The Influence
of Livefeed Supplementation on Growth and Reproductive Performance of
Swordtail (Xiphophorus helleri Heckel 1848) Broodstock
D.P. Kruger, P.J. Britz, J.
Sales-2001
Aquarium Sciences and Conservation, 3(4):
265-273
Abstract:
The influence of supplementation of drum-dried flake
feed with various levels of Daphnia sp. on the growth and fecundity
of broodstock Xiphophorus helleri was evaluated. Weekly
supplementation showed no measurable advantage over flake feed only. A
direct correlation was demonstrated between fecundity and size of female
fish when fed a formulated flake feed only. Fish fed a daily Daphnia
supplement had a mean final weight of 5.97 g,
feed conversion ratio of 1.33 and mean fecundity of 190 embryos per female,
which was significantly higher than the yield from the non-supplemented or
weekly supplemented treatments. Despite these differences, the number of
young harvested during the experiment did not differ (P > 0.05)
between treatments and this discrepancy was ascribed to parental cannibalism
of new born juveniles.
(Department of
Ichthyology and Fisheries Science, Rhodes University, P.O. Box 94,
Grahamstown, 6140, South Africa)