Dissertações em Zoologia (Mestrado) - PPGZOOL/ICB

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2344

O Mestrado Acadêmico foi criado em 1985 e pertence ao Programa de Pós-Graduação em Zoologia (PPGZOOL) do Instituto de Ciências Biológicas (ICB) foi consolidado como um convênio entre Universidade Federal do Pará (UFPA) e Museu Paraense Emílio Goeldi (MPEG).

Navegar

Agora exibindo 1 - 20 de 244

Acesso aberto (Open Access)
Composição e biogeografia da avifauna das ilhas Caviana e Mexiana, foz do Rio Amazonas
(Universidade Federal do Pará, 1994-01-14) HENRIQUES, Luiza Magalli Pinto; OREN, David Conway; http://lattes.cnpq.br/5451507856491990
The islands of Caviana and Mexiana, located in the mouth of the Amazon River, are composed of fluvial sediments and well consolidated lands that date from the Terciary and that were separated from the continent by tectonic action at the beginning of the Holocene. The composition of the avifauna of these islands is analized both from the biogeographical and the ecological points of view. I registered 148 bird species for Caviana Island and 183 for Mexiana Island. The discrepancy between the size of the two islands (Caviana is larger than Mexiana) and the number of species observed is due to undersampling of Caviana. However, the analysis of faunal composition demonstrated that Caviana is richer in forest species than is Mexiana. In contrast, Mexiana showed a greater richness of birds of open habitats. These differences suggest that the rising of sea level at the beginning of the Holocene caused the extinction of greater part of the fauna of the understory ou Mexiana. The portions of Mexiana Island with "teso" vegetation were not submerged, maintaining their characteristic avifauna, which is also represented on Marajó Island. To analyse of the distribuitions of 157 species I subdivided the avifauna into seven categorias: widespread distribution in South America (77 species); widespread Amazonian distribution (25); distribution restricted to eastern Amazonia (7); distribution restricted to south of the Amazon River and east of the Tapajós River (3); distribution restricted to várzea (19); widespread distribution in northern Amazonia and absent from the Tocantins-Xingu interfluvium (5); and widespread distribution in Central Brasil (21). I did not find elements restricted to the Tocantins-Xingu interfluvium. This fact is related to ecological rather than historical factors. The pattern related to northern Amazonia can be interpreted as the result of recent dispersal, the system of islands at the mouth of the Amazon, or by the formation of the Purás and Gurupá Arches, which, associated with the lowering of sea level during Pleistocene, established a connection between lhe right and left banks of the Amazon River. The dispersal occurred in both directions, explaining lhe existence of a large number of species and subspecies with distributions restricted to eastern Amazonia, as well as the dispersal of Central Brasilian elements to north of the Amazon River. This last component of the avifauna is a1so related to the expansion of open vegetations, characteristic of Central Brazil, during glacial periods.
Acesso aberto (Open Access)
Os mosquitos (Diptera : Culicidae) da Estação Científica Ferreira Penna - ECFPn, Caxiuanã, Melgaço Pará, Brasil: ataque, sazonalidade e estratificação arbórea
(Universidade Federal do Pará, 1996-12-10) ROCHA, José Almir Moraes da; BARATA, José Maria Soares; http://lattes.cnpq.br/5244792275470127; MASCARENHAS, Bento Melo; http://lattes.cnpq.br/3279744837272788
This research was developted in 1995 from February to December, at the Ferreira Penna Research Station, in the municipality of Melgaço, state of Pará, within the Caxiuanã National Forest, with the objective of study the seasonal and daily activities in the forest and anthropic environment and the levels at which various species are found in the forest. The collects were made using human bait and CDC light trap with bird bait in the forest at ground and canopy and human bait in the anthropic environment. The total collection consisted of 1.919 mosquitoes belonging to the genera Aedes Meigen, 1818, Anopheles Meigen, 1818, Haemagogus Williston, 1896, Psorophora Robineau-Desvoidy, 1827, Culex Linnaeus, 1758, Coquillettidia Dyar, 1905, Mansonia Blanchard, 1904, Uranotaenia Lynch-Arribalzaga, 1891, Limatus Theobald, 1901, Phoniomyia Theobald, 1903, Ruchomyia Theobald, 1903, Sabethes Robineau-Desvoidy, 1827, Trichoprosopon Theobald, 1901 e Wyeomyia Theobald, 1901. The predominant species were Culex (Melanoconion) portes! Senevet & Abonnec, 1941 (50,65%), Coquillettídia (Rhynchotaenia) venezuelensis (Theobald, 1912) (9,17%) and Haemagogus (Haemagogus) janthinomys Dyar, 1921 (6,51%). The daily and seasonal activities of mosquitoes species was correlated with temperature, relative humidity and rainfall, using the Spearman correlation, and statistically significant relations were found for some species with these factors. The hypothesis of the significative difference between the species and exemplaries mosquitoes number at ground and canopy was tested using X² test, that was just significant between the exemplaries mosquitoes number at ground and canopy in human bait in the forest.
