Abstract in English:The first record of Argyrodiaptomus bergi (Richard, 1897) from a small roadside pool at high altitude in the southern region of Brazil is presented. This is the ninth record of this species in South America (previously known from Argentina and Uruguay) since its original description, and a new occurrence after 36 years, extending its known distribution to the northeast. The environments where this species was found differ sharply, and possible explanations include the loss of habitat, high species selectivity or deficient sampling efforts. An additional description is provided, with scanning electron microscopy (SEM) photomicrographs and line drawings. Similarly to other species of Argyrodiaptomus, such as Argyrodiaptomus falcifer (Daday, 1905), Argyrodiaptomus denticulatus (Pesta, 1927) and Argyrodiaptomus granulosus (Brehm, 1933), this species shows a restricted distribution in the lower stretches of the Paraná and Uruguay rivers, particularly in small pools. The importance of better understanding the dynamics and diversity of small water bodies is discussed.
Abstract in English:Limnodrilus hoffmeisteri Claparede, 1862 is a cosmopolitan Oligochaeta widely used as indicator of organic pollution in water bodies. Previous contributions have shown the effects of organic matter and temperature on the life history of the species, although very little is known about the factors that influence its reproduction. This study aimed 1) to test whether the larger weight of individuals results in an increase in the reproduction rate and 2) to test the influence of two granulometric fractions of sand on the reproduction and growth the species. In the first experiment, specimens of L. hoffmeisteri were separated in two groups with different average weights (small individuals = 6.63 ± 1.28 mg; large individuals = 12.44 ± 3.99 mg) and kept at 15 ± 1ºC for 21 days. The results of this experiment showed that the number of cocoons was statistically similar between the groups, but the mean number of eggs per cocoon produced by large individuals (2.78 ± 0.35) was greater than that produced by small individuals (7.45 ± 2.50). In the second experiment, weekly observations were conducted for 25 weeks in two groups of 30 specimens: one kept in fine sand and the other in medium sand, at 25 ± 1ºC. The single significant difference was in the number of cocoons per adult per day (0.37 ± 0.22 and 0.23 ± 0.24, for fine and medium sand, respectively). Individuals reared in fine sand produced a greater number of descendants compared to those reared in medium sand in the same period of time.
Abstract in English:The present study describes the life history of Aglaoctenus lagotis Holmberg, 1876 from oviposition to adulthood, analyzing the number of eggs in each egg sac, birth rate, number of instars, sex ratio, cephalothorax size of all instars, and developmental time in laboratory. The results indicate that the studied species can produce two egg sacs during the reproductive period, and that the post-embryonic phase includes 12 nymphal instars. A higher mortality rate was observed during the first three instars, featuring a Type III survival curve. The sex ratio was geared towards the female in the adults and no significant difference was observed in the length of the cephalothorax between male and female. This species can therefore be considered monomorphic. Sexual dimorphism was observed in the cuticle color, with males being light brown whereas females are dark brown.
Abstract in English:This work presents the first data on incubation temperature of Phrynops geoffroanus (Schweigger, 1812) in a natural environment, and provides information on nest predation, hatching success and size of offspring born in the nests on sandy beaches along the Upper Xingu River. Thirty-one P. geoffroanus nests were found, of which eleven were completely predated, mainly by Cerdocyon thous (Linnaeus, 1766). Incubation was completed in nine out of the 17 nests protected by netting. The nests presented an average of 13.1 eggs and were distributed over the various geomorphological sectors of the nine sampled beaches. The size and weight of the hatchlings varied significantly between nests, and the incubation period in protected nests lasted for 76.5 days, less than reported for controlled incubation in the laboratory. Daily variation in incubation temperature in the three nests monitored for temperature was lower in those situated in fine sand sediments. Incubation temperature varied from 22 to 39 C and may have affected hatching success, which reached 60.8% in protected nests. Nest distribution in different geomorphological sectors indicated the plasticity of P. geoffroanus in terms of variation in nesting environment, which partly explains the species' broad geographical distribution.
