Scorpions and life-history strategies: from evolutionary dynamics toward the scorpionism problem

This work aims to contribute to the general information on scorpion reproductive patterns in general including species that can be noxious to humans. Scorpions are unusual among terrestrial arthropods in several of their life-history traits since in many aspects their reproductive strategies are more similar to those of superior vertebrates than to those of arthropods in general. This communication focuses mainly on the aspects concerning embryonic and post-embryonic developments since these are quite peculiar in scorpions and can be directly connected to the scorpionism problem. As in previous similar contributions, the content of this communication is addressed mainly to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. A precise knowledge of reproductive strategies presented by several scorpion groups and, in particular, those of dangerous species may prove to be a useful tool in the interpretation of results dealing with scorpionism, and also lead to a better treatment of the problems caused by infamous scorpions.

Scorpions and life-history strategies: from evolutionary dynamics toward the scorpionism problem

This work aims to contribute to the general information on scorpion reproductive patterns in general including species that can be noxious to humans. Scorpions are unusual among terrestrial arthropods in several of their life-history traits since in many aspects their reproductive strategies are more similar to those of superior vertebrates than to those of arthropods in general. This communication focuses mainly on the aspects concerning embryonic and post-embryonic developments since these are quite peculiar in scorpions and can be directly connected to the scorpionism problem. As in previous similar contributions, the content of this communication is addressed mainly to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. A precise knowledge of reproductive strategies presented by several scorpion groups and, in particular, those of dangerous species may prove to be a useful tool in the interpretation of results dealing with scorpionism, and also lead to a better treatment of the problems caused by infamous scorpions.(AU)

Spatial and temporal distribution and microhabitat use of aquatic breeding amphibians (Anura) in a seasonally dry tropical forest in Chamela, Mexico / Distribución espacial y temporal y uso de microhábitat de los anuros con reproducción acuática en un bosque seco estacional en Chamela, México

Abstract: The distribution of amphibians is affected by abiotic and biotic factors, availability of resources and the characteristics of reproductive sites. In particular, reproductive activity of aquatic-breeding anurans that inhabit tropical dry areas is affected by rainfall, which determines the availability and quality of reproductive sites. In this study, we analyzed the spatial and temporal distribution of anurans with indirect development in a tropical dry forest in Western Mexico, during two rainy seasons (July 10-October 4, 2013, and June 26-September 26, 2014). We collected data on the occupancy and reproductive activity of 15 species in four temporary streams, and evaluated their relationship with precipitation, humidity and temperature. We determined richness, abundance and diversity of species in each stream; we also identified differences in the reproductive strategies and microhabitats used by the species. The most abundant species were: Tlalocohyla smithii and Exerodonta smaragdina, whereas the least abundant were Leptodactylus melanonotus and Incilius mazatlanensis. Species richness, abundance and reproductive activity peaked alongside the stream with the greatest number of breeding sites (e.g. pools). We found temporal segregation in the occupancy and reproductive activity of species in all streams which were mainly associated with precipitation. However, occupancy and reproductive activity of some species overlapped up to four weeks during part of the breeding season. Most species used specific substrates for particular reproductive activities (e.g. oviposition), but used a range of microhabitats (leaf-litter, water, rocks, branches, leaves, logs, etc.) for others (e.g. calling). We discuss these behavioral differences as factors that facilitate coexistence of species in this environment in the rainy season. Rev. Biol. Trop. 65 (3): 1082-1094. Epub 2017 September 01.

Resumen: La distribución de los anfibios se ve afectada por factores bióticos y abióticos, la disponibilidad de recursos y las características de los sitios de reproducción. En particular, la actividad reproductiva de los anuros que habitan las zonas tropicales secas se ve afectada por las lluvias, que determinan la disponibilidad y calidad de los sitios de reproducción. En este estudio, se analizó la distribución espacial y temporal de los anuros en un bosque tropical seco en el oeste de México durante dos temporadas de lluvias (10 de julio- 4 de octubre 2013 y 26 de junio- 26 de septiembre 2014). Se tomaron datos sobre la presencia de 15 especies de anuros con reproducción acuática en cuatro arroyos temporales y su relación con la precipitación, la humedad y la temperatura. Se determinó la riqueza, abundancia y diversidad de especies en cada arroyo; así como, las diferencias en las estrategias de reproducción y el uso de microhábitats por cada especie. Las especies más abundantes fueron: Tlalocohyla smithii y Exerodonta smaragdina, mientras que las menos abundantes fueron Leptodactylus melanonotus e Incilius mazatlanensis. La mayor riqueza, abundancia y actividad reproductiva se registró en el arroyo con el mayor número de sitios para la reproducción (charcas). Encontramos una segregación temporal en la presencia y actividad reproductiva de las especies que se asoció principalmente con la precipitación. También se observó una superposición de especies en algunas semanas durante la temporada de lluvias. La mayoría de las especies utilizaron sustratos específicos para determinadas actividades (por ejemplo, puesta de huevos), pero utilizaron una variedad de microhábitats para otras actividades (por ejemplo, vocalización). Discutimos estas diferencias de comportamiento como factores que facilitan la coexistencia de estas especies de anuros en este ambiente durante la estación lluviosa.

