Feeding ecology of the intensively fished Nile Perch, Lates niloticus, in Lake Victoria, Uganda
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
Aquatic Ecosystem Health & Management
Abstract
The diet of Nile Perch (8.0–121.0 cm total length [TL]) from the Ugandan waters of Lake Victoria
was quantified through stomach content analysis of specimens collected from experimental catches and
fish factory samples. A total of 7824 stomachs (5602 from experimental fishing and 2222 from factory
samples) were examined, of which 34.8% contained food. Fish from the experimental catches were smaller
(8.0–41.6 cm TL) and had a higher diversity of prey dominated by unidentifiable fish prey, haplochromine
cichlids, Rastrineobola argentea, Odonata and Caridina nilotica, while larger fish (30.0–121.0 cm TL)
from the factory samples had a predominance of fish remains and haplochromine cichlids. Nile Perch
that had a high proportion of fish prey (versus invertebrates) in their stomachs showed a larger size
for a given age, and were in a better condition (K = 1.24) than those that had primarily invertebrates
(K = 1.10) in their stomachs. Nile Perch exhibited a much smaller size (15 cm versus 30 cm TL) at shift to
piscivory in comparison to Nile Perch examined in earlier studies, when haplochromines were rare in Lake
Victoria. The recovery of haplochromine cichlids coincident with declining Nile Perch densities illustrates
the importance of developing sustainable management options that can define a proper balance between
fishing mortality and Nile Perch predation.
Description
Keywords
Nile Perch diet, Haplochromine resurgence, Introduced species, Ontogenetic shift, Piscivory
Citation
Winnie Nkalubo , Lauren Chapman & Fredrick Muyodi (2014) Feeding ecology of the intensively fished Nile Perch, Lates niloticus, in Lake Victoria, Uganda, Aquatic Ecosystem Health & Management, 17:1, 62-69. http://dx.doi.org/10.1080/14634988.2014.880639