Using the last taxonomic review of chondrichthyans of the world, we selected the species distributed in the north-western Atlantic Ocean (NWA) and compared it with the available published literature related to the class Chondrichthyes in the Venezuelan exclusive economic zone. We also revised information from worldwide databases such as: FAO (NWA-31 area), GBIF, iSpecies, IUCN and OBIS, as well as available museum collection databases. The taxonomic validity was checked using the Catalogue of Fishes of the California Academy of Sciences and recent references. The past published Venezuelan lists of chondrichthyans combined included nine orders, 30 families and 108 species. The updated list with 12 orders, 36 families and 122 species increased by three new orders, six families, three shark genera, nine shark species (one replacing another species), one chimaera genus, two chimaera species, three batoid genera and six batoid species (two replacing other species). Four holotype specimens (two sharks and two rays) are deposited in Venezuelan Museums. Most of the species have an IUCN conservation status, including four species catalogued as Critically Endangered, six as Endangered and 18 species as Vulnerable. Deepsea fisheries, scientific exploration and taxonomic/genetic revisions might add future increments to the Venezuelan chondrichthyan list. K E Y W O R D S batoids, Caribbean Sea, chimaeras, elasmobranchii, holocephali, sharks
Three rays opportunistically obtained near Margarita Island, Venezuela, were identified as lesser devil rays Mobula cf. hypostoma, but their disc widths were between 207 and 230 cm, which is almost double the reported maximum disc width of 120 cm for this species. These morphometric data suggest that lesser devil rays are either larger than previously recognized or that these specimens belong to an unknown sub-species of Mobula in the Caribbean Sea. Better data are needed to describe the distribution, phenotypic variation and population structure of this poorly known species.
The checklist presented in this study includes the latest taxonomic and systematic modifications and updates (early 2018) for the Chondrichthyes that inhabit the Exclusive Economic Zone (EEZ) of Mexico. The list is based on a literature review of field-specific books, scientific publications and database information from collections and museums worldwide available online such as, the Ocean Biogeographic Information System (OBIS), Global Biodiversity Information Facility (GBIF), Encyclopedia of Life (EOL), iSpecies, FishBase and the National Biodiversity Information System (SNIB–CONABIO). Information was cross-referenced with digital taxonomic systems such as the Catalog of Fishes of the California Academy of Sciences, the World Register of Marine Species (WoRMS), and the Integrated Taxonomic Information System (ITIS). There is a total of two subclasses two divisions, 13 orders, 44 families, 84 genera, and 217 species that represent approximately 18% of all living and described species of chondrichthyans worldwide. For the Mexican Pacific and the Gulf of California, 92 species of chondrichthyans are listed compared to 94 species for the Gulf of Mexico and the Caribbean Sea. Additionally, 31 species listed occur on both coasts of Mexico. The species richness of the Mexican chondrichthyans will surely continue to increase, due to the exploration of deep-water fishing areas in the EEZ.
Abstract-Species of the genus Myliobatis have been poorly assessed because of a lack of available information regarding their capture and life history. We provide valuable data based on the commercial landings of the bullnose ray (Myliobatis freminvillei), which we studied during 2 separate time periods (October 2005-December 2007 and JanuaryDecember 2013. A total of 187 individuals were analyzed: 85 females (24.0-96.0 cm in disc width [DW]) and 102 males (22.8-118.0 cm DW). There was no difference in the overall sex ratio (females to males: 4:5); however, differences were found between the annual sex ratio in 2005, 2006, and 2013. Estimated capture per unit of effort for this species was 0.8 individuals/trip (standard deviation [SD] 1.3) or 2.9 kg/trip (SD 5.5), showing an increase in effort through time and significant differences between years. Approximately 25% of both sexes were shorter than the estimated median DW at maturity. No pattern in the reproductive cycle was identified because of the lack of landings during several months; however, mature individuals were observed frequently throughout the study period; gravid females were observed on only 2 occasions. This study provides baseline biological information on the life history of the bullnose ray for necessary fishery management.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.