Reproduction of the speckled swimming crab Arenaeus cribrarius (Brachyura : portunidae) on the Brazilian coast near 23 degrees 30 ' S

The reproductive biology of Arenaeus cribrarius from Ubatuba, São Paulo State, Brazil, was studied. Swimming crabs were sampled monthly for two years with otter trawls in two bays. A total of 941 males and 1,012 females were examined. Mating took place mainly in autumn involving postmolt females and intermolt males. At that time, gonad regression was verified in adult males, due to spermatophore transfer, and the molting of adult females. Ovigerous females or females with mature gonads were present year-round but more frequently captured during spring and summer. We found that 19, of all adult females were premolt, which indicated the occurrence of another mature instar and thus the absence of a well-defined terminal molt after puberty. Intermolt males were captured throughout the whole study period.

Reproduction and recruitment of the South American red shrimp, Pleoticus muelleri (Crustacea : Solenoceridae), from the Southeastern coast of Brazil

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

Conservation puzzle: Endangered hyacinth macaw depends on its nest predator for reproduction

In the Pantanal wetlands of Central Brazil, the endangered hyacinth macaw (Anodorhynchus hyacinthinus), the largest psitacid in the world, makes its nest almost exclusively in natural hollows found in the manduvi tree (Sterculia apetala). The recruitment of manduvis greatly depends on the seed dispersal services provided by the toco toucan (Ramphastos toco), responsible for 83.3% of the seed dispersal. The toco toucan, however, is responsible for about 53% of the preyed eggs, resulting in a case of conflicting ecological pressures in which the reproduction of the hyacinth macaw is indirectly dependent on the seed dispersal services of its nest predator. The case illustrates the intricacies of biotic interactions in species-rich environments where species may be tied by indirect, subtle ecological links which conservationists should be aware of. (c) 2008 Elsevier Ltd. All rights reserved.

Habits hidden underground: a review on the reproduction of the Amphisbaenia with notes on four neotropical species

We review the information currently available on the reproduction of the Amphisbaenia and provide original data on the reproductive biology of four Neotropical species: Amphisbaena alba; A. mertensi; Cercolophia roberti, and Leposternon infraorbitale. In total, we compiled data for 22 species: 17 Amphisbaenidae, 1 Rhineuridae, 3 Bipedidae, and 1 Trogonophidae. The majority of the species were oviparous with the exceptions of Loveridgea ionidesii, Monopeltis anchietae, M. capensis, and Trogonophis wiegmanni. Viviparity was interpreted as a derived trait that evolved independently for at least 3 times within the Amphisbaenia. In most species, reproduction is synchronized with the hot and rainy season and seems to vary with latitude. Although Amphisbaenia eggs have been found in ant nests, it remains disputable whether this is an obligatory or even a preferable location for egg-laying. Incubation time in A. mertensii lasts 59 days and this is the first report encompassing egg-laying to hatching for any Amphisbaenia species. Nonetheless, a two months incubation period seems to be the common rule for oviparous Amphisbaenia. The general pattern of reproductive output in Amphisbaenia is characterized by a low number of eggs/embryos per clutch whose individual size is comparatively large in relation to adult body size. Eggs are markedly elongated on the long axis and arranged in-line within the abdominal cavity possibly to prevent/diminish biomechanic drawbacks of egg bearing. Hatchlings of A. mertensi possess an egg-tooth implanted at the upper jaw, exhibit positive geotropism, and display defensive behaviors known to be present in adults. Our review shows that our current knowledge of Amphisbaenia reproduction is fragmentary, often based on the examination of small samples, and heavily dependent on the publication of anedoctal observations. Future publications on this subject are encouraged.

Reproduction of the fish community of Passa Cinco Stream, Corumbataí River sub-basin, São Paulo State, Southeastern Brazil

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

Reproduction of Pirapitinga do Sul (Brycon opalinus Cuvier, 1819) in the Parque Estadual da Serra do Mar-Núcleo Santa Virgínia, São Paulo, Brazil

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

Reproduction of Cichla kelberi Kullander and Ferreira, 2006 introduced into an artificial lake in southeastern Brazil

O objetivo do estudo foi caracterizar a reprodução de Cichla kelberi em um lago artificial no município de Leme, Estado de São Paulo, Brasil. A época reprodutiva ocorreu na primavera e verão. O L50 e o L100 desta espécie foram de 192 e 235 mm (L50) para machos e fêmeas, respectivamente e 290 mm (L100) para ambos os sexos. A desova foi do tipo parcelado. O tamanho dos ovócitos maduros foi de 428,4 µm, atingindo o máximo em 2.203,2 µm. A média da fecundidade foi de 12.129,2 ovócitos com média de cada desova de 4.897,7 ovócitos. Esta espécie adequou-se à definição de peixes com fecundação externa, não migradoras e com cuidado parental da prole. Os atributos para a introdução dos tucunarés podem ser tentadores. Porém, suas características reprodutivas e alimentares fazem com que não existam competidores ou predadores naturais e, assim, a sua expansão populacional seja de difícil controle e erradicação.

