RESUMO
Bombus brevivillus Franklin is a Neotropical Bombus species whose colonies are disappearing from most of its native range, and little is known about its biology and reproductive habits to help conservation or breeding efforts. Unlike Bombus species from temperate climates whose colonies perish every winter, there are suggestions of perennial colonies that Neotropical Bombus species can present. In this work, we investigated the development of two B. brevivillus colonies (i.e., number of workers, gynes, males, new cocoons, and brood area) between August 2012 and March 2013. We realized that while one colony collapsed and died after the males' and gynes' production, and the reduction of numbers of adult workers, in the other, a new queen assumed the posture at this phase and reactivated the old nest. Despite the reduced number of colonies investigated, this study shows the possibility of nest reactivation in the studied species in queen supersedure events in resemblance to perennial colonies of eusocial bees like Apis species and stingless bees. Such behavior has never been directly described to B. brevivillus in previous studies and opens the possibility for further research in the existence and the extension of perennial colonies in Neotropical Bombus species due to its importance to the species conservation in the tropical environment.
Assuntos
Abelhas , Comportamento de Nidação , Animais , Abelhas/fisiologia , Reprodução , Clima Tropical , Dinâmica PopulacionalRESUMO
BACKGROUND: Reproductive success is determined by the interplay between mating and fertilization success. In social insect species with male-biased sex ratios and queen monogamy, males face particularly strong pre-copulatory sexual selection since they must compete with thousands of other males for a unique mating opportunity. Ejaculate quality is also expected to be under selection, because queens are long-lived and store sperm for life, so males with higher quality ejaculates are expected to provide queens with larger and longer-lived colonies, which in turn may produce more daughter queens (the only direct fitness gains of haplodiploid males). Considering the action of pre and post-copulatory sexual selection on male traits, three scenarios might thus be expected: positive, negative or no association between male mating ability and fertilization success. Here we explored these scenarios in the stingless bee Scaptotrigona aff. depilis, where males gather in large aggregations and queens mate with a single male. Male mating ability was assessed through the capacity of a male to reach an aggregation and persist on it; while sperm viability, sperm number, and sperm morphology were used as proxies for sperm quality. RESULTS: Sperm viability was associated with persistence time in the aggregation, and males that persisted longer presented shorter spermatozoa and higher variation in sperm length than recently arrived males. However, sperm traits of males that reached aggregations did not differ from those of males collected inside their colonies. In addition, males that persisted longer in aggregations were smaller than other males. Male size and sperm viability were not correlated, suggesting that the observed patterns were not due to trade-offs in male resource allocation. CONCLUSIONS: Persistence in male aggregations thus seems to select more competitive males with higher quality sperm. Our work is the first one to reveal an association between male competitive ability and fertilization success in a monogamous social insect. This finding sheds important light on the evolution of male traits in social insects and the general mechanisms of sexual selection.
RESUMO
Os coelhos domésticos são mamíferos lagomorfos da família dos leporídeos criados em diferentes regiões do mundo. São animais muito férteis e bastante prolíficos e possuem ciclos reprodutivos curtos. O porte pequeno e a possibilidade de inclusão de alimentos fibrosos em sua dieta, minimiza os custos de produção e favorece a criação destes animais em áreas relativamente pequenas. Porém, a falta de informação e o atraso tecnológico respondem pelos baixos índices reprodutivos na cunicultura brasileira. Objetivou-se pelo presente estudo reunir informações acerca dos aspectos fisiológicos da reprodução de coelhos.
Domestic rabbits are mammals lagomorphs of Leporidae family, raised in different regions of the world. They are very fertile and prolific, also have short reproductive cycle. The small size and potential inclusion of fibrous food in the diet play down the production costs and favor warren in small areas. Lack of information and technologicall backward respond by low reproductive index of brazilian warren. Were aimed through this paper gather information about physiological aspects of rabbits reproduction.
Assuntos
Análise do Sêmen/veterinária , Espermatozoides/citologia , Sêmen/fisiologia , Coelhos/classificaçãoRESUMO
Os coelhos domésticos são mamíferos lagomorfos da família dos leporídeos criados em diferentes regiões do mundo. São animais muito férteis e bastante prolíficos e possuem ciclos reprodutivos curtos. O porte pequeno e a possibilidade de inclusão de alimentos fibrosos em sua dieta, minimiza os custos de produção e favorece a criação destes animais em áreas relativamente pequenas. Porém, a falta de informação e o atraso tecnológico respondem pelos baixos índices reprodutivos na cunicultura brasileira. Objetivou-se pelo presente estudo reunir informações acerca dos aspectos fisiológicos da reprodução de coelhos.(AU)
Domestic rabbits are mammals lagomorphs of Leporidae family, raised in different regions of the world. They are very fertile and prolific, also have short reproductive cycle. The small size and potential inclusion of fibrous food in the diet play down the production costs and favor warren in small areas. Lack of information and technologicall backward respond by low reproductive index of brazilian warren. Were aimed through this paper gather information about physiological aspects of rabbits reproduction.(AU)