ABSTRACT
Very little is known about the malacofauna in district Swat of Khyber Pakhtunkhwa province, situated in the Northern part of Pakistan. The Swat valley possesses a variety of suitable environmental conditions, providing different types of habitats for both flora and fauna. Taken into consideration these points, the present study was conducted to explore the terrestrial snails diversity in agricultural and non-agricultural fields in the lower Swat valley. A total of 417 shells were collected from three sites: Kokarai, Kanju Township, and Deolai. Based on conchological features, three families: Bradybaenidae, Hygromiidae, and Zonitidae were identified using different terrestrial snail keys. In Kokarai and Deolai, shells of members of all the above-mentioned families were found from agricultural fields. In Kanju Township, shells of members of the family Bradybaenidae and Zonitidae were found. From these findings, it was concluded that district Swat possesses a significant malacofauna which was unexplored before and aided more to the existing literature on malacofauna. It also supports the idea that the agroecosystem is rich in species diversity. Further in-depth and extensive study is recommended to be carried out for a detailed taxonomy of the described terrestrial gastropod families.
Muito pouco se sabe sobre a malacofauna no distrito de Swat, na província de Khyber Pakhtunkhwa, situada na parte norte do Paquistão. O vale do Swat possui uma variedade de condições ambientais adequadas, proporcionando diferentes tipos de habitats para a flora e a fauna. Levando em consideração esses pontos, o presente estudo foi conduzido para explorar a diversidade dos caracóis terrestres em campos agrícolas e não agrícolas no vale inferior de Swat. Um total de 417 conchas foram coletadas em três locais: Kokarai, Kanju Township e Deolai. Com base em características concológicas, três famílias: Bradybaenidae, Hygromiidae e Zonitidae foram identificadas usando diferentes chaves de caramujos terrestres. Em Kokarai e Deolai, conchas de membros de todas as famílias mencionadas acima foram encontradas em campos agrícolas. No município de Kanju, foram encontradas conchas de membros da família Bradybaenidae e Zonitidae. A partir dessas constatações, concluiu-se que o distrito de Swat possui uma malacofauna significativa que antes era inexplorada e ajudava mais a literatura existente sobre a malacofauna. Também apoia a ideia de que o agroecossistema é rico em diversidade de espécies. Recomenda-se a realização de um estudo mais aprofundado e extenso para uma taxonomia detalhada das famílias de gastrópodes terrestres descritas.
Subject(s)
Animals , Biodiversity , Snails/classificationABSTRACT
Abstract Introduction: The snail Hexaplex princeps is the most important gastropod in the fishery of Guerrero, but capture is not legally regulated for lack of enough studies about its reproduction, growth and other fishing aspects. Objective: To assess fishery data for H. princeps in Guerrero. Methods: From October 2016 to December 2017, we analyzed histological samples of the gonads from 6 to 13 individuals per month. We also collected data on pre-reproductive organisms captured in Costa Chica (2013 and 2014), Costa Grande (2017) and Acapulco (2019 and 2020). Results: Both sexes have five stages of gonadal development; most reproductive activity was from December to July, related to sea surface temperatures of 26 to 28 °C. The LC M in females was 94.1 mm (males: 86.1 mm). There was a high percentage of juvenile organisms in the catches (88.6 %). Conclusions: To let these snails reproduce at least once, we recommend a fishing ban from December to July, and that the minimum size of commercial capture be set at 94.1 mm.
Resumen Introducción: El caracol Hexaplex princeps es el gasterópodo más importante en la pesquería de Guerrero, pero su captura no está regulada legalmente por falta de suficientes estudios sobre su reproducción, crecimiento y otros aspectos de la pesca. Objetivo: Evaluar los datos de pesca de H. princeps en Guerrero. Métodos: De octubre 2016 a diciembre 2017, analizamos muestras histológicas de las gónadas de 6 a 13 individuos por mes. También recolectamos datos sobre organismos pre-reproductivos capturados en Costa Chica (2013 y 2014), Costa Grande (2017) y Acapulco (2019 y 2020). Resultados: Ambos sexos tienen cinco etapas de desarrollo gonadal; la mayor actividad reproductiva fue de diciembre a julio, relacionada con las temperaturas superficiales del mar, que se encuentran entre 26 y 28 °C. El LC M en hembras fue de 94.1 mm (machos: 86.1 mm). Hubo un alto porcentaje de organismos juveniles en las capturas (88.6 %). Conclusiones: Para que estos caracoles se reproduzcan al menos una vez, se recomienda una veda de diciembre a julio y que la talla mínima de captura comercial se fije en 94.1 mm.
Subject(s)
Animals , Snails/classification , Fishing Industry , MexicoABSTRACT
Resumen Introducción: Spiraxidae es la familia de gasterópodos terrestres más diversa de México con una distribución principalmente neotropical. Sin embargo, la influencia de las condiciones ambientales de esta región en su distribución aún es poco conocida. Objetivo: Determinar las afinidades zoogeográficas y la influencia de factores ambientales en la distribución de Spiraxidae en México. Métodos: Compilamos registros de distribución de museos y usamos modelos para establecer áreas con composición de especies, concentración de especies, afinidades y relaciones con variables ambientales similares. Resultados: Encontramos 231 especies y subespecies, 96 en el estado de Veracruz y 74 en la Sierra Madre Oriental. La principal afinidad zoogeográfica fue neotropical. El bosque mesófilo de montaña tuvo la mayor cantidad de especies y subespecies (93). Tres de los grupos zonales tienen una composición particular de especies y el 67 % de las especies son especialistas de hábitat. La presencia de especies sigue un gradiente ambiental, con la cubierta de árboles de hoja perenne de hoja ancha y la precipitación media anual como variables determinantes. Las especies del norte tuvieron mayor tolerancia a la aridez y menor cobertura de hojas. Conclusiones: Spiraxidae tiene su mayor diversidad en los estados del Sur de México; sin embargo, la zona nororiental tiene más registros de especies. Estos caracoles se encuentran principalmente en bosques mesófilos de montaña y bosques tropicales siempre verdes. Las especies del norte de México tuvieron una mayor tolerancia a los sitios con poca lluvia y menos cobertura de árboles de hoja perenne de hoja ancha que las especies del sur.
