To analyze the reproductive biology of the peacock bass Cichla piquiti, 361 specimens were collected bimonthly in the Itumbiara Reservoir, southeast Brazil, from December 2004 to November 2005. Males and females in reproductive activity occurred during almost the entire year, with reproductive peak occurring before the beginning of the rains when the water temperature remained low, indicating that these environmental variables do not directly influence in the reproduction of C. piquiti. The long reproductive period, partially spent ovaries contained postovulatory follicles and oocytes in all developmental stages, indicate asynchronous development of oocytes and multiple spawning. The mean total length and body weigth were, respectively, 38.2 ± 7 cm and 965.0 ± 654.0 g for males and 37.4 ± 6.1 cm and 899.0 ± 495.0 g for females, statistically showing no sexual dimorphism in size. The smallest male and female found in advanced maturation stage measured 31.0 cm and 29.0 cm of total length, respectively. The body condition (K) of males and females did not present significant differences during the reproductive cycle and the slope (b) of the length-weight relationship was 3.22, suggesting that reproduction and the annual hydrology cycle do not interfere in the health condition. Cichla piquiti is an exotic piscivore fish that is well adapted to this Neotropical reservoir, which exhibits environmental conditions considerably different from its original habitat. This study indicates that the species presents plasticity in reproduction and in allocation of resources, probably due the aseasonality of the reservoir and the exploitation of native species.Para analisar a biologia reprodutiva do tucunaré Cichla piquiti foram coletados bimestralmente 361 exemplares no reservatório de Itumbiara, sudeste do Brasil, no período de dezembro/2004 a novembro/2005. Machos e fêmeas em atividade reprodutiva ocorreram durante quase todo ano, com pico reprodutivo antes do início das chuvas, quando a temperatura da água permanecia ainda baixa, indicando que estas variáveis ambientais não influenciaram diretamente na reprodução de C. piquiti. O longo período reprodutivo, ovários parcialmente desovados contendo folículos pós-ovulatórios e ovócitos em todos os estádios de desenvolvimento, indicaram desenvolvimento assincrônico dos ovócitos e desova múltipla. A média de comprimento total e peso corporal foram, respectivamente, 38,2 ± 7,0 cm e 965,0 ± 654,0 g para machos e 37,4 ± 6,1 cm e 899,0 ± 495,0 g para fêmeas, estatisticamente não mostrando dimorfismo sexual em tamanho. Os menores exemplares, macho e fêmea, capturados no estádio de maturação avançada mediram 31,0 cm e 29,0 cm de comprimento total, respectivamente. O fator de condição (K) de machos e fêmeas não apresentou diferenças significativas durante o ciclo reprodutivo e o coeficiente angular (b) da relação peso-comprimento foi 3,22, sugerindo que a reprodução e o ciclo hidrológico anual não interferem na condição de saúde. Cichla piquiti é um peixe piscívoro exótico que está bem ad...

Salvador-Jr, L.F., Salvador, G.N. and Santos, G.B. 2009. Morphology of the digestive tract and feeding habits of Loricaria lentiginosa Isbrücker 1979 (Loricariidae) in a Brazilian reservoir -Acta Zoologica (Stockholm) 90 : 101-109.The present study describes some aspects of the morphology of the digestive tract and the feeding patterns of Loricaria lentiginosa . Sixty-three specimens with gut contents were captured quarterly from November 2001 to August 2002 in Porto Colômbia reservoir, Rio Grande basin, southeastern Brazil. The species has bicuspid teeth inserted in the lips, unicuspid teeth in the dentary bone and pharyngeal teeth, besides having short, numerous and slightly separated gill rakers. The stomach is rudimentary and the intestine is relatively short (Intestinal Quotient = 1.32 ± 0.15). Molluscs, especially bivalves, represented the most important item on the diet of this species, followed by organic matter. The characteristics of the digestive tract as well as the dietary pattern, suggest that L. lentiginosa is able to explore bottom food resources, being classified as benthophagous with a tendency to malacophagy, and utilizing organic matter as an associated or additional food resource. Loricariidae species are able to use not only algae, sediment and detritus, but also plant and invertebrate items.

The Black Hawk-Eagle Spizaetus tyrannus (Wied, 1820) is a typical forest raptor classified as an endangered species in the state of Minas Gerais, southeast Brazil. Threats include deforestation and fragmentation of forest areas. Although the present investigation points 16 new records of the species in the Quadrilátero Ferrífero, it is noteworthy that the advance of mining activity and expansion of forestry of Eucalyptus spp. in this region are subtracting the forest remnants and increasingly reducing available habitats for this predator inside its limits.

The tamoatá Hoplosternum littorale (Hancock, 1828) is an alien catfish to the São Francisco River basin. Although it has been registered along all of this hydrological system’s extension, including the segment located upstream of the Três Marias dam, up to now the species had not yet been detected in the Pará River sub-basin. Between the 19th and 28th of October 2009, 27 specimens were collected in this drainage system; over half of them captured in a highly polluted artificial reservoir. The results of the present study reinforce that the implementation of reservoirs and the pollution of the continental waters favor not only the expansion, but also the establishment of non-native teleosts with opportunist habits.

Individuals of the sand stargazer Dactyloscopus tridigitatus were collected monthly over a period of one year in an urbansandy beach in south-eastern Brazil. We sampled 57 males, 64 females, and 6 juveniles, indicating a sex-ratio of approximately 1:1. Total length and weight did not differ significantly between sexes, showing no sexual dimorphism in size. The growth of D. tridigitatus was highly positive allometric and the correlation coefficient was significant for both sexes. Males were observed carrying two egg clumps under each enlarged pectoral fin during most of the year. In contrast, females showed a more restricted reproductive period, concentrated during the austral rainy season. The number of eggs in each clump carried by males did not differ significantly from the number of vitellogenic oocytes of mature females. The number of eggs carried by males was weakly correlated to male total length; however, female fecundity was strongly correlated to female total length. Dactyloscopus tridigitatus consumed a high variety of prey items, including crustaceans, annelids, molluscs, teleosts, insects and eggs. Isopods were the most important component of the diet followed by polychaetes and amphipods. We concluded that promiscuous breeding, paternal care behaviour and invertivorous feeding habits seem to be important traits for the species' success in the studied habitat.