2022 Early Hearing Detection & Intervention Virtual Conference
March 13 - 15, 2022
5/25/2021 | 2:00 PM - 3:30 PM | ENVIRONMENTAL FILTERING AND PREDATION INFLUENCE GROWTH VARIABILITY OF TWO CIHLID SPECIES FROM THE OKAVANGO DELTA, BOTSWANA | Virtual Platform
ENVIRONMENTAL FILTERING AND PREDATION INFLUENCE GROWTH VARIABILITY OF TWO CIHLID SPECIES FROM THE OKAVANGO DELTA, BOTSWANA
Environmental filtering and biotic interactions influence life histories of organisms in seasonally flooded river systems. However, little is understood about factors that affect the early life history of fish in heterogenous, river-floodplain systems of sub-Saharan Africa. Here, we assessed variability in growth rates of Juvenile cichlids (Coptodon rendalli and Tilapia sparrmanii) among regions of the Okavango Delta, Botswana. We sampled fish from three sites along a fluvial gradient from the upper to the lower Okavango Delta using a beach seine net. We determined age using micro-increment analysis from otoliths following standard procedure. We estimated growth rates using the Gompertz Growth Model. Analysis of variance showed significant differences in environmental parameters amongst sites. Similarly, growth rates differed among regions with juvenile fish from the upper Delta showing faster growth compared to those from the lower Delta. Predation and environmental factors were the major drivers of variability in fish growth suggesting that environmental variation influences resources and predator traits which may differ among habitats. Our results are consistent with the idea that biotic and abiotic factors may act in concert to regulate fish populations in seasonally flooded wetland systems.
- Flow regime
- Habitat
- Vertebrates
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Presenters/Authors
Thethela Bokhutlo
(), Botswana International University of Science and Technology, thethela.bokhutlo@gmail.com;
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Ketlhatlogile MOSEPELE
(), Botswana University of Agriculture and Natural Resources, kmosepele@buan.ac.bw;
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Belda MOSEPELE
(), Botswana University of Agriculture and Natural Resources, bmosepele@buan.ac.bw;
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