RCAAP Repository

Longitudinal distribution of Mimagoniates microlepis and Hoplias malabaricus was analyzed in a coastal stream system in Southeast Brazil. Six sites were sampled by electrofishing in seven months, from July 94 to July 95. Densities of M. microlepis, and H. malabaricus and its prey (Poecilia vivipara, Deuterodon sp. and Astyanax janeiroensis) were estimated by the Zippin method; environmental variables of: (i) kind of substratum; (ii) percentage of pools, runs, riffles, instream vegetation, and canopy were registered for each site in each sampling month. The relative importance of each biotic and abiotic variable was tested through simple correlation analyses. We verified that M. microlepis occurrence correlates with canopy; H. malabaricus is correlated with instream vegetation, pools, clay substratum, and P. vivipara densities; and P. vivipara correlates with pools and clay substratum. Our results suggest that environmental variables, and food and shelter availability are the main factors in determining M. microlepis and H. malabaricus distribution.

The leaf mine in Richterago riparia is caused by a lepidopteran larva (lepidopteronome). The leaves of R. riparia show campdodrome venation; the epidermis is unistratified, with stomata and glandular trichomes in adaxial and abaxial surfaces. The mesophyll is bilateral and the vascular system is collateral. During the formation of the mine, the larva consumes the chlorenchyma of the mesophyll and the smaller vascular bundles (veins of third and fourth orders). Structural alterations in the tissues of the host plant were not observed, except for the formation of a wound meristem and the presence of cells with phenolic substances next to the mine. Three cephalic exuviae of the miner were found in the mesophyll. This lepidopteronome is parenchymatic and the epidermis remains intact, but forms a protective layer for the mining insect.

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Twenty-seven species of calyptrate muscoids (Muscidae and Sarcophagidae) were collected from December 1993 to November 1994 with wind oriented traps (W.O.T.) baited with decomposing beef liver at the Rio de Janeiro Zoo. The most abundant species found were Musca domestica (57.84%), Peckia chrysostoma (28.16%), Ophyra aenescens (17.11%), Oxysarcodexia thornax (17.82%), Synthesiomyia nudiseta (13.05%), and Oxysarcodexia diana (14.52%).

Some 263 birds were recorded near and in a 230-ha patch of semideciduous forest in cane fields of central São Paulo, Brazil. Subtracting 67 open-area species, 22 of marshes or creeks, 10 vagrants and 12 recorded later, 152 forest and border species were recorded in 1982-86, much like what was observed in a similar woodlot near Campinas. Both woodlots lost species gradually over the years. Some birds avoided hard cane-field edges, preferring soft bushy edges. Of open-area species, 22 seemed to have disappeared by 1997 due to earlier high El Niño rains or rare permanently open habitats in the sugar cane; 17 new species were mostly nocturnal ones not noted earlier, or occasional visitors. Forest and borders lost 31 species, gaining five of dry regions and one winter visitor. Several migrants from the south appeared only in wet years before recent greenhouse effects, some resident birds were hunted, and canopy hummingbirds were perhaps still present. Dry-forest travel-prone or "metapopulational" species moved their centers of distribution, partly concealing loss of moist-forest diversity.

Spatial and temporal distribution of larvae and juveniles of trahira, Hoplias aff. malabaricus (Erythrinidae), and their relationship with environmental parameters in the Upper Paraná River floodplain were analyzed. Sampling of larvae and juveniles of H. aff. malabaricus has been conducted during the period from November 1991 through February 1995, with 42 sampling stations distributed in four sub-areas: Ivinhema I, Ivinhema II, Baía, and Paraná. During the same period, data were obtained for water temperature, dissolved oxygen, pH, electrical conductivity, river level, precipitation index, and photoperiod. The largest catches of larvae were in the Ivinhema I sub-area (47.06%), and of juveniles in the Paraná sub-area (54.55%). Larvae and juveniles were caught from October to February. Larvae were mainly collected at night and in all types of environments sampled (lotic, semi-lotic, and lentic). Principal Component Analysis of the environmental parameters and larval density showed that the largest catches were obtained in dry season months, with low values for temperature, electrical conductivity, river level, and photoperiod, and with high concentrations of dissolved oxygen and pH. This reproductive strategy may minimizes predation and maximizes food utilization, as it enables the fish to reach advanced developmental stages, while most other species are spawning.

