Se estudió el desempeño reproductivo y larvario de Pteria sterna en relación a factores ambientales anómalos, hipotetizando que la transición entre los eventos de La Niña y El Niño 2008-2009 afectó ...los periodos “normales” para recolectar reproductores maduros y cultivar larvas en laboratorio. Se realizaron muestreos estacionales en 2 periodos reproductivos (febrero y abril 2009), 1 periodo pre-reproductivo (noviembre 2008) y 1 periodo post-reproductivo (junio 2009). De las 40 ostras recolectadas en cada periodo, 20 se utilizaron para evaluar el desove y cultivo larvario y 20 para determinar indicadores de condición reproductiva. La temperatura, salinidad y contenido de seston se monitorearon en cada periodo. Los datos de temperatura superficial del mar (TSM) asociados a condiciones ambientales anómalas se obtuvieron del satélite Aqua-MODIS. Las variaciones en la TSM afectaron más el desempeño reproductivo que el desempeño larvario de Pteria sterna. La inducción al desove falló en noviembre 2008 y fue exitosa en febrero, abril y junio 2009, aunque solo en abril las larvas completaron la metamorfosis y se fijaron, a partir de reproductores más maduros, ovocitos más grandes y condiciones ambientales favorables (21.80 °C; ~31 mg·L–1 seston total; +0.50 °C TSM). Las anomalías positivas de TSM (+0.50 a +1.10 °C) de agosto a diciembre 2008 favorecieron un verano más largo que afectó el desove de febrero 2009. En junio 2009 (22.50 °C, 29.5 mg·L–1 seston total, +0.40 °C TSM), cuando los porcentajes de gónadas y ovocitos maduros eran bajos, las larvas no fueron viables y pocas semillas se fijaron. Además de recolectar reproductores maduros en invierno-primavera para una viabilidad óptima de las larvas y semillas, recomendamos incluir un breve periodo de acondicionamiento en el laboratorio después del pico de desove y un segundo a finales del otoño para promover el reciclaje de nutrientes y la recuperación natural de gametos.
To evaluate the antioxidant activity and oxidative damage by relaxing, wounding, and seeding of a saibo of different origin on Pteria sterna hosts, five oyster treatments were included: (1) relaxed ...(REL) but neither wounded nor seeded; (2) relaxed and wounded (WOU) but not seeded; (3) relaxed, wounded, and seeded with an allograft (ALL); (4) relaxed, wounded, and seeded with an autograft (AUT); and (5) unrelaxed, unwounded, and unseeded as control (CTR). Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and thiobarbituric acid (TBARS) activity were quantified between 3 and 24 h post-seeding. Compared to the CTR oysters, which did not suffer oxidative stress, SOD activity significantly decreased in the gonad and digestive gland in all treatments and decreased in mantle tissue in AUT oysters; this indicates that the entire process of preparing oysters for pearl culture (relaxing, wounding, and seeding) generates oxidative stress in the host. CAT was not a sensitive enzyme for measuring the short-term response of oysters to the wounding–seeding processes but rather a more prolonged or chronic stress. Similar to SOD, the lowest GPx and TBARS activity in seeded oysters evidenced their susceptibility to oxidative stress and damage, particularly in the WOU treatment. Evidence from this study indicates that SOD is a more sensitive enzyme for measuring the short-term response of the host oyster to the wounding and seeding of a saibo. It is also clear that the host undergoes stress at all stages of the pearl culture process, mostly during gonad wounding and regardless of the origin of saibo.
La concha nácar Pteria sterna sostiene una creciente industria perlera en la región subtropical del noroeste de México. En ambientes tropicales del país, el cultivo de perlas puede ser redituable, ...pero la poca información sobre la biología y ecología de la especie limita la definición de protocolos para la creación de granjas perleras. Se determinó el crecimiento absoluto, la tasa de crecimiento, los estadios reproductivos, los cambios en la talla de ovocitos y la talla de primera madurez de juveniles de P. sterna cultivados en la bahía de Acapulco durante el ciclo anual 2009-2010, y se comparó su respuesta en esta área tropical con registros de la especie para otras áreas subtropicales de México. Se comparó el modelo de crecimiento de von Bertalanffy con uno propuesto en este estudio para fines acuaculturales. La tasa de crecimiento fue mayor durante los primeros seis meses (5.3 mm mes-1) y disminuyó a 3 mm mes-1 hasta que los juveniles alcanzaron la talla de 60 mm en un año. El crecimiento fue máximo en febrero y mínimo de julio a septiembre. Ambos modelos describieron bien el crecimiento de P. sterna, pero el ajuste y la estimación de los parámetros fue mejor con el modelo propuesto. La gametogénesis inició en diciembre de 2009 a una talla de 50.9 mm en los machos y 59.5 mm en las hembras; el desarrollo de la gónada fue continuo el resto del año, con un pico de desove en febrero-marzo (~25-26 °C; 2.8 μg L-1 de clorofila a) que coincidió con el máximo del índice gonádico y la mayor talla de los ovocitos. En comparación con ambientes subtropicales, la especie utiliza una estrategia diferente para el manejo de la energía para el crecimiento y reproducción en un ambiente tropical; en la bahía de Acapulco P. sterna puede alcanzar la talla optima de injerto para producción de perlas (70-80 mm de altura de la concha) en 15-17 meses.
