Duration
of egg storage at different temperatures in the astacid crayfish Pacifastacus
leniusculus: critical embryonic phase
J.R.
Pérez, J.D. Celada, J. González, J.M. Carral, M. Sáez-Royuela, R. Fernández-2003
Aquaculture, 219(4): 347-354
Abstract:
The
critical phase that would limit duration of egg storage in the astacid
crayfish Pacifastacus leniusculus was investigated. Weekly monitoring
was conducted during an 84-day period of storage at three different constant
temperatures (15.5±1, 10.5±1.5 and 4±0.5 °C). After artificial
incubation, stage 2 juveniles were only obtained from the lowest storage
temperature, the sole treatment in which eggs did not reach the critical
embryonic stage by the end of the storage. This limiting stage occurs at
phase XII (embryo with pulsating heart) when embryogenesis of stored eggs
ceased and phase XIII (eyed stage) was not reached. Eggs were also stored at
a constant refrigeration temperature (4±0.5 °C) for periods ranging from
84 to 126 days. Mean survival rates to juvenile stage 2 were acceptable
(approximately 50%) and different batches of juveniles were obtained over a
3-month period, depending on the duration of storage. The combined use of
storage and artificial incubation techniques could have important
applications to the development of astacid crayfish culture.
(Dpto.
Producción Animal II, Universidad de León, Campus de Vegazana s/n, 24071,
León, Spain, e-mail of J.M. Carral: dp2jcl@isidoro.unileon.es)