Growth and survival of juvenile gold-lip pearl oyster Pinctada maxima (Jameson, 1901) at different depths with and without regular cleaning

Abstract

The lucrative commercial culture of gold-lip pearl oyster Pinctada maxima (Jameson, 1901) for pearl production has been in existence in the Philippines for several decades, however, no growth studies for this species has been published in the country as of this writing. To fill this gap, the results of two consecutive 60-day growth trials were conducted in the island province of Palawan. The first experiment (E1) examined the growth and survival of 4-month-old hatchery-produced pearl oysters in net trays (200 individuals per tray or 583 individuals m-2) hung in a long line at three different depths (2, 4, and 6 m) below the water surface subjected to cleaning and without cleaning regimes. The second experiment (E2) was a continuation of E1, except that the 6-month-old pearl oysters were raised in 30-individual pocket net baskets. Average shell length increments (SLI) and survival rates (SR) in E1 did not significantly vary among depths (P > 0.05) and between cleaning conditions (P > 0.05). In E2, the SLI did not significantly vary among depths (P > 0.05) and between cleaning conditions (P > 0.05), while the SR was statistically similar among depths (P < 0.05) but not between cleaning conditions (P > 0.05). The results suggest that instead of the usual single row, the three rows of net baskets at different depths and the absence of cleaning could be considered in the early stage of gold-lip pearl oyster farming.