The chemical composition of plants can vary according to factors such as soil and time of collection. Desmodium adscendens (Sw.) D.C. var. adscendens (Papillionaceae) is a plant employed in the treatment of asthma in Ghana, Africa. Studies have shown that butanolic extract inhibits contraction of the ileum and trachea in guinea pigs. In Mato Grosso, this plant is used only in the treatment of ovarian inflammation.The objective of this work was to verify if the plant found in Mato Grosso also relaxes smooth muscle and to understand better its action.The cumulative application of the butanolic fraction relaxed the contraction maintained in the isolated anococcygeus of a rat, induced by high potassium, but not that induced by phenylephrine. Relaxation was not altered by methylene blue. The butanolic fraction reduced in a concentration-dependent way the maximum response of concentration-response curve to calcium in the anococcygeus muscle. The results suggest that the butanolic fraction acts, at least partly, through the blockade of voltage-sensitive Ca+2 channels.

Laboratory studies were conducted to verify the influence of photophase on diapause incidence in the Neotropical brown stink bug, Euschistus heros (Fabr., 1798), fed with soybean [Glycine max (L.)] Merrill pods. Nymphs were maintained at three different photophases: 10 h, 12 h, and 14 h, with constant temperature of 25 ± 1ºC and relative humidity of 65 ± 5%. With 14 h, aproximately 100% of the adults showed mature reproductive organs; the shoulder (spine) length was significantly greater (2.96 and 2.79 mm for females and males, respectively) than those of bugs maintained at the photophase of 12 h (2.60 mm for females and males) and 10 h (2.59 and 2.53 mm for females and males). At the longer photophase (14 h), E. heros showed better reproductive performance and greater feeding activity than insects reared at 10 h and 12 h; in all photophases bugs tended to reduce feeding from the 1st to the 6th week of life. Body color was considered an unreliable parameter to indicate diapause incidence. However, at 14 h, 60% of the insects were dark brown and 40% were reddish brown. These results indicate that E. heros enters reproductive diapause with photophase of 12 hours or less, showing immature reproductive organs or with intermediate development, with shoulder (spine) less developed and reduced feeding activity.

Uteri from four pregnant females and two newborn of shortfin mako, Isurus oxyrinchus, were collected in the southeastern region of Brazil, during September, October, and November of 1993 and 1994. All embryos were near-term with developing dentition and inner organs. Total length ranged from 64.5 to 72.0 cm, and the maximum number of embryos observed in a litter was 20. These observations further confirmed oophagy as a form of nutrition in this species, and its periodicity. The presence of teeth in the embryos' stomachs suggest that tooth replacement begins in the uterine phase.

This study is a contribution to the ex situ and in situ conservation and preservation of Sloths. The behavioral records of the social interaction between mothers and offspring allow the detection of important learning interactions and psychomotor development. The results provide valuable information that may assist in improving management conditions of captive orphan progeny. They also favor a more effective monitoring of released or transferred specimens. Age is of fundamental importance in deciding what is important during the release, transfer, or reintroduction of the species.

The nervous system of the order Scorpiones appears to have a common organizational structure. The combination of an anatomical study using methylene blue as the contrast medium together with a histological analysis using hematoxylin-eosin and Heindenhain´s iron hematoxylin techniques permitted the identkfication of a large number of nerves in B. bonariensis. Many of these are also present in a variety of other species of scorpions, belonging to distinct families of the order Scorpiones. Nevertheless, two pairs of nerves from B. bonariensis originating in the cheliceral ganglion, one pair of esophageal nerves and one pair of nerves from the aortic arch, appear to diverge from this basic organization. They have not been previously described, nor have any equivalents been reported in research on other scorpion species, in which the current homological criteria have been employed.