The reproductive and larval performance of Pteria sterna associated with anomalous environmental factors was evaluated, testing the hypothesis that the transition from La Niña to El Niño in 2008-2009 ...affected the “normal” periods in which ripe broodstock are collected and larvae are reared in a hatchery. Seasonal sampling included 2 reproductive periods (February and April 2009), 1 pre-reproductive period (November 2008), and 1 post-reproductive period (June 2009). Of the 40 oysters collected in each period, 20 were used for induced spawning and larval culture, while 20 were used to evaluate indices of reproductive performance. Water temperature, salinity, and seston content were monitored in each period. Sea surface temperature (SST) data associated with anomalous environmental conditions were obtained from the Aqua-MODIS satellite. Variations in SST affected reproductive performance more than larval performance in Pteria sterna. Spawning induction failed in November 2008 and succeeded in February, April, and June 2009, although only the larvae from April completed metamorphosis and settled, given the riper broodstock, larger oocytes, and favorable environmental conditions (21.80 °C; 31 mg·L-1 total seston; +0.50 °C SST). Positive SST anomalies (+0.50 to +1.10 °C) from August to December 2008 resulted in longer summer conditions that affected spawning in February 2009. In June 2009 (22.50 °C; 29.50 mg·L-1 total seston; +0.40 °C SST), when the percentages of ripe gonads and mature oocytes were small, the larvae were not viable, and few spat settled. In addition to collecting ripe broodstock in winter-spring for optimal larval and spat viability, we recommend including a brief conditioning period at the hatchery following the spawning peak and a second conditioning period in late autumn to promote nutrient recycling and natural gamete recovery.
Globally, pearl culture is a profitable sector generating significant export incomes for producer countries, as well as livelihood opportunities for local communities. Latin America has a long ...history as a pearl producer from extensive fisheries that date back to the 15th century. The presence of pearl oyster beds on the Pacific and Caribbean coasts of many Latin American countries was a major incentive for colonisation of the region and subsequent social and economic development of areas in the Gulf of California and the Caribbean. This review presents the historic background of the pearl fishery in this region since the arrival of the Spanish in the 16th century, describes the current status of pearl culture in Latin America, and outlines future opportunities for sector development. Information on the current status of pearl culture in Latin American countries is divided between two major categories: commercial and pilot‐scale. Commercial pearl production currently occurs only in Mexico and production updates are provided for bead‐nucleated, half pearls (mabé) and non‐nucleated (keshi) pearls from the two pearl farms operating in the Gulf of California. The second category comprises countries whose pearling activities were relevant in the past (Venezuela, Panama) and others that are emerging, but still maintain pilot‐scale production of mabé pearls using Pteria sterna (Ecuador, Peru), Pinctada mazatlanica (Panama) and Pteria hirundo (Brazil). Finally, this review discusses future prospects for pearl culture in Latin America, analysing technology gaps and challenges to be addressed if the cultured pearl sector is to achieve its full potential in this region.
Abalone pearl farming is an aquaculture activity with great potential for future growth and diversification of the global pearl sector, which has been dominated for decades by pearls of marine pearl ...oysters of the genus Pinctada. Despite this potential, there is a significant lack of knowledge regarding methods for nucleus (bead) seeding and the process of pearl formation in abalone, compared to the well-studied pearl oyster model. To address this problem, this review first compares the main anatomical differences and similarities between both groups of mollusks, particularly those associated with the structure and role of mantle tissue on the synthesis of CaCO3 compounds that integrate the inner nacreous layer. The iridescence (orient) and color properties of nacre in a cultured pearl is particularly related to the microstructure of aragonite crystals during biomineralization in each mollusk group. We then analyze the advantages and disadvantages of the adoption in abalone of methods originally developed for pearl oysters to produce bead-seeded pearls and half-pearls (or mabé pearls). For the red abalone Haliotis rufescens in particular, updated information on commercial production of both bead-seeded and mabé pearls is provided as a case of success for Latin America (Chile). Finally, the current status and future prospects for abalone pearl farming are discussed, assessing technology gaps and challenges to be addressed for the pearl sector to achieve its full potential, particularly for Latin America.