Abstract in English:In this work we describe the gonad morphology and spawning season of Hypostomus affinis (Steindachner, 1877) in a tropical reservoir based on 55 males and 125 females. Our aim was to assess eventual adaptations in reproductive tactics developed by this riverine species inhabiting an oligotrophic reservoir with low habitat complexity, few rocks and few other preferred consolidated substrata. We described the stages of cells of reproductive lineage, gonadal development and some reproductive traits which were compared with information in the available literature. Cells from the spermatogenic lineage were spermatogonia, spermatocytes, spermatids and spermatozoa, and cells from the oocytarian lineage were primary oocytes, previtelogenic oocytes, cortical vesicle oocytes and yolk globules or vitellogenic. Five stages were described for the males/females according to the distribution of oocytes and spermatogenic lineage cells: resting; initial maturation; advanced maturation; partially spent/spawned; totally spent/spawn. Females outnumbered males and reached larger size. Synchronic ovary development in two groups was found with diameter of mature oocytes ranging from 2 to 3.35 mm. Indication of early maturation, a longer reproductive period and the production of smaller eggs in small clutches seems to be features of the reservoir population not found in riverine systems. Such changes in tactics may indicate a shift to an opportunistic strategy, helping the population to withstand environmental constraints and to succeed in this oligotrophic and poorly structured reservoir.
Abstract in English:In this study we analyzed the diet of the gymnophthalmid lizard Ecpleopus gaudichaudii Duméril & Bibron, 1839, a typical inhabitant of the forest-floor leaf litter, in an Atlantic Forest area in the state of Rio de Janeiro, southeastern Brazil. The 26 individuals sampled during the study had a mean snout-vent length (SVL) of 36.2 ± 4.2 mm and a mean jaw width (JW) of 4.1 ± 0.5 mm. We did not find differences in SVL between males and females, though the sexes differed in JW when the effect of body size was factored out, with females presenting higher values. The diet of the lizards was composed exclusively of arthropods, especially isopods and orthopterans. The similarity in trophic niches among seasons (volumetric and numerical proportions of prey categories consumed) were 0.096 and to 0.43, respectively. There were also no detectable seasonal differences in mean number and mean volume of prey ingested, as well as no significant influence of lizard SVL on prey number and of lizard JW on mean prey volume, which may reflect the tendency of E. gaudichaudii to feed on few, relatively large prey.
Abstract in English:The immature stages (eggs, larvae and pupae), oviposition and larval behavior of Altinote ozomene (Godart, 1819) are described here for the first time. Larvae were reared from egg clutches collected from the host plants Erato vulcanica (Klatt) H.Rob and Munnozia senecionidis Benth (Asteraceae). Eggs were laid in groups on the undersides of leaves. The number of instars varied from five to eight within the same egg clutch, and the corresponding development time from larva to adult varied from 91 to 115 days. Most (72%) larvae pupated during the sixth instar. The first four instars fed only on the leaf cuticle, whereas later instars consumed the whole leaf. Larvae were gregarious during all instars but rested together only during the day in later instars, either hidden inside dry leaves, on the stem at the base of the host plants, or in the leaf litter. Larvae showed similar morphology and behavior to those previously described for species of Actinote Hübner, 1819 from southeastern Brazil and the Andes.
