Growth of the tropical scallop, Euvola (Pecten) ziczac, in bottom and suspended culture in the Golfo de Cariaco, Venezuela

Abstract

We compared the growth of the scallop Euuolu (Pecten) ziczuc (L.) in three situations whichpotentially could be used for commercial culture, in cages maintained in suspension, in cages on thebottom and in cages partly buried in a sediment bottom. The latter permitted the scallops to burythemselves as in their natural habitat. Throughout the 7-month study, growth, as measured by shelllength and muscle mass, was by far superior for scallops in the partly buried cages. Possible explanationsfor this are ( 1) that the scallops are stressed by enclosures which prevent them from buryingthemselves and (2) that organic material at the sediment/water interface is an important food resourceand E. ziczac has better access to this when it buries itself flush with the bottom. The timing of gonadalgrowth and spawning varied markedly among treatments. Some spawnings coincided with temperatureincreases but others did not. Differences between scallops in suspension compared to those in bottomtreatments suggested that reproduction is as much controlled by conditions in the immediate environmentof the scallops as by large-scale environmental factors. Survival was highest for the scallopsmaintained in partly buried cages.

Fatty acids profiles as selecting criteria of microalgal diets used for hatchery-rearing of the tropical scallopEuvola ziczac

“…Euvola ziczac (L., 1758) is a hermaphroditic scallop which is found from Cape Hatteras (North Carolina) and Bermuda, throughout the Gulf of Mexico, and southward to Santa Catarina state in Brazil (Rios ). Several studies show that the tropical scallop E. ziczac grows rapidly in both suspended and bottom culture in Venezuela (Freites, Vera, Lodeiros & Vélez ; Vélez, Freites, Himmelman, Marin & Senior ; Lodeiros & Himmelman , ; Freites, Lodeiros & Vélez ), but techniques are still under development for optimizing the production of spat (Sarkis & Lovatelli ).…”

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

“…Contribution of food availability to the more rapid growth of the scallop, Euvola ziczac (Pteroida, Pectinidae) in bottom than in suspended culture Vélez et al (1995) showed that growth of the scallop Euvola (Pecten) ziczac (L.) in cages partly buried in a sediment bottom is markedly greater than in similar cages suspended in the water column. This observation is surprising, since numerous studies demonstrate increased growth of scallops when suspended in the water column (Leighton 1979, Wallace and Reinsness 1985, MacDonald and Thompson 1985a.…”

Convergent evolution of life habit and shell shape in scallops (Bivalvia: Pectinidae) with a description of a new genus

“…Tribe Pectinini Aequipecten glyptus (Verrill, 1882) free-living (inferred from shell morphology) UF351155 Aequipecten opercularis (Linnaeus, 1758) free-living [3,4] opercularis 1 opercularis 2 "Amusium" balloti (Bernardi, 1861) glide [3,18] balloti 1 balloti 2 balloti 3 balloti 4 balloti 5 "Amusium" japonicum japonicum (Gmelin, 1791) glide [4], (N. Deguchi, sandy bottom, gillnet) japonicum "Amusium" papyraceum glide [4] papyraceum 1 Amusium pleuronectes (Linnaeus, 1758) glide [3,4,19] pleuronectes 1 pleuronectes 3 pleuro QLD1 pleuro QLD2 Argopecten gibbus (Linnaeus, 1758) free-living [3,4] gibbus 2 gibbus 3 Argopecten irradians irradians (Lamarck, 1819) free-living [3,4,20] irradians Argopecten nucleus (Born, 1778) free-living [4] AMNH 298075_1 Argopecten purpuratus (Lamarck, 1819) free-living [4,21] purpuratus H3 Argopecten ventricosus (Sowerby II, 1842) free-living [4] ventricosus 1 Cryptopecten vesiculosus (Dunker, 1877) free-living [15], (C. Kobayashi, gravel bottom, dredged) vesiculosus 1 vesiculosus 2 Euvola chazaliei (Dautzenberg, 1900) recess (inferred from shell morphology) chazaliei Euvola perula (Olsson, 1961) recess (inferred from shell morphology) UF371263 perula 1 perula 2 Euvola raveneli (Dall, 1898) recess (inferred from shell morphology) UF351301 Euvola vogdesi (Arnold, 1906) recess [4] vogdesi 1 Euvola ziczac (Linnaeus, 1758) recess [4,22] ziczac 1 Leptopecten bavayi (Dautzen...…”

“…For the left valve, the mean number of ribs for A. pleuronectes was 23 (range [19][20][21][22][23][24][25][26][27] Appendix F). This individual was one of 10 specimens collected from the same location at the same time.…”

“…To a lesser extent, similar work has been done in invertebrate groups, specifically arthropods. For example, convergent or parallel evolution has been identified in replicated shifts of host use in insects [21,22], web construction in arachnids [8], larval morphology and antipredator behavior in aquatic insects [23], and adult morphology in barnacles [24]. Outside of arthropods, few studies using invertebrates explicitly test for convergence and parallelism (but see gastropods: [25,26];…”