Abstract Introduction: Spiraxidae is the most diverse family of terrestrial gastropods in Mexico with a mainly neotropical distribution. However, the influence of environmental conditions in this region on its distribution is still poorly known. Objective: To determine zoogeographic affinities and the influence of environmental factors on the distribution of Spiraxidae in Mexico. Methods: We compiled museum distribution records and used models to establish areas with similar species composition, species concentration, affinities and relationship with environmental variables. Results: We found 231 species and subspecies, 96 in Veracruz state and 74 in Sierra Madre Oriental. The main zoogeographic affinity was neotropical. Mountain mesophyll forest had the most species and subspecies (93). Three of zone groups have a particular species composition and 67 % of the species are habitat specialists. Species presence follows an environmental gradient, with broadleaf evergreen tree cover and average annual precipitation as determining variables. Northern species had greater tolerance to aridity and reduced leaf cover. Conclusions: Spiraxidae has its greatest diversity in the Southern states of Mexico; however, the Northeastern zone has more species records. These snails mostly occur in mesophyll mountain forest and tropical evergreen forest. Species from Northern Mexico had greater tolerance to sites with low rainfall and less broadleaf evergreen tree cover than Southern species.
Subject(s)
Animals , Snails/classification , Animal Distribution , MexicoABSTRACT
Abstract INTRODUCTION This paper presents the results of an extensive survey of freshwater mollusks in the Simplício Queda Única Hydroelectric Development area, Southeast Brazil. METHODS Mollusks were collected between 2008 and 2013. All specimens were examined for the presence of larval trematodes. RESULTS In total, 12,507 specimens classified into 16 genera were obtained. Known snail vectors of schistosomiasis and fascioliasis and exotic species were identified, and new records are reported. CONCLUSIONS No specimens parasitized by larval trematodes of medical interest were detected. However, the results reinforce the importance of surveillance in study areas vulnerable to the occurrence of schistosomiasis transmission.
Subject(s)
Animals , Power Plants , Snails/classification , Schistosomiasis mansoni/transmission , Disease Vectors/classification , Fresh Water/parasitology , Snails/parasitology , Brazil , Population DensityABSTRACT
ABSTRACT INTRODUCTION Angiostrongylus cantonensis is causes eosinophilic meningoencephalitis in humans. Worldwide expansion of this nematode is linked to the dispersion of their hosts. This study aimed to determine the prevalence of A. cantonensis infection in Achatina fulica in the nine municipalities that make up Baixada Santista, São Paulo, Brazil. METHODS Angiostrongylus cantonensis larvae were analyzed using optical microscopy. We performed polymerase chain reaction and restriction fragment length polymorphism using restriction endonuclease ClaI, directed to the internal transcribed spacer region 2 of A. cantonensis larval DNA. RESULTS Of the 540 snails analyzed, 117 (21.7%) were infected by A. cantonensis. For morphological and morphometric analyses, 60 larvae were used. Second-stage larvae were, on average, 358.2µm long and 26.4µm wide, while third-stage larvae were, on average, 450µm long and 21.12µm wide. The tails of the larvae ended in a fine tip. CONCLUSIONS All municipalities comprising Baixada Santista had A. fulica that were naturally infected with A. cantonensis. All of the observed characteristics were typical of the species.
Subject(s)
Animals , Snails/parasitology , Angiostrongylus cantonensis/isolation & purification , Disease Vectors , Snails/classification , Brazil , Population Dynamics , Polymerase Chain Reaction , Population Density , Angiostrongylus cantonensis/anatomy & histology , Angiostrongylus cantonensis/geneticsABSTRACT
Abstract Very little is known about the ecology and biology of Drymaeus tripictus, an extremely rare and endemic land snail species from Costa Rican highlands. I studied the ecology and reproductive biology of D. tripictus from April 2009 through June 2010 in an old forest, a young forest and a Cupressuslusitanica plantation in central Costa Rica. Every three months I visited each habitat and collected specimens in 20 random sampling plots (3x3 m2 each). I observed the snail's activity and microhabitat preference in the field, and in the laboratory I recorded high definition videos of its mating behavior and analyzed reproductive morphology with light microscopy. The snail is more abundant in the old forest (0.017 ind./m2) and prefers leaves with little epiphyllous cover (0-25 % cover, chi-square test, p <0.0001). During the dry season the snails become active between 20:00 pm and 8:00 am (chi-square = 22.65, df=3, p < 0.0001); they are inactive mainly during the afternoon (11:00 am to 16:59 pm). I found active individuals mostly on the upper side of leaves, where they feed (Chi-square =6.76, df=1, p = 0.0093). Mating is unilateral, by shell mounting, with cryptic phallus intromission and without role switching or multiple mating. Its reproductive system is morphologically similar to that of Drymaeus costaricensis. Mating behavior is as expected for snails with high-spired shells, except for the lack of role switching. The density of D. tripictus is low even when compared with other endangered bulimulids. Rev. Biol. Trop. 64 (1): 55-68. Epub 2016 March 01.
