Lichen community structure and richness in three mid-elevation secondary forests in Costa Rica / Estructura y riqueza de la comunidad liquénica de tres bosques secundarios de elevación media en Costa Rica

Abstract Introduction: Lichen diversity, community structure, composition and species abundance have been used as indicators of the integrity and ecological continuity of tropical forest ecosystems. Objectives: To assess corticolous lichen species composition, diversity, and ecological importance of three forested stands differing in time of abandonment as indicators of how passive restoration influences the lichen community assemblage. Methods: We surveyed individual lichens on tree stems of a reference old secondary forest and a young secondary forest (50 and 14-year-old natural regeneration after pasture abandonment, respectively), and in a 35-year-old exotic cypress tree plantation, in the oriental Central Valley, in Orosí, Costa Rica. Standard diversity, similarity indexes, and the importance value index were calculated. An NMDS analysis was performed on the community structure parameters and in a presence-absence matrix. Results: We found 64 lichen species in 25 families with 42, 21, and 23 species, and 20, 10, and 15 families, in the young and old secondary forests, and the cypress plantation, respectively. Cryptothecia sp. possessed the highest importance across sites. More than 87 % of the species are rare. The combined IVI of the top three families were: 36, 48.5, and 74.8 % in the young and old forests and the Cypress plantation sites, respectively. Overall, Arthoniaceae is in the top three families. The young forest had the highest species richness, but the old forest presented the best evenness. Similarity and diversity indexes suggest a particularly low resemblance in the lichen communities but a smooth gradient differentiation between the three forests, which was confirmed by the NMDS test. The homogeneity test identified great differences in ecological importance and composition. Conclusions: This region contains a distinctive assemblage of species resulting in a strong community differentiation by site, reflecting the influence of ecophysiological and microclimatic factors that define lichen establishment and survival and suggesting a great regional beta diversity, within a fragmented landscape. Greater connectivity and passive restoration strategies resulted in greater diversity and a more heterogeneous community structure on both forests than the corticolous community of the abandoned plantation. Protection of forest fragments will maximize the integrity of future forests.

Resumen Introducción: La diversidad de líquenes, la estructura y composición de la comunidad y la abundancia de algunas especies y familias se ha usado como indicadores de la salud y continuidad ecológica de los ecosistemas boscosos tropicales. Objetivos: Evaluar la composición, diversidad e importancia ecológica de las especies de líquenes en tres ecosistemas boscosos que difieren en el tiempo regeneración natural, como indicadores de la influencia de la restauración pasiva en el ensamble de la comunidad de líquenes cortícolas. Métodos: Se midieron los líquenes individuales sobre los troncos de árboles en un bosque secundario avanzado (OF), en un bosque secundario joven (YF, con 50 y 14 años de regeneración natural tras abandono del potrero, respectivamente), y en una plantación abandonada de ciprés exótico con 35 años de edad (CP), en la región oriental del Valle Central de Costa Rica. Se calcularon los índices estándares de diversidad, similitud y valor de importancia (IVI), además de un análisis de NMDS sobre los parámetros de la estructura de la comunidad en una matriz de presencia-ausencia. Resultados: Encontramos 64 especies en 25 familias, con 42, 23 y 21 especies y 20, 10 y 15 familias en los sitios YF, CP y OF, respectivamente. Una especie de Cryptothecia sp. presentó el IVI más alto en los tres bosques. Más del 87 % de las especies son raras. El IVI combinado de las tres familias más importantes fue: 36, 48.5 y 74.8 % en los sitios: YF, OF y CP, respectivamente. Arthoniaceae está entre las tres familias más importantes en los tres sitios. El YF es el sitio con más especies, pero el sitio OF presentó la mayor igualdad. Los índices de similitud y diversidad sugieren una semejanza particularmente baja entre las comunidades liquénicas, pero separadas por una gradiente de diferenciación difusa entre los tres sitios, lo cual es confirmado por el análisis NMDS. La prueba de homogeneidad confirmó grandes diferencias en la importancia ecológica y la composición. Conclusiones: La región contiene un ensamblaje propio de especies que resulta en una fuerte diferenciación comunitaria entre bosques, reflejo de la influencia de factores ecofisiológicos y microclimáticos en el establecimiento y supervivencia de líquenes; lo que sugiere una gran diversidad beta regional, en un paisaje fragmentado. Una mayor conectividad y estrategias de restauración pasiva dieron como resultado una mayor diversidad y una estructura comunitaria más heterogénea en ambos bosques que la comunidad cortícola de la plantación exótica abandonada. La protección de fragmentos forestales maximizará la integridad de los bosques futuros.

