Additional Pressure to a Threatened Species: High Persistent Organic Pollutant Concentrations in the Tropical Estuarine Batoid Gymnura altavela.

Persistent organic pollutants (POPs) were determined in Gymnura altavela liver samples from one of the most impacted estuarine environments in the Atlantic Ocean (Guanabara Bay, Brazil). PCBs were the predominant compounds (91.2%) averaging 6773 ± 4659 ng.g-1 lipid weight (lw). DDT, Mirex, HCH and HCB concentrations were 633 ± 715, 6.2 ± 9.3, 3.4 ± 1.4 and 0.5 ± 0.5 ng.g-1 lw, respectively. Recent DDT input in the estuary was minimum, as verified by the p,p'-DDE/∑DDT ratio (0.67). The prevalence of industrial compounds was highlighted by the ΣDDT/ΣPCB ratio (0.08). A negative correlation detected between disc width and PCBs, Mirex and HCH concentrations may be a consequence of maternal offloading. High POP concentrations in G. altavela liver samples from Guanabara Bay suggests that PCBs, in particular, may pressure the conservation of this threatened with extinction tropical estuarine batoid species.

Mitochondrial genome of the longtail butterfly ray Gymnura poecilura (Myliobatiformes: Gymnuridae).

The complete mitogenome the longtail butterfly ray (Gymnura poecilura) was first presented in this study. It is 17,874 bp in length, contains 37 genes with the typical gene order and transcriptional direction in vertebrates. The overall base composition is: 28.5% A, 26.5% T, 15.0% G and 30.1% C. There are 26 bp overlaps and 41 bp short intergenic spaces located in 7 and 16 gene junctions, respectively. Two start codons (ATG and GTG) and two stop codons (TAG and TAA/T) were used in protein-coding genes. The origin of L-strand replication (OL) was found between tRNA-Asn and tRNA-Cys genes. The control region has the same A and C contents (28.8%).