Contribution of food availability to the more rapid growth of the scallop, <i>Euvola ziczac</i> (Pteroida, Pectinidae) in bottom than in suspended culture

Abstract

We conducted a 5-month experiment at Turpialito in the Golfo de Cariaco, Venezuela, to examine whether the previously reported more rapid growth of scallop Euvola ziczac in bottom compared to suspended culture can be attributed to more abundant or higher quality food resources near the sediment/water interface. The various body components (shell, muscle, digestive gland, gonad and remaining tissues) increased in size at a much greater rate for scallops maintained on the bottom, in partly buried cages at 5 m in depth, than in cages suspended at the same depth in the water column. Furthermore, survival was greater on the bottom. Food abundance and quality were examined by analyzing the seston collected in sediment traps at the sediment/water interface in the vicinity of the bottom cages and next to the suspended cages. Phytoplankton abundance (chlorophyll a) and the proportion of various fatty acids in the lipid fraction of the seston were similar on the bottom and in suspension. However, sestonic protein, lipid and carbohydrate levels, and the estimated energetic content of the seston, were higher on the bottom than in suspension, and probably contributed to the greater growth on the bottom. As the increase in the energetic content of the seston on the bottom compared to in suspension was less than the increase in growth (biomass) on the bottom compared to in suspension, and the evidence showed in previous studies above the negative influence of fouling and wave action in suspended culture, we conclude that the more rapid growth of Euvola ziczac in bottom than suspended culture is principally due to stress relative to suspended culture system.

Chronic and severe hypoxic conditions in Paracas Bay, Pisco, Peru: Consequences on scallop growth, reproduction, and survival

“…In bivalves, growth variations have been often attributed to seston quantity and/or quality (Thouzeau et al, 1991;Grant, 1996;Lodeiros et al, 1996;Chauvaud et al, 1998;Lodeiros, 2000;Cantillánez et al, 2007;Hunauld et al, 2005;Lodeiros et al, 2011) to temperature and/or to the synodic month cycle (see Thébault et al, 2008, for review). In the Rinconada Bay (Chile), (Thébault et al, 2008) showed that water temperature, POC concentration and the lunar cycle (by…”

A Way to Decrease the Negative Impact of Aquaculture on other Marine Inhabitants

“…Touching the bottom with only the load (anchor), as well as the use of netting cover of the collector, prevents colonization of bivalve shells by drilling Polydora polychaete worms and barnacles, which retard the growth rate of bivalves at the bottom [36,37]. The anchored position of collectors, in contrast to a hanged culture, reduces stress in cultivated species and increases the growth and survival rates in bivalves [38]. By the second and third years, much fewer invertebrate larvae settle on collector-cages [39]; the main competitor of the scallop, M. trossulus, does not live for more than two years in Possyet Bay [40]; and the overlapping cones in the inner part of collector prevents predators from moving in it.…”

Crecimiento del mejillón verde <i>Perna viridis</i> (Bivalvia: Mytilidae) bajo sistema de cultivo de fondo en la ensenada de Turpialito, Golfo de Cariaco, Venezuela

“…Los estudios realizados en el golfo de Cariaco empleando diferentes métodos de cultivo ("long line" y fondo), en especies de moluscos bivalvos con potencial de cultivo, reportándose diferentes resultados, según la especie analizada, Euvola (Pecten) ziczac, (Vélez et al 1995, González 1995, Freites et al 1996, Hunault et al 2005, Nodipecten nodosus (Freites et al 2003), y a la ostra perlera Pinctada imbricata (Lodeiros et al 2002), encontrándose que de las especies analizadas, E. ziczac, fue la que se adaptó mejor al cultivo de fondo, mostrando un mejor crecimiento y supervivencia, debido a que forma parte de la infauna.…”