Five species of anuran amphibians, all belonging to the family Hylidae, were collected at Praia das Neves, municipality of Presidente Kennedy, southeastern Brazil,. The species were represented by four genera: Scinax, Hyla, Aparasphenodon, and Trachycephalus. Four species (A. brunoi, Hyla albomarginata, Scinax altera, and S. cuspidatus) were found during the dry season (August 1999), and two (A. brunoi and Trachycephalus nigromaculatus) in the rainy season (February 2000). Aparasphenodon brunoi was the most abundant species in Praia das Neves. Some reproductive aspects and feeding habits of this hylid were investigated. Aparasphenodon brunoi was found mainly inside the bromeliad Aechmea lingulata, the largest plant analyzed. Fifteen specimens were collected during the dry season (August 1999) (11 males and 4 females). During the rainy season (February 2000), we collected 14 specimens (3 males, 10 females, and 1 juvenile). Sex-ratio was 1:1. Frogs ranged in snout-vent length from 31.2 to 69.3 mm. Females were larger than males. One female had 1,451 fully developed oocytes in her ovaries. The major groups of prey found in the stomachs were: Insecta, Myriapoda, and Arachnida. Blattodea, Orthoptera, Lepidoptera, and Hymenoptera (only ants) were the main food types in frequency, number, and weight. Aparasphenodon brunoi is a threatened species in many habitats of southeastern Brazil. Only natural vegetation protection may guarantee its survival during the immediate future.

Natural enemies of the gall maker Eugeniamyia dispar (Diptera: Cecidomyiidae) were studied on the urban area of Porto Alegre, RS, Brazil from October 1993 to March 1996. Galls and associated arthropods were followed weekly in the field on individual host plants (Eugenia uniflora, Myrtaceae) and also in the laboratory. Three species of ants attacked the galls, the most common being Pseudomyrmex sp. A proportion of galls was parasitised by Rileya sp. (Eurytomidae). The adults of this solitary ectoparasitoid were also attacked by the ants and fell prey to spider webs.

The development of the galls of the midge Eugeniamyia dispar Maia, Mendonça-Jr. & Romanowski, 1996 (Diptera: Cecidomyiidae) was monitored weekly on its host plant, Eugenia uniflora (Myrtaceae). The work was carried out in the urban area of Porto Alegre, RS, Brazil, from October 1993 to September 1995. Galls were collected from the field and raised in the laboratory to obtain adults. The females oviposit on young leaves of the host plant, with the first instar larvae inducing the gall, which is unilocular. The last instar larvae drop to the soil to pupate and later emerge as adults. The galls occur from late August to early June, when young leaves of the host can be found, with populations peaking during the summer. So far this species is only known from the two southernmost states of Brazil (RS and SC).

We have studied the terrestrial reptile fauna of the Abrolhos Archipelago (a group of five islands located ca. 70 km off the southern coast of the State of Bahia, Brazil) and analyze here some of its ecological aspects such as diet, thermal ecology, activity, and some reproductive parameters. Three lizards comprise the archipelago's terrestrial reptile fauna: Tropidurus torquatus (Tropiduridae), Mabuya agilis (Scincidae), and Hemidactylus mabouia (Gekkonidae). The first two are diurnal and the latter is crepuscular/nocturnal (initiating activity at ca. 17:30). The activity period of T. torquatus extended from 5:30 to 18:30 h. Mean field body temperatures of active T. torquatus, M. agilis, and H. mabouia were, respectively, 34.0 ± 3.7ºC (range 23.8-38.0ºC; N = 75), 34.5 ± 2.2ºC (range 30.8-37.0ºC; N = 6), and 26.3 ± 1.1ºC (range 24.8-28.0ºC; N = 8). The predominant prey items in the diet of T. torquatus were ants, coleopterans, and hemipterans. In the diet of M. agilis, coleopterans were the most frequent prey items. For H. mabouia, the most important dietary items were orthopterans. Clutch size of T. torquatus averaged 4.1 ± 1.1 (range 2-6; N = 15) and was significantly related to female size (R² = 0.618; p = 0.001; N = 15). Clutch size for H. mabouia was fixed (two) and mean litter size of the viviparous M. agilis was 3.3 ± 0.6 (range 3-4; N = 3). Tropidurus torquatus and H. mabouia deposit their eggs under rocks in the study area, with the former burying them but not the latter; in both species, more than one female often oviposit under the same rock.

The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1st, 3rd, 7th, 14th, 28th, 56th and 72nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60ºC) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW--1) on the remaining detritus of Eichhornia azurea was recorded in the 56th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW--1. In the rainy season, higher density was found in the 28th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW--1. Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7th and 14th days in the rainy and dry seasons, respectively.

