Substratum choice for nesting in male Nile tilapia Oreochromis niloticus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Simultaneous activity of male and female gonads in intersex hermit crabs

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

Male and female interactions during courtship of the Neotropical damselfly Mnesarete pudica (Odonata: Calopterygidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Maternal separation stress in male mice: long-term increases in alcohol intake

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Female preferences based on male nutritional chemical traits

Selection favors females that attend to reliable information about male genetic quality and fitness. Male nutritional condition can be a significant sign of mate quality since poor nutrition can be related to reduced sperm quality, low sperm quantity, sexually transmitted diseases, and parasites. We tested whether female Nile tilapia, Oreochromis niloticus, preferred the chemical cues of males that were well fed with high-protein diet over those fed with low-protein diet. Females do not only discriminate between males but also show a preference for well-fed males, discriminating between the odors with respect to nutritional state, suggesting that they were responding to a food-specific chemical cue. It is therefore likely that nutritional condition is related to the production of pheromones in males. Our results suggest that information about male nutritional state can be conveyed in chemical cues and that females attend to these cues during mate choice.

Reconhecimento de cores de objetos e de alimentos de cromaticidades opostas por pintos de corte

The aim of this research was to evaluate, by preference tests, the ability of perception of broiler chicks in the recognition of objects and foods of different colors. The survey was conducted in Brazil and consisted in the conditioning of 60 sexed one-day-old chicks using 30 male chicks and 30 female chicks for three days with blue balls and red food colors chosen for having opposed chromaticities. After the conditioning phase, a preference test was performed, in which the animals were placed individually in the center of an arena test with four options: red food, blue food, red balls and blue balls. Each bird was measured for 10 minutes. Latency to the first peck and the number of pecks, the number of sequential pecks at each object type or food, the total time the bird in each occupied compartment and the first occupied slot were recorded. According to the results, female chicks are less inhibited when in contact with a new situation when compared with males. However, males were able to establish a standard environment in the conditioning phase and opted for the compartment which was closer to that situation, associating the blue color to the ball and red color to the food. Overall, among the types of object colors and between types of food colors, the birds took less time for the decision on the choice of blue food and blue ball, showing a greater attraction, at first, to this color. Between the two ball colors, shorter latency period, greater number of interactions as well as more time spent on site were related to the blue sphere, verifying greater preference for this object. When evaluating the types of food colors, it was observed that the highest averages related to the number of pecks, and sequential pecks occurred with red food. Therefore, it is concluded that the birds recognized the red and blue food object, with the blue color having greater attractiveness for broiler chicks when compared to red.