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Elevation and anthropopression are important factors affecting terrestrial water bear dynamics. In the present study, we characterize the taxonomic composition, diversity, and community structure of tardigrades along an elevational gradient with different anthropopression in Alturas de Boniato, Santiago de Cuba. Samples were collected in four sampling sites and all tardigrades were extracted. Alpha diversity indices were calculated. Hierarchical community organization was determined and variation among sampling sites was calculated using the Jaccard index for beta diversity. Some variables that influenced composition and taxon diversity were also evaluated. A total of 413 tardigrades belonging to seven taxa and five eggs were found. The most abundant taxa were Paramacrobiotus sp., Macrobiotus sp. and Milnesium sp. 1. Differences between sampling sites were largely due to turnover, especially at the higher-elevation sites. Nesting characterized the lower-elevation sites. The variables that had the greatest influence on species composition were anthropopression and a mixture of various macro- and microenvironmental variables.

Los tardígrados u osos de agua son un grupo de invertebrados microscópicos que habitan en ambientes acuáticos y terrestres, y de manera frecuente en los briófitos. El grupo ha sido poco estudiado en Cuba, los trabajos de tardígrados son meramente taxonómicos y no evalúan los patrones de abundancia y diversidad de las comunidades. El propósito de esta investigación fue analizar la diversidad de tardígrados asociados a musgos en el Jardín de los Helechos en Santiago de Cuba. Para esto se realizaron curvas de acumulación de especies utilizando diversos estimadores de riqueza, se determinaron las diversidades alfa observada y estimadas, se estableció el orden jerárquico de la comunidad y se evaluó el patrón de abundancia mediante curvas de Whittaker. Se encontraron 34 tardígrados pertenecientes a las clases Heterotardigrada y Eutardigrada, los géneros presentes fueron Echiniscus, Milnesium, Mesobiotus y Macrobiotus con un total de 8 morfoespecies identificadas. El morfo dominante fue Macrobiotus sp. 1, mientras que Echiniscus sp., Mesobiotus sp. 2 y Mesobiotus sp. 3 resultaron ser especies raras. La curva de rango-abundancia indicó una comunidad equitativa.

Se identifican las algas epibióticas en tres braquiuros que habitan en pocetas intermareales. Los braquiuros se recolectaron mediante buceo SCUBA y se le retiraron todas las algas presentes en el exoesqueleto. Se identifican 15 algas epibióticas sobre Macrocoeloma trispinosum (Latreille, 1825), Omalacantha bicornuta (Latreille, 1825) y Actaea bifrons Rathbun, 1898. Las especies más frecuentes son algas filamentosas y pequeñas de las familias Ceramiaceae y Cladophoraceae. Las algas Sphacelaria tribuloides y Cladophora catenate se identificaron sobre los exoesqueletos de las tres especies de braquiuros.

Se caracterizan las relaciones tróficas de Diadema antillarum Philippi, 1845, Lytechinus variegatus (Lamarck, 1816) y Echinometra viridis A. Agassiz, 1863, mediante la riqueza y diversidad tróficas, amplitud y solapamiento del nicho y sus estrategias de alimentación. Se recolectaron al azar 31 individuos adultos para el análisis del contenido estomacal (D. antillarum = 13, L. variegatus = 13 y E. viridis = 5). En la dieta se identificaron 28 recursos tróficos y el 57% fueron vegetales. A partir de la amplitud del nicho trófico se concluye que estas especies son consumidores generalistas y su dieta se basa principalmente en recursos tróficos vegetales. Los recursos más abundantes en la dieta fueron las algas filamentosas Polysiphonia y Oscillatoria. Las estrategias de alimentación muestran variaciones interindividuales en el uso de los recursos tróficos y la compartimentación del nicho, lo que presupone la coexistencia sin competencia de sus poblaciones.

We investigated the distribution of epiphytic macroalgae on the thalli of their hosts at eight localities along the southeastern coast of Cuba between June 2010 and March 2011. We divided he epiphytes in two groups according to their distribution on the host: those at the base of the thallus and those on its surface. We determining the dissimilarity between the zones and the species involved. We identified 102 taxa of epiphytic macroalgae. There were significant differences between the two zones. In 31 hosts, the number of epiphytes was higher on the surface of the thallus, whereas the number of epiphytes was higher at the thallus base in 25 hosts, and the epiphytes were equally distributed between the two zones in five hosts (R=−0.001, p=0.398). The mean dissimilarity between the two zones, in terms of the species composition of the epiphytic macroalgae, was 96.64%. Hydrolithon farinosum and Polysiphonia atlantica accounted for 43.76% of the dissimilarity. Among macroalgae, the structure of the thallus seems to be a determinant of their viability as hosts for epiphytes.

