Effects of temperature on the rate of embryonic development of cephalopods in the light of thermal time applied to aquaculture

Abstract

AbstractThe temporal description of the embryonic development in ectothermic animals and the speed of development depends on environmental temperature. The concept of thermal time helps in solving this problem by making it possible to define a linear model of development linking developmental rate and temperature. The model has been scarcely applied to cephalopods in spite of being useful for programming embryonic development and hatching events. The potential application of the linear model of development would have particular interest in the case of emerging species for aquaculture such as Octopus vulgaris or Sepia officinalis. Therefore, the main goal of this work is to review the effect of temperature on the rate of embryonic development in cephalopods in relation to the linear model of development and to discuss its potential applications and limitations to cephalopod aquaculture. As a result, a good fitting of the model has been proven not only for the total time of development, but also for the time of the organogenesis phase, in nine species of cephalopods. Usually, threshold temperatures for different developmental phases, pre‐organogenesis, organogenesis and growth, are the same. In addition, the potential use of anisothermic protocols for egg incubation, as well as the problems connected with the asynchronicity of egg laying within a single spawning are also discussed. In consequence, the linear model of development seems to be useful for basic and applied research on cephalopod embryonic development and particularly for the advancement of cephalopod aquaculture.