In bivalve aquaculture, selecting suitable probiotic treatments can be crucial for improving hatchery‐rearing of larvae and juveniles. We assessed the potential of five bacterial strains, previously ...selected in vitro, to improve survival, growth and resistance of catarina scallop Argopecten ventricosus during early and late larval and juvenile developmental stages, as well as during exposure to the pathogen Vibrio alginolyticus. Hatchery‐reared larvae and juveniles were treated with eight treatments of single or combined strains of Bacillus and Lactobacillus at 1 × 106 CFU mL−1 every 48 h for 9 days (larvae) and 21 days (juveniles). Compared with the control, significantly higher survival and growth in size and weight of early veliger larvae occurred with the antibiotic and the RL5 (Lactobacillus graminis) treatments. Significantly enhanced settlement of pediveliger larvae occurred with a different probiotic strain, the mix of Lactobacillus and Bacillus (MIX‐LB), while higher survival and growth of early juveniles occurred with C3 (Lactobacillus plantarum). The mix of Bacillus (MIX‐B) significantly increased survival of juveniles from V. alginolyticus after 120‐h infection, consistent with maximum activity of superoxide dismutase enzyme. In contrast, all untreated and infected scallops died by 96 h. The three Bacillus strains performed poorly when used as single treatments and when given to early developing larvae. Our results indicate that the action mechanism of probiotic strains is stage specific and strain specific, generating different responses by the host, including improved survival and growth (likely from better nutrient assimilation) and higher resistance against pathogens (possibly from strengthening the immune system).
The factors influencing half‐pearl (mabe) production in the red abalone Haliotis rufescens were investigated, as a strategy to optimize the technology for the development of a pearling industry in ...Chile. The effects of abalone size (small, large), implant position (dorsal, central, ventral and their combinations), and number of nuclei (one, two, three) were analysed on the quantity, thickness of the nacre layer and quality (shape, colour, lustre, defects) of the mabe produced. The size of abalone did not exert a clear influence on the quantity and quality of mabe, but the position on the shell (firstly) and number of nuclei (secondly) did. More mabe, with thicker nacre, brighter lustre and fewer defects occurred in small or large abalone implanted with only one nucleus on dorsal position. In contrast, small and large abalone implanted in the ventral position formed less mabe, with thinner nacre, poor lustre and more defects. This likely occurs because mantle tissue folds at the ventral position and does not always cover the nucleus, leaving it partially or totally exposed. Most of the pearls were categories AA in small abalone and A in large abalone; only three AAA gems were produced in large abalone with one nucleus on dorsal position or with three nuclei (DCV). Based on these results, we recommend implanting abalone at 60–100 mm shell length, with only one nucleus on the dorsal position.
We revise the historic context of freshwater pearl culture in Asia, updating the present situation and perspectives of this activity in Mexico, and, possibly, in some Latin American countries. The ...review is based on the results of ten years of research conducted in southeast Mexico (state of Tabasco) to firstly determine the demography of freshwater mussel stocks and, based on this information, identify a target species with a higher potential for pearl farming: the fatmucket mussel Psoronaias crocodilorum. The main advances relative to the seeding technique for keshi pearl production and composite technique for half‐pearl (mabe) production are detailed and placed under perspective with China, as today's greatest producer of freshwater pearls. After ten years, several cohorts of keshi and mabe pearls have been produced, representing the first of their kind in Latin America. Although the yield and quality of these pearls has gradually been improved, some aspects of the keshi technique (preparation and seeding of the donor's mantle into the host's mantle) still require further optimisation. To promote social development, one of the goals of the project included the involvement of local communities in the manufacture and selling of handcrafts made from the shell. The other goal was to share the main outcomes derived from the keshi and mabe techniques with academics, producers, and government authorities through a series of training workshops aimed to create awareness in the local communities for the potential of freshwater pearl culture in Tabasco as an aquaculture‐based, environmentally friendly and viable model for socioeconomic development.
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