ResumenSe conoce muy poco sobre la ecología y biología del caracol terrestre Drymaeus tripictus. Se trata de una especie extremadamente escasa y endémica de las zonas altas de Costa Rica. Estudié la ecología y biología reproductiva de D. tripictus de abril 2009 a junio 2010 en un bosque maduro, un bosque jóven y una plantación de Cupressus lusitanica en Costa Rica. Cada tres meses visité esos hábitats y recolecté especímenes en 20 puntos de muestreo (cada uno de 3x3 m2). Estudié actividad y preferencias de hábitat en la naturaleza. En el laboratorio grabé en alta definición el comportamiento de apareamiento y analicé la morfología reproductiva con un microscopio estereoscópico de luz. El caracol es mas abundante en el bosque maduro (0.017 ind/m2) y prefiere hojas con poca cobertura de epífilos (25% o menos de cobertura, chicuadrado, p < 0.0001). En la época seca, se activan entre las 8:00 pm y las 8:00 am principalmente (chi-cuadrado = 22.65, p <0.0001). En la tarde se inactivan (11:00 am to 16:59 pm). Los individuos activos se encuentran principalmente en el haz de las hojas (Chi-square =6.76, df =1, p = 0.0093), que es donde se alimentan. El apareamiento es unilateral por "montaje de concha", no hacen cambio de roles sexuales y la intromisión fálica es críptica. Su sistema reproductivo es morfológicamente similar al de Drymaeus costarricensis. El comportamiento de apareamiento es como se espera de un caracol de concha con espira alta, excepto por la ausencia de cambio de roles. La densidad de D. tripictus es mas baja que la de otros bulimulidos considerados en peligro.
Subject(s)
Animals , Male , Female , Sexual Behavior, Animal/physiology , Snails/physiology , Reproduction/physiology , Snails/classification , Tropical Climate , Costa RicaABSTRACT
AbstractEcologists have been largely interested in the description and understanding of the power scaling relationships between body size and abundance of organisms. Many studies have focused on estimating the exponents of these functions across taxonomic groups and spatial scales, to draw inferences about the processes underlying this pattern. The exponents of these functions usually approximate -3/4 at geographical scales, but they deviate from this value when smaller spatial extensions are considered. This has led to propose that body size-abundance relationships at small spatial scales may reflect the impact of environmental changes. This study tests this hypothesis by examining body size spectra of benthic shrimps (Decapoda: Caridea) and snails (Gastropoda) in the Tamiahua lagoon, a brackish body water located in the Eastern coast of Mexico. We measured water quality parameters (dissolved oxygen, salinity, pH, water temperature, sediment organic matter and chemical oxygen demand) and sampled benthic macrofauna during three different climatic conditions of the year (cold, dry and rainy season). Given the small size of most individuals in the benthic macrofaunal samples, we used body volume, instead of weight, to estimate their body size. Body size-abundance relationships of both taxonomic groups were described by tabulating data from each season into base-2 logarithmic body size bins. In both taxonomic groups, observed frequencies per body size class in each season were standardized to yield densities (i.e., individuals/m3). Nonlinear regression analyses were separately performed for each taxonomic group at each season to assess whether body size spectra followed power scaling functions. Additionally, for each taxonomic group, multiple regression analyses were used to determine whether these relationships varied among seasons. Our results indicated that, while body size-abundance relationships in both taxonomic groups followed power functions, the parameters defining the shape of these relationships varied among seasons. These variations in the parameters of the body size-abundance relationships seems to be related to changes in the abundance of individuals within the different body size classes, which seems to follow the seasonal changes that occur in the environmental conditions of the lagoon. Thus, we propose that these body size-abundance relationships are influenced by the frequency and intensity of environmental changes affecting this ecosystem. Rev. Biol. Trop. 64 (1): 33-44. Epub 2016 March 01.
ResumenLos ecólogos han estado muy interesados en describir y comprender las relaciones escalares de potencia entre el tamaño corporal y la abundancia de los organismos. Muchos estudios se han centrado en la estimación de los exponentes de estas funciones a través de grupos taxonómicos y escalas espaciales, para sacar conclusiones acerca de los procesos que subyacen a este patrón. Los exponentes de estas funciones generalmente se aproximan -3/4 a escalas geográficas, pero se apartan de este valor cuando se consideran extensiones espaciales más pequeñas. Esto ha llevado a proponer que las relaciones tamaño corporal-abundancia en pequeñas escalas espaciales puede reflejar el impacto de cambios ambientales. Este estudio pone a prueba esta hipótesis mediante el examen de los espectros de tamaño corporal de camarones bentónicos (Decapoda: Caridea) y caracoles (Gastropoda) en la laguna de Tamiahua, un cuerpo de agua salobre situado en la costa oriental de México. Medimos parámetros de calidad del agua (oxígeno disuelto, salinidad, pH, temperatura del agua, materia orgánica en los sedimentos y demanda química de oxígeno) y muestreamos la macrofauna bentónica en tres momentos del año que difieren en sus condiciones climáticas (estaciones fría, seca y de lluvias). Dado el pequeño tamaño de la mayoría de los individuos en las muestras de macrofauna bentónica, se utilizó el volumen del cuerpo, en lugar de peso, para estimar su tamaño corporal. Las relaciones tamaño corporalabundancia de ambos grupos taxonómicos fueron descritas ordenando los datos de cada estación en clases de tamaño corporal cuya amplitud estaba establecida por una escala logarítmica de base 2. En ambos grupos taxonómicos, las frecuencias observadas por clase de tamaño corporal en cada estación se estandarizaron a densidades de captura (es decir, individuos/m3). Análisis de regresión no-lineal se realizaron separadamente para cada grupo taxonómico en cada estación del año para evaluar si los espectros de tamaño corporal seguían funciones escalares de potencia. Además, para cada grupo taxonómico, se utilizaron análisis de regresión múltiple para determinar si estas relaciones variaban entre estaciones. Nuestros resultados indicaron que, mientras las relaciones tamaño corporal-abundancia en ambos grupos taxonómicos siguieron funciones potenciales, los parámetros que definen la forma de estas relaciones variaron entre estaciones. Estas variaciones en los parámetros de las relaciones tamaño corporal-abundancia parecen estar relacionadas con cambios en la abundancia de los individuos dentro de las diferentes clases de tamaño corporal, que parece seguir los cambios estacionales que se producen en las condiciones ambientales de la laguna. Por lo tanto, proponemos que estas relaciones tamaño corporalabundancia se ven influidas por la frecuencia e intensidad de los cambios ambientales que afectan este ecosistema.