Illumina high-throughput sequencing reveals fungal community composition and diversity in root rot of Coptis chinensis in rhizosphere soil / 中草药

Objective To reveal fungal community composition and diversity in health and root rot of Coptis chinensis in rhizosphere soil. Methods High-throughput sequencing technology was used to characterize the fungal community composition, richness, and diversity of health and root rot Coptis chinensis in rhizosphere soil in Shizhu County of Chongqing Province. Spearman analysis was used to evaluate the correlation between soil physicochemical parameters and the first 35 most abundant fungal genera. Results More than 106 267 effective tags were obtained, and the community was composed of six phyla (Ascomycota, Zygomycota, Basidiomycota, Glomeromycota, Chytridiomycota, and Neocallimastigomycota). The fungal community diversity showed no significant difference in healthy and root rot samples. The relative abundance of Ascomycota, Basidiomycota and Chytridiomycota in root rot soil was significantly higher than that in healthy soil. Moreover, the relative abundance of Zygomycota, Glomeromycota, and Neocallimastigomycota in root rot soil was significantly lower than in healthy soil. The relative abundance of Fusarium was significantly higher in root rot samples than in healthy samples. Spearman analysis showed that the relative abundance of Fusarium was significantly positively correlated with pH and available phosphorus, but negatively correlated with alkali-hydrolyzable nitrogen. Conclusion Changes in soil physicochemical characteristics were related to the changes in soil fungal diversity.

Habitat conditions drive phylogenetic structure of dominant bacterial phyla of microbialite communities from several locations in Mexico / Las condiciones del hábitat determinan la estructura filogenética de filos (phyla) bacterianos dominantes de comunidades de microbialitos de diferentes regiones en México

Abstract:Community structure and composition are dictated by evolutionary and ecological assembly processes which are manifested in signals of, species diversity, species abundance and species relatedness. Analysis of species coexisting relatedness, has received attention as a tool to identify the processes that influence the composition of a community within a particular habitat. In this study, we tested if microbialite genetic composition is dependent on random events versus biological/abiotical factors. This study was based on a large genetic data set of two hypervariable regions (V5 and V6) from previously generated barcoded 16S rRNA amplicons from nine microbialite communities distributed in Northeastern, Central and Southeastern Mexico collected in May and June of 2009. Genetic data of the most abundant phyla (Proteobacteria, Planctomycetes, Verrucomicrobia, Bacteroidetes, and Cyanobacteria) were investigated in order to state the phylogenetic structure of the complete communities as well as each phylum. For the complete dataset, Webb NTI index showed positive and significant values in the nine communities analysed, where values ranged from 31.5 in Pozas Azules I to 57.2 in Bacalar Pirate Channel; meanwhile, NRI index were positive and significant in six of the nine communities analysed with values ranging from 18.1 in Pozas Azules I to 45.1 in Río Mesquites. On the other hand, when comparing each individual phylum, NTI index were positive and significant in all groups, except in Cyanobacteria for which positive and significant values were only found in three localities; finally, NRI index was significant in only a few of the comparisons performed. The results suggest that habitat filtering is the main process that drives phylogenetic structure in bacterial communities associated to microbialites with the exception of Cyanobacteria where different lineages can contribute to microbialite formation and growth. Rev. Biol. Trop. 64 (3): 10571065. Epub 2016 September 01.

