Abstract in English:Gills arches of the freshwater fish Prochilodus scrofa Steindachner, 1881 (Lt= 8.0-12.4cm) were removed to be analyzed in a scanning electron microscope. The morphology of the superficial structures of the gill filaments and pharyngeal region of the gills arches was discussed and related to their functional aspects. A great quantity of mucous secretory cells and of microridges, along with the pavement cell surface of the primary lamellae and branchial pharyngeal region, indicate the existence of a protection strategy of the respiratory lamellae. The chloride cells are abundant, specially on the distal portion of the primary lamellae, and bring out the osmo regulatory capacity of this species. This fish seems not to be a filtering one according to: its short and simple gill rakers; presence of several taste buds turned towards the mouth opening; evidence of spines on the external side of the arches and an abundant secretion of mucous in the pharyngeal region. This species probably selects the food to be swallowed through its chemical receptors and retains it with the help of spines and mucous secretion this way protecting the gills filaments against the rubbing of particles over them.
Abstract in English:Diapterus rhombeus (Cuvier, 1829) is one of the most common Gerreidae species in the estuarine region at the Guaratuba Bay, Southern Brazil. Based on studies developed between July, 1993 and January, 1997, it was observed that its presence in the mangrove area is not regular: the smallest individuais are more abundam during late summer and in autumn, and the largest ones during spring and early summer. Its diet comprises plant material and invertebrates, specially polychaets. The morphological aspects of the gonads, the monthly changes on the Condition Factor, and lhe monthly distribution of the individual size groups, suggest that this population spawns during the spring, out the estuarine region. The smaller individuais use the mangrove area of Guaratuba Bay to a growth phase, and the adulls to make somatic reserves to the spawning period.
Abstract in English:Seasonal variation of food items of Bairdiella ronchus (Cuvier, 1830) classified by size was analysed based on monthly samples between september/1993 and september/1996 at the Guaratuba Bay, Southern Brazil. The stomach contents of a hundred eighty-two fishes were analysed by the Occunence Frequency Method and Point Count for a Lot Method. The individuais were divided in two groups, smaller and longer than 140mm, and a comparative study of digestive tract and branchial are was performed for these groups. For fishes smaller than 140mm the following sequence of items was obtained matching both methods by using the Preponderance índices: decapods (subdivided in Brachyura, Caridea and Penaeidea), polychaets, isopods, fishes, unidentified material, copepods, amphipods, molluscs and plant material. For fishes longer than or equal to 140mm the sequence was decapods, polychaets, fishes, copepods, amphipods, isopods, molluscs and plant material, in this order. These results suggest that Bairdiella ronchus at the Guaratuba Bay is a carnivorous species using mainly decapod crustaceans as food throughout the year.
Abstract in English:lsonebula acanthopleon a new species is described and illustrated from specimens of both sexes. The species name refers to the pointed process of the 5th pleonite. Its known hosts are Cyphocharax platanus (Günther, 1880), C. voga (Hensel, 1869) and C. spilotus (Vari, 1987) of the family Curitmatidae (Pisces).
Abstract in English:A check-list of fishes collected in a mangrove in Cacha Pregos, south of ltaparic Island, State of Bahia, Brazil (about 13o07'S,38o48'W) from 1988-1989 and 1991-1992 is presented. Fifteen orders, 46 families and 85 species (Teleostei except one Chondrichthyes) were identified, represented specimens whose adults live in different marine ecossystems.