Subject(s)
Animals , Snails/anatomy & histology , Snails/classification , Water Quality , Palaemonidae/anatomy & histology , Palaemonidae/classification , Body Size , Seasons , MexicoABSTRACT
The aim of this study was to analyse the infection dynamics ofAngiostrongylus cantonensisin its possible intermediate hosts over two years in an urban area in the state of Rio de Janeiro where the presence ofA. cantonensis had been previously recorded in molluscs. Four of the seven mollusc species found in the study were exotic.Bradybaena similariswas the most abundant, followed byAchatina fulica, Streptaxissp., Subulina octona, Bulimulus tenuissimus, Sarasinula linguaeformisand Leptinaria unilamellata. Only A. fulicaand B. similariswere parasitised by A. cantonensis and both presented co-infection with other helminths. The prevalence of A. cantonensisin A. fulicawas more than 50% throughout the study. There was an inverse correlation between the population size ofA. fulicaand the prevalence of A. cantonensisand abundance of the latter was negatively related to rainfall. The overall prevalence of A. cantonensisin B. similariswas 24.6%. A. fulicawas the most important intermediary host of A. cantonensisin the studied area andB. similariswas secondary in importance for A. cantonensistransmission dynamics.
Subject(s)
Animals , Angiostrongylus cantonensis/physiology , Introduced Species , Snails/parasitology , Strongylida Infections/transmission , Animal Distribution , Angiostrongylus cantonensis/pathogenicity , Brazil/epidemiology , Cities , Climate Change , Disease Vectors , Linear Models , Mollusca/classification , Mollusca/parasitology , Rain/parasitology , Snails/classification , Strongylida Infections/epidemiologyABSTRACT
The marine park of Xel-Há has a population of Strombus gigas which breeds in the area. We determined the relationship between reproductive activity, conch density and environmental parameters. Samples were collected from February to December 2012, using the transect method, at four sites of Marine Park Xel-Ha, Quintana Roo, Mexico. Sediment samples were analyzed and classified using Folk & Ward’s method. Temperature, salinity and dissolved oxygen were also recorded. Density had a small correlation with sediment (Pearson r=0.29 with very coarse and r=0.26 with coarse sand), while mating and spawning had a correlation of r=0.54 and 0.62 with medium sand, respectively. Density was high in the four sites and was not associated with mating and spawning (r=0.08 and 0.03, respectively). For reproduction, S. gigas requires specific substrate conditions (sandy effect) and not just a density of 56 Conch Ha-1 (Allee effect).
El parque marino de Xel -Há tiene una población de Strombus gigas que se cría en la zona. Determinamos la relación entre la actividad reproductiva, la densidad de la concha de S. gigas y los parámetros ambientales. Las muestras fueron recolectadas de febrero a diciembre de 2012, utilizando el método de transecto, en cuatro sitios del Parque Marino de Xel -Ha, Quintana Roo, México. Fueron analizados y clasificados utilizando la metodología de Folk & Ward. También se registraron temperaturas, salinidad y oxígeno disuelto. La densidad de concha mostró una baja correlación en la categoría de sedimentos (r = 0.29 , con muy gruesos y r = 0.26 con arena gruesa ), mientras que el apareamiento y desove con arena media mostraron una correlación de r = 0.54 y 0.62, respectivamente. Las densidades en cuatro sitios fueron altas y no se asociaron con el número de apareamientos y desove (r = 0.08 y 0.03, respectivamente). Para la reproducción, S. gigas requiere condiciones específicas de sustrato (efecto arenoso) y no sólo una densidad de 56 Conch Ha-1 (efecto Allee ).
Subject(s)
Reproduction , Snails/classification , MexicoABSTRACT
Introduction Schistosomiasis is a parasitic disease of public health concern in Brazil, and the construction of hydroelectric dams, in addition to increasing permanent human settlement and tourism, has created conditions suitable for the establishment of mollusks that can transmit schistosomiasis. Such areas require a number of actions to prevent the establishment of schistosomiasis. This paper reports on a freshwater malacological survey carried out in the geographical area of the Manso Power Plant. Methods Mollusks were collected in 18 municipalities in the State of Mato Grosso between February 2002 and February 2004 (qualitative study) and from April 2009 to February 2011 (quantitative study). Results Thirty-one species of mollusks were collected, including newly recorded species (Antillorbis nordestensis and Burnupia ingae). In addition, the geographic distributions of known species, including Biomphalaria straminea, a snail vector of Schistosoma mansoni, were expanded. A total of 4,507 specimens were collected in the APM Manso reservoir (Usina Hidrelétrica de Aproveitamento Múltiplo de Manso) during the quantitative study, and Biomphalaria amazonica was found in six of the 10 localities analyzed. The Afroasiatic species Melanoides tuberculata, introduced after February 2009, was the dominant species (relative abundance 94.96%). Conclusions The study area is epidemiologically important due to the occurrence of B. straminea and B. amazonica, which are vectors of schistosomiasis, and M. tuberculata, a snail host of Centrocestus formosanus, which is responsible for centrocestiasis transmission. Observations of M. tuberculata and the exotic freshwater clams Corbicula fluminea and Corbicula largillierti raise concerns about biodiversity. .