ResumenLa estructura y composición de las comunidades son determinadas por procesos evolutivos y ecológicos que se manifiestan en señales de diversidad, abundancia y la relación de especies. El análisis de la relación de especies que coexisten ha recibido atención como una herramienta para identificar los procesos que influyen en la composición de una comunidad dentro de un hábitat particular. En este estudio, evaluamos si la composición genética de bacterias microbialíticas depende de acontecimientos al azar vs factores biológicos/ abióticos. Este estudio se basa en un conjunto de datos genéticos de dos regiones hipervariables (V5 y V6) de gen 16S rRNA generados previamente de nueve comunidades de microbialitos distribuidos en el Noreste, Centro y Sureste de México, recolectados en mayo y junio 2009. Los datos genéticos de los filos más abundantes (Proteobacteria, Planctomycetes, Verrucomicrobia, Bacteroidetes y Cyanobacteria) fueron analizados para determinar la estructura filogenética de la comunidad y de cada filo por separado. Para el análisis conjunto, el índice NTI de Webb mostró valores positivos y significativos en las nueve comunidades analizadas, en donde los valores oscilaron entre 31.5 en Pozas Azules I y 57.2 en el Canal Pirata en Bacalar; en contraste, los valores del índice NRI fueron positivos y significativos en seis de las nueve comunidades analizadas con valores oscilando desde 18.1 en Pozas Azules I hasta 45.1 en Río Mezquites. Por otro lado, en la comparación de cada filo individual, el índice NTI fue positivo y significativo en todos los grupos excepto en Cyanobacteria, en donde valores positivos y significativos fueron encontrados sólo en tres localidades; finalmente, el índice NRI fue significativo sólo en unas cuantas de las comparaciones realizadas. Los resultados sugieren que el filtrado del hábitat es el proceso principal que determina la estructura filogenética de las comunidades bacterianas asociadas a microbialitos con la excepción de las cianobacterias en donde diferentes linajes pueden contribuir a la formación y crecimiento del microbialito.

Community composition and diversity of endophytic fungi from roots of Sinopodophyllum hexandrum in forest of Upper-north mountain of Qinghai province / 中国中药杂志

High throughput sequencing technology is also called Next Generation Sequencing (NGS), which can sequence hundreds and thousands sequences in different samples at the same time. In the present study, the culture-independent high throughput sequencing technology was applied to sequence the fungi metagenomic DNA of the fungal internal transcribed spacer 1(ITS 1) in the root of Sinopodophyllum hexandrum. Sequencing data suggested that after the quality control, 22 565 reads were remained. Cluster similarity analysis was done based on 97% sequence similarity, which obtained 517 OTUs for the three samples (LD1, LD2 and LD3). All the fungi which identified from all the reads of OTUs based on 0.8 classification thresholds using the software of RDP classifier were classified as 13 classes, 35 orders, 44 family, 55 genera. Among these genera, the genus of Tetracladium was the dominant genera in all samples(35.49%, 68.55% and 12.96%).The Shannon's diversity indices and the Simpson indices of the endophytic fungi in the samples ranged from 1.75-2.92, 0.11-0.32, respectively.This is the first time for applying high through put sequencing technol-ogyto analyze the community composition and diversity of endophytic fungi in the medicinal plant, and the results showed that there were hyper diver sity and high community composition complexity of endophytic fungi in the root of S. hexandrum. It is also proved that the high through put sequencing technology has great advantage for analyzing ecommunity composition and diversity of endophtye in the plant.

Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems

Abstract Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC) has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems.

Resumo A identidade e a composição do recurso estruturam a comunidade bacteriana, que, por sua vez, determina a magnitude dos processos bacterianos e seus serviços ecológicos. Porém, a complexa interação entre a identidade do recursos e a composição da comunidade bacteriana (CCB) tem sido pouco avaliada até o momento. Utilizando microcosmos aquáticos, nós testamos quando e como a identidade do recurso interage com a CCB na regulação da respiração bacteriana e da diversidade funcional bacteriana. Diferentes lixiviados de macrófitas aquáticas foram utilizados como diferentes fontes de carbono, enquanto que a CCB foi manipulada através de mudanças sucessionais das populações bacterianas em culturas de recrescimento. Nós observamos que tratamentos com a mesma CCB respiraram diferentemente em cada fonte de carbono; diferentes fontes também suportaram diferentes valores de diversidade funcional bacteriana. Não houve padrão linear claro de mudança na respiração bacteriana em relação ao tempo de sucessão das comunidades bacterianas nos lixiviados, i.e. diferenças na respiração bacteriana entre diferentes CCB foram idiossincráticas. A identidade do recurso regulou a magnitude da respiração, em cada CCB, e.g. o lixiviado de Ultricularia foliosa sustentou os maiores valores de diversidade funcional bacteriana e as menores taxas de respiração bacteriana em todas as CCB. Nós concluímos que a identidade do recurso e a CCB interagem afetando o padrão e a magnitude da respiração bacteriana em ecossistemas aquáticos.

