A new frog of the genus Hylodes (Amphibia : Leptodactylidae) from Minas Gerais, Brazil

A new species of leptodactylid frog is described from Parque das Mangabeiras, in Belo Horizonte, Minas Gerais, south-eastern Brazil. The new species is a member of the Hylodes lateristrigatus group, and is characterized by medium size, snout rounded in dorsal view and protruding in lateral view, presence of vocal slits and sacs, upper surface of finger and toe discs with well-developed scutes, a weakly developed stripe on the upper lip, dorsum, arm, leg, and foot dark brown with small irregular brown and black dots, and absence of red and yellow spots in live specimens. The descriptions of the tadpoles and vocalizations, and information on natural history are provided. Hylodes perplicatus (Miranda-Ribeiro), previously considered a member of the H. nasus species group, is transferred to the H. lateristrigatus species group.

Variações anatômicas no aparelho reprodutor masculino de Chaunus ornatus (Wied-Neuwied, 1821) (Anura, Bufonidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Description of the Tadpole of Hylodes magalhaesi (Bokermann, 1964) (Anura: Hylodidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estrutura populacional de Callinectes ornatus Ordway (Crustacea, Portunidae) no Balneário Shangri-Lá, Pontal do Paraná, Paraná, Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Repertório vocal de Hylodes phyllodes (Amphibia, Anura, Hylodidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Description of a ZZ/ZW sex chromosome system in Thoracocharax cf. stellatus (Teleostei, Characiformes, Gasteropelecidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Diferentes densidades de estocagem na produção de alevinos de trairão (Hoplias cf. lacerdae)

Alevinos de trairão (Hoplias cf. lacerdae), com peso e comprimento total médios de 12,52 g e 10,5 cm, respectivamente, previamente condicionados ao aceite de dietas artificiais, foram distribuídos em seis tanques de alvenaria (5m²) nas densidades de: 1 e 4 alevinos/m². Os peixes dos diferentes tratamentos foram alimentados ad libitum nos horários de 8 e 14 h com ração comercial extrusada contendo 42% de proteína bruta. A cada trinta dias realizou-se a troca do volume total de água de todos os tanques. Ao final do experimento (120 dias) foi avaliado o desempenho produtivo dos peixes, por meio da taxa de sobrevivência, conversão alimentar, ganhos em comprimento e em peso diário. Foram observadas taxas médias de sobrevivência de 86,7 e 96,7% para as densidades de 1 e 4 peixes/m², respectivamente. A conversão alimentar foi de 1,6 e 1,2; o ganho em peso diário e em comprimento de 0,70 e 0,38 g e 8,01 e 7,27 cm, respectivamente. Estes valores não diferiram entre si. Com os resultados obtidos pode-se concluir que as densidades de estocagem de 1 e 4 peixes/m² podem ser utilizadas no cultivo de alevinos de trairão sem que haja comprometimento no seu desempenho produtivo.

Biological and biochemical properties of the Brazilian Potamotrygon stingrays : Potamotrygon cf. scobina and Potamotrygon gr. orbignyi

Stingrays of the family Potamotrygonidae are widespread throughout river systems of South America that drain into the Atlantic Ocean. Some species are endemic to the most extreme freshwater environment of the Brazil and cause frequent accidents to humans. The envenomation causes immediate, local, and intense pain, soft tissue edema, and a variable extent of bleeding. The present study was carried out in order to describe the principal biological and some biochemical properties of the Brazilian Potamotrygon fish venoms (Potamotrygon cf. scobina and P. gr. orbignyi). Both stingray venoms induced significant edematogenic and nociceptive responses in mice. Edematogenic and nociceptive responses were reduced when the venom was incubated at 37 or 56 degrees C. The results showed striking augments of leukocytes rolling and adherent cells to the endothelium of cremaster mice induced by both venoms. The data also presented that injection of both venoms induced necrosis, low level of proteolytic activity, without inducing haemorrhage. But when the venoms of both stingray species were injected together with their mucus secretion, the necrotizing activity was more vigorous. The present study provided in vivo evidence of toxic effects for P. cf. scobina and P. gr. orbignyi venoms. (c) 2006 Elsevier Ltd. All fights reserved.