The crude organic extracts of the endemic gorgonian Phyllogorgia dilatata and two sponge species Aplysina fulva and Mycale microsigmatosa were evaluated for anti-fouling properties through field experiments. To investigate this property in ecologically meaningful conditions, crude extracts from these invertebrates were incorporated at concentrations naturally found in these marine organisms into a stable gel used as a substratum for fouling settlement. Crude extract from A. fulva showed no significant anti-fouling property at the natural concentrations used in the field experiments. In fact, fouling organisms settled significantly more on gels treated with A. fulva extract than on the control gel. On the other hand, both M. microsigmatosa and P. dilatata yielded crude extracts that exhibited a selective action inhibiting only the settlement of barnacles. The evidences obtained here by means of field experiments can provide a basis for future development of one kind of natural antifoulant technology to prevent marine biofouling.

Adult body size, one of the most important life-history components, varies strongly within and between Heliconius erato phyllis (Lepidoptera: Nymphalidae) populations. This study determines if this variation is caused by geographical changes in host-plant used by the larval stage, whose reproductive parameters are influenced by female body size, with estimates of the corresponding heritability. The variation in adult body size was determined together with a survey of passion vine species (Passifloraceae) used by the larvae in seven localities in Rio Grande do Sul State: three located in the urban area of Porto Alegre and Triunfo Counties, two within Eucalyptus plantations (Barba Negra Forest, Barra do Ribeiro County, and Águas Belas Experimental Station -- Viamão County), one in a Myrtaceae Forest (Itapuã State Park -- Itapuã County) and one in the Atlantic Rain Forest (Maquiné Experimental Station -- Maquiné County). Effects of female body size on fecundity, egg size and egg viability were determined in an outdoor insectary. Size heritability was estimated by rearing in the laboratory offspring of individuals maintained in an insectary. The data showed that adults from populations where larvae feed only upon Passiflora suberosa are smaller than those that feed on Passiflora misera. The larvae prefer P. misera even when the dominant passion vine in a given place is P. suberosa. Fecundity increases linearly with the increase in size of females, but there is no size effect on egg size or viability. Size heritability is null for the adult size range occurring in the field. Thus, the geographical variation of H. erato phyllis adult size is primarily determined by the type, corresponding availability and quality of host-plants used by the larval stage. Within the natural size range of H. erato phyllis, the variation related to this caracter is not genetically based, thus being part of H. erato phyllis phenotypic plasticity.

A redescription of conchological and anatomical characters of the planorbid mollusc Plesiophysa ornata (Haas, 1938) is presented, based on topotypic material and specimens from 14 additional localities in the Brazilian states of Rio Grande do Norte, Paraíba, Sergipe, Bahia, Espírito Santo and Minas Gerais. Due to the close similarity of their shells, a sure discrimination of the five species of Plesiophysa described so far (P. pilsbryi, P. granulata, P. guadeloupensis, P. ornata and P. hubendicki) is only possible through their anatomical features. The present study points to the high probability of synonymy of P. hubendicki with P. ornata. Investigations on the anatomy of P. pilsbryi and P. guadeloupensis are needed to define their taxonomic relation with the other nominal species.

Figs are a remarkable food resource to frugivores, mainly in periods of general fruit scarcity. Ficus calyptroceras Miq. (Moraceae) is the only fig species in a type of dry forest in western Brazil. In this study I examined the fruiting pattern as well as fig consumption by birds in F. calyptroceras. Although rainfall was highly seasonal, fruiting was aseasonal, since the monthly proportion of fruiting trees ranged from 4% to 14% (N = 50 trees). I recorded 22 bird species feeding on figs. In the wet season 20 bird species ate figs, while in the dry season 13 did. Parrots were the most important consumers. This group removed 72% and 40% of the figs consumed in the wet and dry seasons, respectively. No bird species increases fig consumption from dry to wet season. However, a group of bird species assumed as seed dispersers largely increases fig consumption from wet to dry season, suggesting the importance of this resource in the period of fruit scarcity. The results of this study points out the remarkable role that F. calyptroceras plays to frugivorous birds, in such a dry forest, since its fruits were widely consumed and were available all year round.