Interaction between resource identity and bacterial community composition regulates bacterial respiration in aquatic ecosystems / A interação entre a identidade do recurso e a composição da comunidade bacteriana regula a respiração bacteriana em ecossistemas aquáticos

Abstract Resource identity and composition structure bacterial community, which in turn determines the magnitude of bacterial processes and ecological services. However, the complex interaction between resource identity and bacterial community composition (BCC) has been poorly understood so far. Using aquatic microcosms, we tested whether and how resource identity interacts with BCC in regulating bacterial respiration and bacterial functional diversity. Different aquatic macrophyte leachates were used as different carbon resources while BCC was manipulated through successional changes of bacterial populations in batch cultures. We observed that the same BCC treatment respired differently on each carbon resource; these resources also supported different amounts of bacterial functional diversity. There was no clear linear pattern of bacterial respiration in relation to time succession of bacterial communities in all leachates, i.e. differences on bacterial respiration between different BCC were rather idiosyncratic. Resource identity regulated the magnitude of respiration of each BCC, e.g. Ultricularia foliosa leachate sustained the greatest bacterial functional diversity and lowest rates of bacterial respiration in all BCC. We conclude that both resource identity and the BCC interact affecting the pattern and the magnitude of bacterial respiration in aquatic ecosystems.

Resumo A identidade e a composição do recurso estruturam a comunidade bacteriana, que, por sua vez, determina a magnitude dos processos bacterianos e seus serviços ecológicos. Porém, a complexa interação entre a identidade do recursos e a composição da comunidade bacteriana (CCB) tem sido pouco avaliada até o momento. Utilizando microcosmos aquáticos, nós testamos quando e como a identidade do recurso interage com a CCB na regulação da respiração bacteriana e da diversidade funcional bacteriana. Diferentes lixiviados de macrófitas aquáticas foram utilizados como diferentes fontes de carbono, enquanto que a CCB foi manipulada através de mudanças sucessionais das populações bacterianas em culturas de recrescimento. Nós observamos que tratamentos com a mesma CCB respiraram diferentemente em cada fonte de carbono; diferentes fontes também suportaram diferentes valores de diversidade funcional bacteriana. Não houve padrão linear claro de mudança na respiração bacteriana em relação ao tempo de sucessão das comunidades bacterianas nos lixiviados, i.e. diferenças na respiração bacteriana entre diferentes CCB foram idiossincráticas. A identidade do recurso regulou a magnitude da respiração, em cada CCB, e.g. o lixiviado de Ultricularia foliosa sustentou os maiores valores de diversidade funcional bacteriana e as menores taxas de respiração bacteriana em todas as CCB. Nós concluímos que a identidade do recurso e a CCB interagem afetando o padrão e a magnitude da respiração bacteriana em ecossistemas aquáticos.

Composition and diversity of Acaroid mites’communities in indoor environ-ments of kindergartens in Wuhu City / 中国血吸虫病防治杂志

Objective To understand the breeding situation of Acaroid mites in indoor environments of kindergartens in Wuhu City so as to provide the evidence for its prevention and control. Methods From March to June and September to De?cember in 2014 dust samples were collected from 15 kindergartens of 3 ranks every month. Acaroid mites in the samples were isolated identified and counted. Results Totally 360 samples were selected and 169 samples 46.94% had mite infestation. Pyroglyphidae accounted for the most in the population with the breeding rate of 45.00%. Totally 18 504 mites were found and Dermatophagoides farina and Dermatophagoides pteronyssinus were the dominant species with the composition ratios of 30.21%5 590 mites and 17.83% 3 300 mites respectively. The third?ranked kindergartens were in the most serious situation con?cerning with 81.67% 98/120 of the breeding rate of Acaroid mites. The differences were statistically significant among the kin?dergartens with different ranks F=6.048 χ2=73.523 both P0.05 . Conclusion Acaroid mites in the kindergartens in Wuhu City were in serious condition and the population and species composition of Acaroid mite community is influenced by the human behavior and indoors environments.