Acesso aberto (Open Access)
O gênero microstrates lacordaire (Curculionidae : Baridinae): sistemática, filogenia e evolução da associação com palmeiras hospedeiras
(Universidade Federal do Pará, 1997-03-11) ROCHA, Roberta Valente da; GORAYEB, Inocêncio de Souza; http://lattes.cnpq.br/2391620537048479
A revision and phylogenetic analysis of the genus Microstrates is presented based on new characters discovered in the course of this study, and on others previously know from the literature. Eleven species are recognized, vvhich can be identified by the key presented. Two new species are described: Microstrates almiri sp. n., Caxiuanã and Belém, Pará; and M. pinrima sp. n., Monte Alegre, Pará. Microstrates bipunctatus Hustache, 1951 is considered a synonym of M. cocois Bondar, 1941. The phylogenetic analysis of the species Microstrates resulted in a hypotesis that may be expressed parenthetically as follows; ((M. cocoscampestris (M. abbreviatus (M. rufus, M. hatschbachi))) ((M. M. piririma) (M. cocais (M. cearanus, M. ypsilon) (M. cucullus, M. bondan)))). The first records of the palm hosts of M. almin sp. n., M. pirinma sp. n. and M rufus Hustache are presented. The species M. almin sp. n. and M. pirinma sp. n., collected in Pará state, represent the first record of Microstrates in the Amazonian Region. Ali species are redescribed and their most important structures for the identification are illustrated. The collection of Weevils in differents species of palms in Pará and Amazonas states confirms the hypothesis of a exclusive association of Microstrates with palms of the genera Syagrus, Butia and Cocos, and also that each species of Syagrus and Butia host only one species of Micro strates. The cladogram mapping and optimization of host palm associations of Microstrates supports the following hypothesis: association with the genus Syagrus is plesiomorphic, with Butia is apomorphic, and with the coconut (Cocos nucifera) is explained by colonization events.
Acesso aberto (Open Access)
Dimorfismo sexual quanto ao tamanho em três espécies de sabiás amazônicos (Aves: Passeriformes: Turdidae)
(Universidade Federal do Pará, 1997-11-28) SOUZA, Suely Basilio de; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Three species of Brazilian thrushes replace one another ecologlcally along the primary and secondary forests of the Eastern Amazonian Region, Turdus T fumigatus and T. leucomelas. These three species are monochromatic, i. e., me and female have similar plumages. Whether these species are monomorphic (i.e., if males and females are of similar size) or not has not been previously investigated. Studies in Mexican forests indicated that some monochromatic birds from the Neotropical Region are in fact cryptically dimorphic, i. e., males and females differ statistically in size when suitable statistic techniques are appiled. This work has three main objectives: (a) to evaluate the pattern of sexual dimorphism in size in T. albicollis phaeopygus, T. fumigatus fumigatus and T. ieucomelas albiventer, (b) to contribute to the study of the sexual dimorphism in size of Neotropical monochromatic birds, and (c) to provide subsidies for evolutionary and ecological studies on the genus Turdus, and also on the family Turdidae as a whole. The working hypothesis here was the three species of Turdus studied would be cryptically dimorphic in a pattern similar to the passeriform forest birds previously studied in the Mexican forests. Of the three species studied, two were found to be monomorphic (T. f fumigatus and T. a. phaeopygus) and one cryptically dimorphic (T. 1. albiventer). In the only cryptically dimorphic species, males differ significantly from females in the length of the wing, tad, tarsus and fourth toe claw. However, a reliable sexual identification cannot be performed from the discriminant linear function obtained. The reason the three species of Turdus are monomorphic or cryptically dimorphic may be associated with their pre-reproductive behavior. During the mating season. vocalization seems to be more important to attract females and for territorial defense than plumage or size. Thus, there is a strong selective pressure for vocalization of males and weak or non-existent pressure for body size. It is suggested that more research for the evaluation of sexual dimorphism in other species of Turdus and. a phylogenetic analysis of this large genus are indispensable in clarifying the evolution of patterns of sexual dimorphism in thrushes.
Acesso aberto (Open Access)
Levantamento da quiropterofauna (Mammalia : Chiroptera) da Ilha de Cotijuba - PA, com observações sobre sua ecologia
(Universidade Federal do Pará, 1999) ROCHA, Mônica Monteiro Barros da; MARQUES-AGUIAR, Suely Aparecida; http://lattes.cnpq.br/8269757332399292
Surveys of Amazonian bats have recorded the occurrence of at least 135 regional species of different feeding habits- insectivorous, frugivorous, polinivorous, carnivorous and hematophagous. Bats contribute to the balance of the Amazonian biota in different ways; e.g. population control of insects, dispersion of seeds and polinization. Flematophaguous bats are potentially dangerous to humans because were they can carry the rabies vírus. The objectives of the present study were: (a) inventory of the bat species of Cotijuba island - PA; (b) descriptions of the activity period, feeding habits, reproduction and roosting sites of the different species; (c) rabies diagnosis of the hematophagous bats coliected. Thirty-one species were recorded, two of which lack more detailed taxonomic studies for diagnosis. Most of the species are frugivorous (for example, Carollia spp., Artibeus spp., Uroderrna spp.), i.e. potential seed dispersers of the local flora. Two hematophagous species were observed: Desmodus rotundus (about 8% of the sample) and Diaemus youngi (less than 1% of the sample). The rabies vírus was not recorded, but there are records of attacks by bats on humans and domestic animals, demanding continuous analyses of new samples, for effective health care monitoring.
