Seasonal variation in the condition index of Pacific oyster postlarvae (Crassostrea gigas) in a land-based nursery in Sonora, Mexico

Authors: Barraza-Guardado, Ramón H¹; Chávez-Villalba, Jorge²; Atilano-Silva, Héctor¹; Hoyos-Chairez, Francisco³

Source: Aquaculture Research, Volume 40, Number 1, December 2008 , pp. 118-128(11)

Buy & download fulltext article:

Price: $48.00 plus tax (Refund Policy)

Abstract:

This study examined the seasonal variation in the condition index (CI) of Crassostrea gigas postlarvae (<5 mm) that were cultivated at a commercial hatchery. Oysters were sampled weekly at the nursery using seawater from a lagoon for the grow-out that precedes commercialization. Temperature, salinity, seston, chlorophyll a, oxygen and pH were recorded at each sampling and water samples were taken to identify phytoplankton groups and their abundance. High levels of primary productivity, chlorophyll a and seston were detected during summer, but the highest CI occurred in winter. During winter, elevated phytoplankton biomass was composed by diatoms and phytoflagellates, which served as the main food source and promoted weight gain in this season. Variations in salinity, oxygen and pH were not related to differences in the CI. However, it appears that the wide temperature variation affected functions, such as feeding activity, apparently enhancing ingestion during winter (mean 16.5±1.4 °C) and reducing ingestion during summer (mean 31±1.5 °C). Winter production resulted in postlarvae with a homogeneous size range and a high CI, indicating that winter is more favourable to start cultivation. The CI represents a practical means to determine the physiological state of postlarvae before transfer to cultivation sites.

Keywords: oyster; postlarvae; condition index; Crassostrea gigas; chlorophyll; seston

Document Type: Research article

DOI: http://dx.doi.org/10.1111/j.1365-2109.2008.02076.x

Affiliations: 1: Departamento de Investigación Científica y Tecnológica, Universidad de Sonora, Sonora, Mexico 2: Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Unidad Sonora, Sonora, Mexico 3: Instituto de Acuacultura, Estado de Sonora, Sonora, Mexico

Publication date: 2008-12-01

Seasonal variation in the condition index of Pacific oyster postlarvae (Crassostrea gigas) in a land-based nursery in Sonora, Mexico

Buy & download fulltext article:

Tools

Key

Text size:

Useful pages