Polychaete dataset of the southwestern Gulf of Mexico including: taxonomic checklist, abundance, bathymetric distribution, functional diversity, geographic location, and sampling sites depth.

A taxonomic list of 69 genera belonging to 33 families of the Polychaeta class (Annelida) collected in 54 deepwater sites of the southwestern Gulf of Mexico is presented. Abundance data of these 69 genera is also included. A dataset of geographical location and depth of sampling sites is given. Graphs of depth related community functional diversity variation are shown. The biological material was obtained from sediment samples collected aboard the Justo Sierra Oceanographic Vessel of the National Autonomous University of Mexico using a Reineck-type box corer with an effective area of 0.16 m2. In each core a subsample of 0.08 m2 and 13 cm deep was taken and washed through a 500-micron sieve with filtered seawater. Abundances were standardized to individuals per square meter. The average abundance contribution percentage graphs were done calculating the average standardized abundance of each guild and the contribution percentage of each one to the four depth categories established: Upper bathyal zone (UBZ); middle bathyal zone (MBZ); lower bathyal zone (LBZ) and abyssal zone (ABYZ). These data could be useful for comparative purposes with new data of polychaete communities in the same area or another region.

Biodiversidad de ofiuroideos (Echinodermata: Ophiuroidea) del talud de la Península de Yucatán, México / Biodiversity of ophiuroids (Echinodermata: Ophiuroidea) from the slope of the Yucatan Peninsula, Mexico

Introduction: The Ophiuroidea class is the most diverse of the Phylum Echinodermata, with 2 064 described species, which can be found from intertidal zones to abyssal depths, but the fauna of Yucatan peninsula needs more study. Objective: To describe the diversity of ophiuroids in the Yucatan continental slope. Methods: Information was compiled from four oceanographic surveys carried out in August 2005, June 2007 (BIOREPES 1 and 2: BRP1 and BRP2), April 2011 and August 2014 (COBERPES 2 and 6: CBP2 and CBP6). The specimens were obtained by trawling with a shrimp net in soft substrates and with a skimmer-type trawl dredge at a depth range of 200 to 1 071 m off the states of Yucatán and Quintana Roo, Mexico. Results: We found members of two superorders, five orders, six suborders, five superfamilies, 18 families, 28 genera and 43 species. Conclusions: The northeast zone Yucatan Peninsula has at least 43 species, of which 19 are new records for the area.

Introducción: La clase Ophiuroidea es la más diversa del Phylum Echinodermata, con 2 064 especies descritas, que se pueden encontrar desde zonas intermareales hasta profundidades abisales, pero la fauna de la península de Yucatán necesita más estudio. Objetivo: Describir la diversidad de ofiuroideos en el talud continental de Yucatán. Métodos: Se recopiló información de cuatro estudios oceanográficos llevados a cabo en agosto de 2005, junio de 2007 (BIOREPES 1 y 2: BRP1 y BRP2), abril de 2011 y agosto de 2014 (COBERPES 2 y 6: CBP2 y CBP6). Los especímenes se obtuvieron mediante la pesca de arrastre con una red camaronera en sustratos blandos y con una draga de arrastre tipo skimmer en un rango de profundidad de 200 a 1 071 m frente a los estados de Yucatán y Quintana Roo, México. Resultados: Encontramos miembros de dos superórdenes, cinco órdenes, seis subórdenes, cinco superfamilias, 18 familias, 28 géneros y 43 especies. Conclusiones: La zona noreste de la Península de Yucatán tiene al menos 43 especies, de las cuales 19 son nuevos registros para el área.

Ichthyofaunal list of the continental slope of the southern Gulf of Mexico.

Four oceanographic cruises were carried out between April 2011 and May 2013 on the continental slope of the southern Gulf of Mexico (GoM) in a depth range of 290 to 1200 m on board the R/V JUSTO SIERRA. A total of 91 trawls covered a total swept area of 170.49 hectares. We recorded 177 fish species belonging to 80 families. Fifteen species extended their distribution into the south of the gulf and 37 increased their depth ranges. Five species could have commercial importance: Aphanopuscarbo Lowe, 1839; Hydrolagusmirabilis (Collett, 1904); Helicolenusdactylopterus (Delaroche, 1809); Lophiusgastrophysus Miranda Ribeiro, 1915, and Merlucciusalbidus (Mitchill, 1818). The most abundant species were Polymixialowei Günther, 1859; Parasudistruculenta (Goode & Bean, 1896); M.albidus, Chlorophthalmusagassizi Bonaparte, 1840; Dibranchusatlanticus Peters, 1876; Nezumiaaequalis (Günther, 1878); Yarrellablackfordi Goode & Bean, 1896; and Laemonemabarbatulum Goode & Bean, 1883. High values of fish species richness, diversity, and evenness were registered throughout the study area. A high percentage of the fish species (97%) collected during this project are distributed in the entire GoM. Most of the species showed a wide depth distribution; however, a vertical zonation of species can be observed.

