Abstract in English:The current study aimed to evaluate the diet of Monodelphis glirina (Wagner, 1842) in forest fragments of Alta Floresta, located in the south of the Amazon, state of Mato Grosso. The diet was determined by the analysis of the stomach contents from 57 subjects sampled between May and September 2009. Nine food categories were present: Coleoptera, Orthoptera, Hymenoptera, Diplopoda, Nematoda, seeds, miscellaneous, hair and bait leftovers (banana and peanut butter). Coleoptera was the category eaten most frequently, rating 50% of abundance and 91.22% of occurrence. "Seeds" were the least abundant (0.11%) and rated 1.75% in occurrence, probably because seeds are easy to digest. The size of the fragments negatively and significantly influenced the amount of Coleoptera in the diet. The rainy season seemed to have significant influence over the abundance of arthropods in the diet. The items in the diet suggest that M. glirina is opportunistic and has a generalist diet, tending to be insectivore when living in the forest and exploring the food resources according to their availability.
Abstract in English:This study analyzed the diet and reproductive dynamics of Trachelyopterus lucenai Bertoletti, Pezzi da Silva & Pereira, 1995, an allochthonous fish species in the subtropical coastal lagoons of the Tramandaí River, Rio Grande do Sul, Brazil. The fecundity of the species is described for the first time. Specimens were captured in the interconnected lagoons Itapeva, Quadros and Malvas, on a monthly basis, from November 2008 to April 2010, with gillnets of different mesh sizes. The food items identified were assessed for abundance and frequency of occurrence. The sex ratio, reproductive period for males and females, for mature females, fecundity, were estimated. These results were analyzed with respect to seasonal variation. We captured 135 individuals, including 82 females and 53 males, especially in months with high temperatures (October 2009 to March 2010). Females were more abundant than males in all months. There was no difference between the mean size of females and males, and both sexes showed allometric growth. The feeding analysis showed a generalist-opportunist food habit; 26 items were consumed, with a predominance of autochthonous items (insects and fish). Temporal variations in diet were associated with variations in water and air temperature and rainfall in the region, but these variations did not differ between males and females. The sex ratio differed significantly from 1:1, with 1.5 females per male. The reproductive period occurred from October to March, with most activity in November and December, and showing no variation between the peaks of gonadal development of males and females. The mean fecundity of mature females was 1,536 oocytes per spawning (n = 17). The feeding habits and reproductive behavior of the species in the study site are similar to those described for where the species is native. Although clearly seasonal, the reproductive period was long, in spite of the low fecundity. These features facilitate the establishment of T. lucenai and make it a good competitor in the new environment.
Abstract in English:Storms, associated with strong winds and heavy rains, are often the most severe physical disturbances in shallow coastal areas causing instability to sedimentary environments. We hypothesized herein that if storms influence short-term assemblage structure of macrofauna, then assemblages should change after storms, while remaining relatively stable over calm weather conditions. The study was conducted at the subtropical Paranaguá Bay, in southern Brazil. We selected four 700 m² sites, at the estuarine outlet, to monitor changes in number of species, number of individuals and Shannon diversity. Sampling was arranged considering the weather forecast so that both before and after conditions could be recorded. Data of each site was tested separately to access the significance of specific (before/after) comparisons using t tests. There were no clear effects of storms on macrofaunal species richness, abundance and diversity at the four sampled sites. Conversely, we showed that short-term variation in abundances occurred regardless of weather conditions. Increased dispersal may be the most common process associated with storms instead of mortality. Storms that intermittently affect the southern coast of Brazil can be thus seen as minor driving forces of shallow-water estuarine macrofauna. Effects of extreme meteorological events remain to be assessed.
Abstract in English:The laboratory-hatched first zoeal stage of twelve brachyuran species collected in the estuarine area of the Caeté River in the Amazonian region are described and illustrated in the present study: P. americanus Saussure, 1857, Eurytium limosum (Say, 1818), Sesarma curacaoense De Man, 1892, S. rectum Randall, 1840, Armases rubripes (Rathbun, 1897), Aratus pisonii (H. Milne Edwards, 1837), Ocypode quadrata (Fabricius, 1787), Uca rapax (Smith, 1870), U. maracoani (Latreille, 1802), U. thayeri Rathbun, 1900, Ucides cordatus (Linnaeus, 1763) and Pachygrapsus gracilis (Saussure, 1858). Through intraspecific comparisons of the respective larval stage, an identification key was generated and provided. Most of the studied species presented morphological differences (e.g. type and presence or absence of setae) when compared to the same species previously described in the literature.
