Feeding Habits of Dwarf Goatfish (Upeneus parvus: Mullidae) on the Continental Shelf in the Gulf of Mexico

Feeding habits of dwarf goatfish on the continental shelf off Alvarado, Veracruz, Mexico, were analyzed to determine seasonal variation and size-class changes in diet composition and trophic overlap between size classes. Food was found in 63% of the 1,437 dwarf goatfish guts analyzed. The 52 dietary items identified consisted mainly of crustaceans, with Solenocera vioscai being the most important prey. Dwarf goatfish exhibited seasonal and size-class changes in prey consumption. Despite the high number of prey items, low values of diversity and diet breadth were found in the trophic spectrum. A high trophic overlap between size classes was observed in the north-winds season between length classes (92-111 vs 112-130 mm) (λ = 0.81) and (92-111 vs 131-150 mm) (λ = 0.80), and (112-131 vs 131-150 mm) (λ = 0.67). In the rainy season high overlaps were obtained between (92-111 vs 112-131 min) (λ = 0.73) and (112-131 vs 131-150 mm) (λ = 0.84) length classes. Dwarf goatfish appear to be opportunistic carnivorous predators that impact benthic and epibenthic invertebrates

Effect of habitat structure on the most frequent echinoderm species inhabiting coral reef communities at Isla Isabel National Park (Mexico)

The spatial distribution and abundance of the seven most abundant species of echinoderms (Diadema mexicanum, Centrostephanus coronatus, Eucidaris thouarsii, Isostichopus fuscus, Pharia pyramidatus, Phataria unifascialis and Acanthaster ellisii) were evaluated in coral communities of Isla Isabel National Park (Mexico). Biological (corals and other benthic groups) and physical (rocks and boulders) structural elements of the habitat were evaluated to determine their relationship to these species. Our results show that species composition and abundance varied among sampling sites and between seasons. Also were obtained significant differences in the echinoderm assemblage among sites across seasons. Similar results were detected for the environmental variables related to benthic habitat structure. D. mexicanum, P. unifascialis, E. thouarsii and C. coronatus were the main contributors to the species abundance and distribution in Isla Isabel. Most echinoderm species were positively related to the coverage of different coral species, algae and various types of benthic organisms as well as to physical benthic variables. These outcomes suggest that the spatial distribution and abundance of these echinoderms are explained by the habitat structure, which should be used to design conservation and management strategies for coral communities

Diving into the vertical dimension of elasmobranch movement ecology

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements

La ictiofauna marina de Baja California Sur, México, desde la perspectiva de un trabajo museológico

One brief account and results of the generated activities through curatorial activities (fixing, preservation, taxonomy and catalogation) carried in the icthyological collection of the Centro Interdisciplinario de Ciencias Marinas are presented. This Icthyological stock carne from Baja California Sur; Concepción Bay (57 families and 146 species), La Paz Bay (84 families and 228 species), Magdalena Bay (65 families and 161 species), San Ignacio Lagoon (19 families and 29 species) and adjacent coasts of the Pacific ocean and Gulf of California (97 families and 244 species). There are however some specimens from other Mexican States and overseas México. This collection is important on a national level, and is the most complete for Mexican Pacific, accounting with 25000 organisms, integrated in 118 families, 270 genera and 403 species

Trophic spectrum of the california kingcroaker menticirrhus undulatus from ojo de liebre lagoon, baja california sur, mexico

A total of 112 stomach contents of the California kingcroaker Menticirrhus undulatus from Ojo de Liebre Lagoon, Baja California Sur (Mexico), were analyzed. The samples were taken from January to November 1995. This species occurred all year round, with highest abundance in July. The index of relative importance indicated that M. undulatus consumed a total of 14 species, and the dominant prey were polychaetes of the genus Marphysa spp. (51.75%), the fish Ilypnus gilberti (31.84%) and mollusk remains (13.91%). According to Levin's index, M. undulatus is considered a specialist predator, with preference for benthic fauna

Temporal and spatial variations in the structure of the rocky reef fish community of the southwest Gulf of California, Mexico

Many rocky reefs exist in the Gulf of California; however, there are few studies on the fish communities that inhabit them. In the present work, these communities are evaluated through visual censuses at four sites of the southwestem coast of the gulf. The specifíc richness, frequency, evenness and diversity were analyzed at each site. Seasonal changes and differences among the sites studied were also analyzed. A total of 76 species was registered. Five species were the most abundant in most of the zones and during the greater part of the study: Stegastes spp., Thalassoma lucasanum, Abudefduf troschelii, Chromis atrilobata and Haemulon maculicauda. Only the first three species were present in all censuses made. Differences were found in the structure of the communities between different seasons and between study sites; however, the diversity values had no significant differences. The zone with the greatest number of species was Cueva de León. A positive relationship was found between specific richness and temperature

Primer registro de Regalecus russellii (Shaw) (Pisces:Regalecidae ) de aguas mexicanas

Se describe un ejemplar joven de Regalecus russelli (Shaw) capturado en la Playa Tecolote, cerca de La Paz, Baja California Sur, el 16 de junio de 1985, y se presenta información sobre otros dos ejemplares de la misma especie que fueron vistos con anterioridad, uno en la localidad citada y el otro en Bahía de La Paz. Todo parece indicar que esta es la primera vez en que la especie se cita de aguas mexicana