Abstract in English:ABSTRACT This study aimed to estimate the growth and size at the onset of sexual maturity in a population of Aegla georginae . Specimens were sampled from November 2007 to October 2008 in the Perau Creek (Ibicuí-Mirim sub-basin; Uruguay River basin). All captured specimens were sexed, and their cephalothoracic length (CL), minor and larger propodi length (MPL, LPL, respectively), height of major chela (HMQ), and abdomen width (AW) were measured. The lengthwise growth of males and females was evaluated using the Bertalanffy model, and the morphological sexual maturity was evaluated using the REGRANS program. The smallest ovigerous female presented a 10.45 mm CL. Males reached larger sizes than did females, but the growth rate was similar between the sexes. Longevity estimates for males and females were 670 and 736 days, respectively. The best relationship used to infer the size at morphological sexual maturity in males was CLxHMQ (12.78 mm) and in females was CLxAW (10.78 mm). Aegla georginae follows a common pattern for aeglids in terms of lifecycle, where sexual dimorphism is associated with the onset of morphological sexual maturity.
Abstract in English:ABSTRACT The number of biological invasions has grown dramatically in recent decades, as well as the world's human population and coastal development. Anthropogenic habitats, such as pier pilings and break waters, have been constantly added to marine environment, usually concentrated in estuarine areas. These habitats are focal points for marine invasions, but relatively little is known about the spread of non-indigenous species (NIS) to nearby natural habitats. This study aimed to determine the extent to which NIS have spread to natural substrates both inside estuarine areas and in the adjacent open sea. We conducted a field survey and a literature review, which have been critically discussed and validated. The updated NIS list of benthic invertebrates comprises 19 species: Ascidiacea (5), Cirripedia (5), Cnidaria (3), Mollusca (3), Polychaeta (1), Decapoda (1), and Echinodermata (1). Our results suggested substantial spread of non-indigenous species into natural substrates. Altogether, 18 and 16 NIS were recorded in artificial and natural substrata, both representing 13% of the total species in each habitat. The percentage of NIS was more pronounced in the estuarine areas, 17.6% in artificial habitats and 18.6% in natural ones. Programs developed for the monitoring of marine invasion have to broaden their focus including natural areas adjacent to ports and marinas, to follow the spread and impact of NIS on these areas.
Abstract in English:ABSTRACT The composition of the spider fauna of riparian forests is insufficiently known. These forests, adjacent to both aquatic and terrestrial environments, are recognised as having important ecosystem functions. We compare the composition of spider assemblages of four riparian forests in different drainage basins, along with their microhabitats (edges and forest interior), in the state of Rio Grande do Sul, southern Brazil. Sampling was carried out in the riparian forests of the following rivers: Piratini, municipality of Arroio Grande; Camaquã, municipality of Cristal; Sinos, municipality of Parobé, and Maquiné, municipality of Maquiné. Two samples per season were collected in two years, by sampling the tree-shrub strata with a beating tray, following fixed transects. There were six transects per drainage basin, two per microhabitat: grassland edge, forest interior and river edge. Overall, 42,057 spiders were sampled (juveniles: 79%; adults: 21%). Among the adults (8,851 individuals), we identified 440 species. Similarity analyses (ANOSIM) indicated that the araneofauna composition of the four drainage basins differ in their quantitative (Morisita) and qualitative (Simpson) similarity indexes. There were no differences in composition among microhabitats. The composition of the Maquiné River basin was the most distinct, possibly due to a greater influence of the Atlantic forest on it and a greater dominance of the Linyphiidae Sphecozone personata (Simon, 1894) (SIMPER analysis, contribution to dissimilarity: 12.15%). Differences in spider composition on large spatial scales most likely reflect regional variations in a number of environmental factors, and result in each area having in increased importance in terms of conservation.
