Thesis (MPhil (Animal Sciences. Aquaculture))--University of Stellenbosch, 2005. / In recent years there has been a renewed interest in the commercial culture of African
Sharptooth Catfish. Its robust characteristics and its air breathing capabilities makes the
African catfish a good candidate for culture in intensive recirculating systems. In light of
the size variation in offspring spawned from undomesticated fish, that may eventually
increase cannibalism, suitable methods for the quantification of some production
performance parameters such as growth and health measurements need to be established for
application in intensive catfish culture. In fish the condition factor (CF) reflects information
on the physiological state of the fish in relation to its welfare. This factor is expressed as
Fulton’s condition index, or the K-factor.
African Sharptooth Catfish fry with average weight of 1.9g ± 0.7867 and average length of
59.375mm ±8.812 were equally allocated into ten 1000L-recirculating tanks. The fish were
fed a commercial feed to apparent saturation at a frequency of 5 times per day. Sixteen fish
were sampled out of each treatment. Weight (g) and length (mm) of each fish were recorded
every seven days over a trial period of 175 days from which Fulton’s condition index K was
calculated. Results were analysed for significant differences using one-way ANOVA and
Tukey’s pair wise comparison test for the various parameters.
Growth parameters (a = -5.083, b = 3.004, R2 = 99.4%) derived from the logarithmic
relationship between body weight (W) and standard length (L) indicated an isometric
growth through the duration of the trail. No significant differences (P>0.05) in condition
factors between treatments were found at the beginning of the trail. Significant differences
(P<0.05) were found at the end of the trail for weight between ponds and condition factor
between treatments. No significant difference (P> 0.05) between length and treatments
were found at the end of the trial.
Mean condition factor was 0.856 ± 0.187. By using this information on condition factor for
African catfish a K-factor calculation chart for African catfish could be calculated, to be
used as a practical measurement tool to measure performance goals on catfish farms.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/3421 |
| Date | 03 1900 |
| Creators | Luckhoff, Paul Daniel |
| Contributors | De Wet, Lourens F., Brink, Danie, University of Stellenbosch. Faculty of Agrisciences. Dept. of Animal Sciences. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Stellenbosch |
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