A cryptic lineage of hammerhead shark closely related to but evolutionarily distinct from the scalloped hammerhead (Sphyrna lewini) was recently documented in the western North Atlantic Ocean. Here, we demonstrate using nuclear and mitochondrial DNA sequences that this cryptic lineage also occurs in the western South Atlantic Ocean, extending its distribution >7,000 km from its only previously ...

Liver, heart and abdominal muscle samples from scalloped (Sphyrna lewini) and smooth (Sphyrna zygaena) hammerhead sharks were analysed to characterise their lipid and fatty acid profiles. Samples were compared both between and within species, but there were no significant differences in total lipids for either comparison, although much greater total amounts were found in the liver samples. With...

Visual temporal resolution and scotopic spectral sensitivity of three coastal shark species (bonnethead Sphyrna tiburo, scalloped hammerhead Sphyrna lewini, and blacknose shark Carcharhinus acronotus) were investigated by electroretinogram. Temporal resolution was quantified under photopic and scotopic conditions using response waveform dynamics and maximum critical flicker-fusion frequency (CF...

New records for nematode species recovered from elasmobranch fishes in Brazil are established and new systematical arrangements proposed. Parascarophis sphyrnae Campana-Rouget, 1955 from the spiral valve of Sphyrna zygaena is referred for the first time in South America as a new host record. Procamallanus (S.) pereirai Annereaux, 1946, from the spiral valve of Raja castelnaui is reported parasi...

BACKGROUND AND AIMS The shark fisheries of Madagascar remain largely unstudied. Remoteness makes fisheries monitoring challenging while the high value of shark fins combined with the extreme poverty in Madagascar creates intensive pressure on shark resources. MATERIALS AND METHODS We use DNA barcoding and species-specific PCR assays to characterize shark fisheries in Antongil Bay in northeast...

Location or stock-specific landing data are necessary to improve management of shark stocks, especially those imperiled by overexploitation as a result of the international shark fin trade. In the current absence of catch monitoring directly at extraction sites, genetic stock identification of fins collected from major market supply chain endpoints offers an overlooked but potentially useful ap...

Previous investigations of the population genetics of the scalloped hammerhead sharks (Sphyrna lewini) in the Eastern Tropical Pacific have lacked information about nursery areas. Such areas are key to promoting conservation initiatives that can protect young sharks from threats such as overfishing. Here, we investigated the genetic diversity, phylogeography, and connectivity of S. lewini found...

Genetic diversity (θ), effective population size (N(e)), and contemporary levels of gene flow are important parameters to estimate for species of conservation concern, such as the globally endangered scalloped hammerhead shark, Sphyrna lewini. Therefore, we have reconstructed the demographic history of S. lewini across its Eastern Pacific (EP) range by applying classical and coalescent populati...

  For this study one species of Shyrnidae family caught along Persian Gulf in Bandarabbas city. Sphyrna lewini were transferred to the laboratory on spring 2007. The antimutagenic activity of the Methanolic and Chloroforamic extracts of muscle, liver and cartilage of Sphyrna lewini with the Ames test was investigated. The use of antimutagens and anticarcinogens in everyday life is the most effe...

we examined the diet and trophic level of sphyrna lewini in the gulf of california (gc) during 2001 and in the gulf of tehuantepec (gt) during 2005 using data from stomach content and stable isotope analysis of δ15n and δ13c. s. lewini diet was represented by pelagic and benthic prey species where the most important in weight was scomber japonicus (27.70±4.54%) in gc, while in gt it was auxis s...