Genetic differentiation of Macrodon ancylodon (Sciaenidae, Perciformes) populations in Atlantic coastal waters of South America as revealed by mtDNA analysis

Abstract

The king weakfish (pescada-gó in Portuguese -Macrodon ancylodon (Sciaenidae), a demersal (bottom-feeding) species found in South America Atlantic coastal waters from the Gulf of Paria in Venezuela to Baia Blanca in Argentina, is an economically important species because of its abundance and wide acceptance by consumers. Because of its wide distribution this fish may be subject to geographic isolation and this may have resulted in distinct populations along its coastal range. Considering that this species represents an important economic resource, confirmation of whether M. ancylodon is a single species or there are different genetic stocks spread over its wide distribution would be an important contribution to conservation policies and population management of the king weakfish. To investigate differences between king weakfish populations we used the cytochrome b and 16S rRNA genes to characterize M. ancylodon specimens caught throughout its South American range from Venezuela to Argentina. Our results clearly distinguished two genetically different groups which show nucleotide divergence and genetic structuring patterns that strongly suggest they may be different species, disagreeing with the widely accepted traditional taxonomy that accepts only one species of Macrodon in the western Atlantic.

Molecular Characteristics of Batanghari, Tambago, Orange, and Mandiangin Giant Gourami Strains

“…Our result was different to Santos et al (2003) study which found high genetic distances in cyt b gene of geographically separated Macrodon ancylodon populations and Craig et al (2009) which also observed a high genetic difference among goliath grouper (Epinephelus itajara) populations. The differences between our result and the study from Santos et al (2003) and Craig et al (2009) might due to we used a different source of populations. In one hand, we used cultivated populations which might be under similar selecti-on pressure from breeder to develop high-quality strains.…”

“…The fragment of cytochrome b gene was multiplied utilizing a pair of primer as follows; forwards L14725L:5'CGA AAC TAA TGA CTT GAA AAA CCA CCG TTG3' and reverse HMVZ16:5'AAA TAG GAA RTA TCA YTC TGG TTT RAT3' (Santos et al, 2003). A total volume of 50 µl of PCR reactions was used during amplification.…”

“…It has been proved that cytochrome b is a useful marker for fish species identification (Griffiths et al, 2010;Perez et al, 2007;Pepe et al, 2005), fish genetic diversity (Perdices et al, 2004), phylogenetic analysis Casey et al, 2004;Doadrio dan Dominguez, 2004), and phylogeographic studies (Kotlik dan Berrebi, 2001;Santos et al, 2003). It is expected that the use of the Cyt b gene in giant gourami strains characterization can be used to analyze their genetic diversity and differences and subsequently be used to strengthen the taxonomic status of giant gourami strains from Sumatera and Kalimantan.…”

Population Structure of Lutjanus purpureus (Lutjanidae - Perciformes) on the Brazilian coast: further existence evidence of a single species of red snapper in the western Atlantic

“…These species include Pristipomoides multidens (Ovenden et al 2004), Lutjanus erythropterus (Zhang et al 2006), and L. synagris (Karlsson et al 2009). Other perciforms, such as the king weakfish, Macrodon ancylodon, also present considerable genetic differentiation at the population level (Santos et al 2003(Santos et al , 2006. These authors recorded the presence of two distinct genetic stocks of M. ancylodon along the Atlantic coast of South America, which they interpreted as the result of a process of allopatric differentiation.…”

Genetic and morphometric differences between yellowtail snapper (Ocyurus chrysurus, Lutjanidae) populations of the tropical West Atlantic

“…2,400 km of coastline as the one inhabited by the studied Brazilian populations of Ocyurus chrysurus. Differences in oceanographic conditions, mainly sea-water temperature, were reported to this area (Castro and Miranda, 1998) being regarded as an important factor in the genetic differentiation of Macrodon ancylodon populations along the Brazilian coast (Santos et al, 2003). Cases where morphometric and genetic data indicate different scenarios of population structuring are not uncommon (Salini et al, 2004;Levi et al, 2004).…”