RESUMO

Herein Lepidocyrtinus Börner is reviewed based on African species and a new diagnosis to the genus is provided, including the description of intermediary stages of two species and a proposal for the interpretation of the dorsal chaetotaxy based in juveniles. In total, 17 species previously assigned as Seira Lubbock are transferred to Lepidocyrtinus, and three of them are redescribed: L. barnardi Womersley and L. dayi Yosii from South Africa, and L. voeltzkowi (Börner) from Madagascar. Neotypes are designated for these last two species. In addition, nine new species are described from Africa: one from Botswana, two from Republic of the Congo, two from South Africa, and four from Madagascar. Finally, identification keys for the current genera of Seirinae and for the African species of Lepidocyrtinus are provided. After our revision, Lepidocyrtinus has now its generic status revalidated with 36 species, 29 of them from African continent, two from Oceania and five from Brazil.

Assuntos

RESUMO

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.

RESUMO

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)

Assuntos

RESUMO

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)

Assuntos

RESUMO

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.

Assuntos

RESUMO

This study describes and illustrates the morphology of the first juvenile stage of Aegla castro Schmitt, 1942. Ovigerous females were collected from May to July 2013, in Couro River (Mauá da Serra, Paraná, Brazil). These females were kept individually under controlled feeding, aeration, water temperature and quality and checked daily for hatching of juveniles. The newly-hatched juveniles were fixed in alcohol series and kept in 70% alcohol with glycerin in a 2:1 ratio prior to study under light microscopy. The newly-hatched juvenile of A. castro is the largest among aeglid species whose juveniles have been described. Aegla castro has asynchronous hatching. Some specimens were analyzed using scanning electron microscopy, revealing details of the setal morphology, some cephalothoracic appendages and lineae aeglicae. The number of setae in newly-hatched A. castro is lower than that described for other species, but does not appear to be diagnostic. However, A. castro is the only species described that combines the presence of four plumose setae on the third maxilliped exopod and 63-65 plumose setae on the maxilla exopod.

Assuntos

RESUMO

A remarkable diversity of life history strategies has evolved among species for achieving reproductive success, including adaptive growth, protandry, iteroparity, and extra molting. Here, we report on the reproductive strategies of the litter-dwelling scorpion, Tityus (Archaeotityus) pusillus, the most abundant and widespread scorpion species in the Atlantic Forest of northeastern Brazil. We observed both iteroparity and protandry reproductive strategies in this species. Females were competent to produce up to three broods after a single insemination, and no correlation between female size and litter size was observed. Most males reached adulthood 1 month before females following four molts, characterizing protandry. Nevertheless, an extra molt was observed to occur in some males (n=4) and females (n=1). These findings highlight the life history traits of T. (A.) pusillus, which may imply in reproductive success and adaptation to changes in environmental conditions.

Assuntos

RESUMO

Insect growth is punctuated by molts, during which the animal produces a new exoskeleton. The molt culminates in ecdysis, an ordered sequence of behaviors that causes the old cuticle to be shed. This sequence is activated by Ecdysis triggering hormone (ETH), which acts on the CNS to activate neurons that produce neuropeptides implicated in ecdysis, including Eclosion hormone (EH), Crustacean cardioactive peptide (CCAP) and Bursicon. Despite more than 40 years of research on ecdysis, our understanding of the precise roles of these neurohormones remains rudimentary. Of particular interest is EH; although it is known to upregulate ETH release, other roles for EH have remained elusive. We isolated an Eh null mutant in Drosophila and used it to investigate the role of EH in larval ecdysis. We found that null mutant animals invariably died at around the time of ecdysis, revealing an essential role in its control. Further analyses showed that these animals failed to express the preparatory behavior of pre-ecdysis while directly expressing the motor program of ecdysis. Although ETH release could not be detected, the lack of pre-ecdysis could not be rescued by injections of ETH, suggesting that EH is required within the CNS for ETH to trigger the normal ecdysial sequence. Using a genetically encoded calcium probe, we showed that EH configured the response of the CNS to ETH. These findings show that EH plays an essential role in the Drosophila CNS in the control of ecdysis, in addition to its known role in the periphery of triggering ETH release.