Subject(s)
Animals , Disease Vectors/classification , Fresh Water/parasitology , Power Plants , Schistosoma mansoni , Snails/classification , Snails/parasitology , Brazil , Population Density , Seasons , Schistosomiasis mansoni/transmissionABSTRACT
The species of the genus Drepanotrema, most of them endemic to the Neotropical region, belong to the Planorbidae. Of the nine species of this genus, six are found in Argentina. The present investigation analysed the individual growth of Drepanotrema cimex in Arenalcito pond (34°11 S, 58°15 W), Martín García Island Natural Reserve of Multiple Uses, Buenos Aires Province, Argentina. A total of 14 samples were collected (n = 1931) from February 2006 to June 2007. Five environmental variables were measured: water temperature, dissolved oxygen (mg L1), electrical conductivity (µS cm1), total dissolved solids, and pH. The individual growth of the species was analysed mathematically by means of the von Bertalanffy equation, where: Lt = 5,6(1-e2,0592 (t0,293)). The parameter L was estimated by the Ford-Walford Method. The population of D. cimex was characterised by a complex and dynamic size structure throughout the annual cycle. The analysis of the curves revealed unimodal (2006) and polymodal (April to June 2007) distributions, which pattern served to identify the existence of cohorts within the population studied.
As espécies do gênero Drepanotrema, a maioria delas endêmicas da região Neotropical, pertencem ao Planorbidae. Das nove espécies desta família, seis são encontradas na Argentina. Este artigo analisa o crescimento individual de Drepanotrema cimex na lagoa de Arenalcito, Reserva Natural de Usos Múltiples Ilha Martín García, Buenos Aires, Argentina (34°11 S - 58°15 W). A amostragem foi realizada entre fevereiro de 2006 e junho de 2007. Durante o curso das campanhas foram obtidas 14 amostras (n = 1931). Cinco variáveis ambientais foram medidas: temperatura da água, oxigênio dissolvido (mg L1), condutividade elétrica (uS cm1), sólidos dissolvidos e pH. O crescimento individual das espécies foi analisada matematicamente por meio da equação de von Bertalanffy em que: Lt = 5,6 (1-e2, 0592 (t0, 293)). O paràmetro L foi estimada pe lo método de Ford-Walford. A população de D.cimex foi caracterizada por uma estrutura complexa e dinâmica de tamanho ao longo do ciclo anual. A análise das curvas mostrou distribuições unimodais (2006) e polimodais (abril-junho 2007), identificando a existência de coortes na população estudada.
Subject(s)
Animals , Snails/classification , Snails/growth & development , Climate Effects , ArgentinaABSTRACT
Ampulariideos são gastrópodes límnicos que habitam as regiões tropicais e subtropicais das Américas, da África e da Ásia. Geralmente são os principais constituintes de ecossistemas límnicos e têm importante papel na cadeia trófica. A anatomia da maioria dos ampulariideos é pobremente conhecida e sua classificação é baseada principalmente em caracteres conquiliológicos, geralmente variáveis, resultando em uma confusa taxonomia. Dentre os quatro gêneros que ocorrem na América do Sul, Asolene é um dos menos estudados. Visando contribuir para a clarificação da taxonomia de Asolene meta e Asolene spixii, bem como fornecer dados adicionais para o entendimento das relações de parentesco dentro da família, foram estudados a morfologia e aspectos moleculares de espécimes coletados no Brasil, incluindo topótipos de A. meta. Asolene spixii ocorre no norte da Argentina, Uruguai, Paraguai e sul do Brasil, enquanto A. meta é endêmica da bacia do rio São FranciscoAs conchas de ambas as espécies são similares, mas a abertura de A. meta é arredondada e em A. spixii é mais alongada. As análises estatísticas (Teste t de Student e Análise Discriminante) revelaram que as variáveis conquiliométricas são significativamente diferentes entre as espécies, sendo a altura da abertura a que mais contribui para a discriminação entre A. meta e A. spixii. A microscopia eletrônica de varredura da rádula não revelou diferenças interespecíficas. A anatomia do estômago é similar em A. meta e A. spixii, no entanto o escudo gástrico de A. meta é mais desenvolvido. A anatomia externa, cavidade do manto e sistema nervoso seguem o mesmo padrão dos demais ampulariideos. As principais diferenças anatômicas encontram-se nos caracteres do rim e da bainha do pênis. O rim anterior de A. meta é alongado e maior que em A. spixii, que é triangular...
