Sea turtles host a diverse array of epibionts, yet it is not well understood what factors influence epibiont community composition. To test whether epibiont communities of sea turtles are influenced by the hosts’ nesting or foraging habitats, we characterized the epibiota of leatherback, olive ridley and green turtles nesting at a single location on the Pacific coast of Costa Rica. We also compared the epibiota of these turtles to conspecific populations nesting elsewhere in the East Pacific. If epibiont communities are influenced by nesting habitats, we predicted that sympatrically nesting turtles would have comparable epibiont taxa. Alternatively, if epibiont communities are influenced by foraging habitats, we predicted the diversity of epibiont taxa should reflect the type and diversity of the hosts’ foraging habitats. We identified 18 epibiont taxa from 18 leatherback, 19 olive ridley and six green turtles. Epibiont diversity was low on leatherbacks (four taxa), but higher for olive ridley and green turtles (12 and nine epibiont taxa respectively). The epibiont communities of olive ridley and green turtles were not statistically different, but both were different from leatherbacks. In addition, conspecific sea turtles from other nesting locations hosted more similar epibiont communities than sympatrically nesting, non-conspecifics. We conclude that epibiont diversity of nesting sea turtles is partially linked to the diversity of their foraging habitats. We also conclude that the surface properties of the skin and carapace of these turtles may contribute to the uniqueness of leatherback turtle epibiont communities and the similarities between olive ridley and green turtle epibiont communities.

Porites panamensis is the scleractinian coral with the widest latitudinal distribution in the eastern tropical Pacific. Here, we report the occurrence of P. panamensis in an estuarine environment of the central Pacific coast of Colombia at the rocky reef of Los Negritos, Málaga Bay. Porites panamensis seems to withstand a wide range of environmental settings, including areas with unfavourable conditions for the survival of most other corals. Such wide tolerance may explain its broad latitudinal distribution in the eastern tropical Pacific.

Sea cucumbers (phylum Echinodermata) are common members of benthic communities in many marine ecosystems. They function as nutrient recyclers and bioturbators of soft bottoms, and are preyed upon by birds, fishes, mollusks, crustaceans and other taxa. In the Central Mexican Pacific, Islas Marietas harbours a complex and diverse community of corals and benthic invertebrates, with a particularly well-represented assemblage of echinoderms. However, little is known about the diversity of holothurians in the area. Between 2012 and 2014 a bimonthly census was conducted at Islas Marietas, and seven species were recorded for the first time at this location: Holothuria (Halodeima) inornata, Holothuria (Mertensiothuria) hilla, Holothuria (Platyperona) difficilis, Neocucumis veleronis, Lissothuria ornata, Afrocucumis ovulum and Pachythyone pseudolugubris. The absence of previous records of these species may be associated with their low densities and cryptic habits. This report acts to fill a critical knowledge gap in the distribution of holothurians in the eastern tropical Pacific and highlights the under-appreciated biodiversity of this Natural Protected Area.

Temporal variation of hyperiid amphipod structure assemblages was studied on Isla Gorgona, eastern tropical Pacific (ETP) off Colombia between September 2005 and August 2006. Forty-six species were found during the entire sampling period: Hyperioides sibaginis, Lestrigonus bengalensis, Phronimopsis spinifera, Tetrathyrus forcipatus and Paralycaea gracilis dominated the assemblage, representing 92%. The dendogram based on the Bray–Curtis similarity index showed that the hyperiid assemblages were separated into two groups, which did not coincide with the seasonality described for the ETP (wet versus dry season). Rather, groups comprised wet (May to November) and dry season months (December to April). The first group included November, December, February and March. During these months, significantly higher hyperiid richness, diversity and abundance were found, although colder subsurface water temperatures in Gorgona were registered only during February and March. The other group included May to October and January, and was characterized by lower hyperiid diversity and abundance values. Significant correlations were found between hyperiid abundance and the possible gelatinous zooplankton hosts (medusae, siphonophores and salps). This study contributes to increasing knowledge of the zooplankton community in the Panama Bight, as well as of a poorly studied group in the ETP.