Modelling early growth of the pearl oyster Pteria sterna under pilot‐commercial production

Abstract

The pearl oyster Pteria sterna produces pearls from animals gathered from the wild but spat collection is increasingly unreliable. Therefore, hatchery support is required to supply spat for aquaculture operations. In this study is described the hatchery processes to produce spat of P. sterna in a pilot‐commercial grade. Growth and survival (relative and absolute) are described for the different developmental stages and critical aspects identified. Growth (height and length) was analysed using depensatory hypothesis and the multi‐model inference (MMI). Spat production cycle is described (egg to spat in size and time); spat ≥ 3 mm = 70 days. Average absolute growth rate for shell height was 7.8 µm/day during embryonic phase, 14.5 µm/day during metamorphosis and 71.4 µm/day for post‐larvae phase. Survival was 75% after 48 hr (D‐larvae stage), 25% at day 14 (umbo stage) and 12% at day 28 (pediveliger stage). Metamorphosis was the main critical phase since survival drop to 0.32%. From 32.5 million eggs, 80,000 commercial spat were produced. Early growth in P. sterna showed depensatory pattern since coefficient of variation in height data increased (2%–28%), and this was supported by MMI. The hatchery procedures presented here guarantee the production of spat for aquaculture activities. Growth depensation leads to the application of a high performance function to analyse individual size‐at‐age variability and to parametrize the models without sub underestimation of values. The best fitted model to describe early growth in P. sterna is the Schnute model case 1.

Progress towards reestablishing Latin America as a major pearl producing region: A review

“…Hatchery‐rearing of larvae and spat has been conducted with certain degree of success in Mexico with Pt. sterna 35–38 and P. mazatlanica , 39,40 and in the Caribbean with P. imbricata 41 . In general, pediveliger larvae settle at 19–21 days of age ( Pt.…”

“…First, native pearl oyster species have a wide distribution in both the Pacific and Atlantic‐Caribbean coasts, where pearls from these species are recognised for their high quality and value, like those produced by other members of the Pteriidae 19–21,55 . Second, the knowledge in some countries and for some species is abundant in relation to natural spatfall 26–29,32 and hatchery‐production of juveniles 37–41 . Many other scientific studies have identified breeding seasons that ensure, with some certainty, the supply of juvenile oysters for pearl culture operations 70,77,83 .…”

“…Hatchery-rearing of larvae and spat has been conducted with certain degree of success in Mexico with Pt. sterna [35][36][37][38] and P. mazatlanica, 39,40 and in the Caribbean with P. imbricata. Juveniles obtained by either wild spatfall or hatchery rearing require a short period of ocean-based 'nursery care' under the most stable environmental conditions possible to improve survival and growth rates before their grow-out stage.…”

“…[19][20][21]55 Second, the knowledge in some countries and for some species is abundant in relation to natural spatfall [26][27][28][29]32 and hatchery-production of juveniles. [37][38][39][40][41] Many other scientific studies have identified breeding seasons that ensure, with some certainty, the supply of juvenile oysters for pearl culture operations. 70,77,83 The research effort to develop appropriate culture techniques and devices for the early nursery and grow-out of pearl oysters to commercial size is also significant.…”

Uso de reservas energéticas durante la primera madurez sexual en laboratorio de la concha nácar Pteria sterna con dietas enriquecidas con glúcidos y lípidos

“…Para sustentar la gametogénesis, esta especie utiliza una combinación de estrategias oportunistas y conservadoras a partir de la energía del alimento en invierno y de las reservas de los tejidos somáticos en primavera (Vite-García y Cáceres-Puig et al 2009). Por el contrario, la reproducción de la especie en condiciones de laboratorio ha sido difícil de controlar (Saucedo 2017;Hoyos-Chairez et al 2020), debido básicamente al desconocimiento que prevalece sobre gran parte de sus requerimientos fisiológicos y nutricionales, los cuales son necesarios para asegurar el óptimo desarrollo de los gametos y más adelante de las larvas cultivadas (Gómez-Robles et al 2013, 2023Hawkyns et al 2014). Estos requerimientos no solo están influenciados por los factores ambientales, sino por la condición de los reproductores (madurez de los gametos), por lo que pueden variar al momento de la primera madurez como macho (protandria) o en los sucesivos cambios macho-hembra-macho que ocurren como parte del hermafroditismo secuencial (Saucedo y Southgate 2008;Gómez-Robles et al 2013).…”