Abstract in English:The purpose of this study was to describe the composition and abundance of rotifers in different environments: one lotie (the Ivinheima River) and another lentic (the Patos Lake) located in the floodplain of the Upper Paraná River. The influence of limnological variables on the structure and dynamics of rotifers was also examined. Samples were taken monthly from March 1992 through February 1993, in the open water region of the lake and river and in the channel between them and, in the littoral region of the lake and river. Of the 96 species identified, the best represented families were: Brachionidae (20 species), Lecanidae (18 species), and Trichocercidae (15 species). 55 species were widely distributed, 13 were pantropical, 16 neotropical (8 endemic to South America). Trichocerca gracilis was a new record for this floodplain. Dipleuchlanis propatula propatula, Lecane curvicornis, L. leontina, L. bulla, Plationus patulus patulus, Platyias quadricornis quadricornis, Testudinella patina, and T. mucronata hauriensis were consistently present. More species were recorded during the high water period, probably because of the interconnection among the different environments of the floodplain that allows fauna exchange and an increase in available habitats. Rotifer densities were higher mainly in the lake, during the high water. Using principal components analysis, was identified four variables that influence the seasonal variation in the rotifer densities: water level, dissolved oxygen, chlorophyll-a concentration, and water temperature.
Abstract in English:In the time period between May/92 to Abril/93, 602 (267 males and 335 females) specimens oi P. brasiliensis Latreille, 1817 were collected. The shrimps were captured by night using a hand net in áreas between 30 to 150 cm deep. The amplitude of length ranged from 1,3 to 13,7 cm, the highest frequencies of capture were registered during the Fali between the classes of 7,0 and 10,0 cm. The males present isometric growth and the females negative allometric one. The size of the pre-adult ranged from 8,8 cm for the females and 9,2 cm for the males. The recruiting occurs chiefly in the Summer with intense growth during the Fall-Winter period, reaching a climax with the migration of pre-adults to the ocean in midwinter.
Abstract in English:In the time period between May/92 to April/93, 2693 (1243 males and 1450 females) specimens of Penaeus paulensis Pérez Farfante, 1967 were collected. The shrimps were captured by night using a hand net in äreas between 30 to 150 cm deep. The abundance of P. paulensis is regulated mainly by the temperature, the summer being the season of greater profusion. The major recruiting period takes place in the Spring with shrimps measuring between 1,0 to 3,0 cm and approximately 2,0 months old. The population reaches the pre-adult in the Fall-Winter period with average length between 8,8 cm (females) and 9,3 cm (males). The migration to the ocean occurs during the Winter. The artisanal fishing in the Conceição Lake is predatory, acting upon the young and pre-adult shrimps, which may jeopardize the marine reproducer stock.
Abstract in English:The Columbina talpacoli (Temminck, 1811) dove, a small bird of the order Columbiformes, is abundant throughout Brazil and interacts closely with city inhabitants. This study describes the morphological and histochemical aspects of the epididymal region and ductus deferens of this species, comparing them with those of other bird species studied. It is believed that a better understanding of the reproductive biology of Columbina talpacoli could help to solve the ecological and sanitary problems involving these birds.
Abstract in English:Survey of 30 stoniach and/or gut contents of the five species of Siphlophis Fitzinger, 1843 revealed predominance of mostly diurnal species of lizards. Remains of nocturnal prey and snakes were also found. For the first time, one frog and one bat are recorded as preys of one species (S. cervimis Laurenti, 1768). Predation on mollusks and birds is not confirmed herein.
Abstract in English:Here is described the diet of Proceratophrys boiei (Wied, 1825), a leaf litter frog of the Atlantic Forest, and test for relationships between frog size and prey size and type. The diet was determined by stomach content analysis. In 38 frogs, was found 76 prey items belonging to 23 taxa. Insects predominate in the diet and the most frequent categories were coleopterans (39.4% of total volume) and orthopterans (25.0%). There was a positive correlation between frog size and volume of prey taken. The most important ontogenetic shift in prey type was an increase in the consume of coleopterans and insect larvae with increasing frog size.
Abstract in English:The influence of the host on the population profile and on the ciliate populations of the bovine rumen was investigated using three suckling crossbred friesian-zebu (Gir) cows, with fistulas. The genera of ciliate observed in the three hosts examined have characterized the populations as type A. The occurrence of the genera of ciliate was related to the host. lt was verified that the rumen ciliate were quantitatively influenced by inherent factors in the host animais, showing a significam difference in the total of ciliate among the hosts in ali stages of the experiment.
