Resumo em Inglês:

Synchronized bipedal movements of the pelvic fins provide propulsion (punting) during displacement on the substrate in batoids with benthic locomotion. In skates (Rajidae) this mechanism is mainly generated by the crural cartilages. Although lacking these anatomical structures, some stingray species show modifications of their pelvic fins to aid in benthic locomotion. This study describes the use of the pelvic fins for locomotory performance and body re-orientation in the freshwater stingray Potamotrygon motoro (Müller & Henle, 1841) during foraging. Pelvic fin movements of juvenile individuals of P. motoro were recorded in ventral view by a high-speed camera at 250-500 fields/s-1. Potamotrygon motoro presented synchronous, alternating and unilateral movements of the pelvic fins, similar to those reported in skates. Synchronous movements were employed during straightforward motion for pushing the body off the substrate as well as for strike feeding, whereas unilateral movements were used to maneuver the body to the right or left during both locomotion and prey capture. Alternating movements of the pelvic fins are similar to bipedal movements in terrestrial and semi-aquatic tetrapods. The pelvic fins showed coordinated movements during feeding even when stationary, indicating that they have an important function in maintaining body posture (station holding) during prey capture and manipulation. The use of pelvic fins during prey stalking may be advantageous because it results in less substrate disturbance when compared to movements generated by pectoral fin undulation. The range of pelvic fin movements indicates more complex control and coordination of the pelvic radial muscles.

Resumo em Inglês:

In anurans, acoustic communication is a major mechanism of pre-zygotic isolation, since it carries information about species recognition. Detailed descriptions of the acoustic properties of anuran advertisement calls provide important data to taxonomist and to the understanding of the evolution of the group. Herein we re-describe the advertisement call of the hylid frog Dendropsophus microps (Peters, 1872) after analyzing a larger sample than that of previous descriptions. We also compare the acoustic properties of the call in two populations and discuss the effect of the presence of the sister species, Dendropsophus giesleri (Mertens, 1950), a potential competitor, in one of the populations. Additionally, we provide information on calling sites and size of males. Males of D. microps emit two types of calls, which differ mainly in pulse repetition rate. Type "A" call has a mean frequency band varying from 4574 to 5452 Hz, (mean dominant frequency = 4972 Hz). Type "B" call has a mean frequency band varying from 4488 to 5417 Hz (mean dominant frequency = 4913 Hz). The calls of D. microps and D. giesleri are the only in the D. parviceps species group that have harmonic structure. The spectral properties of the call showed low intra-individual variation, being considered static, while the temporal properties were highly variable. Compared with males from the Boracéia population, males from the Ribeirão Grande population called from lower perches, and their calls had slightly lower frequency bands and significantly higher pulse rates in their type "B" calls. Inter-populational differences in acoustic properties, body size and use of calling sites could be related to selective forces associated with the presence of the sister species, a potential competitor for the population from Ribeirão Grande.

Resumo em Inglês:

The large fruit-eating phyllostomid bat, Artibeus lituratus (Olfers, 1818), forearm 69-75 mm, body mass 66-82 g, has a diversified geographic distribution in the Neotropical region. Therefore it is subjected to different climatic conditions that affect its reproduction, leading to different reproductive strategies such as continuous reproduction, seasonal monoestry or seasonal bimodal polyestry. In this study we used morphometric and histological methods to analyze the annual reproductive activity of A. lituratus males in a population living in the Atlantic Forest, Southeastern Brazil. Testis mass, epididymis mass, gonadosomatic index, seminiferous tubule diameter, and Leydig cell nucleus diameter showed no significant differences (p > 0.05) in the two seasons (wet: October to March; dry: April to September). Additionally, the cauda epididymis was packed with sperm throughout the period of study. Our data indicate that in this population spermatogenic activity was continuous throughout the year. Slight variations in accumulated frequency of pre-meiotic, meiotic and post-meiotic stages of the seminiferous epithelium cycle were observed when compared to other bat species, probably due to species-specific characteristics.

Resumo em Inglês:

The activity time of the lesser bamboo bat, Tylonycteris pachypus (Temminck, 1840), was investigated at two observation locations in southern China: Longzhou and Guiping. Two bouts of activity (post dusk and predawn), with an intervening period of night roosting at diurnal roosts, were identified. The period of activity within each bout was usually less than 30 minutes. The activity periods of individuals belonging to the Longzhou population right after dusk and just before dawn lasted longer than those of the the Guiping population. We also found that the nocturnal emergence time of T. pachypus from the Longzhou population happened earlier than in the Guiping population. These findings indicate that the activity time of T. pachypus was quite short at night, and that different locations may affect the nocturnal activity rhythm of this species.

Resumo em Inglês:

The structure and composition of stream benthic communities are strongly influenced by spatial and temporal factors. This study evaluated the intra and inter-annual variations in Chironomidae communities in subtropical streams. The organisms were sampled from 10 small-order streams during the summer and winter of 2010-2012. The number of chironomid specimens sampled was 7,568, distributed in 49 genera. Chironomid abundance and richness varied intra and inter-annually and community composition varied intra-annually (2010 and 2011). Water temperature, total organic carbon, nitrogen, and rainfall were correlated with chironomid community composition. The intra-annual variation of the community was dependent on climatic variations (temperature and rainfall) and changes caused by intensive agricultural use. We conclude that the temporal variation observed in the Chironomidae community correlates with climatic variations (rainfall) and changes in the total organic carbon and total nitrogen, caused by intensive agricultural land use.

