Composição faunística de insetos predadores em fragmento florestal e em área de hortaliças na região de Jaboticabal, estado de São Paulo

A population survey was carried out in a forest fragment and in an area of vegetables, from November/1996 to February/1998, aiming to determine the predator insect species and the influence of abiotic factors. The samples were taken weekly by light traps. The results were evaluated using faunistic analysis and simple correlation with temperature, relative humidity and rainfall. In the forest fragment higher similarity in the abundance of species was observed comparing to the area of vegetables, but the largest number of captured individuals (95%) occurred in this last habitat. Metius sp., Polpochila impressifrons (Dej.), Eulissus sp. and Doru sp. were predominant species in both areas, evidencing they may play an important role as pest predators in areas of vegetables. Arthrostictus speciosus (Dej.) and Leptotrachelus sp. predominated in the forest fragment, and the same was observed with Paederus sp. in the vegetable area. This species is probably adapted for open and hot places, while A. speciosus and Leptotrachelus sp. can be adapted for dark and humid places of forests.

Piranha Attacks on Humans in Southeast Brazil: Epidemiology, Natural History, and Clinical Treatment, with Description of a Bite Outbreak

There are many tales describing ferocious schools of piranha attacking humans, but there are few scientific data supporting such behavior. The very few documented instances of humans attacked and eaten by piranha schools include 3 that occurred after death by other causes (eg, heart failure and drowning). These predaceous fishes, however, do occasionally injure bathers and swimmers in lakes and rivers. The characteristic profile of most injuries is a single bite per victim, generally related to the fish defending its brood. This paper describes an outbreak of piranha bites in a dammed river portion in southeast Brazil. The outbreak was caused by the speckled piranha, Serrasalmus spilopleura, a widespread species which benefits from the growing tendency of damming rivers all over Brazil. This article focuses on the epidemiological and clinical aspects of the injuries, as well as on piranha biology, to gain a better understanding of the natural history of bite outbreaks.

Fruit and seed exploitation by small rodents of the Brazilian Atlantic forest

In the Brazilian Atlantic forest (BAF) there are at least 57 rodent species and most of them are considered omnivorous. These species feed, more or less frequently, on fruits and seeds. Nevertheless the potential role of each species as frugivorous, seed predator or seed disperser is still unclear. In the present study we analyzed patterns of fruit and seed exploitation by eight small rodent species from an Atlantic Forest site. We offered to captive animals fruits of 30 plant species (23 genera, 15 families). After 48 h we recorded consumption patterns of pulp/aril and seed. Rodent species differed in their patterns of fruit and seed exploitation. The smallest species, Akodon serrensis, Oligoryzomys nigripes, and Wilfredomys pictipes (body size range : 26-45 g), and also the medium-sized Oecomys aff. concolor (84 g) fed mainly on pulp and also on small to medium-sized seeds (< 10 mm diameter). The medium-sized rodent, Oryzomys russatus (91 g) fed on pulp and also on seeds with diameter ≤ 15 mm. Thus larger seeds remain intact after being manipulated by such species. The medium-sized Delomys dorsalis (72 g) and the larger Trinomys iheringi (274 g) and Nectomys squamipes (253 g) form a third group, which consumed both fruit and seed of most species independent of their size. These later two species and also O. russatus are probably the main seed predators in the rodent community of the BAF.

Dynamics of handling time and functional response by larvae of Chrysomya albiceps (Dipt., Calliphoridae) on different prey species

One way to understand the behavioural patterns exhibited by a predator in response to prey density is to evaluate its functional response. Such evaluation yields information about basic mechanisms of prey-predator dynamics, and is an essential component of prey-predator models. In this paper we analysed experimentally the functional response and the handling time spent by Chrysomya albiceps on different prey species and larval instars of blowflies. The type II functional response was observed when second instar larvae of Chrysomya megacephala and Chrysomya macellaria were consumed. The handling time spent by the predator was significantly different between instars and species. The implications of the functional response and handling time for the interaction dynamics of Brazilian Chrysomyinae species are discussed.