A distinctive avian assemblage (Aves: Passeriformes) in Western Darién, Panama is uncovered through a disease surveillance program / Un conglomerado distinto de aves (Aves: Passeriformes) descubierto en el Darién occidental, Panamá por un programa de vigilancia de enfermedades

Basic knowledge about the distribution of flora and fauna is lacking for most tropical areas. Improving our knowledge of the tropical biota will help address contemporary global problems, including emerging tropical diseases. Less appreciated is the role that applied studies can have in improving our understanding of basic biological patterns and processes in the tropics. Here, I describe a novel avifauna assemblage uncovered in Western Darién province in the Republic of Panama that was uncovered during a vector-borne disease surveillance program. I compared the passerine bird species composition at 16 sites using records from recent ornithological expeditions sponsored by the Smithsonian Tropical Research Institute in Central and Eastern Panama. Based on the results of a Mantel test, geographic distance did not correlate with pairwise distinctiveness of sites. Instead, based on an index of distinctiveness modified from the Chao-Jaccard index, most sites were more or less similarly distinctive, with one site, Aruza Abajo, significantly more distinctive than the rest. I found that the distinctiveness of this site was due not only to the presence of several rare and range-restricted taxa, but also to the absence of taxa that are common elsewhere. This finding provides more evidence of high species composition turnover (beta-diversity) in the Panamanian biota, which appears to be driven by a combination of soil and climate differences over narrow distances. Rev. Biol. Trop. 62 (2): 711-717. Epub 2014 June 01.

El conocimiento básico sobre la distribución de la flora y fauna es escaso en la mayoría de las zonas tropicales. Mejorar el conocimiento de la biota tropical ayudará a enfrentar los problemas globales contemporáneos, incluyendo las enfermedades tropicales emergentes. Menos apreciado es el papel que los estudios aplicados pueden tener en mejorar nuestra comprensión de los patrones biológicos y procesos básicos en estas regiones. A continuación, describo un conglomerado distinto de aves encontrado en la provincia occidental de Darién en la República de Panamá, el cual fue descubierto durante un programa de vigilancia de enfermedades transmitidas por insectos vectores. En este estudio comparé la composición de especies de aves paseriformes de 16 sitios con registros de expediciones ornitológicas recientes en Panamá Central y Oriental patrocinadas por el Instituto Smithsonian de Investigaciones Tropicales. Basado en los resultados de la prueba de Mantel, el carácter distintivo de los sitios en comparaciones pareadas no se correlacionó con la distancia geográfica entre sitios. En cambio, con base a un índice de disimilitud modificado a partir del índice de Chao-Jaccard, la mayoría de los sitios presentaron grados de disimilitud más o menos equivalentes, sin embargo Aruza Abajo fue mucho más distintivo que el resto. Yo encontré que el carácter distintivo de Aruza Abajo fue la presencia de varias especies raras y de rango restringido, pero también existe ausencia de especies comunes en otros sitios. Este hallazgo proporciona evidencia del elevado reemplazo de especies de aves (diversidad beta) en la avifauna panameña, la cual parece estar determinada por una combinación de diferencias del suelo y clima en cortas distancias geográficas.

