Ecological distribution and reproductive period of the hermit crab Loxopagurus loxochelis (Anomura, Diogenidae) on the northern coast of São Paulo State, Brazil

The present study aimed to determine the ecological distribution of Loxopagurus loxochelis as a function of selected environmental factors, as well as its reproductive period based on the combined analysis of the presence of ovigerous females and the development of the gonad. The collections were carried out monthly from January to December 2000 in the region of Ubatuba (SP), using a fishing boat equipped with two double rig nets, in isobaths of 5, 10, 15, 20, 25, 30, 35 and 40 m, at which depths samples of sediment and water were collected. The cephalothoracic shield length and sex of the animals were determined; the abdomen was dissected to verify gonad development stages. A total of 334 individuals was obtained ( 196 males, 48 ovigerous females and 90 non-ovigerous females) with sizes varying from 3.0 to 8.6 mm (5.7 +/- 1.0 mm). A greater abundance of L. loxochelis (95.2%) was observed at depths of 20 and 25 m. These sites mainly revealed a substratum stable with a very fine sand fraction, which facilitates the habit of embedding shown by this hermit. With regard to gonadal analysis, it was possible to classify four gonad development stages for each sex: immature, rudimentary, developing and developed. It was observed that in the winter months about 71% of the females had gonads either developing or developed and 67% were ovigerous. Therefore, the winter period can be considered the peak of reproduction for this species, characterizing a typical seasonal-continuous reproduction.

Population structure and breeding season of the South Atlantic hermit crab, Loxopagurus loxochelis (Anomura, Diogenidae) from the Ubatuba region, Brazil

A population of Loxopagurus loxochelis was studied in terms of seasonal abundance, size frequency distribution, sex ratio, and reproductive period (percentage of ovigerous females). Specimens were collected monthly over a period of two years (from September 1995 to August 1997) in the non-consolidated areas of the Ubatuba, Mar Virado, and Ubatumirim bays (northern coast of São Paulo State, Brazil) with a double-rig trawl net. A total of 1,084 individuals were analysed. Animal size (minimum, maximum, and mean +/- SD shield length) was 2.8, 9.1, and 6.88 +/- 1.13 mm for 625 males; 2.8, 8.2, and 5.78 +/- 0.98 mm for 236 non-ovigerous females; and 4.6, 8.0, and 6.24 +/- 0.68 mm for 223 ovigerous females, respectively. Sexual dimorphism was recorded by the presence of males in the largest size classes. The sex ratio was 1.4 : 1 in favour of males. The highest incidence of ovigerous females occurred during winter and spring (June to October), with a low percentage in summer and fall (November to May), indicating continuity in the reproductive cycle. This strategy of reproduction is related to temperature. The occurrence of L. loxochelis in the Ubatuba region represents the final point of northern distribution of this species as a function of water mass influence, and could be its real limit on the Atlantic coast of South America.

Population biology of the burrowing crab Neohelice granulata, (Crustacea: Decapoda: Varunidae) from a tropical mangrove in Brazil

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

Reproductive output of the spider crab Epialtus bituberculatus (H. Milne Edwards, 1834) (Crustacea, Decapoda, Brachyura) associated with beds of the alga Sargassum cymosum (C. Agardh, 1820) on the southeastern Brazilian coast

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Obesity: effects of physical exercise and metformin on metabolic aspects of monosodium glutamate treated rats

The present study investigated the effects of swimming training and metformin on metabolic aspects of obese rats. Wistar rats were divided into control (C), obese (O), Trained Obese (TO) and metformin obese (MO) groups. Obesity was induced by subcutaneous monosodium glutamate injection (4 mg/g body weight). Exercise program consisted in swimming 1 h/day, 5 days/week, for 8 weeks, supporting a load corresponding to 5% of body weight. Metformin was dissolved in the drinking water (1.4 mg/ml) for 8 weeks. At the end of the experimental period, rats were sacrificed and blood was collected for determinations of serum glucose, insulin and triglycerides and hematocrit. Samples of gastrocnemius muscle and liver were removed to evaluate triglycerides content MSG-induced obesity, increased serum glucose, insulin and triglycerides, while physical training was able to recover serum glucose and insulin and metformin treatment recovered serum insulin and slightly reduced the serum glucose. MSG-induced obesity also increased liver triglycerides content and physical training and metformin administration recovered these parameters. It was concluded that in MSG obese rats, physical exercise and metformin induced important metabolic alterations associated with an improvement in glucose homeostasis and in liver fat content. Obesity and Metabolism 2009; 5: 129-133.