Reproduction of a fish assemblage in the state of São Paulo, southeastern Brazil

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

Reproduction of species of the genus Cichla in a reservoir in Southeastern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reproduction of Oligosarcus hepsetus (Cuvier, 1829) (Characiforms) in the Serra do Mar State Park, São Paulo, Brazil

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

The opportunistic feeding and reproduction strategies of the annual fish Cynopoecilus melanotaenia (Cyprinodontiformes: Rivulidae) inhabiting ephemeral habitats on southern Brazil

A maioria dos peixes da família Rivulidae são popularmente conhecidos como anuais por completarem todo seu ciclo biológico em pequenos corpos de água temporários que secam obrigatoriamente em determinados períodos do ano causando a morte dos indivíduos adultos. Possuem características biológicas peculiares como pequeno porte, maturação sexual precoce, reprodução contínua, um elaborado padrão de corte e uma grande capacidade reprodutiva entre os peixes. Os rivulídeos se encontram amplamente distribuídos nas Américas do Norte, Central e Sul. Este trabalho analisou a dieta e a biologia reprodutiva de Cynopoecilus melanotaenia. Foram coletados 263 exemplares e a análise de 233 conteúdos gastrointestinais revelou uma dieta invertívora composta principalmente por microcrustáceos (Cladocera, Amphipoda e Ostracoda) e insetos imaturos (Chaoboridae, Culicidae, Syrphidae, mas principalmente larvas de Chironomidae). Foi registrada a lepidofagia na dieta dos machos. A fecundidade foi estimada pela análise de 59 pares de ovários maduros e variou entre 2 a 157 ovócitos (média, 19 ± 26[DP]). A espécie apresentou desova parcelada, uma estratégia para aumentar a chance de sobrevivência a depleções prolongadas. Este trabalho apresenta a primeira investigação sobre a biologia reprodutiva de C. melanotaenia. Os resultados encontrados sugerem a estratégia reprodutiva oportunista de C. melanotaenia e fornecem novas informações biológicas que podem contribuir para pesquisas de conservação e manutenção da espécie em seu ambiente natural.

Visual communication stimulates reproduction in Nile tilapia, Oreochromis niloticus (L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Stomach contents and notes on the reproduction of the Onefin Skate Gurgesiella dorsalifera (Chondrichthyes: Rajidae) off Southern Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Environmental color affects Nile tilapia reproduction

We investigated the effects of environmental color on the reproductive behavior of Nile tilapia, Oreochromis niloticus. Two environmental colors were tested by covering the aquarium (60 x 60 x 40 cm) with white (12 groups) or blue (13 groups) cellophane and observing reproductive behavior in groups of 2 males (10.27 ± 0.45 cm) and 3 females (10.78 ± 0.45 cm) each. After assignment to the respective environmental color (similar luminosity = 100 to 120 Lux), the animals were observed until reproduction (identified by eggs in the female's mouth) or up to 10 days after the first nest building. Photoperiod was from 6:00 h to 18:00 h every day. Food was offered in excess once a day and water quality was similar among aquaria. Daily observations were made at 8:00, 11:00, 14:00 and 17:00 h regarding: a) latency to the first nest, b) number of nests, c) gravel weight removed (the male excavates the nest in the bottom of the aquarium), d) nest area, and e) mouthbrooding incubation (indication of reproduction). The proportion of reproducing fish was significantly higher (6 of 13) in the group exposed to the blue color compared the group exposed to the white color (1 of 12; Goodman's test of proportions). Moreover, males under blue light removed significantly larger masses of gravel (blue = 310.70 ± 343.50 g > white = 130.38 ± 102.70 g; P = 0.01) and constructed wider nests (blue = 207.93 ± 207.80 cm² > white = 97.68 ± 70.64 cm²; P = 0.03) than the control (white). The other parameters did not differ significantly between light conditions. We concluded that reproduction in the presence of blue light was more frequent and intense than in the presence of white light.