Diversity and distribution of Chirostyloidea and Galatheoidea (Decapoda, Anomura) in the Southern Gulf of Mexico.

We examined the diversity, abundance, distribution, and average size of squat lobsters collected during eight cruises conducted on the continental shelf and slope of the Gulf of Mexico (Mexican/USA border to the Caribbean Sea). Six species belonging to two genera of Chirostyloidea, and 25 species of four genera of Galatheoidea are reported. A total of 1513 specimens were obtained of which 95 were Chirostylidae, two Galatheidae, 285 Munidopsidae, and 1131 Munididae. Of the species collected, 13.8% were only known from Caribbean Sea. Three species of Chirostylidae-Gastroptychus salvadori, Uroptychus capillatus, and Uroptychus spiniger-as well two of Munidopsidae, Munidopsis bradleyi and Munidopsis riveroi, are recorded for the first time in the Gulf of Mexico. The upper bathymetric range of one species and the lower one for eight species are extended. Biological and ecological traits of squat lobsters in the southern Gulf of Mexico are also provided.

An unusual new species of paguroid (Crustacea, Anomura, Paguridae) from deep waters of the Gulf of Mexico.

A new hermit crab species of the family Paguridae, Tomopaguropsisahkinpechensis sp. n., is described from deep waters (780-827 m) of the Gulf of Mexico. This is the second species of Tomopaguropsis known from the western Atlantic, and the fifth worldwide. The new species is morphologically most similar to a species from Indonesia, Tomopaguropsiscrinita McLaughlin, 1997, the two having ocular peduncles that diminish in width distally, reduced corneas, dense cheliped setation, and males lacking paired pleopods 1. The calcified figs on the branchiostegite and anterodorsally on the posterior carapace, and the calcified first pleonal somite that is not fused to the last thoracic somite, are unusual paguroid characters. A discussion of the affinities and characters that define this new species is included, along with a key to all five species of Tomopaguropsis.

A new species of Munidopsis Whiteaves, 1874 (Crustacea: Anomura: Galatheoidea: Munidopsidae) from the Gulf of Mexico and Caribbean Sea.

A new species of squat lobster, Munidopsis shulerae sp. nov., from the Gulf of Mexico and western Caribbean, is fully described and illustrated. This new species is named in honor of the late Barbara Shuler Mayo (1945-1988), who first recognized this new taxon in her 1974 unpublished doctoral dissertation, but never formalized it. This new species is placed in the Anoplonotus group based on the presence of simple, narrow rostrum, spineless eyes, fused sternites 3 and 4, well-marked carapace regions, unarmed pleonal tergites, and smooth dactyls of pereopods 2-4. Among western Atlantic congeners, M. shulerae sp. nov. is most similar to M. polita (Smith, 1883), from which it can be distinguished by the straight shape of the rostrum with a tuberculate dorsal carina extending to the epigastric region, coarse ornamentation of the carapace, and a conspicuous submarginal protuberance on each side of the carapace between the antennal and ocular peduncles.

Crangonidae and Glyphocrangonidae (Decapoda; Caridea) of the Southern Gulf of Mexico.

Distribution and abundance of species of Crangonidae and Glyphocrangonidae in the Mexican deep-waters of the Gulf of Mexico were analyzed through six research cruises onboard of the R/V Justo Sierra of the Universidad Nacional Autónoma de México using an otter trawl in a depth range of 300-1200 m. We collected two and five species of the Crangonidae and Glyphocrangonidae families, respectively. We provide information about its depth and geographic distribution, abundance, frequency of occurrence and size structure. Glyphocrangon, composed of five species (G. aculeata, G. alispina, G. haematonotus, G. longleyi and G. spinicauda), was the most common and abundant component during the benthic trawls with a total of 1125 individuals. The family Crangonidae recorded only one genus and two species (Parapontocaris caribbaea and P vicina) with 21 individuals. A taxonomic key for these crangonid and glyphocrangonid shrimps of the Gulf of Mexico is also provided.