Ampullariidae are freshwater snails inhabiting tropical and subtropical regions in Asia, Africa and the Americas. They are often major constituents of freshwater ecosystems and play important roles in food webs. The detailed morphology of mostampullariids is poorly known and their classification is based primarily on oftenvariable shell characters, resulting in taxonomic confusion. Among the four genera in South America, Asolene is one of the least studied. To clarify the taxonomy of Asolene meta and Asolene spixii and provide additional data to understand systematic relationships within the family we assessed morphological and moleculardata from specimens collected in Brazil, including the type locality of A. meta. A.spixii occurs in northern Argentina, Uruguay, Paraguay and southern Brazil while A. meta is endemic to the basin of São Francisco river. The shells are similar in both species but the aperture of A. meta is rounded and in A. spixii it is more elongated. Statistical analysis (Test t and Discriminant Analysis) showed that the conquiliologicalvariables are significantly different between the species and the aperture height contributes most to the discrimination between A. meta and A. spixii. The scanning electron microscopy didn´t reveal interspecific variations. The stomach are similar inA. meta and A. spixii, although the gastric shield in A. meta is more developed. The external anatomy, mantle cavity and nervous system are the same as in ampullariids. There are a few anatomical differences, primarily in the characters of the kidney andthe penial sheath. The elongated anterior kidney in A. meta is larger than that of A. spixii, which is triangular...
Subject(s)
Animals , Snails/anatomy & histology , Snails/classificationABSTRACT
Autocoptis paulsoni n. sp. is described from Haiti. it is characterized by its large size, its cylindricaltapered shape, its fine costate sculpture on the teleoconch, a distinct but weak circum basal keel and its abbreviate conical juvenile shell. it is most similar to Autocoptis gruneri (Dunker 1844), which is redescribed, and its distribution is reviewed. The taxonomic status of the genus Autocoptis Pilsbry 1902 and its subgenus Urocoptola Clench, 1 935 are reviewed. The genus is endemic to Hispaniola and satellite islands.
Para Haití se describe Autocoptis paulsoni n. sp. Esta especie se caracteriza por su gran tamaño, su forma cilíndrica-cónica, teleoconcha en forma de costillas, una clara pero débil quilla circumbasal y concha juvenil cónica y abreviada. Es muy similar a Autocoptis gruneri (Dunker, 1844), que se describe de nuevo y su distribución se revisa. También se presenta el estado taxonómico del género Autocoptis y del subgénero Urocoptola. El género es endémico de La Española y las islas satélites.
Subject(s)
Animals , Female , Male , Snails/anatomy & histology , Snails/classification , HaitiABSTRACT
In Mexico and elsewhere in the Caribbean, the queen conch Strombus gigas is an endangered species. Understanding the genetic connectivity of their populations will support management strategies for long term conservation of the species. Genetic diversity and population differentiation was assessed from samples collected at Banco Chinchorro and Isla Cozumel in the Mexican Caribbean and at Arrecife Alacranes in the Gulf of Mexico. Samples were obtained from the commercial capture at Banco Chinchorro (n=50) and Isla Cozumel (n=40) on March 2004. On November 2004, a non-invasive method for the Arrecife Alacranes sampling was applied, taking the hemolymph of live animals (n=65) and releasing them to the wild. The mitochondrial DNA variation at two genes (COI and Cyt-b) was analyzed. Genetic diversity at the three locations ranged between 0.55-0.65 in COI and 0.87-0.94 in Cyt-b, showing no bottleneck evidences. A non-significant fixation index (F ST=0.019, p=0.161) and a Maximum Parsimony Network tree that did not show particular clades associated with any of the geographical locations, suggested a lack of statistically significant genetic differentiation among populations. Nevertheless, the cline patterns observed in both genetic diversity and haplotypic frequencies from Banco Chinchorro through Arrecife Alacranes, and the larger genetic distance between these locations from those between Isla Cozumel, Banco Chinchorro and Arrecife Alacranes, suggest the possibility of a pattern of isolation-by distance. The role of the main current systems over the potential genetic differences in S. gigas populations along the Mexican Caribbean, and the conservation management of S. gigas at these locations as discrete units is discussed. Rev. Biol. Trop. 59 (3): 1115-1126. Epub 2011 September 01.
El caracol rosado Strombus gigas es una especie amenzada en México y otros sitios del Caribe. Su conservación a largo plazo requiere la comprensión de la conectividad entre sus poblaciones. En este estudio se evaluó la diversidad y diferenciación genética de muestras recolectadas en tres sitios del Caribe y Golfo de México adyacentes a la Península de Yucatán. Las muestras se obtuvieron de la captura comercial en Banco Chinchorro (n=50) e Isla Cozumel (n=40) en marzo de 2004. En noviembre de 2004 se obtuvieron muestras de Arrecife Alacranes (n=65) de animales vivos, mediante un método no invasivo diseñado para la obtención de hemolinfa; los organismos muestreados se liberaron de vuelta al medio natural. Se analizó la diversidad genética de dos genes del ADN mitocondrial (COI y Cyt-b). La diversidad genética en las tres localidades varió entre 0.55 - 0.65 en COI y 0.87 - 0.94 en Cyt-b no indicando reducción por cuello de botella. Un índice de fijación no significativamente diferente de cero (F ST=0.019, p=0.161) y un árbol en Red de Máxima Parsimonia que no mostró clados particulares asociados con localidades específicas, sugiere que no hay diferencias genéticas significativas entre sitios. Sin embargo, los patrones clinales observados en la diversidad genética y en las frecuencias haplotípicas, así como la mayor distancia genética registrada entre las localidades más alejadas (Banco Chinchorro y Arrecife Alacranes) sugiere un posible un patrón de aislamiento por distancia. Se discute el papel de los sistemas de corrientes principales del Caribe mexicano sobre la posible diferenciación genética de S. gigas. Asimismo, se discute el manejo de las localidades estudiadas como unidades discretas.