Land Flatworms (Platyhelminthes: Tricladida) in Remnants of Deciduous Forest in the Northeast Region Of Southern Brazil / Planárias Terrestres (Platyhelminthes: Tricladida) Em Remanescentes De Floresta Decidual Do Nordeste Do Rio Grande Do Sul, Brasil

Land flatworms show high endemism due to their restricted mobility. In southern Brazil, land flatworm communities have been found mainly in areas of ombrophilous forests. Thus, this study documents land planarian species composition in remnants of deciduous seasonal forest in the northeast region of southern Brazil. Direct, diurnal samplings reveal the occurrence of 26 species of land flatworms, of which one belongs to the subfamily Rhynchodeminae and the others to the subfamily Geoplaninae. The Rhynchodeminae genus Rhynchodemus Leidy 1851 and the following Geoplaninae genera occurred: CephaloflexaCarbayo & Leal-Zanchet, 2003, Choeradoplana Graff, 1896, Imbira Carbayo et al., 2013, IssocaFroehlich, 1955, LuteostriataCarbayo, 2010, Obama Carbayo et al., 2013, Paraba Carbayo et al., 2013, Pasipha Ogren & Kawakatsu, 1990 and XerapoaFroehlich, 1955, besides the collective group Pseudogeoplana Ogren & Kawakatsu, 1990. The genus Obama had the highest species richness (S=6), followed by Paraba (S=4) and Pasipha (S=3). Eighteen species were recorded exclusively in one of the two study areas, and eight species occurred in both sites. The known distribution of Luteostriata abundans (Graff, 1899), Choeradoplana iheringiGraff, 1899, Obama ficki (Amaral & Leal-Zanchet, 2012), Imbira guaiana (Leal-Zanchet & Carbayo, 2001) and Pasipha hauseri (Froehlich, 1959) is increased. Results emphasize the relevance of expanding taxonomic studies on land flatworms and including more study areas in southern Brazil.

Os tricladidos terrestres apresentam alto grau de endemismo, devido especialmente è sua capacidade de locomoção reduzida. No Rio Grande do Sul, dados sobre as comunidades de planárias terrestres são principalmente conhecidos de áreas de floresta ombrófila mista. O presente estudo teve como objetivo analisar a composição das espécies de planárias terrestres em remanescentes de floresta estacional decidual, situados na região nordeste do Rio Grande do Sul. Com base em coletas diurnas diretas foram registradas 26 espécies, pertencentes ès subfamílias Geoplaninae e Rhynchodeminae. Foram registrados os seguintes gêneros de Geoplaninae: CephaloflexaCarbayo & Leal-Zanchet, 2003, Choeradoplana Graff, 1896, Imbira Carbayo et al., 2013, IssocaFroehlich, 1955, LuteostriataCarbayo, 2010, Obama Carbayo et al., 2013, Paraba Carbayo et al., 2013, Pasipha Ogren & Kawakatsu, 1990 e XerapoaFroehlich, 1955, além do grupo coletivo Pseudogeoplana Ogren & Kawakatsu, 1990 e do gênero de Rhynchodeminae Rhynchodemus Leidy 1851. O gênero Obama apresentou a maior riqueza de espécies (S=6), seguido por Paraba (S=4) e Pasipha (S=3). Dezoito espécies foram registradas exclusivamente em uma das áreas de estudo, enquanto oito espécies ocorreram em ambas localidades. Amplia-se a distribuição conhecida de Luteostriata abundans (Graff, 1899), Choeradoplana iheringiGraff, 1899, Obama ficki (Amaral & Leal-Zanchet, 2012), Imbira guaiana (Leal-Zanchet & Carbayo, 2001) e Pasipha hauseri (Froehlich, 1959). Além disso, os resultados enfatizam a importância de ampliação dos estudos taxonômicos de planárias terrestres, bem como das áreas de estudo no sul do Brasil.

Longitudinal variation in the composition of the benthic macroinvertebrate fauna of a typical North coast Jamaican river

Benthic macroinvertebrate fauna plays a major role in river ecosystems, especially those of tropical islands. Since there is no information on the distribution of benthic invertebrates along a Jamaican river, we report here on the composition of the benthic fauna of the Buff Bay river, on the Northern coast of Jamaica. A total of 14 samples were collected from five sites, using kick nets and a Surber sampler, between May 1997 and October 1998. We also examined the applicability of the rhithron/potamon model, and some of the premises of the River Continuum Concept (RCC) in relation to the distribution of invertebrate taxa. The results showed a total of 38 taxa of identified invertebrates. A group of dominant taxa, composed mainly of immature stages of insects, occurred at all sites. Two notable characteristics of the river were the absence of a true potamonic fauna and the low representation of the shredder functional feeding group in the community We conclude that, while there was minor variation in the composition of the benthic macroinvertebrate fauna among the sites, this was a response to local conditions within the river system. The characteristics of the community did not conform to either of the models.