Tabela de vida ecológica do minador-dos-citros, Phyllocnistis citrella stainton (Lepidoptera: Gracillariidae)

The construction of ecological life tables is a useful tool to understand the population dynamics of insects in the field. In this work, ecological life tables were developed for Phyllocnistis citrella (Stainton) in an orchard of Citrus sinensis situated in Santa Rita do Passa Quatro, Sao Paulo State, during 2002. The occurrence of generation overlay in the field was avoided by obtaining the eggs from infestation on young citrus plants (Citrus limonia) kept under controlled conditions. The samples were taken every other day and the number of live, dead, predated and parasitized individuals were recorded. The occurrence of arthropod predators was determined through visual search on the plants of the orchard. The key factors of mortality acting on P.citrella populations were: pupae parasitism caused by Ageniaspis citricola (Logvinovskaya), action of uncertain factors on prepupae and predation of 3rd-instar larvae. The most abundant arthropod predators belonged to the families Formicidae, Chrysopidae, Coccinellidae, Reduviidae e Araneae. In two of five generations of P. citrella, approximately 4% of A. citricola pupae were hyperparasitized by Galeopsomyia fausta (LaSalle) (Hymenoptera: Eulophidae).

Genetic conservation of Brazilian fishes - Present state and perspectives

Natural environments have been worldwide affected by the growing impact of anthropogenic actions that promote the reduction or the extinction of several vertebrate species. Aquatic ecosystems represent one of the most affected environments and many fish species and/or populations have been increasingly fragmented distributed due to habitat degradation, predatory fishing, introduction of exotic species, river sedimentation, deforestation, pollution, reduction of food resource, and construction of hydroelectric dams. Actually, more than 150 Brazilian fish species, including freshwater, estuary and coastal species, can be considered threatened. Information on the diversity, conservation biology and population analysis on threatened species or populations, with several DNA markers, can be extremely useful for the success of fish species-recovery and maintenance programs. Although DNA analysis in Neotropical fish species are just beginning, they tend to increase with the widespread attention to the use of molecular approaches to minimize problems related to the risk of extinction. The accumulation of information on biology and pattern of genetic variation of fish species, associated with ecological and demographic data, and also education and respect to the nature, constitutes a crucial task to develop efficient conservation strategies in order to preserve the genetic diversity in aquatic environments.

Reproductive modes in frogs and their unexpected diversity in the Atlantic forest of Brazil

Amphibians, and especially the anurans (frogs and toads), exhibit a greater diversity of reproductive modes than other tetrapod vertebrates. Twenty-nine reproductive modes have been recognized for the anurans; we propose 10 more, elevating by more than 34% the number of reproductive modes known for anurans worldwide. These newly recognized reproductive modes for the frogs elevate by almost 48% the number of anuran reproductive modes known for the Neotropics. The highly complex topography of the Atlantic forest, breaking up the biome into many small microhabitats, and the high humidity, which reduces desiccation risks, have enabled the evolution of reproductive specializations such as eggs or tadpoles that develop out of water. Nearly 90% of the Atlantic forest has been cleared, and because several anurans are endemic to this region or have specialized reproductive modes dependent on the forest, this partly explains the generalized population declines and large numbers of species that have disappeared in the last few decades. © 2005 American Institute of Biological Sciences.