Abstract in English:We examined the effects of meal size on the postprandial metabolic response of the lancehead Bothrops alternatus (Duméril, Bibron & Duméril, 1894), fed mice equaling to 5, 10, 20, and 40% of the snake's body mass. The maximum O2 consumption rates measured during digestion increased with meal size, reaching levels up to 2.8-7.8-fold higher than the metabolic rate measured during fasting. Specific Dynamic Action (SDA) duration also increased with meal size, lasting from 54 to 212 hours to complete. Under our experimental conditions, 30ºC, the majority of our snakes failed to completely digest prey with a relative size of 40%. The SDA coefficient ranged from 17 to 27% of the energy content of the meal and was not affected by meal size.
Abstract in English:The enzymatic activities involved in the digestion of proteins and carbohydrates were compared among three organs of the digestive track of two Siluriformes fish species, and between two areas: a reservoir, and an area downriver of it. Our aim was to test the hypothesis that the digestive organs of species with varied feeding habits have different enzymatic activities, and that the enzymatic activity differs among seasons and environmental conditions. The iliophagous/herbivorous species Hypostomus auroguttatus Kner, 1854 had higher trypsin-like, chymotrypsin-like peptidase and β-glucosidase activity in the intestine when compared with the omnivorous species Pimelodus maculatus Lacepède, 1803, whereas the latter had more hepatic trypsin-like activity than the former. The peak of activity of the three enzymes in H. auroguttatus was recorded in the winter and spring. On the other hand, P. maculatus tended to have the more prominent peptidase and β-glucosidase activity in the summer, and the smallest in the winter. The intestine of H. auroguttatus had higher enzymatic (trypsin, chymotrypsin and β-glucosidase) activity than the stomach and the liver. For P. maculatus, the highest β-glucosidase activity was found in the liver. The enzymatic activity of H. aurogutattus did not differ between lotic and lentic systems, whereas P. maculatus had comparatively higher stomach and hepatic trypsin levels and hepatic chymotrypsin-like activities in the reservoir than down in the river. These findings indicate that, in H. auroguttatus, most digestive activity occurs in the intestine, which is long and adapted for the digestion of bottom-river vegetable matter and detritus. The seasons and the type of the system (lentic vs. lotic) seem to affect the enzymatic activity for these two species differently, a likely consequence of their different lifestyles.
Abstract in English:Stalked barnacles Octolasmis lowei Darwin, 1851 are frequently found attached to decapod crustaceans. Their epibiotic association depends on many factors, which are mainly related to characteristics of the host's biology. This study evaluated the infestation and distribution of stalked barnacles in the branchial chambers of crabs, and analyzed the data with respect to the host's sex, maturity stage, molt cycle and size. The crab species Arenaeus cribrarius Lamarck, 1818, Callinectes danae Smith, 1869, Callinectes ornatus Ordway, 1863, Hepatus pudibundus Herbst, 1785, Libinia ferreirae Brito Capello, 1871, and Persephona punctata Linnaeus, 1758 were sampled and found to be infested by O. lowei. No juvenile crabs were infested. The prevalence of infestation by O. lowei was significantly different among C. danae, C. ornatus, and H. pudibundus males and females. All infested hosts were in the intermolt period. The mean size of infested crabs was larger than that observed for non-infested individuals. Internally, stalked barnacles were concentrated on the central gills or walls and floor of branchial chambers, suggesting that these gills provide more favorable conditions for the settlement and development of these epibionts. These results highlight the relationship between epibiont infestation and host biology, as well as the role of decapod crustaceans as a suitable substrate for the development of stalked barnacle O. lowei.