Zooplankton community structure of the lower Xingu River (PA) related to the hydrological cycle

Abstract The zooplankton community of the lower Xingu River shows strong fluctuations in species richness and number of organisms during periods of water level fluctuation. Pulses of density and species richness are adapted to the pulses in water flows and water level. This is conected with reproductive strategies of some zooplankton groups. The spatial heterogeneity of the lower Xingu River consisting of braided channels, bedrocks, macrophyte stands, is probably a relevant factor for the species richness of the zooplankton communities, and may be a fundamental factor for the overall aquatic biodiversity of the lower Xingu River.

Resumo A comunidade zooplanctônica do Baixo Rio Xingú apresenta grandes flutuações em riqueza de espécies e na densidade (no org./m3) durante os diferentes períodos de flutuação do nível da água. Pulsos de densidade e de riqueza de espécies, são adaptados e ajustados aos pulsos em nível da água e fluxo. Isto está conectado com as estratégias reprodutivas de certos grupos de zooplancton. A heterogeneidade espacial do baixo Rio Xingú consistindo de canais anastomosados, pedrais, macrófitas aquáticas é provavelmente um fator relevante que impulsiona a riqueza de espécies das comunidades zooplanctõnicas e pode ser um fator fundamental para a alta biodiversidade aquática do Rio Xingú.

Zooplankton community structure of the lower Xingu River (PA) related to the hydrological cycle / Estrutura da comunidade do zooplancton do Baixo Rio Xingu (PA), em relação ao ciclo hidrológico

The zooplankton community of the lower Xingu River shows strong fluctuations in species richness and number of organisms during periods of water level fluctuation. Pulses of density and species richness are adapted to the pulses in water flows and water level. This is conected with reproductive strategies of some zooplankton groups. The spatial heterogeneity of the lower Xingu River consisting of braided channels, bedrocks, macrophyte stands, is probably a relevant factor for the species richness of the zooplankton communities, and may be a fundamental factor for the overall aquatic biodiversity of the lower Xingu River.

A comunidade zooplanctônica do Baixo Rio Xingú apresenta grandes flutuações em riqueza de espécies e na densidade (no org./m3) durante os diferentes períodos de flutuação do nível da água. Pulsos de densidade e de riqueza de espécies, são adaptados e ajustados aos pulsos em nível da água e fluxo. Isto está conectado com as estratégias reprodutivas de certos grupos de zooplancton. A heterogeneidade espacial do baixo Rio Xingú consistindo de canais anastomosados, pedrais, macrófitas aquáticas é provavelmente um fator relevante que impulsiona a riqueza de espécies das comunidades zooplanctõnicas e pode ser um fator fundamental para a alta biodiversidade aquática do Rio Xingú.

Zooplankton community structure of the lower Xingu River (PA) related to the hydrological cycle / Estrutura da comunidade do zooplancton do Baixo Rio Xingu (PA), em relação ao ciclo hidrológico

Abstract The zooplankton community of the lower Xingu River shows strong fluctuations in species richness and number of organisms during periods of water level fluctuation. Pulses of density and species richness are adapted to the pulses in water flows and water level. This is conected with reproductive strategies of some zooplankton groups. The spatial heterogeneity of the lower Xingu River consisting of braided channels, bedrocks, macrophyte stands, is probably a relevant factor for the species richness of the zooplankton communities, and may be a fundamental factor for the overall aquatic biodiversity of the lower Xingu River.

Resumo A comunidade zooplanctônica do Baixo Rio Xingú apresenta grandes flutuações em riqueza de espécies e na densidade (no org./m3) durante os diferentes períodos de flutuação do nível da água. Pulsos de densidade e de riqueza de espécies, são adaptados e ajustados aos pulsos em nível da água e fluxo. Isto está conectado com as estratégias reprodutivas de certos grupos de zooplancton. A heterogeneidade espacial do baixo Rio Xingú consistindo de canais anastomosados, pedrais, macrófitas aquáticas é provavelmente um fator relevante que impulsiona a riqueza de espécies das comunidades zooplanctõnicas e pode ser um fator fundamental para a alta biodiversidade aquática do Rio Xingú.

