Embryonic development and larval and post-larval growth of the tropical scallop Nodipecten (= Lyropecten) nodosus (L. 1758) (Mollusca: Pectinidae)

Abstract

This work describes for the first time the embryonic development of the tropical scallop Nodipecten nodosus. Larval and post-larval growth parameters and some characteristics of larvae shell morphology were also ascertained. The larvae were obtained from the induced spawning of a group of broodstocks under controlled laboratory conditions. After fertilization, larval cultivation was carried out in conical tanks at a temperature of 26±27 C. Larval density was controlled as a function of larval growth to give 10, 5 and 3 larvae mL À1 from days 1, 3 and 8 respectively. The larvae were nourished with a 1:1 mix of Isochrysis galbana (clone T-ISO) and Chaetoceros gracilis in portions varying between 30 000 and 70 000 cells mL À1 . Expulsion of polar groups was observed 5 and 15 min after fertilization, whereas the first cellular division occurred after 30 min. The first gastrule ciliates and trocophore larvae were noted after 8 and 18 h had elapsed, respectively, whereas prodissoconch I, or D-larvae, were discerned after 26 h. Subsequently, larvae with prodissoconch II or veliger-conch appeared at 30 h. Larval development continued for 10±12 days, followed by metamorphosis, at an approximate length of 208±230 mm. The growth of the post-larvae was evaluated for 9 days. Larval and post-larval growth corresponded to the linear equations L 71.85 10.85t, r 2 0.99, and L 44.09 17.81t, r 2 0.94 respectively. Accordingly, larval morphology and size disparities are discussed with respect to other tropical pectinids.

Early life cycle and effects of microalgal diets on larval development of the spiny rock-scallop, Spondylus limbatus (Sowerby II, 1847)

“…The appearance of first pre-metamorphic larvae (double-ringed pediveligers with an eyespot) observed in this study on day 12 agrees with that reported for S. tenebrosus (Parnell, 2002) and the tropical scallop N. nodosus (De la Roche et al, 2002). Parnell (2002) recorded a minimum precompetent period for 21 day old larvae (in which settlement was first observed), which was longer than that reported in the present study (16 days, when first post-larvae appeared).…”

“…Size and other physical cell characteristics (presence of umbonate larva, eyespot, double ring and foot) of S. limbatus larvae obtained in this study closely agree with those reported for S. tenebrosus (Parnell, 2002) and other Pectinoidea larvae, such as Argopecten ventricosus (Ibarra et al, 1997), Amusium balloti (Rose et al, 1988), Chlamys asperrimus (Rose and Dix, 1984), Nodipecten nodosus (De la Roche et al, 2002;Velasco et al, 2007) and Argopecten nucleus (Velasco et al, 2007). Nevertheless, our results diverge partially from those of Soria et al (2010), which reported longer sizes for pediveligers (234.0 ± 28.03 μm) than those obtained in the present study (185.2 ± 3.9 μm) for the same species.…”

“…Treatment containing the diatom CG and the flagellate IG at a cell ratio of 3:1 presented the best growth rate. Combination of Isochrysis and Chaetoceros species has been reported to be successful for larval bivalve rearing (De la Roche et al, 2002;Gonzalez-Araya et al, 2012;Marshall et al, 2010;Pernet and Tremblay, 2004;Rico-Villa et al, 2006). Levels of polyunsaturated fatty acids (PUFA) are essential for bivalve larvae growth (Brown et al, 1997).…”

Larval rearing of calico scallops, Argopecten gibbus, in a flow-through system

“…Standard hatchery techniques for A. gibbus scallop culture at BBSR follow a similar protocol to that used worldwide for pectinid species, involving a static system with full exchange of water periodically (Bourne et al 1989;Buestel et al 1982). Although this protocol yields satisfactory results in terms of growth (10 lm day )1 , reaching 190 -18 lm in height for Day 12 pediveligers) and survival rate (20%-60% to metamorphosis depending on larval batches) compared to other pectinid species (Bourne et al 1989;de la Roche et al 2002;Uriarte et al 1996;Rupp 1997;Couturier et al 1996), it has drawbacks similar to other standard hatchery static systems. These include a partial reliance on antibiotics and a high labour demand, two factors which play a limiting role in optimising hatchery rearing of bivalves in general (Southgate and Ito 1998;Andersen et al 2000).…”

Manutenção e reprodução de Anomalocardia brasiliana em condições laboratoriais

“…A manipulação da temperatura (De La Roche et al, 2002), administração de microalgas (Farías et al, 1998), aplicação de serotonina (Mouëza et al, 1999), adição de gametas na água, exposição ao ar e água do mar esterilizada com ultravioleta (Da Costa et al, 2010), estão entre os estímulos que podem ser aplicados isoladamente ou em combinação (Velasco et al, 2007).…”