Abstract in English:Pathological alterations and autoecology of Didymocylindrus simplex in Katsuwonus pelamis (Linnaeus, 1758) in the Southwestern Atlantic Ocean off of South America are presented. This is the first record of the species in the region; the specimens are described. The pathologic changes observed most often were infiltration of lymphocytes and slight fibrosis of the connective tissue surrounding the parasite. The typical aggregated distribution pattern was observed for Didymocylindrus simplex Ishii, 1935. Statistical analysis demonstrated no correlation between the abundance and prevalence of parasites with the total length of the host. The sex of the host does not influence the prevalence and intensity of infection.
Abstract in English:We describe Metarthrodes oxum sp. nov. from Camacan, state of Bahia, Brazil, the second species of Caelopyginae described from the state, after Metarthrodes xango Pinto-da-Rocha, 2002. Metarthrodes oxum sp. nov. can be recognized by the presence of a pair of white spots on area I, white C-shaped stripes on lateral grooves of area III, posterior margin with transverse white stripe, grooves of mesotergal areas well-marked, posterior margin of dorsal scute slightly concave, and medial third of femur IV of male with three large and spiniform retrolateral tubercles. We tested the generic placement of the new species via cladistic analysis. Metarthrodes oxum sp. nov. clustered within Metarthrodes, forming a clade with M. pulcherrimus (Mello-Leitão, 1931), M. nigrigranulatus Roewer, 1913 and M. longipes (Soares, 1945), which was unresolved in the consensus cladogram of the 72 optimal trees found, and is supported by the following synapomorphies (all present in males only): trochanter IV with long internal apophysis; retrolateral submedian tubercle on femur IV, and a pair of white spots near the groove. We also provide an updated identification key for the species of Metarthrodes.
Abstract in English:Two new species of Alpaida O.P.-Cambridge, 1889 are described based on male and female specimens from seven restinga areas from northeastern to southern Brazil. Alpaida teresinha sp. nov., from Rio de Janeiro and Espírito Santo, differs from other species of the genus in the wider lobe of the conductor, the concave median apophysis and with the posterior lobe ventrally positioned, and the wrinkled distal projection of the terminal apophysis in males. Females can be recognized by having widely spaced epigynal lips and by the narrow epigynal notch in ventral view. Alpaida toninho sp. nov., from Bahia, Espírito Santo, Rio de Janeiro and Santa Catarina, can be distinguished by the round lobes of the terminal apophysis, and by the median apophysis with a distal lobe and a projection in males, and by the epigynum elliptical, with a short scape in females.
Abstract in English:A new species of Stygnidae Simon, 1879, Imeri ajuba sp. nov., is described based on males and females from Coari, Amazonas, Brazil. The new species, differs from the only other species of the genus, Imerilomanhungae Pinto-da-Rocha & Tourinho, 2012, in having the following characteristics: three white marks on posterior margin of dorsal scutum, one white mark on free tergite I, three pairs of tubercles on area I, one pair of tubercles on area II, femur IV with ventromesal row of five tubercles, truncus of penis with six pairs of setae on lateral and ventral sides and ventral plate with two pairs of distal setae on dorsal portion.
Abstract in English:A remarkable new species of Avicularia Lamarck, 1818, Avicularia rickwesti sp. nov., is described from Dominican Republic. Female specimens of the new species are unusual by having two very short and broad spermathecae with distal half strongly sclerotized, a feature not found in any other aviculariine. Additionally, it has the leg coxae with spiniform setae, smaller on leg I and prolateral leg II, larger, black on retrolateral leg II, prolateral and retrolateral leg III and prolateral leg IV. Males are unknown. The new species is known only from two localities, in southwestern Dominican Republic. This is the first record for the subfamily on Hispañola which is close to the northern boundary for the Aviculariinae distribution.
Abstract in English:Linyphiidae is currently the second richest family of spiders in the order Araneae but is poorly known and studied in Brazil, particularly in the northern states. In this contribution we describe a new species of Exechopsis Millidge, 1991 from the State of Amazonas, based on both males and females. The male of Meionetaadami Millidge, 1991 is described for the first time. Mermessus conjunctus (Millidge, 1991), Novafrontina uncata (F. O. Pickard-Cambridge, 1902), Sphecozone fastibilis (Keyserling, 1886), Sphecozone ignigena (Keyserling, 1886) and Vesicapalpus simplex Millidge, 1991 are recorded for the first time from Amazonas. Sphecozone crassa (Millidge, 1991) are presented additional record from Amazonas.