Acesso aberto (Open Access)
Biologia e estrutura populacional das espécies da família sciaenidae (Pisces : Perciformes), no estuário do rio Caetê município de Bragança, Pará-Brasil
(Universidade Federal do Pará, 1999-03) CAMARGO-ZORRO, Mauricio; ISAAC, Victoria Judith; http://lattes.cnpq.br/3696530797888724
This study aimed to assess the average biomass and spatial and temporal distribution of the family Sciaenidae fishes in the estuary of the Caeté River, northern of Brazil, with special reference to the species Stellifer rastrifer, Stellifer naso, Macrodon ancylodon and Cynoscion microlepidotus. Age at first sexual maturity (L50), spawning season, the length-weight relationships, food diet, population consumption by biomass (Q/B), population structure and dynamics were estimated. 6 Bimonthly samples were taken in the estuarine area of the Caeté River, from October 1996 to August 1997. The average biomass of the family Sciaenidae was 0,840g/m². The spatial distribution in the system was related to spawning and recruitment. Juveniles of S. rastrifer, S. naso e M. ancylodon occurred inside some areas in the estuary, although larger individuals were abundant outside where salinity is higher. The L50 values were 10cm, 10,7cm e 21,5cm respectively. Two spawning periods in a year were found, which determine the recruitment of two cohorts, with different growth parameters. The length-weight relations were allometric and no differences were found by sex. An ontogenetic change was found in the diet composition of these species; young prey zooplancton and adults feed predominantly on larval stages of decapodes and poliquetes, and juveniles of fishes. Diet overlaps changed during the ontogenic development of each species. The relation Q/B indicated that S. rastrifer and S. naso consume more food in relation to the body size, in opposite to the larger species like M. ancylodon and C. microlepidotus. The fishes of the Caeté River presented higher growth and low longevity when compared to the same species inhabit the higher latitudes.
Acesso aberto (Open Access)
Comportamento alimentar e dispersão de sementes por guaribas (Alouatta belzebul) na Estação Científica Ferreira Penna (Caxiuanã / Melgaço / Pará)
(Universidade Federal do Pará, 1999-04-13) SOUZA, Luciane Lopes de; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
The behaviour of two free-ranging groups of red-handed howler monkeys (Alouatta belzebul) was monitored at the Ferreira Penna Research Station (Pará) over' a thirteen-month period in 1997/98, in order to record their ecological characteristics, especially their diet and seed dispersal. Quantitative behavioural data were obtained using instantaneous scan sampling. Invariably, the howler monkeys were relatively inactive, dedicating more than half their activity time to resting, and much smaller proportions to locomotion, feeding and social behaviour. Use of the home range was strongly influenced by the distribution of food patches, in particular fruiting trees. The diet was basically folivorous-frugivorous, although fruit was the item consumed most frequently (54.1 % of feeding records for the principal group, denominated "L") in the "winter" months (November-April), whereas leaves were consumed far more frequently (84.5 %, group L) in the "summer" (May-August). Seeds took 22:49±6:12 h, on average, to pass through the digestive tract, and ingested seeds were dispersed a mean distance of 172,0±113,8 m, although this distance was significantly greater in the winter. Germination rates recorded in tests in both field and laboratory were inconclusive on the effects of ingestion on viability. The germination rate of ingested seeds was significantly greater than the control (uningested) in only a few cases, such as that of Ficus guianensis, the principal source of fruit. Even so, ingestion did not have a marked negative effect on viability in any case. Overall, the present study reforces the view of A. belzebul as a typical howler monkey, ecologically, albeit relatively frugivorous, and playing a important role as a seed disperser in the Amazon Forest.