Subject(s)
Animals , Endangered Species , Genetic Variation , Snails/classification , Snails/genetics , DNA, Mitochondrial/genetics , Geography , Haplotypes , Mexico , Population DynamicsABSTRACT
Genetic diversity in two populations of the snail Strombus gigas (Gastropoda: Strombidae) from Yucatan, Mexico, using microsatellite. The pink conch Strombus gigas is an important fisheries resource in the Caribbean region, including the Yucatán Peninsula. We analyzed the genetic diversity and genetic structure of two populations (Alacranes Reef and Chinchorro Bank) with the use of five microsatellite molecular markers. The results indicate that the two populations are in the same rank of genetic diversity (He), from 0.613 to 0.692. Significant deviation from H-WE was observed in the both populations due to deficit to heterozygotes, this was attributed to inbreeding as a consequence of over- fishing; nevertheless, other possible causes considered are mixing of individuals from two or more populations, and the existence of null alleles. Levels of genetic differentiation indicated the existence of a single homogenous population in the Yucatan Peninsula (F ST de 0.003, p=0.49), which fits with highest levels of gene flow is significant (2.3 individuals) between both populations. Results from this study support the hypothesis that S. gigas is part of a single panmictic population in the Yucatan Peninsula; therefore, this fishery resource should be regulated the same way for both areas. Rev. Biol. Trop. 59 (3): 1127-1134. Epub 2011 September 01.
El caracol rosado S. gigas, es una especie de gran importancia pesquera en la región del Caribe que incluye la Península de Yucatán, en la cual, se analizó la diversidad y estructura genética de dos poblaciones (Arrecife Alacranes y Banco Chinchorro) mediante el uso de cinco marcadores moleculares del tipo microsatélites. Los resultados indican que las dos poblaciones analizadas se encuentran en el mismo rango de diversidad genética (He) de 0.613 a 0.692. En ambas poblaciones también se observó una desviación significativa al equilibrio H-WE, la cual fue atribuida a factores como la endogamia a consecuencia de una sobre-explotación pesquera. Sin embargo otra explicación posible es que se deba a una mezcla de individuos de dos o más poblaciones, y la existencia de alelos nulos. Los niveles de estructura genética indican la existencia de una sola población homogénea en la península de Yucatán (F ST de 0.003, p=0.49) y el flujo genético fue significativo (2.3 individuos) entre las dos poblaciones. Los resultados de este estudio aceptan la hipótesis de que las poblaciones S. gigas forman parte de una sola población panmíctica en la Península de Yucatán, por lo tanto, el recurso pesquero debe regularse de igual manera en ambas regiones.
Subject(s)
Animals , Genetic Variation , Microsatellite Repeats/genetics , Snails/genetics , Gene Flow , Mexico , Snails/classificationABSTRACT
The toxic effect of binary and tertiary combinations of Euphorbia hirta Linn latex powder with other plant molluscicidal compounds, were evaluated against the freshwater snails Lymnaea (Radix) acuminata and Indoplanorbis exustus in pond. These combinations showed significant time and dose dependent effect against both the snails. These compounds at higher doses were also lethal to freshwater fish Channa punctatus (Bloch) (Channidae {Ophicephalidae}), which shares the habitat with these snails, but the LC90 (24h) doses of snails have no apparent killing properties in fish populations when treated in mixed population of snails and fish.
Os efeitos tóxicos das combinações binárias e terciárias do pó de látex da Euphorbia hirta Linn assim como outros compostos vegetais moluscicidas foram avaliados em sua ação sobre caramujos de água doce Lymnaea (Radix) acuminata e Indoplanorbis exustus em represas. Estas combinações mostraram significante efeito dose e tempo dependente contra ambos os caramujos. Estes compostos em doses altas foram também letais para peixes de água doce Channa punctatus (Bloch) (Channidae {Ophicephalidae}), que compartilham o ambiente com estes caramujos mas a dose LC90 (24h) para caramujos aparentemente não tem propriedade de matar as populações de peixes quando uma população mista de peixes e caramujos são tratadas.
Subject(s)
Animals , Euphorbia/chemistry , Latex , Molluscacides , Plant Extracts , Snails , Disease Vectors , Lymnaea , Latex/isolation & purification , Molluscacides/isolation & purification , Snails/classificationABSTRACT
The currently known distribution range of Achatina fulica Bowdich, 1822, in the state of São Paulo, Brazil, is presented. The record of A. fulica naturally infested with Aelurostrongylus abstrusus larvae (Railliet, 1898) (Nematoda: Metastrongylidae) can be found in the city of Guaratinguetá. It was found A. fulica with Metastrongylidae larvae without known medical and veterinary importance in the cities of Carapicuíba, Embu-Guaçu, Itapevi, São Caetano do Sul, São Paulo and Taboão da Serra.
É apresentada a distribuição de Achatina fulica Bowdich, 1822 no Estado de São Paulo, Brasil. É fornecido o registro de A. fulica naturalmente infestada por larvas de Aelurostrongylus abstrusus (Railliet, 1898) (Nematoda: Metastrongylidae) no município de Guaratinguetá. Foi encontrada A. fulica portando larvas de Metastrongylidae sem importância médica e veterinária conhecida nos municípios de Carapicuíba, Embu Guaçu, Itapevi, São Caetano do Sul, São Paulo e Taboão da Serra.
