RCAAP Repository

Biological aspects of Leptinaria unlamellata (d'Orbigny, 1835) were studied, such as: onset of sexual maturity, occurrence of self-fertilization and shell length measurement at different stages of development. In isolated specimens of L. unilamellata, sexual maturity was reached at 74 days (minimum time) and 104 days (maximum time). For the grouped specimens, the minimum time was 71 days. The occurrence of self-fertilization was observed in both species, 100% of specimens. The total numberof young per birth varied from one to 22 (average: 7,35 ± 5,78), the total number of offsprings per mollusc varied from two to eight (average: 4,1 ± 1,41) and total number of young per mollusc varied from five to 46 (average: 30,21 ± 8,08). As to the shell length in different growth stages, it was observed that in L. unilamellata, growth rhythm was similar until 15 days for age. After this period grouped specimens showed a high growth rhythm until 105 days after which the growth rhythm of grouped specimens became constant and the growth rhythm isolated specimens became greater. Grouped and isolated specimens reached a maximum size of 18,7 mm and 20,6 mm respectively. In the moment of the sexual maturity, the length of the shell in the individuals that were kept grouped was smaller than the isolated ones for L. unilamellata. In this specie individuals that were kept isolated reach larger length of shell.

Biological aspects of Bradybaena similaris (Férussac, 1821) were studied, such as: onset of sexual maturity, occurrence of self-fertilization, oviposition, incubation period, eclosion rate and shell length measurement at different stages of development. It was noted that in isolated B. similaris the minimum and maximum time for reaching sexual maturity were 109 and 180 days, respectively. When kept in groups, the minimum time was 78 days. The occurrence of self-fertilization was observed in 18.4% of specimens. The total number of eggs per oviposition varied from one to 38 (average: 3,5 ± 7,15), the total number of eggs per mollusc varied from one to 39 (average: 7,0 ± 10,21) and the total number of oviposition per mollusc varied form one to six (averege: 2,0 ± 1,27). Thirty ovipositions (894 eggs) were followed and the minimum eclosion time of the young was 14 days, the maximum eclosion time was 35 days and the average 23,69 days. The eclosion average percent was 81,22. As to the shell length in different growth stages, it was observed that in B. similaris the length of the shell was similar until 30 days for age. After this period isolated specimens acquired a greater growth rhythm when compared to that of grouped specimens. The maximum shell length of isolated specimens was 17,4 mm whereas grouped specimens reached 14,5 mm. In this specie, individuals that were kept grouped became sexually mature earlier than isolated ones. Individuals kept isolated reach larger length of shell. In the moment of the sexual maturity, the length of the shell in the individuals tha were kept isolated was smaller than the grouped.

Aiming at obtaining the community profile and verifying the occurrence of antagonism and association among ciliates, samples of rumen content were analysed in 100 bovines soon after their death. The animals were killed at the Juiz de Fora Municipal slaughter house (Juiz de Fora, Minas Gerais State, Brazil) between August 1996 and May 1997. Ciliates occurred, respectively, in the following percents and samples number: Entodinium Stein, 1859 (50,48; 100), Diplodinium Schuberg, 1888 (5,59; 98), Eudiplodinium Dogiel, 1927 (6,91; 97), Ostracodinium Dogiel, 1927 (9,68; 95), hotricha Stein, 1859 (4,15; 93), Dasytricha Schuberg, 1888 (3,31; 93), Metadi nium Awerinzew & Mutafowa, 1914 (3,06; 90), Eremoplastron Kofoid & MacLennan. 1932 (7,39; 87), Epidinium Crawley, 1923 (5,31; 73), Charonina Strand, 1928 (1,33; 65), Eodinium Kofoid & MacLennan, 1932 (1,49; 59), Diploplastron Kofoid & MacLennan, 1932 (0,88; 24), Elytroplastron Kofoid & MacLennan, 1932 (0,36; 16), Polyplastron Dogiel, 1927 (0,04; 03) and Buetschlia Schuberg, 1888 (0,02; 01). When the antagonistic behaviour and the association were analyzed, it was observed that Eudiplodinium was detected in the absence of Polyplastron and in the presence of Epidinium in 94% and 73% of the samples, respectively. These data confirm the antagonism and the coexistence among particular populations of rumen ciliates and allowed the identification of 94% of the samples examined as being of profile type B, none of type A and 3% of mixed A-B community and of type O. It is suggested the use of the term community profile instead of population profile, as the respective types involve associations of various ciliate populations.

A controlled experiment, related with the mating system of Scinax rizibilis (Bokermann, 1964), was conducted to assess if larval variation could be due to size of male or its ability to manage an amplexus. Adult individuals were caught during breeding activity (from February 1993 to January 1994), in a temporary pond in the municipality of Ribeirão Branco. São Paulo State, southeastern Brazil. The duration of the larval period was not different between tadpoles of large and small males, nor was it different between tadpoles coming from natural or artificial pairs. The reproductive status of the male (if it had managed an amplexus) also did not influence the total length nor the mass of the tadpoles close to metamorphosis. However, tadpoles of larger and heavier males were, on average, approximately 5.5% and 11% larger and heavier, respectively, than tadpoles of smaller males. These results indicate that the breeding system of S. rizibilis could potentially have a directional effect on the larval characteristics.