Acesso aberto (Open Access)
A comunidade zooplanctônica em um canal de maré no estuário do rio Caeté, Bragança (Pará, Brasil)
(Universidade Federal do Pará, 1999-04-30) PERES, Ariadne da Costa; ISAAC, Victoria Judith; http://lattes.cnpq.br/3696530797888724
There are few studies mede about zooplankton in estuaries of Bragança region, Pará State. This work was done in a tidal creek, named Furo do Chato, next to Ajuruteua, Bragança's district which is part of Pará State seashore and aimed to study lhe zooplankton qualitative and quantitative composition, as well as lhe sazonal variations and the environmental effect variables of the zooplankton composition. From August/96 to January/97 every three weeks for a period of 24 hours, zooplankton samples were taken every two hours. Furo do Chato is a tida l creek with strong coaste! influence. Hence the great majority of lhe zooplankton categories found are from coaste! water. Besides holoplankton and meroplankton components, lhe zooplankton samples from Furo do Chato has a strong bentonic component. Ten phyla were identified: Protozoa, Mollusca, Chordata, Annelida, Cnidaria, Arthropoda, Urochodata, Chaetognatha, Nematoda e Bryozoa. The Copepoda class had higher representative, even for density, biomass as well as occurrence frequency in the community. The most abundant and frequent Categories (>40%) were Pseudodiaptomus marshi, Acartia lilljeborgi, Acartia tansa, Harpacticoida, Sagitta sp., Oikopleura dioica, Cnidaria, Isopoda, crabs zoeas, shrimps post-larvae and fish larvae. The average densities and biomass were low (1,07 indiv./m³ e 16,43 mg/m³). The zooplankton community is more abundant in the transition months than in the dry period. The highest abundances took place at night and during the spring lides. Tide, salinity and different moon phases did not infiuence in the zooplankton as a whole, but only in some categories isolated.
Acesso aberto (Open Access)
Avaliação das comunidades de formigas em uma área de extração madeireira
(Universidade Federal do Pará, 1999-07-30) KETELHUT, Suzana Maria; HARADA, Ana Yoshi; http://lattes.cnpq.br/4410204692155098
This work presents a comparative study of ant fauna communities inhabiting in a primary tropical forest and two types of logging systems (Managed and Traditional) located in Paragominas, PA, Brazil. From each area, ants were sampled using pitfall traps (Majer & Delabie 1994) in six 200m transects separated from each other by 100m. Differences in ant fauna diversity in the three forest types were tested using índices of diversity (Shannon, Simpson and Fisher's Alpha) and richness estimates protocols (Colwell Coddington 1994). Species composition was evaluated through affinity analysis (Scheiner 1992) and indices of similarity (jaccard and Morisita-Horn). A total of 134 ant species belonging to seven subfamilies and 42 genera were identified in the entire area. From these, 90 species were found in Primary Forest, 90 in Managed logged forest and 84 in the Traditional logged Forest. Differences between habitats could be detected by comparing diversity and similarity indices in different transects/habitats. There were no differences in índices when absolute values were compared for each habitat. Results from richness estimate protocols indicate that ant fauna was similar between habitats and suggests that ant fauna diversity was underestimated. Periodic variations on pluviosity had a strong effect on diversity and richness estimates in the three forest types. The ant fauna composition was similar between habitats; however, a high mosaic diversity could be detected by using affinity analysis, suggesting that the ant community is composed of complex gradients. Thus differences in ant composition would be detectable at smaller scales.
Acesso aberto (Open Access)
Alimentação, distribuição espacial e sazonal das espécies de Arius (Siluriformes : Ariidae) do Estuário amazônico
(Universidade Federal do Pará, 1999-08-30) MENDES, Fabrício Lemos de Siqueira; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
The Family Ariidae (Order Siluriformes) contains marine and estuarine catfishes distributed along the coasts of ali the continents, inhabiting tropical and subtropical shores where they live in shallow waters with sandy or muddy bottoms. In the Amazon River estuary in Pará State, Brazil, there are seven species belonging to the genus Anus (A. couma, A. parkeri, A. rugispinis, A. quadriscutis, A. grandicassis, A. phrygiatus e A. proops). The aim of this study is to identify feeding preference, feeding overlap, spatial distribution and seasonal distribution of the species of genus Anus (Siluriformes, Ariidae) of the Annazon stuary. Collections were made from August to October 1996, and February to April and August to October 1997. Specimens were captured with bottom nets without escape doors belonging to the piramutaba fishing fleet of the Amazon estuary. There are two species groups in the genus Anus: those that feed on crustaceans (A. rugispinis, A. quadriscutis, A. grandicassis, A. phtygiatus e A. proops), and those that feed on fish (A. couma, A. parken). In relation to feeding overlap, ali the species demonstrated a certain degree of feeding overlap, as well as spatial overlap. A. couma and A. phrygiatus. are the most abundant in the 5-10 m depth range and A. rugispinis, A. quadriscutis, A grandicassis and A. parkeri e A. proops in the 10-20 m range. A. phrygiatus is the only species that has a greater abundance during the rainy season, and the other species are present both in the dry as well as the rainy season.