Demographic aspects of Chrysomya megracephala (Diptera, Calliphoridae) adults maintained under experimental conditions: Reproductive rate estimates

The objective of this work was to evaluate some aspects of the populational ecology of Chrysomya megacephala, analyzing demographic aspects of adults kept under experimental conditions. Cages of C. megacephala adults were prepared with four different larval densities (100, 200, 400 and 800). For each cage, two tables were made: one with demographic parameters for the life expectancy estimate at the initial age (eo), and another with the reproductive rate and average reproduction age estimates. Populational parameters such as the intrinsic growth rate (i) and thefinite growth rate (lambda) were calculated as well.

Reproductive aspects of Harttia carvalhoi Miranda Ribeiro, 1939, a small loricariid from streams of serra da Mantiqueira eastern, SP, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biological aspects of Schizodon nasutus Kner, 1858 (Characiformes, Anostomidae) in the low Sorocaba river basin, São Paulo state, Brazil

Four biological aspects of Schizodon nasutus in the low Sorocaba river basin, São Paulo, Brazil were analysed. These were accomplished during the year seasons. The fish diet and the feeding activity were investigated by studying the repletion index, which showed no significant differences between seasons. The food items analysed by frequency of occurrence and dominance showed a predominance of vegetable items in the diet. The reproduction, analysed by using the gonadosomatic index, indicated that the reproductive period occurs during the summer period when temperatures are higher and rainfalls are more intense. The amount of accumulated fat and condition factor varied according to reproduction, especially for females.

Prenatal testosterone exposure as a model for the study of endocrine-disrupting chemicals on the gerbil prostate

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

Histological aspects and structural characteristics of the testes of Dendropsophus minutus (Anura, Hylidae)

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

Demographic aspects of Chrysomya megacephala (Diptera, Calliphoridae) adults maintained under experimental conditions: reproductive rate estimates

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

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.

Morphological characterization and reproductive aspects in genetic variability studies of forage peanut

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Kinetic aspects of rat (Rattus-norvegicus albinus) submandibular glands lactic-dehydrogenase

Submandibular glands of male rats were homogenized with 33 mM sodium potassium phosphate buffer, pH 6.5, containing 1 mM MgCl2 and 0.1 mM DTT and purified with ammonium sulphate, phosphocellulose chromatography, eluted with KC1 0.5 M, followed by Blue Sepharose CL-6B chromatography, eluted with NADH 0.5 mM. The enzyme kepts stable for 60 days when stored at -15-degrees-C in 33 mM phosphate buffer. In other experiment the enzyme was purified by oxamate-agarose chromatography from a crude extract of submandibular gland and the results obtained were better than by phosphocellulose and Sepharose CL-6B chromatography. The Km values for pyruvate. NADH, lactate and NAD+ were established. Sodium oxamate at 0.1 and 0.9 mM concentrations inhibited the LDH activity by 40 and 85%, respectively (competitive); with sodium oxalate the inhibition was of 30% (uncompetitive) and with 3-acetyl pyridine adenine dinucleotide was 80%.

Phenological aspects of Syngonanthus elegans (Bong.) Ruhl. (Eriocaulaceae) from Serra do Cipo - MG. Brazil

S. elegans (Eriocaulaceae) is known in Brazil as star flower and is used economically for ornamental purposes. The fact that there is no control over its collection, brings about great damage to its population. Thus the importance of phenologic data for the conservation of the species. This paper reports the marking of 60 individuals in three different phases of development and the collection of monthly data about their phenology. S. elegans is a perennial plant with a rhizomatous stem that characterizes its vegetative growth. The pubescent leaves present in plants can prevent heat loss and their pigments can raise the ultra-violet radiation absorption. The young leaves present in plants during the begining of the dry season use rhizome reserves. Hydric scarcity may be the main reason for the mortality of the species. Vegetative growth and sexual reproduction are very important for the population's survival.,The blooming period in S. elegans occurs from om February to July and the dispersal of seeds occurs from August to December.