The purpose of this work is to analyse the taxonomy and distributional patterns of the species of the genus Munida Leach, 1820 which occur along the Brazilian coast. The species of Munida present some peculiar characteristics, rarely found in any other marine group. They live in groups with great number of individuals (gregariousness) and with several species found together in the same population (sintopy). In addition, they exhibit a great degree of intraspeciftc variation and, paradoxally, a little variability among the species. These factors make a better understanding of the systematics of this group very difficult. In the present study the utilization of non variable characters was emphasized. As a corollary of this study, "species-complexes" were defined including groups of species morphologically very similar but yet well characterized. Sixteen species with distribution along the Brazilian coast were studied. An identification key is provided. A general discussion where the main problems on taxonomy and distributional patterns of species were analysed was done.

The project PRS-GEDIP was carried out in the Rio Grande do Sul coast, with some few stations off Maldonado (Uruguay), by means of a convention between Instituto Oceanográfico USP (IOUSP) and the Grupo Executivo do Desenvolvimento da Indústria da Pesca (GEDIP) of Rio Grande do Sul. The purpose of this project was the acquisition of data in order to have a better biotic and abiotic characterization of the southern Brazilian coast. Among the Galatheidae, about 1200 specimens of the genus Munida Leach, 1820 were collected, including five species as follows: Munida flinti Benedict, 1902; M. forceps A. Milne Edwards, 1880; M. iris A. Milne Edwards, 1880; M. irrasa A. Milne Edwards. 1880 and M. longipes A. Milne Edwards, 1880. The description, material examined, remarks and maps of the stations where each species was collected are done.

Hyla cochranae Mertens, 1952 is revalidated and the description of the tadpole and vocalization is provided. Based on external morphology, the genus Aplastodiscus A. Lutz, 1950 is recharacterized and a redescription of A. perviridis A. Lutz, 1950 is given. New data on geographical distribution and biology of both species are provided.

Two piscivorous fishes, peacock bass (Cichla monoculus Spix & Agassiz, 1831) (Perciformes) and piranha (Pygocentrus nattereri Kner, 1860) (Characiformes), were introduced in some Rio Doce valley lakes (19º50'S, 42º40'W) for sport fisheries enhancement. As a consequence, small individuals and species were practically vanished in the host lakes. In this study, the effects of peacock bass and piranha introductions on the diet of a native piscivorous fish, the trahira - Hoplias malabaricus (Bloch, 1794) are presented. Trahira's diet from three lakes were was compared with the stomach contentsdiet of trahira's living in another between three lakes with and three withoutstocked with the piscivorous species peacock bass and piranha. In the lakes with introduced fishes species, the consumption of fish was significantly smaller and this food item have been this item partly replaced by aquatic invertebrates. This shift on of trahira's diet to the low abundance of its original prey, is attributed to the small fishes. This diet plasticity adaptative capacity he diet plasticity detected for trahira might be allowing its maintenance in the lakes with peacock bass and piranha.

The following new species are described from Brazil: Falsischnolea apicalis sp. n., Dorcasta singularis sp. n. and Paraesylacris candida sp. n. and from Venezuela: Amphicnaeia piriana sp. n. and A. zonula sp. n. New synonyms established: Acestrilla apicalis Breuning, 1942 and A. strandiella Breuning, 1943 = A. minima Bates, 1885. Bisaltes acutipennis Thomson, 1868 is transferred to the genus Ataxia Haldeman, 1847 (Pteropliini). Falsestola Breuning, 1940 is considered a synonym of Hesycha Fairmaire & Germain, 1859 and transferred to the tribe Onciderini. Hesycha ocellifera Martins & Galileo, 1990 is synonymized with Hesycha inermicollis (Breuning, 1940).

The number of xo alleles of a population of stingless bees can be estimated by observing the male proportion of the first brood comb produced by a new queen (about 40 Fl bees) and the total number of colonies. A proportion of 50% diploid males indicates insemination of the queen by a single male with some xo sex allele: 25% diploid male would indicate insemination by two males (one with some xo as the queen and another with different one). Diploidy was confirmed by cytology of the testis. The original population (78 colonies) of Ribeirão Preto, State S. Paulo, Brazil, had 8 xo sex alleles. From this population, 10 colonies were orphaned and taken to the Serra do Mar (Sea Mountains) at Espirito Santo State (1200 km far) in order that the virgin queen of each colony would cross with males of this region. Ten days after the nine hives (one was lost) were brought back to Ribeirão Preto. No one of them produced diploid males. New samples took from all the Meliponary revealed that the number of xo sex alleles to have increased to 17,3. Than, this methodology can be used to increase the genetic variability of the stingless bees populations.

