Premium
Importance of broodstock holding temperature on fecundity and egg quality in three groups of photo‐manipulated A tlantic cod broodstock
Author(s) -
Hansen Øyvind J,
Puvanendran Velmurugu,
Mortensen Atle
Publication year - 2012
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.2011.03018.x
Subject(s) - broodstock , biology , gadus , atlantic cod , fecundity , human fertilization , ovulation , zoology , fishery , oocyte , reproduction , fish <actinopterygii> , aquaculture , ecology , anatomy , population , endocrinology , embryo , demography , sociology , hormone
We conducted a study to evaluate the effects of holding water temperature on the fecundity and egg quality of photo‐manipulated A tlantic cod broodstock. Adult cod G adus morhua were distributed among several 25‐m 3 tanks. Three separate photoperiods were used for each group to obtain three spawning per year (in M ay, J uly and D ecember). While photoperiod was controlled, the temperature was not controlled and followed the ambient seasonal pattern. Due to the uncontrolled seasonal temperature used, each spawning group experienced different temperatures at a particular gonadal developmental stage. Otherwise, all groups were treated the same. Results showed that the May and July spawning groups released significantly more eggs per kg of fish (four and three times more respectively) than the D ecember spawning group. The egg fertilization success and proportion of normal eggs were also higher in the M ay and J uly groups. Possible reason for the difference may be that the M ay and J uly groups experienced lower temperatures (4–7°C) during oocyte maturation and ovulation than the D ecember group (7–9°C). Our results show the importance of using lower/natural temperatures during oocyte maturation and ovulation to obtain good quality eggs in photo‐manipulated cod broodstock.