Anchovy egg development in the Gulf of Cádiz and its comparison with development rates in the Bay of Biscay

Multinomial models were used to analyse anchovy (Engraulis encrasicholus, L.) egg development in the Gulf of Cádiz and provide the required egg development model for the application of the daily egg production method in this area. Also, models were modified to allow for a statistical comparison between the egg development in the Gulf of Cádiz and in the Bay of Biscay. The Gulf of Cádiz data was obtained from an incubation experiment carried out during July 2007, where wild adults were collected, an in vitro fecundation was immediately performed and viable eggs were maintained in an on-land incubator at five different controlled temperatures (approximately 10, 14, 18, 22 and 26 °C). Eggs were sampled hourly and classified into stages until they developed into larvae. The model of the combined data from the Gulf of Cádiz and the Bay of Biscay show no differences between areas, suggesting that for the same temperatures, the total duration of the egg phase is similar for the Gulf of Cádiz and for the Bay of Biscay.

► A temperature controlled egg development experiment for Gulf of Cádiz anchovy was carried out.
► Results of the experiment were compared with anchovy egg development in the Bay of Biscay.
► A temperature-dependent egg development model for Gulf of Cádiz anchovy was developed.
► The development model provides one of the requirements to apply the daily egg production method in this area.