The infection, known as yellow spot disease, produced by metacercariae of Clinostomum spp. was studied in fishes of the Taquari river, located in Jataizinho, Paraná State, Brazil. A total of 1,582 specimens, belonging to 36 species, were collected between March 1999 and April 2001. Yellow spot disease was observed only in Gymnotus carapo Linnaeus, 1814 (Gymnotiformes, Gymnotidae) and Cichlasoma...

Three hitherto unknown oxyuroid nematode species of the family Pharyngodonidae are described from the intestine of South American freshwater fishes, two of them being established as species new to science: Spinoxyuris annulata sp. n. from Myleus ternetzi (Norman) (Serrasalmidae) from French Guiana (Sinnamary River) and Ichthyouris ovifilamentosa sp. n. from Cichlasoma sp. (Cichlidae) from Amazo...

Herichthys minckleyi is an endangered, trophically polymorphic cichlid endemic to the Cuatro Ciénegas basin of Coahuila, Mexico. A molariform morph has stout pharyngeal teeth whereas a papilliform morph has numerous fine pharyngeal teeth. Individuals with intermediate pharyngeal dentition also exist, as does yet another morph, called piscivore. Previous studies indicated that morphs utilize dif...

The preparation process of protein enzymolysis technology for the three-spot seahorse (Hippocampus trimaculatus Leach) degreased bone meal was developed. Two enzymes with better enzymolysis effect were selected from the five proteases, and the optimization condition of the Alkaline Protease is temperature - 54.7°C, pH - 9, duration of 6 h, the acquired rate of polypeptides was 11.77%; and that ...

Dental polymorphism in teleost fishes often involves production of a robust dentition, or "molarization", in one morph. The lower pharyngeals of a sample of wild-caught individuals of the polymorphic Cuatro Cienegas cichlid, Cichlasoma minckleyi (Kornfield and Taylor) (Proc. Biol. Soc. Wash. 96 (1983) 253), were measured to investigate morphological changes associated with molarization. Princip...

Several morphologically defined species of cichlid fishes (Cichlasoma) endemic to the Cuatro Cienegas basin of Mexico and differing in tooth structure, body shape, and diet are allelically identical at 27 gene loci. The presence of only one Mendelian population in each of three drainage systems studied and the occurrence of two of the morphotypes in the same broods indicate that the supposed sp...

The Midas cichlid, Cichlasoma citrinellum, is a polychromatic fish that occurs in Nicaragua. All of these fish start life as normally colored, cryptic individuals. In some populations a few fish change into conspicuously colored morphs, most frequently gold. When kept in unmixed color groups, golds and normals grow at the same rate; but when they are mixed, growth of the golds becomes faster an...