Abstract in English:The Plata pompano, Trachinotus marginatus (Cuvier, 1832), is an endemic carangid of the Southwestern Atlantic Ocean, occurring from Rio de Janeiro to Uruguay. This study describes the reproductive period, spawning type, the size at first gonadal maturation and the length-weight relationship of individuals sampled from landings of the artisanal and commercial fishing fleets in Rio Grande that operate along the coast of Rio Grande do Sul state, southern Brazil (~ 32ºS) to the Uruguayan border (~ 34ºS). Monthly collections from September 2008 through January 2010 yielded 274 individuals ranging from 142 to 444 mm in total length (TL). The gonadal development stages were defined according to the histological examination of the ovaries and the testes. The relationship between TL (mm) and total weight TW (g) was statistically different between males (TW = 0.000463*TL2.7655) and females (TW = 0.000361*TL2.8131), showing negative allometric growth for both sexes. The sizes at first maturity were 187.2 mm and 254.9 mm for females and males, respectively. The presence of two modal groups of oocyte diameters suggested that total spawning occurred. The interpretation of the monthly variations of the condition factor and gonadosomatic index, which are associated with higher frequencies of the more advanced stages of gonadal development, identified the spring and summer months as the reproductive period, with a peak in the reproductive activity during November and January. These results suggested that the species has an opportunistic reproductive strategy.
Abstract in English:The northwestern region of São Paulo was extensively deforested during the agricultural expansion in the last century and only small fragments of the original vegetation cover remained. In this study, we investigated how habitat features influence the composition, richness, and diversity of anurans in environments homogenized by agricultural activities. We sampled monthly six breeding ponds located in pasture areas during twelve months. We recorded ten environmental descriptors for each breeding pond. We found 18 anuran species. The breeding ponds were structurally similar, but species composition differed among them. The environmental descriptors influence varies for each species, as demonstrated by the different associations between species and environmental descriptors shown in the Canonical Correspondence Analysis (CCA). Seven of the ten environmental descriptors explained 67% of the species richness, showing that environmental characteristics influenced the occurrence of the different species. There is no such data set for the region and also for most Brazilian regions, despite its importance in guiding species-oriented conservation actions.
Abstract in English:The objective of this study was to develop a rapid multimetric index using benthic macrofauna as bioindicators of ecological conditions for the upper reaches of the Piabanha-Paquequer-Preto Basin located in the state of Rio de Janeiro, Brazil. A total of 33698 macroinvertebrates were collected in 27 sites. Benthic macroinvertebrates were sampled using the multi-habitat method that consists in sampling 20 m² of substrate collected in approximate proportion to the representation of all major habitat types in the reach. A subsampling procedure was used. The main steps followed to develop and test the index were: exclusion of unsuitable metrics using box-whisker plots, considering the degree of overlapping among interquartile limits (1º-3º) and confirmed by Mann-Whitney U test (p < 0.05) using six reference rivers and six impaired rivers. From all the candidate potential metrics, 36 were considered suitable. After identifying redundant metrics, through Spearman correlation analysis, and considering practical application criteria, six core metrics were selected to compose the Piabanha-Paquequer-Preto Multimetric Index (PPPMI) using the continuous method: Family richness, Shannon-Wiener family diversity, EPT family richness, %Diptera, %MOLD (Mollusca + Diptera) and %Collectors. The sensitivity of the index was tested in 15 rivers using a Principal Components Analysis (PCA) of the six environmental variables. The first axis of the PCA was highly correlated to the PPPMI scores (r = 0.703, p < 0.001). The PPPMI responded to a set of environmental variables associated to a gradient of human disturbance affecting the ecological condition of the waterbodies. This indicates that the PPPMI is an effective tool for biological monitoring and decision making in the hydrographic region of the Piabanha-Paquequer-Preto rivers.
Abstract in English:Even though the caatinga has been identified as an important area of endemism for South American birds, few studies have been conducted on the distribution, evolution and ecology of birds in this biome. Understanding how habitats contribute to maintain the regional bird diversity is extremely important. In this study, carried out in the backwoods of the state of Alagoas, we present a rapid survey of a caatinga area and discuss the composition of the avifauna in different habitats. From the record of 105 species, we estimated a local richness of 120 (± 5) species. Among the areas surveyed, the dense caatinga shrub areas contributed with more than 42% of the species, holding most of the forest-dependent birds. The open field areas and the vegetation patches contributed 26 and 24% of the observed richness, respectively. The bird community at the vegetation patches is more similar to that registered in the open caatinga shrub areas, than to the fauna of the open fields where these patches are located. Our results support the need to conserve environments which harbor typical caatinga vegetation, and also vegetation patches with those characteristics in greatly altered environments.