Acesso aberto (Open Access)
Composição e diversidade de espécies da anurofauna da Estação Científica Ferreira Penna, Floresta Nacional de Caxiuanã, Pará, Brasil
(Universidade Federal do Pará, 1999-08-30) BERNARDI, José Antônio Renan; OREN, David Conway; http://lattes.cnpq.br/5451507856491990
This study compares the composition of the anurofauna of the four principal habitats (terra firme forest, capoeira, igapô and aquatic vegetation) in the areas of two black water streams (igarapé Arauá and Laranjal), at the "Ferreira Penna Scientific Station" (Estação Científica Ferreira Penna (ECFPn)), located in the "Caxiuanã National Forest (FLONA de Caxiuanã)", Pará, Brazil. The samples of the areas were conduct using transects measuring 850 m in length and 10 m in width. Both areas were studied in the four periods of the year and related to annual rainfall seasonality (period of transition rainy/dry season, dry season, transition dry/rainy season, and rainy season). Shannon-Weiner índex of diversity and Jaccard index of similarity were used to compare the two areas and the habitats. Samples of anurans totalled 924 individuais belonging to 29 species distributed in 15 genera and 5 families. Hylidae was the most abundant, followed by Leptodactylidae, Dendrobatidae, Bufinidae and Pipidae. Terra firme forest showed the highest diversity. The number of species recorded was highest in the rainy season. This study and those of Ávila-Pires and Hoogmoed (1997) indicate a total of 41 species of frogs for this region, a quite high number for eastern Amazonia, reinforcing the hypothesis that the low diversity of the species of frogs normally related to this region is at least partially a result of the low number of herpetological inventories carried out up to now.
Acesso aberto (Open Access)
Variação sazonal e espacial da estrutura de comunidades dos peixes demersais da Região de Foz dos Rios Amazonas e Tocantins - PA (0º 10'S - 2º30'N; 47º50'W - 50º30'W) - Brasil
(Universidade Federal do Pará, 1999-11-23) TORRES, Marcelo Ferreira; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
The composition, abundance and frequency of the demersal fish fauna from the Amazon estuary were studied in three areas which ones were defined as circumscribed within the isobath ranges of 5-10 m, 10-20 m and 20-50 m. The main objectives of this work were to compare the diversity, abundance and distribution of demersal fish fauna in these three areas during one hydrological cycle, and evaluate the infiuence of environmental variables on the community structure. Samples were taken on board of two piramutaba fishing vessels, using a bottom trawl net, for a given seasonal survey of six 15-day trips in the dry season (March and Apri1/97) and in the rainy season (August and September/97). A number of 91 species were caught in a total of 237 samples and Sciaenidae and Ariidae were the most diverse families, represented by 25% of total species. The Ariidae' species which ocurred in the area were very abundant. The most abundant species were Macrodon ancylodon (Sciaenidae) (56,2%) and Brachyplatystoma vaillantii (Pimelodidae) (13,6%) in the rainy season, and Macrodon ancylodon (31%) and Stellifer rastrifer (15,8%) (Sciaenidae) in the dry season. In area 1 Brachyplatystoma vaillantli (Pimelodidae) and Macrodon ancylodon (Sciaenidae) were the most abundant species in both periods, and the same occurred for Macrodon ancylodon and Stellifèr rastrifer (Sciaenidae) in area 2, and for Macrodon ancylodon (Sciaenidae) and Bagre bagre (Ariidae) in area 3. The most frequent species sampled were Macrodon ancylodon (Sciaenidae) (40,9%) and Anchoa spinifer (Engraulididae) (35%) in the rainy season, and Macrodon ancylodon (Sciaenidae) (45,6%) and Anus grandicassis (Ariidae) (38,4%) in the dry season. In area 1 Brachyplatystoma vaillantii and Brachyplatystoma flavicans (Pimelodidae) were the most frequent species, considering each period; the same was observed for Macrodon ancylodon (Sciaenidae) and Bagre bagre (Ariidae) in area 2, and Macrodon ancylodon (Sciaenidae) and Anchoa spinifér (Engraulididae), in area 3. The dominant species were: Macrodon ancylodon (Sciaenidae) in the rainy season (56% of the specimens collected); and Macrodon ancylodon, Stellifér rastrifer (Sciaenidae) and Anus quadriscutis (Ariidae) in dry season, which represented 61% of fishes caught. In area 1, Brachypiatystoma vaillantii (Pimelodidae) and Macrodon ancylodon (Sciaenidae), were dominant (73%) in the rainy season, and both of them together with Anus grandicassis (Ariidae) were dominant (53%) in the dry season. area 2 only Adacrodon ancylodon (Sciaenidae) was dominant (64%) in the rainy season, and Macrodon ancylodon and Stellifer rastrifèr (Sciaenidae) were dominant (53%) in the dry season. In area 3, just one species Macrodon ancylodon (Sciaenidae) was considered dominant (70% in the rainy season and 49% in the dry season). Distribution patterns were influenced by salinity. Area 1 presented the greatest diversity and evenness as compared with the others. Area 2 presented the greatest richness, and area 3 presented the highest dominance. Three communities were identified: one characterized by species from continental waters that explore shallow areas at depths of less than 20 m; another one formed by salinity resistant species, distributed through a wide range from the estuary, mostly in the area circumscribed within the isobath range of 10-20 m; and a third one with marine species distributed in areas at depths of 10 m to 50 m.
