Larval rearing
of burbot (Lota lota L.) using Brachionus calyciflorus rotifer
as starter food
A. Shiri Harzevili, D. De Charleroy, J. Auwerx, I. Vught, J. Van Slycken,
P. Dhert, P. Sorgeloos-2003
Journal of Applied Ichthyology, 19(2): 84
Abstract:
Burbot Lota lota L. is one of the
endangered freshwater fish species in western Europe for which the
development of controlled larval rearing procedures could produce enough
material for stock enhancement. The suitability of the freshwater rotifer Brachionus
calyciflorus as a start food for larviculture of burbot was
investigated. After yolk-absorption, the larvae were stocked in 40-L tanks
under different feeding conditions: clear water rearing conditions with
rotifers (Brachionus calyciflorus) for 10 days (R), green water
conditions (Chlorella sp.) with rotifers offered for 10 days
(MALR), green water conditions (Chlorella sp.) for 3 days
followed by clear water in combination with rotifer feeding for 7 days
(AL3R), and clear water conditions with Artemia nauplii offered for
10 days (Art). After the 10-day feeding, all groups received Artemia
nauplii up to 35 days post-hatching. Larval survival was counted at day
10 and at the end of the 35-day rearing experiment. At day 35, a significant
survival difference was noted between the groups where rotifers were
supplemented with algae vs only Artemia. At the end of the
experiment, the highest survival rate (69.20%) was obtained with larvae
receiving only algae in the first 3 days of feeding. Lowest survival
rate (24.90%) was obtained with larvae receiving only Artemia for 35 days.
This indicates that smaller prey are essential for burbot at first feeding.
Larval length and wet weight were measured at the time of mouth opening, at
days 7, 10, and 21, and at the end of the experiment (day 35). On day 35,
mean length of the larvae varied significantly between the treatments.
However, the final wet weight of the larvae did not vary significantly
between the treatments.
(Fish Culture Centre, Institute for Forestry and Game
Management, Ministry of the Flemish Community, Linkebeek, Belgium)