Using molecular markers for pedigree reconstruction of the greater amberjack (Seriola dumerili) in the absence of parental information

Ensuring appropriate levels of genetic diversity in captive populations is essential to avoid inbreeding and loss of rare alleles by genetic drift. Pedigree reconstruction and parentage analysis in the absence of parental genotypes can be a challenging task that relies in the assignment of sibship relationships among the offspring. Here, we used eight highly variable microsatellite markers and three different assignment methods to reconstruct the most likely genotypes of a parental group of wild Seriola dumerili fish based on the genotypes of six cohorts of their offspring, to assess their relative contributions to the offspring. We found that a combination of the four most variable microsatellites was enough to identify the number of parents and their contribution to the offspring, suggesting that the variability of the markers can be more critical than the number of markers. Estimated effective population sizes were lower than the number of breeders and variable among years. The results suggest unequal parental contribution that should be accounted for breeding programs in the future.     

Diet of peccaries (Tayassu tajacu and T. pecari) in a dry forest of Venezuela

The diets of Tayassu tajacu and T. pecari were assessed by means of direct observations, stomach content, and faecal analyses. The study was conducted in a dry forest located in the central Llanos region, Venezuela, where both species coexist. Peccaries were observed during one week of every month from August 1986 to May 1987. Fruits and seeds of Pithecellobium saman and Guazuma ulmifolia and roots and stems of Cissus rhombifolia comprised most of the diet of both peccary species. Proportions of these items differed significantly between species. There was no Acacia macracantha in stomachs nor in faeces of T. tajacu , but it was one of the most important items found in stomachs of T. pecari. Leaves appeared in all stomachs but in very low proportions (<1%). Insect pupae and larvae were found in small quantities. Results suggest that peccaries behave as frugivores and seed predators as most seed remains appeared cracked. Differences in the diet and behavioural traits described elsewhere may allow these similar species to coexist in the tropical dry forest of central Venezuela.