Acesso aberto (Open Access)
Pesca, alimentação e ecologia reprodutiva e embrionária de carataí (Pseudauchenipterus nodosus) (Siluriformes, Auchenipteridae) no rio Marapanim, Marapanim, Pará
(Universidade Federal do Pará, 2000-10) ASSUNÇÃO, Maria Ivaneide da Silva; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
This study presents information on the fisheries, diet, reproduction and embryonic development of carataí fish, Pseudauchenipterus nodosus (Siluriformes, Auchenipteridae), based on data collected between December 1998 and April 1999 in Marapanim River, Pará State, Brazil. Daily and biweekly samplings were collected by means of weirs and pound nets at four sites along the river: the bay, the estuarine funnel, mid-river and the upper portion. It was confirmed that fishing took place during the reproductive period of the species, and that its features varied according to the different sites. Most of the fishermen’s yield was sold in neighboring districts. Catch data along the river pointed the upper portion (33%) and mid-river (44%) as the most productive sites and indicated that carataí performs a biweekly ascending movement. The species ingested larger amounts of food in turbid waters, mainly in tide streams: its diet included annelids, arthropods, mollusks and fishes. Local observations and frequency distributions of ovaries at mature, reproductive and spent stages respectively indicated that carataí spawns in places with fresh and clean waters, on river and creek shores, under a canopy of undisturbed forests. Spawning occurred during the last peaks of the highest waters of spring tides, and following their retraction the eggs were incubated in the soil for about 11 days until the coming syzygy, under temperatures of 22 to 27.5 °C. After hatching, the embryos either remained enclosed within the egg shell until flooded by the tide, or got out of the shell and onto the ground, where they could survive for a couple of hours. Those latter embryos had the ability of taking up exogenous food as they hatched, while those incubated in water would tend to hatch prematurely and show little perception of the surrounding environment. Intervention in the annual recruitment of carataí in Marapanim River seemed to be more dependent on local rain distribution and on the integrity of the forest than on fishing activities.
Acesso aberto (Open Access)
Caracterização da comunidade de quirópteros (Mammalia) em áreas naturais e manejadas da Floresta Nacional do Tapajós, PA - Brasil
(Universidade Federal do Pará, 2000-12-01) SALDANHA, Nélio; MARQUES-AGUIAR, Suely Aparecida; http://lattes.cnpq.br/8269757332399292
Bats represent 25% of the mammal World fauna, being the most diversified and abundant mammals in the Neotropical region. About 128 species of bats have been recorded only in the Brazilian Amazonia. They possess a great morphological variability that allows them to occupy different trophic niches in an ecosystem. Bats play an important role on the maintenance and regeneration of the ecosystems they live, being efficient in seed dispersal, pollination, and biological contral of insects. They also constitute good bioindicators for the status and dynamics suffered by those ecosystems. The present study aims to characterize the batfauna of primary forest, secondary forest, and a selective logging experiment areas at the Tapajós National Forest - PA, Brazil. The levels of impact by the logging and by the secondary forest areas on the bat community were then compared to the primary forest controls in each habitat and in its microhabitats; or physiognomies: understory matrix, natural gaps, logging gaps, and wood storage decks. Comparisions were conducted trough analysis of distribution, diversity, relative abundance, number of species, and guild densities. The samples constitute 55 species, most of them frugivorous, and pertaining to six families. Concerning to the number of bat species and their diversity, the logging area exhibits some impact, but not so accentuated as the secondary forest area. Comparison among habitats suggests that the secondary vegetation provides a higher bat density. However, this vegetation structure benefits only a few species. Frugivores/omnivores and aerial insectivores bats are the most succeed guilds in secondary vegetation. Comparison among physiognomies have suggested that the understory bats avoid opened spaces in the vegetation. Succession stages observed hem show dynamics that need a periodic monitoring, so that a more realistic model could be designed.