Se determino la composicion floristica de microalgas epifitas sobre Ulva spp. en la Bahia de Santiago de Cuba. Para ello, se hicieron muestreos en cinco localidades (Alameda, Punta Sal, Belmare, Caracoles, Cayo Granma) ubicadas segun el gradiente de contaminacion del ecosistema, de febrero a mayo de 2007. Se identificaron 27 especies de microalgas pertenecientes a 24 generos y 3 divisiones sobre Ulva lactuca, U. fasciata, U. flexuosa y U. rigida . La taxocenosis de microalgas epifitas estuvo dominada por cinco especies de diatomeas ( Cocconeis pinnata, Eunotia sp., Licmophora lyngbyei, Pinnularia sp., Navicula sp.) y dos de cianoficeas ( Anabaena lemmermannii y Oscillatoria limosa ). La mayor riqueza de especies epifitas se observo en febrero y marzo; su distribucion parece condicionada por la abundancia y distribucion del sustrato, la forma del talo, y el nivel de contaminacion. En la bahia, la menor riqueza de microalgas epifitas se presento en el lobulo interior (Alameda y Punta Sal), y la mayor hacia el lobulo exterior (Belmare, Caracoles y Cayo Granma). Spatial variation of epiphytic microalgae composition in Ulva spp. (Chlorophyta: Ulvaceae) in the Santiago de Cuba bay The floristic composition of epiphytic microalgae on Ulva spp. in the bay of Santiago de Cuba was determined. Sampling was carried out in five locations (Alameda, Punta Sal, Belmare, Cayo Caracoles and Granma) located according to a pollution gradient, from February to May 2007. We identified 27 species belonging to 24 genera and 3 divisions, on Ulva lactuca, U. fasciata, U. flexuosa and U. rigida . The taxocoenosis of epiphytic microalgae was dominated by five species of diatoms ( Cocconeis pinnata, Eunotia sp. Licmophora lyngbyei, Pinnularia sp., Navicula sp.) and two of the blue-green algae ( Anabaena lemmermannii and Oscillatoria limosa ). The greatest richness of epiphytic species was recorded on February and March. Their distribution seems to be conditioned by abundance and distribution of the substrate, thallus shape and contamination level. The lowest richness of epiphytic microalgae was observed in Alameda and Punta Sal (the interior lobe of the bay), which are more contaminated, and a higher richness was observed in healthier localities: Belmare, Cayo Caracoles and Granma, from the outer lobe.

Marine crustaceans constitute one of the best studied groups in the Cuban waters. However, the level of systematic knowledge about them differs among the ecoregions of the platform. This paper presents the systematic list of hermit, porcelain and brachyuran crabs of the coast of Santiago de Cuba, on the southeast platform of Cuba. The records of the species have been compiled between 2009 and 2013, in ten locations, which differ in the type of habitats. Additional material was examined in the collection of the Universidad de Oriente Museum Charles Ramsdem. Eighty-one species are represented (seven hermits, eight porcelains and sixty-six true crabs). Data on their local and global distribution, their habitat, and notes on their reproductive period and fishing use are also provided.

El objetivo del presente trabajo es el estudio del género Callinectes en la zona costera del municipio de Santiago de Cuba. Se realizó una recolecta de 257 ejemplares durante marzo de 2007 a abril de 2008, en ocho estaciones a lo largo de la costa. El género resultó estar ampliamente distribuido en el litoral y representado al menos por cuatro especies: C. sapidus, C. similis, C. rathbunae y C. larvatus, las dos últimas no incluidas en la lista publicada de crustáceos (Crustacea: Decapoda) cubanos. Las especies más abundantes resultaron ser C. sapidus y C. similis. C. rathbunae fue la más ampliamente distribuida. El análisis del contenido estomacal permitió identificar nueve categorías alimentarias, siendo las más importantes los peces y las macroalgas. Las especies de Callinectes tienen un amplio espectro trófico; comen no sólo lo disponible, sino también lo más abundante.Biodiversity, morphometry and diet of Callinectes crabs (Decapoda: Portunidae) in Santiago de Cuba. On the basis of fishery intensity and proximity to river mouth, a total of 257 swimming Callinectes crabs were collected from March 2007 to April 2008 in eight localities. Captures were made with hanging nets, to a maximal depth of 1.5m, establishing a top time of 2 hr. The genus was widely distributed, and it is represented at least by four species: C. sapidus, C. similis, C. rathbunae and C. larvatus, the last two not included in the last list of Cuban crustaceans (Crustacea: Decapoda). The size and shape of the gonopods were very useful as taxonomical criteria, considering the prevalence of males. The most abundant species were C. sapidus (47.08%), and C. similis (30.35%). C. rathbunae, which was identified at 75% (6) of the localities, showed a better distribution, followed by C. sapidus, which appears in the 63% (5). Sex rate (Rs) by species (male:female) was 6.20 for C. rathbunae, 3.58 for C. similis, 1.40 for C. larvatus and 0.40 for C. sapidus. The most abundant species had a lower Rs value. Morphometrical analysis and weight allowed us to know the average carapace width (CW) and weight (W). C. sapidus had an average CW = 110.57 mm (DS 21.55, n = 121) and W = 84.46 g (SD 43.25, n = 121); C. rathbunae a CW = 115.50 mm (DS 14.94, n = 36) and W = 140.44 g (DS 55.02, n = 36); C. larvatus a CW = 76.04 mm (DS 10.88, n = 22) and W = 31.70 g (DS 14.67, n = 22); and C. similis had the minimal parameter values, with a CW = 59.77 mm (DS 14.09, n = 78) and W = 13.80g (DS 10.00, n = 78). These are the first records of the coastal crabs in the area. All values are lower than in previous reports. The largest individuals (CW>140 mm: C. rathbunae and C. sapidus) were captured in localities with adequate environmental characteristics. The stomach content suggests nine dietary categories, mainly fishes and macroalgae. The genus Callinectes has a diversified trophic spectrum. These crabs eat the available food, but they have a preference for the most abundant items. Rev. Biol. Trop. 57 (3): 671-686. Epub 2009 September 30.