Subject(s)
Animals , Snails/classification , Snails/parasitology , Strongylida/classification , Brazil , Geography , Population Density , Population Dynamics , Strongylida/anatomy & histologyABSTRACT
Fatty acids composition of the marine snails Phyllonotus pomum and Chicoreus brevifrons (Muricidae). Muricid species of P. pomum and C. brevifrons are of economic importance in the Caribbean. This study includes a comparative evaluation of fatty acid content in the total lipid composition of Phyllonotus pomum and Chicoreus brevifrons. Snail samples were collected during the rainy, dry and transition seasons, in Punta Arena, Sucre (Venezuela). Total lipids were extracted and the specific fatty acid contents were analyzed by gas chromatography. Lipid concentrations varied between 0.87 and 1.85%, with minimum and maximum values corresponding to C. brevifrons collected during rainy and dry seasons, respectively. In the case of total lipids, a high concentration of unsaturated fatty acids (57.21-70.05%) was observed followed by saturated fatty acids (20.33- 31.94%), during all seasons. The polyunsaturated occurred in higher proportion among the unsaturated fatty acids, except for P. pomum which showed higher proportion of monounsaturated fatty acids (38.95%) during the transition season. The prevailing fatty acids were: C14:0, C16:0, C18:0, C20:1, C22:1 ω-11, C22:1 ω-9, C18:3 ω-3, C20:5 ω-3 and C22:6 ω-3, among which docosahexaenoic acid was the predominant polyunsaturated fatty acid, showing values between 4.62 and 33.11%. The presence of high concentrations of polyunsaturated fatty acids found in P. Pomum and C. brevifrons allow their recommendation for human consumption with appropriate resource utilization. Rev. Biol. Trop. 58 (2): 645-654. Epub 2010 June 02.
Se comparó el contenido de ácidos grasos en los lípidos totales de los caracoles Phyllonotus pomum y Chicoreus brevifrons, recolectados en tres diferentes épocas del año en Punta Arena, estado Sucre, Venezuela. Las concentraciones lipídicas oscilaron entre 0.87 y 1.85%, correspondiendo el valor mínimo y el máximo a C. brevifrons colectado en lluvia y sequía, respectivamente. La esterificación de los ácidos grasos presentes en estos lípidos seguida de la cromatografía de gases permitió la caracterización y cuantificación de los ácidos grasos. En los lípidos totales de las dos especies, en todas las épocas, se observaron elevadas concentraciones de ácidos grasos insaturados (57.21-70.05%) seguido de los saturados (20.33-31.94%). Entre los ácidos grasos insaturados, predominaron los de tipo poliinsaturados, exceptuándose el extracto lipídico de P. pomum en época de transición donde las grasas monoinsaturadas fueron las mayoritarias (38.95%). Los ácidos grasos que prevalecieron fueron: C14:0, C16:0, C18:0, C20:1, C22:1 ω- 11, C22:1 ω-9, C18:3 ω-3, C20:5 ω-3 y el C22:6 ω-3, siendo este ϊltimo el predominante entre los αcidos grasos poliinsaturados, presentando porcentajes de distribuciσn comprendidos entre 4.62 y 33.11%. Debido a las altas concentraciones de ácidos grasos poliinsaturados encontradas en ambos caracoles, se recomienda su consumo para la alimentación de los seres humanos.
Subject(s)
Animals , Humans , Lipids/analysis , Snails/chemistry , Chromatography, Gas , Fatty Acids/analysis , Seasons , Seafood/analysis , Snails/classificationABSTRACT
Four species of land snails are described from Costa Rica and Panama. Two are new species and two have remained poorly known since their first discovery. A fifth species from Mexico and Guatemala is illustrated for comparative purposes because it has not been figured since 1877, and previous figures of it are inadequate for comparative purposes. The Spiraxidae subfamilies and the piraxinae genera are redefined. Rev. Biol. Trop. 58 (1): 195-202. Epub 2010 March 01.
Se describen cuatro especies de caracoles terrestres de Costa Rica y Panamá. Dos son especies nuevas y dos han permanecido poco conocidas desde su descubrimiento. Se ilustra en detalle una quinta especie de México y Guatemala, para efectos comparativos, ya que no se había ilustrado desde 1877, y sus descripciones previas no son adecuadas para una comparación. Se redefinen las subfamilias pertenecientes a Spiraxidae y el género Spiraxinae.
Subject(s)
Animals , Female , Male , Snails/anatomy & histology , Snails/classification , Costa Rica , PanamaABSTRACT
Records of the gastropod Melanoides tuberculatus (Müller, 1774), family Thiaridae, in the Piranhas-Assu River basin in Rio Grande do Norte reveal the dispersal of this native Southeast Asian and East African species into aquatic environments of the Brazilian semiarid region, including artificial environments (reservoirs) and lotic systems. The eutrophic conditions of the local waterbodies appear to favor the present situation, where this invasive species reaches extremely high densities, sometimes over 10,000 ind.m-2 as in Armando Ribeiro Gonçalves Reservoir. These observations indicate the immediate need for new studies on the spatial distribution of the species and its potential impact on the biodiversity and water quality of the waterbodies of the semiarid region of the state. Implantation of regular and systematic monitoring of the aquatic resources of the region is urgently required.
Registros da presença do gastrópode Melanoides tuberculatus (Müller, 1774), família Thiaridae, na bacia do Rio Piranhas-Assú no Rio Grande do Norte, revelam a dispersão desta espécie nativa do sudeste asiático e leste africano para ambientes aquáticos do semiárido brasileiro, incluindo ambientes artificiais (reservatórios) e sistemas lóticos. As condições eutróficas dos corpos d'água potiguares parecem favorecer a presente situação, em que a espécie invasora atingiu densidades extremamente elevadas, com valores acima de 10.000 ind.m-2, como no reservatório Armando Ribeiro Gonçalves. Estas observações indicam a necessidade imediata de novos estudos sobre a distribuição espacial da espécie e seu potencial de impacto sobre a biodiversidade e qualidade da água dos corpos d'água do semiárido potiguar. Neste contexto, torna-se urgente a implantação de um regular e sistemático monitoramento dos recursos hídricos da região.