Morphological, physiological and behavioral changes during post-hatching development of Octopus maya (Mollusca: Cephalopoda) with special focus on the digestive system

摘要

We examined changes in the histology, physiology and enzymatic activity of the digestive gland — as well as changes in morphology and feeding behavior—of Octopus maya during rearing, to define the phases characterizing post-hatching development. Morphometric changes showed that juvenile O. maya exhibited a non-growth phase during the first 10 d post-hatching (DPH). Histological analysis revealed that the digestive gland morphology changed with age, from a simple tubular gland in octopuses 2 DPH toa tubulo-acinar and vacuolar structure with digestive cells characterized by vacuoles in octopuses 45 DPH. Digestive enzyme activity was erratic until 14 DPH, after which the activity started to stabilize. O. maya at 2 and 3 DPH rarely presented attack responses to either visual or both visual and chemical stimuli from prey. In contrast, at 4 DPH, octopuses responded to visual stimuli from crabs and palaemonids, but did not display preference in attacking either prey type. Based on our results, we havedefined for the first time 2 phases in the early life history of O. maya: post-hatching and juvenile.