Age structure, growth and survival rates of the commercial fish Prochilodus nigricans (bocachico) in North-eastern Ecuador
The bocachico, Prochilodus nigricans, is a commercially important fish distributed throughout the central and western Amazon. Age and growth of this species in eastern Ecuador were determined by otolith and scale increment analyses. For otolith analyses, we used thin sections of the astericus, and c...
Saved in:
Published in | Environmental biology of fishes Vol. 77; no. 1; pp. 63 - 77 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Dordrecht
Springer
01.09.2006
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The bocachico, Prochilodus nigricans, is a commercially important fish distributed throughout the central and western Amazon. Age and growth of this species in eastern Ecuador were determined by otolith and scale increment analyses. For otolith analyses, we used thin sections of the astericus, and clear visualization of annuli required the use transmitted polarized light. Accuracy and precision of age estimation were compared to select the best ageing structure. Precision indices showed that otoliths are more reliable than scales to determine the age of bocachicos. Based on marginal increments analysis, we found that annulus formation in both structures occurs once a year between August and December. Seasonal changes in growth were associated with hydrological cycle of the river. The Ecuadorian Prochilodus at the juvenile-adult stage grew faster (i.e., K = 0.29 for ages 2 and older) than conspecific populations from Bolivia and Brazil (K = 0.5). In addition, annual mortality rate (A = 0. 56) was lower than reported for Prochilodus populations elsewhere in the Amazon. We conclude that this population is presently not overexploited, but conservation and management schemes for this population will need to consider that it is an international, trans-boundary migrant.[PUBLICATION ABSTRACT] |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 |
ISSN: | 0378-1909 1573-5133 |
DOI: | 10.1007/s10641-006-9055-y |