Abstract in English:Panurgillus, a generic name used by J.S. Moure throughout various years in litt. as a substitue of Panurginus in the Neotropical Apifauna, is formally described. All specimens of the species here described were collected during surveys of bees and melittophilous plants in th state of Rio Grande do Sul, southem Brazil. Various species of Panurgillus also occur in other states of southem Brazil, in Argentina and probably in Uruguay, Paraguay and Eastem Bolivia. The bees are small (3,9-7,4 mm), black, with generally a few yellow paintings, two submarginal cells, the lst m-cu distant to the base of the second submarginal cell, the clypeus not projected, the facial foveae distinct, scopa with simple, long hairs and the gonobase absent. Panurginus vagabundus Cockerell, 1918 is transferred to Panurgillus as the type species and thirtcen new species are described: P. eustictus, P. flavitarsis, P. formosus, P. guariticola, P. hamatus, P. harterae, P. holostictus, P. malvcicearum, P. minutus, P. pereziae, P. plumosulus, P. politus and P. reliculatus. From some structures were took SEM photographs.
Abstract in English:Among the new substances that were synthesised by the chemical industiy during the last decades, with the aim to improve human prosperity, some cause negative effects on non target organisms like fish. Among the pesticides, the organophosphates (OP) are widely used in cattle management, agriculture and aquaculture activities. Brachydanio rerio Hamilton-Buchman, 1822 is used world-wide in fish-tests for the establishment of the lethal levels of pesticides. Nevertheless, these fish show morphological changes in their hepatocytes when exposed experimentally for 24 hours to the sublethal dose of 0.025 µl/l of the OP Dimethoate 500, in acute tests. Right hours after exposure, a high density of cells with cytoplasmic granulation is seen as well as focal necrosis. The main changes that occurred in the first 24 hours of exposure were the loss of the typical polygonal cell shape and of detectable cell limits, lateral migration of nuclei, nuclear size and shape, condensation of chromatin and pycnosis, increased cytoplasmic granulation followed by vacuolisation. After 48 hours in clean water, 72 hours from contamination, besides significant morphological changes and necrosis, focal regeneration of the hepatocytes, canaliculi, ducts and sinusoids were seen. Even having been exposed to the half of the dose considered as safe according to the general pesticide allowance rules, significant changes of the liver tissue were observed.
Abstract in English:The external morphology of two cicadelline species, Versigonalia ruficauda (Walker, 1851) (Cicadellini) and Tretogonia cribrata Melichar, 1926 (Proconiini), is analyzed. The head, axillary sclerites, wing venation, female genitalia, and tegumentary processes are described. Notes on other Cicadellini - Amblyscarlidia albofasciata (Walker, 1851), Tettisama quinquemacidata (Germar, 1821), Macugonalia lencomelas (Walker, 1851), and Diedrocephala variegata (Fabricius, 1775) - and Proconiini - Ciccus adspersus (Fabricius, 1803), Homoscarta superciliaris (Jacobi, 1905), Ichthyobelus sp., and Rhaphirrhinus phosphoreus (Linnaeus, 1758) - are added. A technique for dissecting the female genitalia is presented. The facial porlion of head in V. ruficauda, T. cribrata, and remaining species has a large sclerite (frons or postfrontofrons) clearly defined by the frontogenal suture. Below the frons, and separated from it by the epistomal suture, a smaller sclerite is present (clypeus). The identification of these sclerites is based on comparisons with descriptions in the literature of a generalized Pterygota, a Psocoptera, a fossil Hemipteroidea, and other Homoptera. The conclusions about the identities of frons and clypeus corroborate the hypotheses of Hamilton (1981) on the homologies of cephalic areas in Rhynchota. The facial sclerites have modifications related with the xyleniomyzous diet. The frons is swollen, providing a larger area for attachmcnt of cibarial muscles. Other modifications increasing the area of frons are observed in the Proconiini. In C. adspersus its lateral margins are