Abstract in English:Harbor terminals and urban sewage effluents affect the composition and distribution of epibenthic organisms. In this study, we hypothesized that the benthic community structure at the Vitoria Harbor changes spatially in a ~3 km scale, and that these changes are associated with environmental gradients resulting from point-source sewage and differences in the physical and chemical parameters of the water along the harbor access channel. Four sites, internal (PI), intermediate-internal (PMI), intermediate-external (PME) and external (PE), varying from 0.5 to 4.0 km off the harbor, were sampled on five quadrats at six sampling dates (N = 30 per site). The epibenthic community on the shallow sublitoral rocky shore was sampled fortnightly from December 2005 to February 2006 by point-intersection method. A total of 27 taxa were registered with higher richness and diversity values at the external sites. The similarity analysis indicated two distinct systems, with the internal sites PI and PMI apart from the external PME and PE, which showed 97% of dissimilarity. While the internal sites presented some estuarine characteristics and a high coverage (> 60%) of hydrozoans and bryozoans with silt/clay, the external ones showed coastal water influence and higher amounts of sedimentary material substrate (> 50%). This pattern reflects the estuarine gradient and the suspended sedimentary material at the internal sites, which is carried out to the external parts of the channel. The data showed two distinct benthic communities and support the hypothesis that the community structure varies along the harbor access channel in a gradient from the inner to the outer portion of the estuary.
Abstract in English:Species of fruit flies (Tephritidae) were surveyed in a transect of the Amazonian Rainforest in the district of Clevelândia do Norte, municipality of Oiapoque, state of Amapá, Brazil. This study describes the diversity of fruit fly species sampled inside this transect (2.2 linear km). Eleven McPhail traps were serviced weekly from June 2002 to June 2003. A total of 55 samples were obtained, totaling 125 specimens of Tephritidae. Anastrepha Schiner, 1868 was the most abundant and diverse genus, with 18 species caught. Two new species, A. oiapoquensis Norrbom & Uchôa, 2011 and A. siculigera Norrbom & Uchôa, 2011, were discovered in this survey. Anastrepha coronilli Carrejo & González, 1993 (n = 40) was the most abundant species. Six species, Anastrepha amita Zucchi, 1979, A. duckei Lima, 1934, A. flavipennis Greene, 1934, A. minensis Lima, 1937, A. pseudoparallela (Loew, 1873), and A. submunda Lima, 1937, are recorded for the first time from Amapá. Three of them, A. minensis, A. pseudoparallela, and A. submunda, are reported for the first time from northern Brazil. This paper updates to 36 the number of frugivorous species of Tephritidae in Amapá.
Abstract in English:Based on material collected on streams and lakes from the Amazon River floodplain, Brazil, Microvelia urucara sp. nov. is described, illustrated and compared with similar species. The new species, like many other Neotropical Microvelia Westwood, 1834, does not present striking modifications on the body or appendages, but can be separated from its congeners by features of the male genitalia. Distributional data is presented for other veliids collected along the Amazon River, and Paravelia capixaba Moreira, Nessimian & Rúdio, 2010 and Microvelia summersi Drake & Harris, 1928 are recorded for the first time from the Brazilian Amazon. Rhagovelia jubata Bacon, 1948 is newly recorded from the state of Amazonas, and Microvelia mimula White, 1879, M. pulchella Westwood, 1834 and M. venustatis Drake & Harris, 1933 are recorded for the first time from the state of Pará.