La fauna bentónica de macroinvertebrados juega un papel importante en los ecosistemas fluviales, especialmente los de las islas tropicales. En vista de que hay poca información disponible para los ríos de Jamaica, presentamos la composición de la fauna bentónica de la bahía riverina Buff, en la costa norte de Jamaica. Para ello, recolectamos un total de 14 muestras en cinco sitios, mediante el uso de redes de golpe y trampa Surber, entre mayo 1997 y octubre 1998. También se examinó la aplicabilidad del modelo de subdivisión de ríos ritrón/potamón y algunas de las premisas del concepto de Río como un Continuo, en relación con la distribución de los táxones de invertebrados. Los resultados mostraron un total de 38 táxones de invertebrados identificados, hay un grupo de taxones dominantes, compuesto principalmente por los estadios inmaduros de insectos, que se presentaron en todos los sitios. Dos características notables del río fueron la ausencia de una fauna de potamón verdadera y la escasa representación del grupo funcional alimenticio triturador en la comunidad. Llegamos a la conclusión de que, si bien hay una variación de menor importancia en la composición de la fauna de macroinvertebrados bentónicos entre los sitios, esto fue una respuesta a las condiciones locales dentro del sistema fluvial y las características de la comunidad que no se ajusta a ninguno de los modelos. Este estudio representa la primera publicación de una descripción longitudinal de la fauna bentónica de macroinvertebrados de un sistema fluvial de Jamaica.

Inventário de planárias terrestres (Platyhelminthes, Tricladida) em remanescente de Floresta Estacional Decidual do Sul do Brasil / Land flatworm (Platyhelminthes, Tricladida) inventory in a remnant of Subtropical Deciduous Forest in Southern Brazil

Os tricladidos terrestres são predadores de topo de cadeia no seu microhábitat, alimentando-se de outros invertebrados de solo. A riqueza de espécies de tricladidos pode indicar a diversidade de outros grupos. A composição das comunidades de planárias terrestres da Floresta Estacional Decidual, que ocupa um quarto da cobertura vegetal do Estado do Rio Grande do Sul, é pouco conhecida. O presente trabalho teve como área de estudo o maior remanescente dessa formação florestal no Rio Grande do Sul, apresentando os seguintes objetivos: inventariar as espécies de planárias terrestres no Parque Estadual do Turvo (PE-Turvo) e comparar as comunidades desse Parque com as de outras áreas do estado com inventários desses tricladidos. Na área de estudo, foram inventariadas 26 espécies, sendo duas pertencentes às subfamílias Rhynchodeminae e Bipaliinae, e as demais, à subfamília Geoplaninae. Além dos gêneros Rhynchodemus Leidy 1851 e Bipalium Stimpson, 1857, foram registrados os seguintes gêneros de Geoplaninae: Geoplana Stimpson 1857, Choeradoplana Graff 1896, Pasipha Ogren & Kawakatsu 1990 e Notogynaphallia Ogren & Kawakatsu 1990, além do grupo coletivo Pseudogeoplana Ogren e Kawakatsu, 1990. O maior número de espécies foi registrado para o gênero Geoplana (10), seguido pelo gênero Pasipha (4). Geoplana rubidolineata Baptista & Leal-Zanchet, 2005 havia sido registrada anteriormente apenas para sua localidade-tipo, no nordeste do estado. Bipalium kewense Moseley, 1878, de distribuição cosmopolita, foi encontrada apenas em local submetido a alto impacto antrópico, não tendo sido registrada em áreas de floresta. Para comparar as comunidades de planárias terrestres do PE-Turvo com as de outros tipos de vegetação do estado, utilizou-se o método de ordenação NMDS. Essa análise indicou que as comunidades de planárias terrestres do PE-Turvo e de outras áreas de Floresta Decidual, Semidecidual e Floresta Ombrófila Densa diferenciam-se das comunidades de áreas de Floresta Ombrófila Mista. A alta riqueza de espécies observada no PE-Turvo reforça sua importante contribuição para a conservação da diversidade regional.