Body size and clonality consequences for sexual reproduction in a perennial herb of Brazilian rupestrian grasslands / Consequências do tamanho de corpo e da clonalidade para a reprodução sexuada de uma herbácea perene doa campos rupestres brasileiros

Body size is one of the most important factors regarding herbaceous perennial plants life-histories, and several fitness components of these organisms are related to size. Clonal plants show distinct kinds of reproduction and can develop offspring by sexual or asexual ways. We aimed to understand how body size affects Comanthera nivea (Eriocaulaceae) sexual reproduction and to verify how clonal growth is related to flower head production in this species. We sampled 600 rosettes in rupestrian grasslands and performed linear regression analysis between body size and number of produced flower heads. We also compared the flower head production between isolated rosettes and rosettes within clones. Our results showed that body size was significantly related, but explained only a small part of flower head production. The flower head production was higher in rosettes within clones than in isolated ones. The clones presented a rosette or a small group of rosettes that concentrated the sexual reproduction. Clonality was positively associated with sexual reproduction. Clonality can represent an important way of allowing the persistence of plants by sexual reproduction in markedly seasonal stressful environments. The cases of clonality enhancing the sexual reproduction must be considered and put in focus on reproductive biology research.

O tamanho de corpo é um dos atributos de história de vida mais importantes para plantas herbáceas perenes e muitos componentes da aptidão desses organismos são relacionados ao tamanho. As plantas clonais apresentam diferentes tipos de reprodução e podem gerar prole por vias sexuadas ou assexuadas. Nosso objetivo foi compreender como o tamanho de corpo afeta a reprodução sexual em Comanthera nivea e verificar como o crescimento clonal relaciona-se à produção de capítulos dessa espécie. Nós amostramos 600 rosetas em campos rupestres e utilizamos regressões lineares para verificar a relação entre o tamanho de corpo e o número de capítulos produzidos pela planta. Nós também comparamos a produção de capítulos entre rosetas isoladas e rosetas pertencentes a clones. Nossos resultados mostram que o tamanho de corpo tem influência positiva significativa na produção de capítulos, mas explica apenas parte da variação nos dados. A produção de capítulos é maior em rosetas pertencentes a clones que em rosetas isoladas. Os clones geralmente apresentam uma roseta, ou um grupo de rosetas, que concentra a reprodução sexual. A clonalidade apresentou ligações significativas com a reprodução sexuada. Em ambientes sazonais a clonalidade pode representar uma importante forma de persistência das plantas já que pode permitir um melhor desempenho da reprodução sexuada em vista dos estresses ambientais. Os casos nos quais a clonalidade representa uma via de melhor desempenho para a reprodução sexuada devem ser considerados e colocados em foco na pesquisa em biologia reprodutiva.

Investimento materno e história reprodutiva de mães residentes em contextos com diferentes graus de urbanização / Maternal investment and reproductive history of mothers living in contexts with different degrees of urbanization

A presente pesquisa tem como objetivo caracterizar o investimento materno e a história reprodutiva de mães que vivem em diferentes contextos. Para tal, 150 mães que residiam em três contextos com diferentes graus de urbanização foram entrevistadas. Por meio da análise estatística dos dados constatou-se que houve diferenças significativas entre os contextos, além de correlações positivas entre os núcleos reprodutivos, como idade da primeira relação sexual e idade da mãe no nascimento do primeiro filho. Conclui-se que as estratégias reprodutivas são influenciadas pela história de vida das mães, das condições sociodemográficas atuais e do contexto onde vivem.

The present study has the purpose to characterize both the maternal investment and the reproductive history of mothers from different contexts. To this end, 150 mothers living in three contexts with different degrees of urbanization were interviewed. Through statistical analysis of the data, it was found that there were significant differences between contexts as well as positive correlations between reproductive cores, such as age at first sexual intercourse and mother' age at the birth of the first child. It was concluded that reproductive strategies are influenced by the mothers' life history, current sociodemographic conditions, and the context where they live.

Reproductive strategies and genetic variability in tropical freshwater fish

We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus) based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1), acid phosphatase (EC 3.1.3.2), esterase (EC 3.1.1.1), glycerol-3-phosphate dehydrogenase (EC 1.1.1.8), glucose-6-phosphate dehydrogenase (EC 1.1.1.49), glucose-6-phosphate isomerase (EC 5.3.1.9), Iditol dehydrogenase (EC 1.1.1.14), isocitrate dehydrogenase - NADP+ (EC 1.1.1.42), L-lactate dehydrogenase (EC 1.1.1.27), malate dehydrogenase (EC 1.1.1.37), malate dehydrogenase-NADP+ (EC 1.1.1.40), phosphoglucomutase (EC 5.4.2.2) and superoxide dismutase, (EC 1.15.1.1). The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.