Abstract in English:Recognition and identification of red-rumped mice of the genus Juliomys González, 2000 has been a problem among many mammalogists, and specimens of this genus are commonly confused with other Atlantic Forest sigmodontine rodents. Herein we provide an expanded diagnosis for the genus based on the analyses of the three living species of Juliomys, and provide morphological comparisons to the small bodied and bright colored rodents Rhagomys rufescens (Thomas, 1886) and Oligoryzomys flavescens (Waterhouse, 1837), which occur in sympatry with Juliomys spp. in forested areas of southeastern Brazil. These taxa are superficially similar, and are therefore commonly misidentified in the field and museum collections. We also provide morphometric data and a key to the living species of Juliomys, and an updated distribution map of the genus and its species.
Abstract in English:From a series of biological samples collected from different freshwater environments in Costa Rica, Central America, the exotic Asian cyclopoid Mesocyclops thermocyclopoides Harada, 1931 was identified. We analyzed the morphology and appendage ornamentation of different Neotropical populations of this species, including specimens from Honduras, southeastern Mexico, and Costa Rica. We also examined Asian specimens from Taiwan, Indonesia, Vietnam, and Thailand, and performed a comparison of the Neotropical and Asian populations including a Principal Component Analysis (PCA). The Neotropical and Asian specimens show subtle morphological variations in the antennules, antennae, mandibles, swimming legs 1-4, and fifth legs. Some characters in the Neotropical group appear to diverge from the Asian pattern and the PCA indicated that intercontinental populations of M. thermocyclopoides are far from being homogeneous. These intra-specific differences are described to expand the known morphological range of this species and to provide the first comparative analysis of an exotic copepod in the Americas. Our analysis suggests that the geographic isolation of the American populations and the subtle morphological divergences with respect to the Asian patterns could be related to speciation processes in the Neotropical region, but also intra-Asian differences are reported. In the Neotropical region this species appears to be restricted to southeastern Mexico, Central America, and one Caribbean island; its potential as biological control of mosquito might enhance its spread in the region.
Abstract in English:In the present work, we investigated whether it is possible to detect morphometric changes in Rhodnius neglectus Lent, 1954 (a candidate vector of Chagas disease in Central Brazil) populations in the transition from sylvatic to laboratory conditions. We analyzed size and shape variation in wings of sylvatic parents and their laboratory descendents (first, third and fifth generations) using geometric morphometric techniques. Sexual size dimorphism and shape of wings were maintained, but wing size decreased from sylvatic specimens to their laboratory generations. Size variation in R. neglectus should reflect the expected morphometric changes between sylvatic and domestic populations and can be applied to analyze the level of adaptation of R. neglectus to domestic habitats. This information might be useful to detect persistent infestations in dwellings after insecticide application, or new infestations from the sylvatic environment, and is therefore important to guide vector surveillance strategies for Chagas disease.
Abstract in English:We report boring activity of larval Lutrochus germari Grouvelle, 1889 and Stegoelmis sp. in submerged woody debris and describe the resulting grooves and faecal pellet production. This ability of the larvae was shown by three types of evidence: 1) examination of collected woody debris, 2) rearing of larvae and 3) gut content analysis. The larvae excavated galleries deep into the submerged woody debris. This is the first record of gallery-forming behaviour in submerged woody debris by aquatic beetles, adding larval Lutrochus germari and Stegoelmis sp. to the list of borers in Neotropical aquatic systems.
Abstract in English:Saddleback toads (Brachycephalidae: Brachycephalus) are a remarkable group of highly endemic species from the southern Atlantic Rainforest of Brazil. They are brightly colored, diurnal, minute frogs that live in the leaf litter of high-elevation cloud forests. Little is known about the natural history of these frogs, particularly their diet. In the present study we provide the first published account of a Brachycephalus species diet. Specimens of Brachycephalus brunneus Ribeiro, Alves, Haddad & Reis, 2005 (N = 20) were collected from two locations in the Serra do Mar mountain range in the state of Paraná, southern Brazil. A total of 137 food items were recorded, with Acari being the most common item (62.4%). This prevalence is much higher than the actual availability of Acari in their environments (37.7% of all items in leaf litter samples) and therefore indicate their preference for this food item.