Biological control of sheep parasite nematodes by nematode-trapping fungi: In vitro activity and after passage through the gastrointestinal tract

The main method used for the control of gastrointestinal nematodes in sheep production is the application of chemotherapeutic agents, which often lead to the selection of parasites resistant to given active principles. Biological control can be considered a promising alternative, contributing to an increase in the efficacy of verminous control. We determined the in vitro activity and in situ survival of the predatory fungi Arthrobotrys musiformis and Arthrobotrys conoides during passage through the gastrointestinal tract of sheep after oral administration of conidia in microencapsulated form and as a liquid in natura. Initial in vitro tests showed that both fungi were efficient in the predation of trichostrongylid L3 larvae present in the faeces of sheep naturally infected with gastrointestinal nematodes. The fungi presented high nematophagous activity, which was 99.3% for A. conoides and 73.7% for A. musiformis. A. conoides did not survive passage through the gastrointestinal tract under the conditions of the present experiment. On the other hand, A. musiformis was reisolated after administration in either microencapsulated or liquid form, suggesting that this species is a promising alternative for the control of nematodes in sheep since it survives without any protection (in natura). © Springer 2005.

Size-fecundity relationships and reproductive investment in female frogs in the Pantanal, south-western Brazil

The ovarian complement of anurans exhibiting different reproductive modes is highly diverse, and intraspecific variation in reproductive output of anurans is generally related to variation in female properties and/or environmental conditions. The size-fecundity relationships, reproductive investment, and correlation between ovary mass and fat body mass were investigated for females of an anuran assemblage in the Pantanal, Brazil. Female body size was positively correlated with clutch size among seven of the eight species analyzed. However, these results seem to be influenced by seasonal variation in fecundity. Interspecific size-fecundity relationships revealed that female SVL was positively correlated with clutch size and egg size regardless of reproductive mode. Among 11 species analyzed, the reproductive investment (RI: ovary mass relative to body mass) varied from 5.5 to 18%, and there were no differences among reproductive modes and activity patterns (explosive/prolonged). RI correlated negatively with female size. Among three Leptodactylus species examined, negative correlation between ovary mass and fat body mass was verified for two species. Variations in the reproductive strategies are closely related to the reproductive activity patterns and reproductive modes exhibited by individual species, but are also influenced by environmental conditions. However, regardless of reproductive mode or activity pattern, each species seems to exhibit a reproductive strategy that allows them to respond differently to the same environmental restrictions.

Acoustic repertoire and calling behavior of Scinax fuscomarginatus (Anura, Hylidae)

Vocalizations are important in anuran communication, especially during the breeding season. Calling affects spatial organization of males at breeding sites, promotes attraction of new individuals to the chorus, and attracts mature females for reproduction. We describe four distinct vocalizations (advertisement calls, sporadic calls, and two types of aggressive calls) emitted by adult males of Scinax fuscomarginatus. With the exception of the advertisement call, the remaining descriptions are novel. We also describe calling sites, calling season, and nightly calling activity. Fieldwork was made in a fragment of Cerrado (Estação Ecológica de Itirapina), Municipalities of Itirapina and Brotas, State of São Paulo, southeastern Brazil. At this ecological station, S. fuscomarginatus exhibits a complex acoustic repertoire, social interactions and a prolonged reproductive pattern similar to observations of congeneric species at other localities. Copyright 2005 Society for the Study of Amphibians and Reptiles.

Trophic eggs in the foam nests of Leptodactylus labyrinthicus (Anura, Leptodactylidae): An experimental approach

The South American pepper frog, Leptodactylus labyrinthicus, is a large species that lays eggs in foam nests in holes dug out of the banks of different bodies of water. Recently, it was reported that only 6-10% of eggs are fertilized in foam nests of L. labyrinthicus and the remaining unfertilized eggs are consumed by the tadpoles inside the nest. Here we tested experimentally the influence of the ingestion of trophic eggs on the survivorship and growth of L. labyrinthicus tadpoles. Tadpoles fed on trophic eggs and subsequently fed on dry fish food grew larger than those fed only on dry fish food, and this suggests that the ingestion of trophic eggs is an adaptation to improve tadpole growth. The ingestion of trophic eggs also seems to be important for the maintenance of tadpoles in environments with unpredictable rainfall, as they were able to survive for about 70 days feeding only on these trophic eggs and one tadpole managed to complete metamorphosis feeding on trophic eggs only. Details of the spawning behaviour observed in the field, occurrence of multiple mating, and predation on eggs by terrestrial invertebrates and vertebrates are also reported.

