Spawning, settlement, and growth of the New Zealand veneridRuditapes largillierti(Philippi 1849) in culture

Abstract

Spawning, larval rearing, and growout of Ruditapes largillierti (Philippi 1849) were investigated in a series of trials conducted at the University of Tasmania (UTAS), Launceston and Georges Bay, St Helens, Tasmania, Australia. Intramuscular injection of serotonin (3 × 10 -7 to 1.5 × 10 -6 moles) failed to induce spawning in female Ruditapes largillierti, although some males did spawn. Fecundity of R. largillierti induced to spawn by thermal stimulus ranged from 0.5 to 0.9 × 10 6 eggs female -1 . Fertilised eggs developed into trochophore larvae by 24 h at 20°C and D veligers with a mean shell length † Author to whom correspondence is to be addressed. M98023 Received 12 May 1998; accepted 17 August 1998of 85.3 ± 4.7 μm within 48 h. Early larvae were frequently deformed and their mortality rates were very high. Development to pediveliger stage (mean shell length 200.3 ± 7.3 μm) took between 11 and 16 days at 20°C, and metamorphosis to spat (mean shell length 240 (μm) occurred between Days 16 and 19. There was no significant difference in efficacy of epinephrine, norepinephrine, or untreated groups for inducing larval settlement. Average growth of juveniles held subtidally within trays or baskets (mesh size 1.7-12.0 mm) was 1.3 mm month -1 . The aquaculture potential of this subtidal venerid clam warrants further investigation.

Combined effects of salinity and temperature on survival and growth during the early life cycle of the rock oyster Saccostrea cuccullata (Born, 1778)

“…Opposite to what was previously reported by Kent et al (1999), the fertilization method used here was very effective as high survival of larvae was observed in treatments where appropriate environmental…”

Survival and growth of hatchery-produced postlarvae and spat of the Caribbean scallopsArgopecten nucleusandNodipecten nodosus

“…Both the low temperature and the epinephrine applied during the first 48 h of settlement promoted greater final accumulated survival in the two scallops. Higher percentages of settlement, metamorphosis, and/or survival have been obtained by lowering the temperature for species including Argopecten purpuratus (Uribe et al 1993), C. gigantea (Bourne et al 1989) and Pinctada imbricata (Röding, 1798) (O'Connor & Lawler 2004) and with exposure to epinephrine in A. purpuratus (Abarca & Castilla 1997; Martínez et al 1999), Chlamys varia (Mesías‐Gansbiller et al 2008), Crassostrea gigas (Lamarck, 1819) (Robert & Gérard 1999), Mytilus galloprovincialis (Lamarck, 1819), Venerupis pullastra (Montagu, 1803), Ostrea edulis (Lamarck, 1819) (García‐Lavandeira, Silva, Abad, Pazos, Sánchez & Pérez‐Parallé 2005) and Ruditapes largillierti (Philippi, 1849) (Kent, Maguire, Duthie & Pugh 1999). Nevertheless, it has also been reported that these stimuli had no effects on P. yessoensis (Kingzett, Bourne & Leask 1990), Ruditapes philippinarum (Adams & Reeve, 1850) (García‐Lavandeira et al 2005) and Pinctada margaritifera (Linné, 1758) (Doroudi & Southgate 2002).…”