Visual and acoustic communication in the Brazilian torrent frog, Hylodes asper (Anura : Leptodactylidae)

We studied the signaling, territorial, and courtship behaviors of the diurnal frog Hylodes asper. Visual and acoustic communication were used during intraspecific interactions involving males, females. and subadults. Hylodes aspcr has a complex visual communication system, of which foot-flagging is the most distinctive display observed in the repertoire of visual signals. The splash zone produced by the waterfalls and torrents creates a high, nearly constant, humidity near the streams, reducing the risk of desiccation which enables the diurnal activity of H. asper. Although the ambient sound pressure levels (SPL), measured at the calling sites, are similar to the SPL of the advertisement calls, the high-pitched calls of H, asper, are spectrally different from the noise produced by the water current. Thus. The ambient noise produced by the water current may not interfere significantly with the acoustic communication of this species. The noise and the nearly constant and high humidity produced by the torrents and waterfalls, along with the availability of Light, probably favored the evolution of contrasting colors and visual communication in H. asper: Males of H, aspcr excavate underwater chambers that are probably used to shelter the eggs and to prevent the clutch from being drifted downstream.

A NEW SPECIES OF HYLODES FROM SOUTHEASTERN BRAZIL (AMPHIBIA, LEPTODACTYLIDAE)

A new species of leptodactylid frog is described from the Serra das Cabras in São Paulo, southeastern Brazil. The new species is a member of the Hylodes lateristrigatus group and is characterized by its small size and high number of notes per call. Descriptions of the tadpole and advertisement call and information on natural history are provided.

KARYOTYPE AND NUCLEOLUS ORGANIZER REGIONS OF PYRRHULINA CF AUSTRALIS (PISCES, CHARACIFORMES, LEBIASINIDAE)

The mitotic chromosomes and nucleolus organizer regions (NORs) of the Upper Parana Basin fish Pyrrhulina cf. australis were studied. The karyotype (2n = 40; 6st + 34a) is characterized by the presence of four chromosome pairs with NORs, one of them with NORs in both terminal regions. Comparison of this karyotype with those of other Characiformes, revealed a strong similarity to the family Erythrinidae.

Fecundity of the crab Callinectes ornatus Ordway, 1863 (Decapoda, Brachyura, Portunidae) from the Ubatuba region, São Paulo, Brazil

The objective of the present study was to characterize the fecundity of Callinectes ornatus from the northern coast of São Paulo, Brazil. To study the fecundity and its relationships to size, brood weight, and egg size, the ovigerous females were collected at 2-month intervals for two consecutive years (January, 1991 to November, 1992) in the Ubatuba region using a fishing boat equipped with an otter-trawl type of net. After collecting, the animals were screened, bagged, labeled, and stored frozen. Only data from 38 females carrying early stage eggs were considered. In the laboratory, the specimens were thawed at room temperature, the pleopod structure with the egg mass was removed and the eggs were carefully removed from the pleopods. The samples were then fixed in 10% formalin and stored in 70% ethanol, until the time for processing. Processing followed the method of Hines (1982, 1988). Following the frequency determination of carapace width and fecundity, mean egg number, mean volume and mean dry weight of brooded egg mass were determined for each class obtained. Data were analyzed by regressions of log-log transformations for allometric plots (Y = aX(b)) of reproductive variables versus carapace width. Carapace width was one of the main factors for the determination of fecundity, which ranged 171 570 +/- 94 634 eggs, with females of the same size class presenting a wide amplitude of variation. This supports the hypothesis that portunid females present staggered spawning, possibly presenting more than one period of reproduction within one year. The present species showed lower fecundity than the remaining portunids studied, but they did show a rapid and efficient embryonic development, presumably capable of assuring reproductive success.

Diel activity rhythm in Callinectes ornatus Ordway, 1863 and Callinectes danae Smith, 1869 (brachyura, portunidae) under laboratory conditions

The locomotory and feeding activity rhythms of Callinectes ornatus Ordway, 1863 and Callinectes danae Smith, 1869 were examined under laboratory conditions. Light significantly influenced the activity of these organisms. However, activity in both species was affected by the presence of food, independently of photoperiod regime.