distinctly pronounced and its upper portion has a pair of lateral elevations. In Ichthyobelus sp. and R. phosphoreus the upper part of frons is greatly developed, occupying 4/5 of dorsal area of head on middle line. The vertex is limited to a small portion (1/5) of that area. The clypeus is also swollen, a fact related with the greater development of cibarium. This character is more conspicuous in the Proconiini. In this tribe the clypeus has a convex projection occupied by the cibarium, which is greatly devcloped. The pronotum and forewings in T. cribrata are covered by pits, each with a seta on external margin. These pits are similar (and maybe homologous) to struetures in the abdomen of a membracid (Goniolomus tricomiger Stål. 1869). The pronotum is smooth in V. ruficauda. However, pits similar to those of T. cribrata, although smaller. oceur near the forewing veins. A strong costal vein is present in the forewings of the 10 studied species. This vein is formed by a fusion between precosta (PC), costa anterior (CA), and costa posterior (CP). Vestiges of subcosta posterior (ScP) and media (M) occur in the forewing base. A vein formed by a fusion between anal (A) and jugal (J) veins is observed along the inner margin of clavus. In the hindwings, PC, CA, and CP are also fused. The occurrence of PC can be inferred by the presence of the wing coupling lobe. which represents its final part. Jugal anterior (JA) is fused to anal posterior (AP"). Jugal posterior (JP) occurs as a small rudiment at hindwing base. The characters of fore - and hindwings confirm the observations of Dworakowska (1988) on the Cicadellidae. The presence of PC and J corroborates Kukalová-Peck's (1983) model of the primitive pterygote venation. Comparisons between the Cicadellinae and a description of a fossil species of the order Diaphanopterodea (Kukalová-Peck 1992) revealed remarkable similarities in female genitalia. Such similarities (manifested in the positions of gonocoxites eight and nine, gonangulum, valvulae eight and nine, and lergite nine) permit a correct interpretation of the genital structurcs in the subfamily. The sclerites of the genital chamber described by Young (1977) in females of various Cicadellini are the reduced eighth abdominal sternite. Sclerotized plates in this sternite occur in A. albofasciata, T. quinquemaculata, T. cribrata, C. adspersus, and H. superciliaris. Comparisons carried out among these Cicadellinae, allied with data from the literature, indicate that the eighth sternum can provide useful characters for the subfamily taxonomy. Features of potential taxonomic interest in valvulae eight and nine include tegumentary processes (valvulae eight), shaft form, and teeth form and distribution (valvulae nine). Lists with the terms suggested for head, wings, and female genitalia are included, together with synonyms proposed by other taxonomists and morphologists.
Abstract in English:A second study of the testate amoebae of the region of Porto Alegre, Rio Grande do Sul revealed the presence of Arcella Ehrenberg, 1830.Difflugia Leclerc, 1815, Lesquereusia Schulumberger, 1845, Centropyxis Stein, 1857, Bulinularia Penard, 1911 and Euglypha Dujardin, 1841 genera. Our finds demand emendations of the diagnostic characteristics of several species.
Abstract in English:The coral reef is an ecossystem which evokes great interest, for its beaury, species diversity and fisheries potential. The coast of Paraíba State, northeast Brazil, possesses several natural reefs and shipwrecks which are inhabited by a rich fish fauna. In order to survey the reef fish fauna of Paraíba State, a total of 118 dives, utilizing SCUBA diving techniques, were carriedoutin 27samplingpoints (depths: 0,5-66m), from February/1995 to May/1996. Specimens were collected whenever underwater identification was precluded. A total of 157 known species belonging to 59 families were found. Four unidentified species, one dasyatid, one haemulid, one scarid, and one labrid were recorded. Haemulidae was the most representative family in number of individuais, whereas Carangidae was the most speciose family. This paper is part of a broader study of the northeast Brazilian reef fishes.