Relative Triacylglycerol and
Morphometric Measures of Condition in Sunshine Bass Fry
S.E. Lochmann, G.M. Ludwig-2003
North American Journal of Aquaculture, 65(3):
191–202
Abstract:
Condition measures are assessed for wild populations
of fish fry to examine production and the implications for recruitment
variability. These condition measures might guide management decisions, such
as those in fish culture. We developed two condition measures, one based on
morphometric measurements and one based on lipid class composition, for
sunshine bass (white bass Morone
chrysops × striped bass M.
saxatilis) fry. Prey concentrations were varied during three tank
studies. Fry were sampled periodically and analyzed morphometrically and
biochemically. Discriminant function analyses of morphometrics and lipid
class composition were used to classify fry into treatment groups. The most
successful discriminant function, which was based on morphometrics,
correctly classified 75% of the test fry. We developed a condition measure
based on relative triacylglycerol (TAG) content. Well-fed fry (15–20
prey/mL) had significantly higher average relative TAG values than poorly
fed fry during the third week in two of the studies. Undernourished fry had
relative TAG values of approximately 0.5, whereas well-fed fry had values
ranging from 1.0 to 5.0. Relative TAG and the morphometric discriminant
function are indicators of feeding success and might be used to guide
management decisions, such as fertilization or feeding, during phase-I
fingerling production of sunshine bass.
(Aquaculture/Fisheries Center, University of Arkansas
at Pine Bluff, 1200 North University Drive, Mail Slot 4912, Pine Bluff,
Arkansas 71601, USA)