Resumo em Inglês:

This study evaluates whether humic acid (HA; Aldrich) protects the silver catfish, Rhamdia quelen (Quoy & Gaimard, 1824), against exposure to acidic pH. Survival, levels of Na+, Cl- and K+ plasma, hematocrit, hemoglobin and erythrocyte morphometry were measured. Fish were exposed to 0, 10, 25 and 50 mg L 1 HA at four pH levels: 3.8, 4.0, 4.2 and 7.0 up to 96 hours. None of the fish exposed to pH 3.8 survived for 96 hours into the experiment, and survival of fish subjected to pH 4.0 decreased when HA concentration increased. Plasma Na+ levels decreased when pH was acidic, with no influence of HA, while Cl- levels declined at low pH with increased HA concentration. The levels of K+ at pH 4.0 and 4.2 increased without HA. Hematocrit and hemoglobin augmented under the effect of HA. At pH 4.0 and 4.2, erythrocytes of fish not exposed to HA were smaller, an effect that was partially offset by the presence of HA, since the values at pH 7.0 were higher. Although HA showed some positive effects changes in hematological and plasma K+ª in silver catfish caused by exposure to acidic pH, the overall findings suggest that HA does not protect this species against acidic pH because it increased mortality and Cl- loss at pH 4.0.

Resumo em Inglês:

The Neotropical Sasoninae Neodiplothele Mello-Leitão, 1917 is revised and now includes eight species. Neodiplothele can be distinguished from other Sasoninae by the absence of the posterior median spinnerets and differs Neotropical relatives as Cosmopelma by the absence of cuspules on coxae of leg I and Paracenobiopelma by the absence of cuspules on the labium. The male of N. irregularis Mello-Leitão, 1917 and N. picta Vellard, 1924 are described and illustrated for the first time. Neodiplothele leonardosi Mello-Leitão, 1939 is considered a junior synonym of N. irregularis. Five new species are described from Brazil: N. aureus sp. nov. from the states of Ceará, Rio Grande do Norte, Paraíba, and Minas Gerais, N. itabaiana sp. nov. from Sergipe, N. martinsi sp. nov. from Bahia, Espírito Santo, and Minas Gerais, N. indicattii sp. nov. from Espírito Santo, Minas Gerais, Rio de Janeiro, and São Paulo, N. caucaia sp. nov. from Ceará, Goiás, and Mato Grosso do Sul. Two informal groups are proposed based on genitalia morphology: irregularis group and picta group. An identification key and new distribution records for all known species are given.

Resumo em Inglês:

Two new species of Alpaida, A. levii and A. yanayacu, the male of A. iquitos Levi, 1988 and the female of A. gurupi Levi, 1988 are described and illustrated for the first time. Alpaida levii, described from the states of Pará and Amazonas, is closely related to A. delicata (Keyserling, 1892), but differs in that males have a curved and distally pointed terminal apophysis, and females have the epigynum longer than wide and a drop-shaped median lobe. Alpaida yanayacu is only known from Ecuador and is characterized by long and rounded lateral lobes in ventral view and median lobe wide at base. A brief discussion about the morphological similarity among A. levii, A. delicata and A. truncata (Keyserling, 1865) is presented. Based on the information provided, new diagnoses are proposed for A. delicata and A. truncata. New records of A. antonio Levi, 1988, A. bicornuta (Taczanowski, 1878), A. boa Levi, 1988, A. deborae Levi, 1988, A. delicata, A. erythrothorax (Taczanowski, 1873), A. guimaraes Levi, 1988, A. guto Abrahim & Bonaldo, 2008, A. gurupi, A. iquitos, A. leucogramma (White, 1841), A. murtinho Levi, 1988, A. negro Levi, 1988, A. rossi Levi, 1988, A. septemmammata (O. Pickard-Cambridge, 1889), A. simla Levi, 1988, A. tayos Levi, 1988, A. truncata, A. urucuca Levi, 1988, A. utiariti Levi, 1988 and A. veniliae Levi, 1988 are presented.

Resumo em Inglês:

Enchenopa luizaesp. nov. (holotype female from Brazil, State of São Paulo, municipality of São José dos Campos, Parque Natural Municipal Augusto Ruschi at 23°04'05°S", 45°56'22"W, 06.VIII.2011, R. La Rosa leg. deposited in DZUP) is described and diagnosed from the Atlantic Forest Vale do Paraíba, São Paulo, Brazil. The new species is very similar to Enchenopa monoceros (Germar, 1821) in overall aspects but much larger and with inconspicuous lateral secondary carinae. The fourth instar nymph is also briefly characterized.

Resumo em Inglês:

Legitimate flowers visitors pollinate the flower during the visit and thus influence the production of fruits and seeds. We tested whether the visitation rate of potential pollinators is associated with the amount of seeds per fruit produced by the self-compatible bromeliad Tillandsia stricta (Bromeliaceae). We determined whether hummingbirds are legitimate visitors by testing for a correlation between visits and pollination (seed production) at the Guapiaçú Ecological Reserve (Reserva Ecológica de Guapiaçú), state of Rio de Janeiro. We tested 30 flowers, five of which were also monitored to test the possibility of spontaneous self-pollination. The remaining 25 flowers were exposed to floral visitors. Twenty-two flowers formed fruits and seeds, from which three formed seeds without floral visits. The hummingbird Amazilia fimbriata (Gmelin, 1788) was the only legitimate visitor. The average number (± standard deviation) of seeds was 27 units (±15) per fruit. The floral visitation rate by A. fimbriata was 6.6 (±3.4) visits/per flower. The number of floral visits and the amount of seed produced were positively correlated (r² = 0.58, p < 0.01). Thus, A. fimbriata is a legitimate floral visitor of T. stricta, and influences seed production per fruit in this bromeliad.