Abstract in English:A new species of Seira Lubbock, 1869 is described and illustrated. Seiraglabra sp. nov. is the second species described from the municipality of Areia (Caatinga biome) and the seventh from the state of Paraíba, Brazil. Compared with other species of the genus, Seira glabra sp. nov. has some remarkable reductions on dorsal chaetotaxy, specially on the methatorax and first abdominal segment. The most similar species to S.glabra sp. nov. is Seira praiana. Both lack macrochaetae on the first abdominal segment.
Abstract in English:Immatures are important sources of information about characters, thus potentially improving classification and phylogenies. Euschistus (Mitripus) grandis Rolston, 1978 occurs in southern and southeastern Brazil. There are no references in the literature about this species other than the original description and distribution records. Our aim is to describe the egg and five nymphal instars of E. (M.) grandis, addressing the ontogeny of the external scent efferent system. Specimens of E. (M.) grandis were collected on Solanum pseudocapsicum Linnaeus (Solanaceae) in São Francisco de Paula, Rio Grande do Sul, Brazil, and reared in the laboratory. The egg of E. (M.) grandis is white and barrel-shaped, chorion translucent bearing spines connected by thin sheets forming polygons. Aero-mycropilar processes translucent and slightly clubbed. The nymphs bear anterior dorsal abdominal scent glands (DAG) with slit-like ostiole continued by a short groove; from the second instar onward median and posterior DAGs with rounded ostiole bearing closing cuticular valve. Spout peritreme flat and curved anteriorly, evaporatorium network-shaped surrounding ostiole plus peritrema; alveoli surface with trabeculae. Nymphs of E. (M.) grandis can be distinguished from other species of Euschistus by the color pattern and morphological features. The most striking morphological characteristic of 4th and 5th instar nymphs of E. (M.) grandis is the broad, deflected projection of humeral angles.
Abstract in English:Aeneolamiabucca sp. nov. is described and illustrated based on specimens collected in the municipality of São José do Barreiro, state of São Paulo, Brazil. This new species can be distinguished from others of the genus by presenting an aedeagus with two long and slender processes directed upward (in the other species of the genus, this processes are directed downward); paramere with only one subapical strong spine and a concavity located below this spine, which is unusual in the Neotropical genera.
Abstract in English:The type locality of the South American Tern, Sterna hirundinacea, has long been considered to be the state of Santa Catarina in South Brazil. This conclusion was probably based on two syntypes, from the Muséum national d'Histoire naturelle in Paris, France, one from Laguna and the other from an unspecified locality. The latter was probably shot on the coast of Rio de Janeiro. A recent molecular study has shown that Brazilian and Patagonian populations of S. hirundinacea are not completely panmictic, though genetic differentiation between them is low. No data from the Falkland Islands and Pacific coast populations have been available for comparison. If future analysis shows that Pacific and/or Falkland/Malvinas populations are genetically isolated from the Brazil-Patagonian ones, the name S. hirundinacea would apply only to birds from the latter populations. Given that the two syntypes were collected at two widely spaced localities, doubts exist as to the precise locality where one syntype was taken, and to clear up uncertainties, a lectotype of S. hirundinacea is herein designated.
Abstract in English:Harvestmen feed on live, dead and fresh, or decomposing animals, fungi, and plant matter, being very dependent on chemoreception to find food. Herein we performed an experiment to test if individuals of Discocyrtus pectinifemur Mello-Leitão, 1937 (Gonyleptidae) (n = 23) behave differently when in contact with olfactory cues from different sources (rotten prey, non-rotten prey and a control). Using dead crickets in a box covered with a mesh, and recording the time the harvestmen spent in the vicinities of the box, we show that D. pectinifemur detects non-rotten prey and stays longer on it than on the other two treatments. Our results contrast with a previous study on another species, showing that we should not generalize results obtained for one species. Our data also suggest that olfactory receptors occur on the legs of these harvestmen and that D. pectinifemur might choose dietary items based on olfaction.