11 research outputs found
Comparative ecology of the European eel, Anguilla anguilla (L.1758), in a large Iberian river
A total of 1,816 eels were sampled in
1988, from seven sampling areas. Four areas were
located in brackish water and the remaining three
were located in freshwater reaches of the
Tagus river basin. Eels were more abundant in
the middle estuary and decreased both in the
upstream and in the downstream directions, with
a predominance of males in higher density areas.
Smaller individuals preferred more peripheral areas, such as margins and upper reaches in the
brackish water zone, and the tributaries of the
freshwater habitats. It was assumed that this
distribution pattern resulted from three main
factors: (i) the dominance of larger specimens;
(ii) the need to avoid predators and; (iii) the
search for better trophic conditions. The condition
of the individuals generally decreased toward
the upper reaches, apparently due to a corresponding
decrease in feeding intensity. The presence
of the Belver dam in the main river, 158 km
upstream from the sea, seemed to impose major
alterations to the described patterns. The concentration
of specimens below this impassable
obstacle yielded a reduction in the proportion of
females and a decrease in the condition and
survival of the eels, contributing to a reduction in
the spawning success of this population. Suggestions
to diminish the effects of the dam, and to
preserve the fishery are also presente
Diet and feeding daily rhythm of Pimelodella lateristriga (Osteichthyes, Siluriformes) in a coastal stream from Serra do Mar - RJ
The present study was carried out in Mato Grosso fluvial system, a costal drainage from Serra do Mar. We analysed the diet and the feeding daily rhythm of Pimelodella lateristriga from samples carried out during 24 hours over a 4 hour fishing interval, in June, July and September, 2006 as well as in January and February, 2007. Diet was described from the Feeding Index (IAi) and feeding daily rhythm was verified through the Gut Fullness Index (GFI). Pimelodella lateristriga diet was composed of 37 items, being aquatic insects the most important ones. IAi analysis revealed that Diptera, Trichoptera and Ephemeroptera amounted to 90% of the diet. Autochthonous invertebrates were the most important consumed items. Pimelodella lateristriga concentrated its feeding activities in the nocturnal period (10:00 PM to 2:00 AM) with marked significant differences (F = 16.11; gl = 5; p < 0.05) between each diurnal and nocturnal periods. Between 6:00 AM and 6:00 PM, foraging activity was gradually reduced. We concluded that P. lateristriga has an insectivorous diet and a nocturnal feeding habit with greater activity between 10:00 PM to 2:00 AM
Interpreting noncoding genetic variation in complex traits and human disease
Association studies provide genome-wide information about the genetic basis of complex disease, but medical research has primarily focused on protein-coding variants, due to the difficulty of interpreting non-coding mutations. This picture has changed with advances in the systematic annotation of functional non-coding elements. Evolutionary conservation, functional genomics, chromatin state, sequence motifs, and molecular quantitative trait loci all provide complementary information about non-coding function. These functional maps can help prioritize variants on risk haplotypes, filter mutations encountered in the clinic, and perform systems-level analyses to reveal processes underlying disease associations. Advances in predictive modeling can enable dataset integration to reveal pathways shared across loci and alleles, and richer regulatory models can guide the search for epistatic interactions. Lastly, new massively parallel reporter experiments can systematically validate regulatory predictions. Ultimately, advances in regulatory and systems genomics can help unleash the value of whole-genome sequencing for personalized genomic risk assessment, diagnosis, and treatment