Land triclads are top-predators in their microhabitats, feeding on other soil invertebrates. The species richness of triclads may indicate the diversity of other faunal groups. The community composition of land flatworms of areas of Deciduous Forest, which occupies a quarter of the vegetal cover of the state, is poorly known. The present study inventoried land planarians of the largest remnant of this type of forest in the State of Rio Grande do Sul, the Turvo State Park (SP-Turvo) and compared their communities with those of other localities of the state with inventories of land flatworms. We inventoried 26 species, two of them belonging to the subfamilies Rhynchodeminae and Bipaliinae, and 24 to the subfamily Geoplaninae. Besides the genera Rhynchodemus Leidy 1851 and Bipalium Stimpson, 1857, the following Geoplaninae genera were recorded: Geoplana Stimpson 1857, Choeradoplana Graff 1896, Pasipha Ogren & Kawakatsu 1990 and Notogynaphallia Ogren & Kawakatsu 1990, as well as the collective group Pseudogeoplana Ogren & Kawakatsu, 1990. The highest species richness was registered for the genus Geoplana (10), followed by the genus Pasipha (4). Geoplana rubidolineata Baptista & Leal-Zanchet, 2005 was previously only known from its type-locality, located in the northeast of the state. Bipalium kewense Moseley, 1878 which shows a cosmopolitan distribution was observed in a man-disturbed area, not being registered in forest areas. We employed an NMDS ordination to compare land planarian communities of the Turvo State Park to those of other types of forest of the state. The analysis indicated that land planarian communities of the Turvo State Park and those of other areas with Deciduous, Semideciduous and Dense Ombrophilous Forests differ from those of Mixed Ombrophilous Forests of the region. The high observed species richness in the Turvo State Park reinforces its important contribution for the conservation of the regional diversity.

Spatio-temporal variation of the structural organization of demersal communities in the Southwestern Gulf of Mexico

Structural patterns of a sublittoral community were analyzed through a two-year series of samples in the Southwestern Gulf of Mexico. The groups involved in the study comprise fishes, molluscs, echinoderms and crustaceans. The time-space progressions of Second 0rder diversity values range between N2=5.3 and N2=9.8 at depths of 40 and 20 m respectively, through the first year of samples. In the second year the highest value (N2=22.2) was found at 30 m. The community ordination data through cluster and principal components analysis show five assemblages: benthic, benthic-demersal, demersal, mid water column, and temporary. There is a striking difference in trophic web structure between the dry season and rainy season. Fish community resource partitioning shows that the components are organized in three guilds: ichthyophagous, carcinophagous and omnivorous. However, a partial overlap of niches was commonly observed, and juvenile stages showed a narrower trophic spectrum than adults. Rev. Biol. Trop. 55 (2): 509-536. Epub 2007 June, 29.

Se analizaron los patrones estructurales de la comunidad sublitoral a través de dos años de muestreo. Los grupos involucrados en el estudio fueron: peces, moluscos, equinodermos y crustáceos. Las progresiones espacio-temporales de la diversidad de segundo orden para el primer año se encuentran entre los intervalos de N2=5.3 y N2=9.8 en las profundidades de 40 y 20 m respectivamente. En el segundo periodo el valor más alto (N2=22.2) fue registrado a 30 m. La ordenación de la comunidad a través del análisis de agrupamientos y de Componentes Principales, muestran 5 ensamblajes: béntico, béntico-demersal, demersal, a media columna de agua y temporal. Hay una fuerte diferencia en la estructura de la red trófica entre las estaciones de secas y lluvias. La repartición de recursos en la comunidad de peces, muestran que sus componentes están organizados en tres gremios: Ictiófagos, Carcinófagos y Omnívoros. Sin embargo, comúnmente se presenta un solapamiento parcial en el nicho, los estadíos juveniles muestran un espectro trófico muy cercano a los adultos.