Euryphorus suarezi n. sp. (Copepoda: Caligidae) parasitic on an elasmobranch from the Gulf of Mexico.

Currently, the caligid genus Euryphorus Milne Edwards, 1840 contains two valid species. A new species, Euryphorus suarezi, is described based on adult females and males collected from the spotted eagle ray Aetobatus narinari (Euphrasen) (Elasmobranchii: Myliobatidae), captured off Campeche and Tabasco, Mexico (southern coast of the Gulf of Mexico). The new species is mainly distinguished from its congeners by the absence of dorsal plates, the presence of postantennal process, bifurcated maxillule, maxilliped with slender corpus, and leg 4 with 3-segmented endopod. Leg 6 is conspicuous in the male. Additional differences are described. This is the first record of a species of Euryphorus from an elasmobranch host, which may provide insight into the evolutionary relationships within the Caligidae.

Application of ecotoxicological tools to evaluate the quality status of mangroves under restoration in the Yucatán Peninsula, Mexico.

Ecotoxicological tools, namely biomarkers and bioassays, may provide insights on the ecological quality status of mangroves under restoration. We investigated how 1) physicochemical parameters and water bioassays using Artemia franciscana; and 2) quantification of sublethal (osmoregulatory capacity, biochemical, and oxidative stress) and individual biomarkers (density, length-weight relationship [LWR], parasitic prevalence) in the sentinel fiddler crab Minuca rapax, can improve restoration indicators in mangroves from the Yucatán Peninsula, Southern Gulf of Mexico. We showed that water quality was improved with restoration, but still presented toxicity. Regarding sublethal biomarkers, M rapax from restored areas lower osmotic regulatory capacity, higher oxidative stress, and showed lipid peroxidation. As to the individual biomarkers, the density, LWR, and the prevalence of parasites in M. rapax was higher in restored areas. The use of bioassays/biomarkers were useful as early warning indicators to better assess the health of mangroves under restoration.

Microplastic distribution in urban vs pristine mangroves: Using marine sponges as bioindicators of environmental pollution.

Sessile benthic organisms are considered good bioindicators for monitoring environmental quality of coastal ecosystems. However, these environments are impacted by new pollutants such as microplastics (MPs), where there is limited information about organisms that can be used as reliable bioindicators of these emerging contaminants. We evaluated MP concentrations in three compartments: surface sediment, water and in three marine sponge species (Haliclona implexiformis, Halichondria melanadocia and Amorphinopsis atlantica), to determine whether these organisms accumulate MPs and reflect their possible sources. Results showed MPs in all three compartments. Average concentrations ranged from 1861 to 3456 items kg-1 of dry weight in marine sponges, 130 to 287 items L-1 in water and 6 to 11 items kg-1 in sediment. The maximum MP concentration was in the sponge A. atlantica, which registered 5000 items kg-1 of dry weight, in water was 670 items L-1 and in sediment was 28 items kg-1, these values were found in the disturbed study area. The three sponge species exhibited MP bioaccumulation and showed significant differences between disturbed and pristine sites (F = 11.2, p < 0.05), suggesting their use as bioindicators of MP.

Parasites of two coexisting invasive sailfin catfishes (Siluriformes: Loricariidae) in a tropical region of Mexico

Currently many species of Amazon sailfin catfishes (Loricariidae) have been introduced to wild environments outside their native range. There is, however, little knowledge about their role as vectors of parasites that can infect native fish or even humans through its consumption. The aim of the present study was to determine the parasitic fauna of the invasive sailfin catfish species Pterygoplichthys pardalis (leopard pleco) and P. disjunctivus (vermiculated pleco) from freshwater systems in the southeast of Mexico. Four ectoparasite species were found in P. pardalis (1 protozoan: Ichthyophthirius multifiliis ; 2 monogeneans: Urocleidoides vaginoclastrum and Heteropriapulus heterotylus ; 1 digenean: Clinostomum sp.), and only one in Heteropriapulus disjunctivus (H. heterotylus ). No endoparasites were found. Ichthyophthirius multifiliis , U. vaginoclaustrum and Clinostomum sp. , were considered as rare species (prevalence <5%) since they were found in a single individual of P. pardalis . H. heterotylus was the only species shared among both host species and it occurs throughout the year. This monogenean species represents 96% of total parasites recorded in P. pardalis and 100% in P. disjunctivus. Monthly values of prevalence, intensity and abundance of H. heterotylus in both host species showed important intra-annual variations, but not differ significantly between both hosts.(AU)

Actualmente muchas especies de peces conocidos como plecos o peces diablo (Loricariidae) han sido introducidas en ambientes silvestres fuera de su área de distribución natural. Sin embargo, hay poco conocimiento acerca de su papel como vectores de parásitos que puedan infectar a los peces nativos o incluso los seres humanos a través de su consumo. El objetivo del presente estudio fue determinar la fauna parasitaria de las especies de plecos Pterygoplichthys pardalis (pleco leopardo) y P. disjunctivus (pleco vermiculado) en sistemas de agua dulce del sureste de México. Fueron encontradas cuatro especies de ectoparásitos en P. pardalis (1 protozoario: Ichthyophthirius multifiliis ; 2 monogeneos: Urocleidoides vaginoclastrum y Heteropriapulus heterotylus ; 1 digeneo: Clinostomum sp.) y una en P. disjunctivus (H. heterotylus ). No se encontraron endoparásitos. Ichthyophthirius multifiliis, U. vaginoclaustrum y Clinostomum sp. fueron consideradas como especies raras (prevalencia <5%), ya que estuvieron en un solo individuo de P. pardalis . Heteropriapulus heterotylus fue la única especie compartida entre ambas especies de peces y que estuvo presente durante todo el año, y representó el 96% del total de parásitos registrados en P. pardalis y el 100% en P. disjunctivus. La prevalencia, intensidad media y abundancia media de H. heterotylus mostraron importantes variaciones intra-anuales en ambas especies de peces, pero no difirió significativamente entre ambos hospederos.(AU)