João Bráullio de Luna Sales

New molecular phylogeny of the squids of the family Loliginidae with emphasis on the genus Doryteuthis Naef, 1912: Mitochondrial and nuclear sequences indicate the presence of cryptic species in the southern Atlantic Ocean

The family Loliginidae Lesueur, 1821, is currently considered to include seven genera and approximately 50 species of neritic and coastal squids. These commercially important species occur in tropical and temperate coastal waters around the world. The taxonomy of the family has been revised a number of times in recent years, focusing in particular on genera such as Doryteuthis, Sepioteuthis, Alloteuthis, and Uroteuthis, which are represented by populations in the New World, Oceania, Europe/Africa, and Asia. However, no detailed phylogenetic analysis is available for the loliginids of the southern Atlantic, in particular the genus Doryteuthis. The present molecular study analyzed 81 loliginid taxa from around the world. The partial sequencing of the mitochondrial 16S and Cytochrome Oxidase I genes, and the nuclear rhodopsin gene revealed a number of important patterns, recovering the monophyletic status of the majority of the genera and revealing possible cryptic species in Doryteuthis plei D. pealei, Uroteuthis duvauceli and Sepioteuthis lessoniana.

Molecular Phylogeny of the Genus Lolliguncula Steenstrup, 1881 Based on Nuclear and Mitochondrial DNA Sequences Indicates Genetic Isolation of Populations from North and South Atlantic, and the Possible Presence of Further Cryptic Species

Squid of the genus Lolliguncula Steenstrup, 1881 are small bodied, coastal species capable of tolerating low salinity. Lolliguncula sp. are found exclusively in the New World, although only one of the four recognized species (Lolliguncula brevis) occurs in the Atlantic Ocean. Preliminary morphological analyses suggest that Lolliguncula brevis populations in the North and South Atlantic may represent distinct species. The principal objective of the present study was to verify the phylogenetic relationships within the genus and test for the presence of possible cryptic species. Both gene and species tree topologies indicated that Lolliguncula brevis specimens from the North and South Atlantic represent distinct phylogenetic clades. In contrast with previous studies, L. panamensis was identified as the basal species of the genus. Our results provide important insights into the phylogenetic relationships among the Lolliguncula specimens analyzed, and confirm the genetic separation of Lolliguncula brevis populations of the North and South Atlantic at the level of sister species.

Phylogeographical Features of Octopus vulgaris and Octopus insularis in the Southeastern Atlantic Based on the Analysis of Mitochondrial Markers

ABSTRACT The genus Octopus occurs in tropical and temperate oceanic waters throughout the world, and currently includes 112 species, although the phylogenetic relationships among the different taxa are still poorly understood. The cosmopolitan Octopus vulgaris is one of the most widely analyzed cephalopods in genetic studies, primarily because of its ample range and the problems associated with the morphological identification of specimens, which indicate the possible existence of a species complex with a worldwide distribution. Two large-bodied octopus species—O. vulgaris and Octopus insularis—are found in the western South Atlantic. The limits of the geographical range of the O. insularis are still unclear. The current study is based on a phylogeographic analysis of the 2 species in the South Atlantic, with the objective of confirming their monophyletic status and the limits of their geographical distribution in this region. The analyses were based on the mitochondrial genes 16S rDNA and Cytochrome Oxidase subunit I (COI). The topologies generated for both genes confirmed the monophyletíc status of the 2 species. In the case of O. vulgaris, it was possible to confirm the monophyletic status of the specimens from this region relative to those of other areas around the world, although 3 distinct haplogroups were clearly differentiated, corresponding to the Americas, Europe and Africa, and Asia. The differentiation among these 3 groups may be determined by the limitations of the dispersal of paralarvae among continents. Further studies are needed to confirm the possible occurrence of distinct groups in the western South Atlantic, as well as the influence of oceanic currents on the phylogeographical distribution of O. vulgaris on the Brazilian coast.

Divergence of cryptic species of Doryteuthis plei Blainville, 1823 (Loliginidae, Cephalopoda) in the Western Atlantic Ocean is associated with the formation of the Caribbean Sea

Although recent years have seen an increase in genetic analyses that identify new species of cephalopods and phylogeographic patterns, the loliginid squid of South America remain one of the least studied groups. The suggestion that Doryteuthis plei may represent distinct lineages within its extensive distribution along the western Atlantic coasts from Cape Hatteras, USA (36°N) to northern Argentina (35°S) is consistent with significant variation in a number of environmental variables along this range including in both temperature and salinity. In the present study D. plei samples were obtained from a large number of localities along the western Atlantic coasts to investigate the distribution of these possible species in a phylogeographic context. Phylogeographic analyses were performed using the mitochondrial Cytochrome Oxidase I gene and nuclear Rhodopsin gene. Divergence times were estimated using Bayesian strict clock dating with calibrations based on fossil records for divergence from the lineage containing Vampyroteuthis infernalis (162mya), the probable origins of the North American loliginids (45mya), and the European loliginids (20mya) and fossil statolith from Doryteuthis opalescens (3mya). Our results suggest a deep genetic divergence within Doryteuthis plei. The currently described specie consists of two genetically distinct clades (pair-wise genetic divergence of between 7.7 and 9.1%). One clade composed of individuals collected in northwestern Atlantic and Central Caribbean Atlantic waters and the other from southwestern Atlantic waters. The divergence time and sampling locations suggest the speciation process at approximately 16Mya, which is in full agreement with the middle Miocene orogeny of the Caribbean plate, ending up with the formation of the Lesser Antilles and the adjacent subduction zone, coinciding with a particularly low global sea level, resulting in the practical absence of continental shelves at the area, and therefore an effective geographic barrier for D. plei. Furthermore, this study also provides evidence of previously undocumented sub-population structuring in the Gulf of Mexico.

DNA-based identification reveals illegal trade of threatened shark species in a global elasmobranch conservation hotspot

Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which hampers reliable species identification and law enforcement on illegal catches. We used partial sequences of two mitochondrial genes (COI and/or NADH2) to identify 17 shark species from 427 samples being harvested and marketed on the northern coast of Brazil. Nine species (53%) are listed under some extinction threat category according to Brazilian law and international authorities (IUCN – International Union for Conservation of Nature; CITES – Convention on International Trade of Endangered Species of Wild Fauna and Flora). The number increases to 13 (76%) if we also consider the Near Threatened category. Hammerhead sharks are under threat worldwide, and composed 18.7% of samples, with Sphyrna mokarran being the fourth most common species among samples. As illegal trade of threatened shark species is a worldwide conservation problem, molecular identification of processed meat or specimens lacking diagnostic body parts is a highly effective tool for species identification and law enforcement.