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

Abstract

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 to a 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 have defined for the first time 2 phases in the early life history of O. maya: post-hatching and juvenile.KEY WORDS: Cephalopoda · Digestive gland · Post-hatching development · Digestive enzyme · Feeding behavior · Octopus maya Resale or republication not permitted without written consent of the publisherAquat Biol 9: [35][36][37][38][39][40][41][42][43][44][45][46][47][48] 2010 immediately on post-hatching, as previously assumed for squid (Forsythe & Van Heukelem 1987), and that first-feeding hatchlings were extremely sensitive to starvation. The occurrence of the no net growth phase was only revealed after daily individual weight data had been obtained (Vidal et al. 2002).In a similar way, Boucaud-Camou & Boucher-Rodoni (1983) reported that Sepia officinalis hatchlings go through 3 stages that include (1) an embryonic phase characterized by intracellular yolk digestion, linear low growth rate, weak activity of the digestive gland and negative reactions of chymotrypsin, indicating negative extracellular digestion (during these first 4 d the animals do not eat); (2) a post-hatching phase that begins with the first meal inducing the secretory activity of the digestive gland that has grown at the expense of the inner yolk sac; and (3) a juvenile-adult phase, observed at the end of the first month of life, in which the digestive gland has the same histophysiology as that of adults and in which animals are able to catch a greater variety of prey. In this sense, Budelmann et al. (1997) pointed out that the microscopic anatomy of the digestive gland, like the duct appendages of cephalopods, undergoes a variety of changes during postembryonic and juvenile development that result in diverse anatomical features and functions, although some are not yet completely understood. These include (1) synthesis and secretion of digestive enzymes; (2) absorption and metabolism of nutrients; (3) synthesis and storage of lipids, lipoproteins, glycogen, pigments, vitamins and protein; (4) binding of Fe, Cu, Ca and non-physiological hea...

Cytological ontogeny of the digestive gland in post-hatching Octopus maya, and cytological background of digestion in juveniles

“…The reduction in the proportion of lipids in the tissues and the increase of predatory capacity reveal that the maturity process helps prepare for the capture and ingestion of nutritionally complex prey (Moguel et al 2010). A similar behavior has been observed in other holobenthic octopus species (e.g.…”

“…Once in the DG, the nutrients are stored and later transported to the blood. This occurs in Octopus maya hatchlings (Moguel et al 2010) and in paralarvae of Loligo vulgaris reynaudii (Vidal et al 2005), in which a reduction of the body lipid content during the process of yolk-reserve absorption is observed. In this process, the DG goes from being a reserve and yolk distribution organ to being the organ responsible for the processing of ingested food (Perrin 2004).…”

“…Although in Octopus maya this type of study has not been performed, the results from other research on the structural changes of the DG and lipid levels during post-hatch development could indicate the presence of an enzymatic adjustment process, and therefore a digestive process (Moguel et al 2010). The reduction in the proportion of lipids in the tissues and the increase of predatory capacity reveal that the maturity process helps prepare for the capture and ingestion of nutritionally complex prey (Moguel et al 2010).…”

“…Previous studies have demonstrated that to develop a balanced food for rearing cephalopods, it is necessary to know the digestive physiology and the way in which the food is consumed, transformed, absorbed and assimilated (Arvy 1960, Mangold & Young 1998. Some morpho-physiological features of the DG have been studied in O. maya, such as the digestive enzyme activity (Aguila et al 2007), the absorption of the inner yolk, which is necessary for arm elongation (Moguel et al 2010) and the development phases of the digestive cells with age (LopezRipoll 2010). However, it is still necessary to elucidate many of the steps involved in the digestive processes of these octopuses.…”

Paralarvas y juveniles de Octopus bimaculatus (Cephalopoda: Octopodidae) en el Pacífico sur de México

“…México (Roper et al 1995), sin embargo el rango geográfico de distribución de esta especie es incierto. Verril (1883) propuso que O. bimaculatus se distribuye desde San Diego, California hasta Panamá, e incluso más al sur; pero Berry (1910Berry ( , 1911 (Moguel et al 2010). El objetivo de este estudio fue aportar información sobre la distribución de paralarvas y juveniles de O. bimaculatus, redefiniendo la extensión de ámbito geográfico para esta especie en el Pacífico Sur de México.…”