Abstract in English:ABSTRACT Secretory cells of the cephalic salivary glands (CSGs) of eusocial bees produce and accumulate lipid-like secretion in the lumens of their alveoli. Correspondingly, secretory cells present typical ultrastructural features of lipid-compound producers. Previous work on bees has revealed inter-specific differences in the chemical composition of secretion, and the production mechanisms and secretory cycle of secretory cells. In this work a comparative analysis of the mechanisms of lipid storage in the CSGs of Apis mellifera (Linnaeus, 1758) and Scaptotrigona postica (Latreille, 1807) workers was carried out. The ultrastructural location of lipids was ascertained using imidazole-osmium (IO), using individuals in different stages of their life cycles. Lipid deposits were identified inside glandular cells and in the alveolar lumens in all individuals, but differences were observed between the species. The glandular cells of A. mellifera workers presented positive reactions to IO as droplets dispersed in the cytoplasm, as vesicles and in the channels formed by apical plasma membrane infolds. In S. postica , lipid compounds were detected inside the mitochondrial matrix and in smooth endoplasmic reticulum cisterns. In both species, forager workers exhibited the largest amounts of lipids stored in the alveolar lumen. The differences between the species are discussed, taking into account specific behavioral differences.
Abstract in English:ABSTRACT Campylothorax viruaensis sp. nov., a new species of paronellid springtail from the Amazon Rainforest, state of Roraima, Brazil, is herein described and illustrated. The new species is characterized by: pale yellow body with dark blue pigment on abdomen III and IV; dorsal chaetotaxy presenting S5i macrochaeta on head, mesothorax with 6-8 macrochaetae in p1-4 complex; A5 as macro or microchaeta on abdomen IV; collophore anterior side with 4+4 anterior long chaetae; and mucro with five teeth. Other characteristics usually omitted in traditional descriptions for the genus are presented such as morphology of apical region of third and fourth antennal segments, labial papillae, chaetotaxy of subcoxae, collophore, abdomen V and ventral region of head. Trunk specialized chaetae (S-chaetae) are also presented. Campylothorax viruaensis sp. nov. is the fourth record of Campylothorax from Brazil, the second from the Brazilian Amazon Rainforest and the first from the state of Roraima.
Abstract in English:ABSTRACT Species of two genera of the tribe Discocerinini from the Neotropics are reviewed with an emphasis on the fauna from Brazil. The two species, Orasiopa (Reymontopa ) mera (Cresson, 1939) and Pectinifer aeneus (Cresson, 1918), are described, illustrated and new occurrence data are provided. Phylogenetic relationships of these two genera into the tribe are discussed. To facilitate identification of these species, we have included diagnoses of the Discocerinini and both genera and have also provided an annotated key to the New World genera in this tribe. We have also provided illustrations, photographs, and scanning electron micrographs of external structures and of structures of the male terminalia for included species.
Abstract in English:ABSTRACT A new species of Isotomiella from Pará State is described and illustrated. This new species belongs to the digitata group, but differs from other by the number of chaetae on manubrium and dens, teeth on the tenaculum and size of the sensilla on abdominal tergites V-VI.
Abstract in English:ABSTRACT Strategies that increase foraging efficiency may also increase predation risk. We investigated how individuals of Hingstepeira folisecens Hingston, 1932, which build shelters at the orb hub, modulate their foraging behaviors in response to the trade-off between capturing prey and becoming exposed by leaving their shelters. We evaluated whether the position of the prey on the web alters the frequency at which spiders leave their shelters. Hingstepeira folisecens spiders were more likely to capture prey positioned below than above the entrance of the shelter. Moreover, when the prey was near the entrance of the shelter, the spider pulled the threads with the entangled prey without leaving the shelter. Conversely, when the prey was distant from the entrance of the shelter, an "attack" behavior (leaving the shelter) was favored. We argue that the "pulling behavior" may be an adaptation to reduce exposure to predators.
Abstract in English:ABSTRACT The behavior of wild olingos is poorly known. From May-Jul 2015, I surveyed nocturnal mammals in southeast Peru and recorded the behavior of olingos. Multiple olingos were observed in close proximity on four occasions: two occasions in which multiple olingos were feeding on the inflorescences of a Parkia pendula tree; an adult and immature olingo traveling together; and a pair of olingos copulating. The copulation lasted at least 142 minutes, and was characterized by the male biting the hind neck and back of the female, constant female vocalizations, and rapid head turning by the female toward the male. Olingos and kinkajous were similarly abundant. These observations offer insight into the behavior of the wild olingo.