The Trichoptera fauna in two first-order streams of Serra dos Pireneus. Goiás State, was studied from June/1993 to July/1994. The Trichoptera larvae abundances were lower in the rainy season in the two streams. The temporal distributions of the functional groups (feeding categories) was similar in both streams. The ordination by Detrended Correspondence Analysis (DCA) detected a higher temporal heterogeneity of the Trichoptera community in one of the sampling stations, probably associated with higher discharge variation. There is a large variation of abundance of some genera between the two studied streams.

This paper reports twenty mite species belonging to eighteen genera in nine families, associated with three species of euphorbiaceous weed species: Chamaesyce hirta (Linnaeus) Millsp., Euphorbia heterophylla L. and Phyllanthus tenellus (Muell. Arg.) Roxb., in three different monoculture areas of Hevea brasiliensis. The largest richness of mite species was observed on C. hirta, with nine species. The most abundant species were Pronematus sp. and Polyphagotarsonemus latus (Banks, 1904), collected on C. hirta and E. heterophylla.

The silverside, Atherinella brasiliensis (Quoy & Gaimard, 1824), a resident species of the shallows of bays, estuaries and coastal lagoons, was studied during two annual cycles, using beach seines (July 1996 to June 1998), in the continental margin of the Sepetiba Bay, aiming to assess recruitment and distribution patterns. A wide recruitment period, with young-of-the-year appearing from early spring to early autumn, was shown, with peaks of juveniles (Total Length-LT = 10-30 mm) being recorded in two periods of the year; one in November and another in March. The highest abundances, of both juvenile and adults, were recorded in Coroa Grande and Itacuruçá, sites located in the outer Bay, during the whole summer, with significant differences were found. In spite of not having been found any statistically significant relationship between the environmental factors and the occurrence of this species, a trend of higher abundance in colder and more saline waters was detected. High values of growth coefficient (K = 0.93) and low asymptotic lenght (L∞ = 11.6 cm) indicated that this species shows a high growth rate and short life cycle, with life span of 3.09 years, in this system.

Descriptions of the morphology and behavior of the immature stages of Adeloneivaia schubarti Rêgo Barros & Mielke, 1970 are given for the first time. The larvae was reared (in captivity) on Stryphnodendron adstringens (Mart.) Coville (Leguminosae-Mimosoideae). Egg, larval instars, pupa and adults are illustrated in color and line drawings.

The study of Chasmagnathus granulata Dana 1851 was done with the setae morphology point of view. The main objective of this description was to find differents kinds of morphologicals types of setae. During this work anomalous structures were found in megalopal phase, such as: many kinds of rostral and lateral spines, as well as many kinds of spines on the telson and one kind of dorsal spine which never was cited before in the literature concerning to this specie.

Brasacanthus sphoeroides gen. n.. sp. n. is described from the marine fish, Sphoeroides greeleyi (Steindachner), taken in Paranaguá Bay, Paraná State, Brazil. The new genus differs from Acanthocephalus Koelreuter, 1771, the nearest genus in the family Echinorhynchidae, by having very flat and variable lemnisci in both sexes and a uterine egg reservoir in the female. The species is characterized by its spherical body form and in having parallel or diagonal testes.

Psammocyclopina georgei sp. n. is described from submersed sands in the Magellan Strait, South Atlantic Ocean. This is the second species of the genus, previously known only from the Indian Ocean (Mozambique). Psammocyclopina Wells, 1967 is the sistergroup of Metacyclopina Lindberg, 1953. Psammocyclopinidae fam. n. is accordingly proposed to unify these genera into one monophyletic unit. The sistergroup of the new family is a cluster of cyclopinid genera composed of Cyclopinodes Wilson, 1932, Pseudocyclopina Lang, 1946, Parapseudocyclopinodes Lindberg, 1961, Hemicyclopina Herbst, 1952, Procyclopina Herbst, 1955, Heterocydopina Plesa, 1968, Neocyclopina Herbst, 1952, and an as yet undescribed new genus (Martinez Arbizu, in prep.). Global occurrence of psammocyclopinids is briefly reviewed.

The holotype of Stylura brusiliensis Lima, 1928 was found at the Instituto Oswaldo Cruz. Rio de Janeiro. Brazil, and the holotype of Iscadia montei Lima, 1936 is probably lost.

A case of dimorphism among the males of the pinnotherid crab, Zaops ostreum (Say, 1817), is reported. The morphological features of the two types of males are also given.

Five new genera and fourteen new species of gall midges from restingas of Rio de Janeiro State are described. The larva, pupa, male, female and gall are described for each species. The new genera are: Arrabidaeamyia, Epihormomyia, Manilkaramyia, Mayteniella and Parazalepidota. The new species are: Arrabidaeamyia serrata, Asphondylia peploniae, Clinodiplosis diodiae, Clinodiplosis profusa, Clusiamyia granulosa, Dasineura couepiae, Epihormomyia miconiae, Lopesia grandis, Lopesia marginalis, Lopesia singularis, Manilkaramyia notabilis, Mayteniella distincta, Parazalepidota clusiae and Paulliniamyia ampla. Also, the larva of a previously described species, Clusiamyia nitida Maia, 1996 is described and Asphondylia byrsonimae Maia & Couri is transferred to Bruggmaniella.