Transferrin variation in jaraquis, Semaprochilodus taeniurus and S. insignis, in the Amazon region

Abstract

Transferrin variants were examined in population samples of fish, locally known as jaraquis, Semaprochilodus taeniurus and S. insignis. Both species were sampled on two occasions from two geographical areas in the Amazon region. The two species showed no common transferrin type. The 122 specimens of S . taeniurus showed three genotypes encoded by two codominant alleles at the transferrin gene locus ( T n . The 69 specimens of S. insignis showed another two transferrin alleles.Hence the different Tf genotypes support their taxonomic differences, and are predictably capable of identifying any suspected hybrid species. No hybrid was found.

The monotony of transferrin and esterase electrophoretic patterns in pirarucu, Arapaima gigas (Schinz, 1822) from Santa Cruz Lake, Tefé River, Amazonas, Brazil

“…This author skilfully demonstrated the application of two general formulae developed for testing parentage and distinguishing sibs in natural random-mating populations, isolated subpopulations, or domesticated breeds. Thus, analysis of parentage based on single-locus polymorphisms, such as the transferrin (Tf) gene locus which is widely known to show a high degree of genetic polymorphism, displaying a series of autosomal co-dominant alleles in many vertebrate species, especially in fish (Jamieson and Turner, 1978;Monostory et al, 1984;Teixeira and Jamieson, 1985;Jamieson and Birley, 1989;Teixeira et al, 1990;Teixeira et al, 2002), and apparently appearing to be polymorphic in pirarucu, may be very important in defining whether this species displays social or genetic monogamy.…”

“…On account of demonstrating a high evolutionary change rate in its molecular structure and a high degree of genetic polymorphism in many vertebrate species, the Tf gene locus has been very helpful in studies regarding the characterization of population genetic structure for several commercial fish species, mainly the marine ones (Jamieson and Turner, 1978;Jamieson and Birley, 1989). The distributions of genotypes and alleles at that locus have already provided some information on the population genetic structure of Amazonian aquatic species, such as tambaqui, Colossoma macropomum, in a native population (Teixeira and Jamieson, 1985) and hatchery stocks (Calcagnotto and Toledo-Filho, 2000), two jaraqui species, Semaprochilodus taeniurus and S. insignis (Teixeira et al, 1990), one turtle species, Podocnemis expansa (Teixeira et al, 1996), and one pescada species, Plagioscion squamosissimus (Teixeira et al, 2002). However, at the moment there is no available information on electrophoretic Tf locus genotypes, applied to the study of pirarucu and its natural stocks.…”

Stable karyotypes: a general rule for the fish of the family Prochilodontidae?

“…As these fish are quite important to commercial fishing enterprises (Barletta et al, 2010), a number of studies examining their morphology (Ribeiro, 1983(Ribeiro, , 1985, reproduction (Vazzoler et al, 1989), biology (Leite & Araújo-Lima, 2002;Oliveira, 2003;Lima & Araújo-Lima, 2004;Leite et al, 2006), physiology (Val et al, 1984(Val et al, , 1998, and genetics (Feldberg et al, 1987;Teixeira et al, 1990;Oliveira et al, 2003) have already been undertaken.…”