Early naturalists suggested that predation intensity increases toward the tropics, affecting fundamental ecological and evolutionary processes by latitude, but empirical support is still limited. Several studies have measured consumption rates across latitude at large scales, with variable results. Moreover, how predation affects prey community composition at such geographic scales remains unknown. Using standardized experiments that spanned 115° of latitude, at 36 nearshore sites along both coasts of the Americas, we found that marine predators have both higher consumption rates and consistently stronger impacts on biomass and species composition of marine invertebrate communities in warmer tropical waters, likely owing to fish predators. Our results provide robust support for a temperature-dependent gradient in interaction strength and have potential implications for how marine ecosystems will respond to ocean warming.
During the TALUD XV research cruise off the southern part of the Baja California Peninsula, Mexico, samples of macro-invertebrates obtained in the deep-sea (296-2136 m) revealed a rich fauna of bivalves (17 species belonging to 10 families). The number of species per station varied from one to five. The richest families were Nuculidae, Nuculanidae, Neilonellidae, Limidae, and Cuspidariidae. Solemyidae, Lucinidae, Poromyidae, Verticordiidae, and Pectinidae were each represented by a single species. Some species groups need a thorough revision and were tentatively identified (Nuculana cf. hamata, Limatula cf. saturna). Significant new distribution information is provided for two species, both recorded for the first time from off western Mexico: Ennucula panamina with an extension of its known distribution over 20° of latitude north and Jupiteria callimene with an extension of 16° 42' of latitude to the north. One species (Ennucula taeniolata) is reported in shallower depth and one in deeper water (Acesta sphoni). New records are provided for an additional nine species. Environmental and habitat conditions are given for the first time for many of the bivalve species.
Eighteen species of deep-sea bivalves were collected below the Oxygen Minimum Zone (OMZ) core off western Mexico. This material was obtained during the research cruises XVI, XVIB (off the northwestern Peninsula of Baja California), and VIII (Gulf of California) of the TALUD project aboard the R/V El Puma. The samples were taken with an epibenthic sledge (710–2077 m deep) and with a box corer (750–2600 m). The species belong to 10 families: Solemyidae, Nuculanidae, Malletiidae, Tindariidae, Limopsidae, Propeamussiidae, Tellinidae, Periplomatidae, Poromyidae and Lyonsiellidae. Environmental parameters (oxygen, salinity, sediments composition and temperature) are given for each sampling station. Tolerance to oxygen depletion is analysed for all deep-water species collected by the TALUD survey off the Baja California Peninsula. The additional file includes shell characteristics and distributional information for each species.
Most species of Polyplacophora are found in shallow, coastal water, and their distribution and ecology is generally well known. On the contrary, information related with distribution, biology and ecology of deep-sea chitons is scarce. Specimens of the deep-sea mollusks fauna were obtained during sampling operations of western Mexico (TALUD project) aimed at the study of invertebrate fauna occurring under the Oxygen Minimum Zone (OMZ). The material reported herein is part of the Polyplacophora fauna collected with a benthic sledge off the west coast of the Baja California Peninsula, in the eastern Pacific, Mexico. The deep-sea chiton Tripoplax cf. balaenophila Schwabe & Sellanes 2004 was collected in 530–625 m depth, in the following environmental conditions: dissolved oxygen, <0.25 ml/l; temperature, 6.44 °C; salinity, 34.47. It represents a range extension of 63° of latitude (ca 8280 km) to the north for this species previously known only from the type locality, off Concepción, Chile. Tripoplax cf. balaenophila is associated with the lower boundary of the Minimum Oxygen Zone occurring off western Mexico, an habitat characterized by severe hypoxic conditions and colonized by well-adapted species that are generally abundant. Assignment of species to Tripoplax or Lepidozona is still a conflictive issue. The existing discrepancy in slit number and the assignment of “balaenophila” to Tripoplax cannot be solved without a more thorough review of both genera. The disjunct distribution of the genera Tripoplax in the eastern Pacific is also an interesting biogeographical issue.
Autonomous reef monitoring structures (ARMS) have been proposed as a standardized, passive, nondestructive sampling tool. This study assessed the ability of ARMS to capture the cryptic species diversity of two coral reefs by recording species richness and taxonomic representativeness using conventional taxonomy. The capacity of ARMS, as artificial substrates, to favor the establishment of nonindigenous species over native species was also evaluated. The use of ARMS allowed the detection of 370 species morphotypes from nine phyla, yielding 13 new records of geographic distribution expansion, one exotic species for the Gulf of México and the Caribbean Sea, and six newly described species. It was also possible to make spatial comparisons of species richness between both reefs. ARMS captured cryptic diversity exceptionally well, with the exception of echinoderms. Furthermore, these artificial structures did not hinder the colonization ability of native species; in fact, the colonization patterns on the structures themselves represented the spatial differences in the structure of benthic assemblages. This study represents the first effort to make a conventional taxonomic description of the cryptic fauna of the Yucatan Peninsula using ARMS. It is recommended to assess coral reef species diversity, but more taxonomists specialized in marine invertebrates are needed.
27 February 2023 in Journal of the Marine Biological Association of the United Kingdom
Molluscs are a diverse phylum in coastal lagoons because the numerous taxa collectively display broad ranges of optima and tolerance with respect to ambient conditions. We report on the taxonomic composition, habitat preferences and feeding guilds of molluscs from Río Lagartos coastal lagoon, Mexico. Molluscs were collected in the rainy season (September/October 2017), during the winter (Nortes) season (February 2018) and at the end of the warm, dry season (May 2018). Samples were taken using a Ponar dredge, a cylindrical PVC core barrel, or a beach seine. We studied the abiotic characteristics (sediment grain-size distributions, submersed aquatic vegetation abundance and salinity) to explore assemblage differences across the broad salinity gradient that characterizes the system (~30–78 PSU). Molluscs were represented by 39 species, 34 genera, 23 families and two classes. Stenohaline species were more numerous overall than euryhaline species, but their occurrence in samples was low (35 years ago. Species accumulation curves revealed that the full species richness was not captured in our study. Euhaline environments displayed greater mollusc species richness and had a larger proportion of amount (mass) of submersed aquatic vegetation. In the hypersaline environments, species richness may be favoured by the lower dominance of sands. Suspension feeders were the most diverse group in both the euhaline and hyperhaline environments.