morph.

Vieja hartwegi was described by Taylor and Miller in 1980 based on 45 juvenile and sub-adult specimens, but this species shows an enormous variation in coloration patterns during ontogenic development and between individuals. Additionally, morphological data have demonstrated the existence of two forms in V. hartwegi: the typical morph of a moderately deep to slightly elongated body shape with midlateral band, and a rheophilic morph with an elongated to slightly deep body shape and lack of midlateral band.

Validity and Redescription of Profundulus balsanus Ahl, 1935 (Cyprinodontiformes: Profundulidae).

Profundulus balsanus was described by Ahl in 1935 and later placed in synonymy with P. punctatus. Recent molecular studies have demonstrated that specimens identified as P.

Bothriocephalus acheilognathi (Cestoda) in the endangered fish Profundulus hildebrandi (Cyprinodontiformes), Mexico.

The Asian fish tapeworm, Bothriocephalus acheilognathi, has been considered one of the most dangerous parasites for cultured carp and a risk for native freshwater fish populations worldwide. This cestode is highly pathogenic for fishes especially fry. In this paper we record B.

Spatial and temporal variation of fish assemblages in a coastal lagoon of the Biosphere Reserve La Encrucijada, Chiapas, Mexico.

Composition and abundance of the ichthyofauna in estuarine and coastal lagoon systems of the South Pacific in Mexico have been scarcely studied. In particular, there is a lack of information on how environmental variables determine the spatio-temporal structure of fish assemblages in those habitats. In this study, fishes were sampled by drop net during twelve months (May 2004 - April 2005) in 22 sites distributed along the Carretas-Pereyra lagoon, located in the Biosphere Reserve La Encrucijada, Chiapas, Mexico.