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The pandalid shrimp, Heterocarpus ensifer occurs on continental slopes over the eastern and western Atlantic, and over some portions of the Indian and Pacific oceans. Despite its wide distribution, studies on the biology of this species are scant. In particular, there is no information on morphometric relationships or reproductive issues from any western Atlantic population. Although the general morphology of males and females of H. ensifer appears similar, we hypothesized that size at the onset of sexual maturity (SOM) and sexual dimorphism of H. ensifer could be examined with morphometric analyses, using those body dimensions most commonly measured in shrimp: carapace length (CL), body length (BL), rostral length (RL), and body weight (BW). We examined 754 H. ensifer from the southern Gulf of Mexico. SOM, determined through sequential reduced major axis regressions of BL, RL, relative rostral length (RRL = RL/CL), and BW against CL, was 23-24 mm CL in females and 21-22 mm CL in males. These sizes closely matched those of the smallest ovigerous females and the smallest males with appendices masculinae. Juveniles of both sexes showed similar morphometry and allometries, but ontogenetic allometry and morphometric sexual dimorphism occurred after maturity. In particular, the positive relationship (with negative allometry) between RL and CL shown in juveniles was lost after SOM in females and changed to enantiometry in males, despite a wide dispersion of data. The rostral polymorphism may be related to the protracted, year-round reproductive activities of this Gulf of Mexico population. Morphometric techniques may be useful to compare populations of H. ensifer from disparate locations. RESUMENEl camarón pandálido Heterocarpus ensifer habita en el talud continental de los océanos Atlántico oriental y occidental y en algunas partes del Índico y Pacífico. A pesar de la amplia distribución de esta especie, los estudios sobre su biología son escasos. En particular, no existe información sobre 3 ) e-mail: elozano@mar.icmyl.unam.mx © Koninklijke Brill NV, Leiden, 2007 Crustaceana 80 (5): 555-568 Also available online: www.brill.nl/cr 556 ENRIQUE LOZANO-ÁLVAREZ ET AL.relaciones morfométricas o aspectos reproductivos de ninguna población del Atlántico occidental. Aunque la morfología general es similar en ambos sexos de H. ensifer, se planteó la hipótesis de que la talla de primera madurez sexual (TPM) y el dimorfismo sexual pueden examinarse a través de análisis morfométricos, utilizando las dimensiones corporales más comúnmente medidas en camarones: longitud cefalotorácica (LC), longitud corporal (LCo), longitud rostral (LR) y peso corporal (PCo). Se examinaron 754 H. ensifer recolectados en el sur del Golfo de México. La TPM, determinada por medio de regresiones secuenciales con eje mayor reducido de las dimensiones LCo, LR, longitud rostral relativa (LRR = LR/LC) y PCo contra la LC, fue de 23-24 mm LC en hembras y 21-22 mm LC en machos. Estas tallas coincidieron con las tallas de las hembras ovígeras más pequeñas y los...

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.

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 Autóno-ma 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.

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.

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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.