Assuntos

RESUMO

The multivariate allometric growth patterns from longitudinal data of leg and rostral segments of all instars of Belostoma elegans (Mayr) and B. cummingsi De Carlo are presented for the first time, and the allometric coefficients are compared. The segments of the middle and hind legs present allometric coefficients with opposite polarity to those of forelegs. This discrepancy in the ontogenetic trajectories may be due to the different functions of the legs. The foreleg main function is to capture of the prey, while the middle and hind legs are adapted to swimming. The relative size of rostral segments is an important taxonomic character in Belostoma. In B. cummingsi, the proximal segment is longer than the middle one, while in B. elegans they are subequal. Our purpose is to explain these differences through the analysis of their ontogenetic trajectories in an attempt to illuminate the morphological differences among species from a developmental perspective.

Los patrones de crecimiento alométrico de los segmentos del rostro y de las patas de Belostoma elegans (Mayr) y B. cummingsi De Carlo son presentados y comparados por primera vez. Se emplearon datos longitudinales de todos los estadios ninfales en un contexto multivariado. Los segmentos de la pata media y posterior presentan coeficientes alométricos con polaridad opuesta a los de la pata anterior. Estas diferencias observadas pueden deberse al diferente rol que presentan las patas. La función principal de la pata anterior es la captura de las presas, mientras que las patas media y posterior están adaptadas para la natación. El tamaño relativo de los segmentos del rostro es una característica taxonómica importante en Belostoma. En B.cummingsi el segmento proximal es más largo que el medio, mientras que en B. elegans son subiguales. Nuestro propósito es explicar estas diferencias a través del análisis de las trayectorias ontogéneticas en un intento de aclarar diferencias morfológicas entre especies desde una perspectiva del desarrrollo.

Assuntos

RESUMO

The effects of food concentration and temperature on embryonic and postem-bryonic duration of three tropical species, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), were investigated as part of life cycle studies which included growth, body size and reproduction. These are the very first experimental studies undertaken on these species. The long-term growth experiments were performed under controlled laboratory conditions at all combinations of temperature (22"C, 27"C and 32"C) and constant food concentration (0.03, 0.05, 0.10, 0.25, 0.50 and 1.00 mgC/L) of the unicellular green alga Scenedesmus acutus.Animals were examined twice daily throughout their life cycle from the neonate to third adult instar. In all three species, temperature exerted the most powerful influence on embryonic duration but there was also a smaller food effect. In D. gessneri,postembry-onic durations remained more or less the same at food levels 0.25 mgC/L but were influenced by temperature. At food concentrations of 0.1 mgC/L or lower, postembryonic durations became increasingly prolonged, particularly at high temperatures. This threshold concentration is affected by temperature: in D. gessneri,it was 0.1 mgC/L at 22oC and 27oC but higher at 32oC (between 0.25 and 0.50 mgC/L). At the same temperature of 27oC, the food threshold level varied between species: it was higher (0.25 mgC/L) for D. sarsiand lower (0.05 mgC/L) for M. reticulatacompared with D. gessneri(0.1 mgC/L). In both embryonic and postembryonic durations there is a body size effect as the absolute durations were longest in the largest species and shortest in the smallest species In all three species, prolongation of postembryonic duration at combinations of high temperature and lowered food levels was accompanied by increased number of juvenile instars.

Os efeitos de temperatura e concentração de alimento na duração do desenvolvimento embrionário e postembrionário de três espécies tropicais, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), foram investigados como parte dos estudos de ciclo de vida incluindo crescimento, tamanho do corpo e reprodução. Estes são os primeiros estudos experimentais realizados com estas espécies. Os experimentos de crescimento de longa duração foram feitos em condições controladas de laboratório em todas as combinações de temperature (22°C, 27°C e 32°C) e concentração constante de alimento (0.03, 0.05,0.10,0.25, 0.50 and 1.00 mgC/L) de alga verde unicelular Scenedesmus acutus.Os animais foram analisados duas vezes por dia durante o ciclo de vida desde neonata ao terceiro estádio adulto. Nas três espécies, a temperatura exerceu um maior efeito no tempo do desenvolvimento embrionário mas ocorreu também um pequeno efeito de concentração de alimento. Em Daphnia gessneri, a duração postembriônica permaneceu mais ou menos a mesma na concentração de alimento de 0.25 mgC/L mas foi influenciada pela temperature. Na concentração de 0.1 mgC/L ou mais baixa, a duração postembrionária tornou-se mais prolongada, particularmente em alta temperatura. O valor absoluto do nivel crítico de concentração de alimento foi afetado pela temperatura: em D. gessneri, foi 0.1 mgC/L em 22°C e 27°C mas aumentou em 32°C (entre 0.25 e 0.50 mgC/L). Na mesma temperatura de 27°C, o nivel crítico de alimento variou entre as espécies: foi mais alta (0.25 mgC/L) para D. sarsi e mais baixa (0.05 mgC/L) para M. reticulata comparada com D. gessneri (0.1 mgC/L). Em ambos, no desenvolvimento embrionário e postembrionário ocorreu o efeito do tamanho do corpo visto que as durações absolutas foram mais longas nas espécies maiores e mais curtas.na espécie menor. Nas três espécies, o prolongamento do desenvolvimento postembrionário nas combinações de alta temperatura e menores concentrações de alimento foi acompanhado por aumento no número de estádios juvenis.

