Application of the thermal time model of embryonic development duration to the culture of octopod cephalopods

Abstract

Data about the effect of temperature on the duration of embryonic development, or the incubation process, are relatively abundant for octopod cephalopods. Experimental data can be used to fit the thermal time classic model of development in order to predict the duration of the process and the range of temperatures within which development proceeds according to the model and with high survival (permissive range), with potential applications for basic research and production activities. The present work is aimed at fitting this classical model to fourteen data sources dealing with eleven species of octopods, seven of them not being previously analyzed, and discussing the constraints and applications of the model. As a result, it is possible to hold that the thermal time model of development duration suitably fits experimental data in octopods, and can be used to schedule hatching events in a production facility. Nevertheless, the range of temperatures tested in the literature is usually too limited to allow an appropriate estimation of the permissive range, so an extension of the temperature range to the known limits of each species is suggested. In addition, when the model is applied to whole spawnings with culture purposes, it is recommended to set the very first hatchings as the criterion for the end of the incubation. Further research is needed to ascertain if temperature fluctuations within and/or out of the permissive range can have implications for the parameterization of the model in octopod species.

Keywords

• Incubation temperature
• Thermal time
• Embryonic development length
• Development rate
• Octopod cephalopods