The present study investigated potential bio-markers (ovarian fluid paramet
ers, egg weight and weight increase during water hardening, biochemical egg
composition, egg enzyme activities) for egg quality determination in the c
ommon carp (Cyprinus carpio), the silver carp (Hypophthalmichthys molitrix)
, the grass carp (Ctenopharyngodon idella) and the bleak (Chalcalburnus cha
lcoides).
For all investigated species, the study revealed highly significant correla
tions between the egg fertilization rate and the weight of water-hardened e
ggs, the percent weight increase during water hardening and the ovarian flu
id pH, protein concentration, and aspartate aminotransferase activity. The
fertilization rate was further correlated with the activities of malate deh
ydrogenase and pyruvate kinase of the eggs, and in C. calpio and Cha. chalc
oides with the respiration activity, too. Investigated biochemical paramete
rs of the eggs (protein, peptides, fructose, galactose, glucose, non-esteri
fied fatty acids, esterified fatty acids, total DNA and RNA) were not corre
lated with the fertilization rate.
The possible use of the analysed parameters for prediction of egg quality d
uring short-term storage was also investigated in C. carpio and Cte. idella
: during short-term storage for 4 h at 4 degreesC, the fertilization rate s
ignificantly decreased. Also, the weight of the eggs after water hardening,
the percent weight increase due to water hardening and the ovarian fluid p
H and ovarian fluid aspartate aminotransferase changed in comparison to fre
sh samples and were highly significantly correlated with the fertilization
rate. In contrast, the biochemical composition of the eggs (protein, peptid
es, fructose, galactose, glucose, non-esterified fatty acids, esterified fa
ttyacids, total DNA and RNA) and egg enzyme activities (phosphofructokinase
, pyruvate kinase, protease, lipase, NAD-dependent malate dehydrogenase, re
spiration rate, NADP-dependent isocitrate dehydrogenase, aspartate aminotra
nsferase) remained constant. (C) 2001 Elsevier Science B.V. All rights rese
rved.