RESUMO

The effects of food concentration and temperature on embryonic and postem-bryonic duration of three tropical species, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), were investigated as part of life cycle studies which included growth, body size and reproduction. These are the very first experimental studies undertaken on these species. The long-term growth experiments were performed under controlled laboratory conditions at all combinations of temperature (22"C, 27"C and 32"C) and constant food concentration (0.03, 0.05, 0.10, 0.25, 0.50 and 1.00 mgC/L) of the unicellular green alga Scenedesmus acutus.Animals were examined twice daily throughout their life cycle from the neonate to third adult instar. In all three species, temperature exerted the most powerful influence on embryonic duration but there was also a smaller food effect. In D. gessneri,postembry-onic durations remained more or less the same at food levels 0.25 mgC/L but were influenced by temperature. At food concentrations of 0.1 mgC/L or lower, postembryonic durations became increasingly prolonged, particularly at high temperatures. This threshold concentration is affected by temperature: in D. gessneri,it was 0.1 mgC/L at 22oC and 27oC but higher at 32oC (between 0.25 and 0.50 mgC/L). At the same temperature of 27oC, the food threshold level varied between species: it was higher (0.25 mgC/L) for D. sarsiand lower (0.05 mgC/L) for M. reticulatacompared with D. gessneri(0.1 mgC/L). In both embryonic and postembryonic durations there is a body size effect as the absolute durations were longest in the largest species and shortest in the smallest species In all three species, prolongation of postembryonic duration at combinations of high temperature and lowered food levels was accompanied by increased number of juvenile instars.

Os efeitos de temperatura e concentração de alimento na duração do desenvolvimento embrionário e postembrionário de três espécies tropicais, Daphnia gessneri(1.5mm), Diaphanosoma sarsi(1.2mm) and Moina reticulata(0.8mm), foram investigados como parte dos estudos de ciclo de vida incluindo crescimento, tamanho do corpo e reprodução. Estes são os primeiros estudos experimentais realizados com estas espécies. Os experimentos de crescimento de longa duração foram feitos em condições controladas de laboratório em todas as combinações de temperature (22°C, 27°C e 32°C) e concentração constante de alimento (0.03, 0.05,0.10,0.25, 0.50 and 1.00 mgC/L) de alga verde unicelular Scenedesmus acutus.Os animais foram analisados duas vezes por dia durante o ciclo de vida desde neonata ao terceiro estádio adulto. Nas três espécies, a temperatura exerceu um maior efeito no tempo do desenvolvimento embrionário mas ocorreu também um pequeno efeito de concentração de alimento. Em Daphnia gessneri, a duração postembriônica permaneceu mais ou menos a mesma na concentração de alimento de 0.25 mgC/L mas foi influenciada pela temperature. Na concentração de 0.1 mgC/L ou mais baixa, a duração postembrionária tornou-se mais prolongada, particularmente em alta temperatura. O valor absoluto do nivel crítico de concentração de alimento foi afetado pela temperatura: em D. gessneri, foi 0.1 mgC/L em 22°C e 27°C mas aumentou em 32°C (entre 0.25 e 0.50 mgC/L). Na mesma temperatura de 27°C, o nivel crítico de alimento variou entre as espécies: foi mais alta (0.25 mgC/L) para D. sarsi e mais baixa (0.05 mgC/L) para M. reticulata comparada com D. gessneri (0.1 mgC/L). Em ambos, no desenvolvimento embrionário e postembrionário ocorreu o efeito do tamanho do corpo visto que as durações absolutas foram mais longas nas espécies maiores e mais curtas.na espécie menor. Nas três espécies, o prolongamento do desenvolvimento postembrionário nas combinações de alta temperatura e menores concentrações de alimento foi acompanhado por aumento no número de estádios juvenis.