Please use this identifier to cite or link to this item:
Files in This Item:
File Description SizeFormat 
Influence of body weight and substrate granulometry.pdf487.88 kBAdobe PDFThumbnail
Type: Artigo de Periódico
Title: Influence of body weight and substrate granulometry on the reproduction of Limnodrilus hoffmeisteri (Oligochaeta: Naididae: Tubificinae)
Author: Lobo, Haroldo
Alves, Roberto da Gama
Resumo: -
Abstract: Limnodrilus hoffmeisteri Claparede, 1862 is a cosmopolitan Oligochaeta widely used as indicator of organic pollution in water bodies. Previous contributions have shown the effects of organic matter and temperature on the life history of the species, although very little is known about the factors that influence its reproduction. This study aimed 1) to test whether the larger weight of individuals results in an increase in the reproduction rate and 2) to test the influence of two granulometric fractions of sand on the reproduction and growth the species. In the first experiment, specimens of L. hoffmeisteri were separated in two groups with different average weights (small individuals = 6.63 ± 1.28 mg; large individuals = 12.44 ± 3.99 mg) and kept at 15 ± 1ºC for 21 days. The results of this experiment showed that the number of cocoons was statistically similar between the groups, but the mean number of eggs per cocoon produced by large individuals (2.78 ± 0.35) was greater than that produced by small individuals (7.45 ± 2.50). In the second experiment, weekly observations were conducted for 25 weeks in two groups of 30 specimens: one kept in fine sand and the other in medium sand, at 25 ± 1ºC. The single significant difference was in the number of cocoons per adult per day (0.37 ± 0.22 and 0.23 ± 0.24, for fine and medium sand, respectively). Individuals reared in fine sand produced a greater number of descendants compared to those reared in medium sand in the same period of time.
Keywords: Cocoon
Growth rate
Indetermined growth
CNPq: -
Language: eng
Country: Brasil
Publisher: -
Institution Initials: -
Access Type: Acesso Aberto
Issue Date: 2011
Appears in Collections:Artigos de Periódicos

Items in DSpace are protected by Creative Commons licenses, with all rights reserved, unless otherwise indicated.