Acesso aberto (Open Access)
Impactos da exploração madeireira sobre a fauna de formigas e conseqüências para a remoção de sementes florestais na Amazônia Oriental
(Universidade Federal do Pará, 2001) KALIF, Kemel Amim Bittencourt; MOUTINHO, Paulo Roberto de Souza; http://lattes.cnpq.br/7277077476036269
Logging in the Amazon Forest affects approximately 1.5 million hectares of forestlands each year. These activities result in forest structural and microclimatic changes that could potentially affect diversity and animal species composition. Regeneration of these areas could be jeopardized since animals disperse most seeds. On the other hand, it is possible not to affect seed dispersal mechanisms by maintaining forest fauna integrity through the implementation of reduced impact logging techniques. By using ants as an ecologically representative animal group and integrated into the regeneration processes through dispersion and predation, this work evaluated; (1) if logging affects fauna (diversity and species composition), (2) if reduced impact logging techniques are capable of preserving it, and (3) if logging affects ants ecological efficiency in seed removal (dispersion and predation). Logging effects on ants' diversity and species composition, as well as seed removal done by these insects, were studied in three different forest areas in the municipality of Paragominas in the state of Pará. The first area was a forest that went through high impact logging (FC), the second a forest affected by reduced impact logging techniques (FB), and the third one a primary forest used as the control group (FP). Ants’ were sampled four times during 1998 using the Winkler method at four transects per area. The seed removal experiment was conducted by distributing seeds of six wood species through twelve points in each area. During the experiment the daily number of ants and other arthropods that visited the seed points was quantified. The amount of seeds removed was counted at the end of the experiment. Diversity and abundance of ant species were not affected by logging activities. However, species composition changed by 36% in FB and by 37% in FC. The Pheidole genus experienced richness and abundance reduction only in FC. Seed removal was also significantly lower (-33%) in FC compared to the ones registered in FB and FP. Ants represented 92% of all arthropods that visited the seed points in the three forest areas. The bigger seeds were the most removed ones, independently of its seed disperser adaptations and of the studied forest area. The results obtained suggest that forest logging can affect ant species composition, without affecting its diversity (except that of Pheidole). Reduced impact logging techniques have the capacity of preserving Pheidole species diversity, which guarantees seed movements similar to those of a primary forest. Nevertheless, conventional logging can reduce, both the number of species and occurrences of this genus, thus resulting in a reduced number of removed seeds. Such reduction probably jeopardizes forest regeneration after wood extraction.
Acesso aberto (Open Access)
Análise biogeográfica da avifauna de uma área de transição cerrado-caatinga no Centro-Sul do Piauí, Brasil
(Universidade Federal do Pará, 2001-01-16) SANTOS, Marcos Pérsio Dantas; SILVA, José Maria Cardoso da; http://lattes.cnpq.br/6929517840401044
Acesso aberto (Open Access)
O coatá-de-testa-branca (Ateles marginatus) do baixo Rio Tapajós, Pará: distribuição, abundância e conservação
(Universidade Federal do Pará, 2001-02-16) RAVETTA, André Luís; FERRARI, Stephen Francis; http://lattes.cnpq.br/3447608036151352
The white-fronted spider monkey, Ateles marginatus, is an endangered species according to IUCN. Endemic to Brazilian Amazonia, its status is due to a combination of a relatively restricted geogaphic distribution and the growing human presence within this area. The present study focussed on the BR-163 (Santarém-Cuiabá) highway, on the right bank of the lower Rio Tapajós, a region of prolonged and intense human occupation. The principal aim of the present study was an evaluation of the distribution and abundance of A. marginatus within this area, and analysis of the factors determining these variables. Residents were interviewed informally at 16 sites in order to confirm the presence or absence of the species. Line transect population surveys were conducted at eight sites, representing differing degrees of habitat fragmentation, with a total transect length of 697.6 km. Groups of A. marginatus were monitored at two sites for the collection of data on their behaviour and ecology. The results indicate that the species is absent from some areas, including natural lacunae in its distribution as well as a zone of local extinction, that appears to extend as least as far as 60 km south of the city of Santarém. A total of 23 species of nonflying mammals were recorded in the population surveys, but the presence of A. marginatus was confirmed at only three sites. The study indicates that isolated fragments of forest of less than one hundred hectares are unable to support populations of A. marginatus. In the case of larger fragments, the presence and abundance of the species appears to be influenced more directly by human factors (hunting and logging). The species seems to be relatively rare even in continuous forest, which is similar to other populations of Ateles in Brazilian Amazonia. Two groups, one with eight members and the other with at least twenty, were identified during monitoring. As in other members of the genus, the formation of subgroups (fission-fusion), a relatively high proportion of females in the population and a frugivorous diet are also observed in A. marginatus. The study reveals the critical situation of the species in the region, in the face of human occupation, and the urgent need both to deter the process of habitat fragmentation and establish new protected areas.
