Caracterización socio productiva y ambiental en la Comunidad de San Joaquín, Municipio El Tuma La Dalia II semestre 2015

El estudio caracterización socio productivo y ambiental en la comunidad San Joaquín Municipio El Tuma – La Dalia Matagalpa 2015 – 2016 se tomó en cuenta los siguientes objetivos. Analizar las características sociales, productivas y ambientales de la comunidad San Joaquín. La población sujeta de estudio fue 65 productores, la técnica de investigación una encuesta. Para el procesamiento de los datos se realizó una base datos en el programa spss versión 5, determinando porcentaje y frecuencia de los indicadores y para los gráficos el programa Excel, Se determinaron los siguientes resultados: Entre los productores encuestados el sexo que sobresale es el masculino, la edad más avanzada es de 79 años, el 79% tiene un nivel académico de primaria, su situación financiera es regular, cuentan con escuela de primaria y no existe ningún centro de salud. La principal actividad agrícola es la producción de granos básico (Arroz, maíz, frijol) con un rendimiento de 96,900 kg maíz, 88,000 kg frijol y 7,400 kg arroz, en cuanto a lo pecuario la producción de aves de patio con 655 y las dificultades encontradas son los bajos recursos económicos y los altos costos de insumos.La contaminación de las fuentes de agua se da por el uso de agroquímicos, no se le da manejo adecuado a las aguas mieles y la mayoría de los productores no practican ninguna obra de conservación de suelo en sus unidades productivas. Palabras claves: socio, productivo, ambiental, productores, comunida

Behavioral assays to assess the ability of G. marleyi to detect and preferentially differentiate between Caribbean reef fish hosts in John Brewers Bay, St Thomas, US Virgin Islands

Dataset: Behavioral assays of G. marleyiGnathiid isopods are common crustacean parasites that inhabit all oceans from shorelines to depths of over 3000 m and use chemical cues to find their marine fish hosts. While gnathiids are host-generalists, hosts vary in their susceptibility to infestation. However, the mechanisms that mediate differential susceptibility are unknown. Here we used laboratory experiments to investigate if the chemical attractiveness of hosts explains differences in susceptibility of Caribbean reef fishes to infestation by a common Caribbean gnathiid isopod, Gnathia marleyi. We showed that while G. marleyi can detect and locate hosts using only chemical cues, they do not exhibit a preference for chemical cues produced by more susceptible fish species. We conclude that species-specific chemical cues are not the main mechanism driving differences in host susceptibility to gnathiid isopod infestation and that visual or post-attachment factors such as ease of obtaining a blood meal are likely mediators.  For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/887279NSF Division of Ocean Sciences (NSF OCE) OCE-153679

Field experiments to determine the ability of gnathiid isopods to detect and locate Caribbean reef fish hosts using chemosensory cues in John Brewers Bay, St Thomas, US Virgin Island from June to August, 2019

Dataset: Field experiments of gnathiid isopods and Caribbean reef fish hostsGnathiid isopods are common crustacean parasites that inhabit all oceans from shorelines to depths of over 3000 m and use chemical cues to find their marine fish hosts. While gnathiids are host-generalists, hosts vary in their susceptibility to infestation. However, the mechanisms that mediate differential susceptibility are unknown. Here we used field experiments to investigate if the chemical attractiveness of hosts explains differences in the susceptibility of Caribbean reef fishes to infestation by a common Caribbean gnathiid isopod, Gnathia marleyi. We showed that while G. marleyi can detect and locate hosts using only chemical cues, they do not exhibit a preference for chemical cues produced by more susceptible fish species. We conclude that species-specific chemical cues are not the main mechanism driving differences in host susceptibility to gnathiid isopod infestation and that visual or post-attachment factors such as ease of obtaining a blood meal are likely mediators.  For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/887304NSF Division of Ocean Sciences (NSF OCE) OCE-153679

Differentially susceptible host fishes exhibit similar chemo-attractiveness to a common coral reef Ectoparasite

Gnathiid isopods are common crustacean parasites that inhabit all oceans from shorelines to depths of over 3000 m and use chemical cues to find their marine fish hosts. While gnathiids are host-generalists, hosts vary in their susceptibility to infestation. However, the mechanisms that mediate differential susceptibility are unknown. Here we used a combination of field and laboratory experiments to investigate if the chemical attractiveness of hosts explains differences in susceptibility of Caribbean reef fishes to infestation by a common Caribbean gnathiid isopod, Gnathia marleyi. We showed that while G. marleyi can detect and locate hosts using only chemical cues, they do not exhibit a preference for chemical cues produced by more susceptible fish species. We conclude that species-specific chemical cues are not the main mechanism driving differences in host susceptibility to gnathiid isopod infestation and that visual or post-attachment factors such as ease of obtaining a blood meal are likely mediator

Video S2 from Comparative behavioural observations demonstrate the ‘cleaner’ shrimp <i>Periclimenes yucatanicus</i> engages in true symbiotic cleaning interactions

Example video of a <i>Periclimenes yucatanicus</i> cleaning interaction in Curacao, Netherlands Antilles. Here <i>P. yucatanicus</i> can be seen cleaning a Blue Tang (<i>Acanthurus coeruleus</i>). Multiple flinches by the client indicates cheating by <i>P. yucatanicus</i>, and is met by no aggressive or retaliatory response by <i>A. coeruleus</i>

Vertical limits of host infestation by gnathiid isopods (Isopoda: Gnathiidae) parasitic on Caribbean coral reef fishes

Abstract Parasites play significant roles in the function of ecosystems and can make up a large proportion of overall biomass. Yet, fundamental aspects of their ecology are often understudied relative to other organisms. Gnathiid isopods are the primary ectoparasites of fishes in coral reef ecosystems. While some studies have investigated their host-detection capabilities, the means by which they seek hosts are largely unknown. Gnathiids are benthic and live on the bottom, and all collection efforts involving live hosts have thus far involved traps set at or near the reef substrate. We investigated the distance gnathiids will travel vertically in the water column to attach to a fish host. The majority of gnathiids collected were at or less than 1 m above the reef substrate, and gnathiids were collected in serially diminishing numbers at 2 and 3 m above it. No gnathiids were collected from any fish hosts set more than 3.5 m above the reef substrate. Results suggest that gnathiids will actively seek host fishes in situ and will travel further from their benthic habitat than previously known. By swimming into the water column, gnathiids can exploit larger, highly-mobile fishes, which can serve as a major source of dispersal