Growth and Survival of Black-lip Pearl Oyster Pinctada margaritifera (Linnaeus, 1758) in Bamboo and Metal-framed Pocket Net Baskets Subjected to Cleaning and Without Cleaning Conditions

Abstract

The farming of black-lip pearl oyster Pinctada margaritifera (Linnaeus, 1758) has been a viable industry for small and large-scale farmers in the South Pacific, but not in the Philippines, where it is monopolized by large-scale farms primarily based on the gold-lip pearl oyster Pinctada maxima. To promote the industry among small-scale players, we simplified the culture method by using bamboo slats as frame materials and compared them to the common material used in pearl oyster culture, metal rods. A total of 400 individuals seven-month-old hatchery-produced P. margaritifera were used as experimental animals, distributed in the following treatments with five replications: T1 (metal-framed pocket net basket with monthly cleaning), T2 (metal-framed pocket net basket without monthly cleaning), T3 (bamboo-framed pocket net basket with monthly cleaning), and T4 (bamboo-framed pocket net basket without monthly cleaning). Growth was fast in the first four months and slowed down after that. Two-way analysis of variance found no significant differences between the average anteroposterior shell (APS) length increments of pearl oysters between two types of frame, and between two cleaning conditions. Survival rates did not significantly differ between types of basket frame, and between cleaning conditions. Parameters of the “Typical” von Bertalanffy growth model (L∞ = 118.41 mm, K = 1.03 year-1, and t0 = 0.12) suggested that oyster would take about 23.16 months to reach 100 mm APS length, a size suitable for nucleus implantation. The life span of bamboo slats as basket frame was half of the metal frame, and the absence of cleaning has reduced the operational cost by up to 82.08%.