7/27/2019 Actividad Atpasa Paralarvas Octopus
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ATPase ACTIVITY IN Octopus vulgaris (Cuvier, 1797)
(MOLLUSCA,
CEPHALOPODA) NEWBORN PARALARVAEPozuelo I. and BRUZN, M.A. IFAPA
Centro El Toruo. Camino Tiro Pichn s/n. ElPuerto de Santa Mara
(Cdiz) Spain 11500. First author email address:
[email protected] Presenting author email
address:[email protected] The common octopus
Octopus vulgaris (Cuvier, 1797) fishery is currently exploited
tosuch an extent that an adequate management with specific
restrictive measures isstrongly needed. This would undoubtedly help
to optimise sustainable fisheryexploitation. On the other hand, O.
vulgaris aquaculture has proved unfeasible oncommercial scale.
Transition from plankton to benthos seems the bottleneck for
thewhole life-cycle culture, due to insufficient growth and high
mortality rates of reared-in-captivity paralarvae. Nutritional
deficit of paralarvae during planktonic stage has beenregarded as
the most important factor causing mortality (Iglesias et al.,
2007). The studyof biological phenomena during early-life-stages
ontogeny is a good instrument toenhance O. vulgaris aquaculture
development, since knowledge of life-history traits isan important
criterion for effective management of natural resources (Young et
al.,2006). We have studied ATPase activity during the early days of
O. vulgaris paralarvaewith the aim to contribute to the knowledge
of some nutritional requirements in thisspecies, which enhances the
development of profitable diets. Octopuss paralarvae bornin
captivity were cryopreserved either immediately after egg hatching
(0-days-oldparalarvae), or after three days maintained under
starving conditions (3-days-oldstarving paralarvae), or after being
fed with Artemia salina (L., 1758) during three days(3-days-old
paralarvae fed with A. salina). Cryosections were subjected to
ATPaseactivity assay (Garca del Moral, 1993; Bancroft, 2002).
ATPase assessment was carried
out according to the following activity scale: (-) absence; (+)
moderate; (++) high;(+++) very high. ATPase activity showed
different patterns of expression at pH 9.4 andpH 4.6. At pH 9.4,
activity was moderate in liver, pancreas, posterior salivary
glands,stomach, and caecum of the three paralarvae types. Activity
(moderate) in crop andhepatopancreatic duct was only found in
0-days-old paralarvae and 3-days-oldparalarvae fed with A. salina.
At pH 4.6 high levels of activity were recorded inposterior
salivary glands, liver, pancreas, caecum, intestine, and crop (the
latest notobserved in 0-days-old paralarvae). The stomach showed
moderate activity in the threetypes of paralarvae. Although ATPase
activity showed similar spatial-temporal patternof expression at
acid and alkaline pH, activity was clearly higher at acid pH,
except forthe hepatopancreatic duct. The highest levels of activity
were recorded in liver,
pancreas, and caecum, probably linked to transport processes
related with nutrientabsorption (caecum and liver), and fluid
absorption (pancreas). Activity in pancreasseems to be related to
ionic equilibrium regulation (Wells and Wells, 1989). This workwas
supported by INIA project RTA04-122-C2 (MCyT-Spain)
