Temperature-dependent development rates of cod Gadus morhua eggs

Authors: Geffen; Fox; Nash

Source: Journal of Fish Biology, Volume 69, Number 4, October 2006 , pp. 1060-1080(21)

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Abstract:

Temperature development relationships were determined for batches of Irish Sea cod Gadus morhua eggs incubated in flow-through incubators. Hatching began 16·4 days after fertilization (DAF) at 6° C, 10·3 DAF at 8° C, 9·4 DAF at 10° C and 7·4 DAF at 12° C. Egg mortality increased at the higher temperatures, but survival was >80%. Results were compared with published data at four comparable stage end points: the end of blastula, the end of gastrula, the point of growth of the embryo completely surrounding the yolk and the point when 50% of the eggs were hatched. All the studies showed a curvilinear relationship between age at stage and temperature. There was a 12 day inter-study difference in time to 50% hatch at 2° C and 4 day difference at 10° C. There were no consistent trends that differentiated eastern v. western, or northern v. southern populations. A single model for cod egg incubation time from fertilization to 50% hatch was derived based on data from six cod populations, but it is recommended that individual stock relationships should be used where possible.

Keywords: developmental stages; egg development; egg quality; gadoids; stage duration

Document Type: Regular paper

DOI: http://dx.doi.org/10.1111/j.1095-8649.2006.01181.x

Affiliations: 1: The Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft, Suffolk, NR33 OHT, U.K.

Publication date: 2006-10-01