Chrisestom M. Mlewa

Translocation of marbled African lungfish, Protopterus aethiopicus (Telostei: Protopteridae), and its fishery in Lake Baringo, Kenya

The translocation of the marbled African lungfish Protopterus aethiopicus into Lake Baringo created a new fishery for the local community, who capture them primarily in a bottom-set long line fishery. Its introduction, development and current fishery status in the lake are documented. Annual catch data were obtained from the District Fisheries Office, while catch and effort data of the long line fishery were recorded at one active fish-landing site between February and October 2001. Lungfish comprise a significant component of commercial landings, sometimes exceeding catches of the Baringo tilapia Oreochromis niloticus baringoensis as the most landed species by weight. Daily catch rates and effort varied considerably, ranging from 5.51–15.18kg day−1 and from 50–590 baited hooks day−1, respectively. Daily catch per fisher ranged from 0–35.72kg, while the overall mean catch per unit effort (CPUE) was only 0.003kg per hook-hour. This study provides the only baseline CPUE data for a lungfish long line fishery that the authors are aware of, for comparison with future studies in this or other lakes where lungfish are similarly exploited. Recommendations for improved management and the maintenance of a viable lungfish long line fishery in Lake Baringo are presented.

Daily Growth of Young-of-the-Year of the Baringo Tilapia, Oreochromis Niloticus baringoensis (Trewavas, 1983)

Otolith microstructure analysis was used to validate microincrement deposition rate and to determine daily growth rates of young-of-the-year (YOY) Baringo tilapia, Oreochromis niloticus baringoensis. Micro-increment formation was validated as daily by correlating the number of circuli on otoliths with the known age of cultured fish. For wild young-of-the-year fish collected from Lake Baringo, Kenya, in August and October 2007 length was positively correlated with the age of fish (total length (mm) = 0.1187 age (/day) + 1.1344 (r2 = 0.97); standard length (mm) = 0.0964 age (/day) + 0.7082 (r2 = 0.97)) and growth rate was subsequently estimated at 0.12 cm/day.

Are wild African lungfish obligate air breathers? Some evidence from radio telemetry

ABSTRACT Laboratory studies have resulted in classification of the marbled African lungfish, Protopterus aethiopicus, as an obligate air-breather. However, there have been no investigations of the extent of dependence on aerial respiration by this species in the wild. We used radio telemetry to obtain quantitative information on the surfacing frequency of lungfish in Lake Baringo. The results showed radio-tagged lungfish came to the surface during the period immediately following their release but that aerial respiration later ceased, indicating that the fish were able to meet their metabolic oxygen requirements solely through aquatic respiration. These results suggest that under certain conditions lungfish in the wild may not be obligate air breathers and that the use of aerial respiration may be a function of ecological as well as physiological factors.