Schooling behavior of Mugil curema (Perciformes: Mugilidae) in an estuary in southeastern Brazil

Schools of mullets, Mugilidae, are abundant in estuaries and shallow marine waters. We report on the schooling behavior of juvenile white mullet, Mugil curema, in the estuary of the Canto da Paciência stream, in Ubatuba, southeastern Brazil. Schools of small fish (15 to 35 mm TL) were composed of a larger number of individuals (up to a hundred individuals), and were found feeding mainly in shallow nearshore waters, whereas schools of larger fish (40 to 100 mm TL) were observed only in deeper waters. Three patterns of swimming were observed for the schools: stationary feeding, slow movement while searching for food, and rapid displacement. The variations observed in school structure and behavior seem to be related to the balance between predation risk and increasing food intake. Copyright © 2007 Sociedade Brasileira de Ictiologia.

Alimentação de Serrasalmus maculatus (Kner, 1858) (characiformes; serrasalmidae) no trecho inferior bacia do rio Sorocaba, São Paulo, Brasil

The aim of this study was to discuss aspects of the diet of Serrasalmus maculatus. Fish were collected using gill nets, whose lengths measured 100 m and mesh diameters varied from 3 to 8 cm. A total of 107 individuals were collected. Their length varied from 62 to 210 mm. They were mainly represented by female and immature individuals. No individual was caught in temperatures below 21°C. Four feeding item categories were observed: fish muscle pieces, parts of fish fins, plant fragments, and insects. Comparisons made among individual length classes revealed some significant differences within stomach consumed contents. Individuals whose length exceeded 165 mm consumed only parts of fish muscles and plants. The food availability in the environment and the class lengths amplitude may, however, have influenced the results, in which ontogenetic differences should not be precisely observed.

Os Répteis do Município de São Paulo: Diversidade e ecologia da fauna pretérita e atual

The reptile fauna in the municipality of São Paulo is well sampled due to intensive collection in the last 100 years. In the present work we provide a checklist of reptile species in São Paulo municipality based on preserved specimens in scientific collections. The reptile fauna was also characterized by three ecological parameters: habitat use, substrate use, and diet. We recorded a total of 97 reptile species (two turtles, one crocodilian, 19 lizards, seven amphisbaenians, and 68 snakes). Approximately 70% of the lizards and 40% of the snakes are typical of forest habitats of the Serra do Mar mountain range. Other squamates are typical of open formations that occur mainly on inland Cerrado habitats. All turtles and the crocodilian are associated to riparian habitats. Approximately 63% of the lizards are predominantly terrestrial, and the remaining species are arboreal. Most species of snakes are terrestrial (38%) or subterranean/criptozoic (25%) whereas a smaller proportion are arboreal (18%) or aquatic (9%). Lizards feed upon arthropods. Almost 50% of the snake species are specialized or feed mainly upon anuran amphibians. Other important items consumed by snakes are mammals (24%), lizards (18%), subterranean vertebrates (10%), and invertebrates (earthworms, mollusks and arthropods; 15%). A total of 51 reptile species have not been recorded for the last six years. Probably many of these species are extinct in the region due the intense local urbanization and habitat loss. The survey of species collected in São Paulo municipality and received in the Instituto Butantan in recent years allowed the identification of 10 lizards at least 42 snake species already occurring in the region. The high species richness of the original fauna seems related to the geographic location of the municipality, in a contact zone between forested areas of the Atlantic Forest (ombrophilous forest) and open formations (savannas, high-altitude grassland). Thus, the original habitat composition probably allowed sympatry among different species pools typical of both open and forested formations. The extant snake fauna recorded in the last three years indicates a higher loss of the species in open formations when compared to the forested areas.