Acesso aberto (Open Access)
Estudo de Simuliidae (Diptera : Nematocera) e seus criadouros em igarapés do município de Santo Antônio do Tauá, estado do Pará, Brasil
(Universidade Federal do Pará, 2001-05-03) SANTOS, Emerson Monteiro; GORAYEB, Inocêncio de Souza; http://lattes.cnpq.br/2391620537048479
Considering the importance of black flies to human and animal health and to stream ecology, the simuliid fauna of Santo Antônio do Tauá. Pará state, northern Brazil, was studied through determination of the breeding habitat, introduction in streams of artificial breeding substrates for colonization by larvae, analysis of the aquatic insects associated with simuliid breeding sites, biting times and frequencies of anthrophilic black fly species, qualitative and quantitative analyses of the vegetation at breeding sites, physical and chemical analyses of stream water at these sites, analyses of local weather conditions, and morphometrics of immature Simulium quadrifidum to determine the number of larval instars. The aquatic insect faunas and the respective relative abundances of Simuliidae in two streams were studied. The species that were collected are Simulium perflavum, Simulium quadrijidum, Simulium incrustatum and Simulium goeldii. The immature forms of Simulium perflavum were the predominant ones in disturbed environments, clear waters. Simulium quadrifidum predominated in generally unaltered, black water environments, with low nutrient levels. Simulium incrustatum was more abundant in environments with low vegetation and found Only in clear waters. Simulium goeldii was registered only in areas of primary forest (that is, those showing little alteration) and was more abundant in black waters. The factor that most interfered with simuliid larvae colonizing the artificial substrates was the constant oscillation in the water level of the streams during the time that these substrates were exposed in the water. Aquatic insects were more abundant during the dry season. The biting habits of female Simulium incruslatum were studied for the first time in Pará: two daily peaks in biting frequency were observed with human volunteers, one in the morning and the other in the afternoon, with biting frequencies showing significant differences among vegetation types during these periods, and a significant negative correlation with air temperature in secondary forest during the dry season. The number of larval instars was determined for Simulium quadrificlum, and females of this species were found to oviposit only during the afternoon at 16:30h. New records of predators of adult black flies are presented.
Acesso aberto (Open Access)
Determinação da idade e crescimento da piramutaba Brachyplatystoma vaillantii (Valenciennes, 1840) (Siluriformes : Pimelodidae) capturada no Estuário amazônico
(Universidade Federal do Pará, 2001-05-31) PIRKER, Lilianne Esther Mergulhão; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
The specimens of piramutaba (Brachyplatystoma vaillantii) analyzed in this research were obtained from experimental fisheries in the amazon estuary. For the study of age determination pectorals and dorsal spines, opercules, otoliths (lapillus) and vertebrae were analyzed. From the analysis of these structures it was concluded that the vertebrae is the most appropriate bony structure for the age determination of piramutaba. This is so because the vertebrae showed good resolution in annulus (59%), and it also has a significant exponential relationship (r² = 0,9889 and P<0,05) between the radius of the vertebrae and the fork length of fish. The seasonal rings were validated using length frequency analysis. Two annual rings are formed on the vertebrae of piramutaba. The weight-length relationship seen in piramutaba describes its growth as allometric and the equation that describes its growth is: Wt = 6,1 * 10-6 * Lf3,1129. The sexual proportion of piramutaba observed was not 1:1, as the number of females was superior to the males. On vertebraes of piramutaba a maximum of ten rings were observed. The von Bertalanffy growth model was utilized in this research to estimate the length and weight equations. The growth parameters (k, t0 e L∞) were estimated through four different methods: rings reading, backcalculation, rings modal progression and length frequency analysis. The growth parameters were k = 0,138 ano-1, t0 = -0,239 e L∞ = 110,5 cm (tings xeaffing); k = 0,119 ano-1, t0 = -0,202 e L∞ = 110,5 cm (backcakulation); k = 0,096 ano-1, t0 = -0,146 e L∞ = 110,5 cm (rings modal progression) and k = 0,127 ano-1, t0 = -0,236 e L∞ = 110,5 cm (length frequency analys is).
Acesso aberto (Open Access)
Variação geográfica de Osteocephalus taurinus Steindachner, 1862 (Amphibia : Anura : Hylidae)
(Universidade Federal do Pará, 2001-06) ESTUPIÑÁN-TRISTANCHO, Ruth Amanda; OREN, David Conway; http://lattes.cnpq.br/5451507856491990
Osteocephalus taurinus is an Amazonian and Orinochian nominal species with a wide geographic distribution. Its great morphologic variation has suggested that O. taurinus is in fact a species complex. This study examines the geographic variation of morphometric and morphologic characters. The species complex hypothesis is tested. Simultaneously, in order to explain the present body form distribution by biogeographic, rainfall and ecological patterns previously established for Amazonia, these patterns were assessed. From total 431 specimens studied, 16 populations were selected for analysis 20 of inner anatomic structures, 14 morphometric and 6 morphologic external characteres. Statistical analyses and isoline maps indicated that O. taurinus not is a especies complex and exist a interpopulation and intrapopulation variation on the morphometry and morphology of O. taurinus. Polymorphic anatomical characters ocurrs in this species. The first axis of a principal component analysis showed a clinal variation of body size along the entire geographic distribution was most plainly evident in males. Clinal variaton in other characters studied was independent of cline. Spatial size distribution indicated the largest specimens occur in the Amazon lands low, where rainforest vegetation divides savanna areas to the north and south of South America. These two last areas more often presented the smaller forms. In this study, the distribution observed for O. taurinus was not explained by traditional divisions of Amazonia, and suggest some noise generated by high intrapopulational variation. This spatial model of O. taurhius body size did not show a pattern of isolation by distance, which may suggest a recent arca colonization by this species. Simultaneusly, the study confirms the early Pliocenic origin hypothesis for Osteocephalus, which allowed O. taurinus had time to disperse before the Andes emerged as a geographical barrier.