MORTALITY AND QUALITY INDICES OF LIVE WEST AFRICAN HARD-SHELL CLAMS (GALATEA PARADOXA BORN) DURING WET AND DRY POSTHARVEST STORAGE

Abstract

Freshly harvested clams (Galatea paradoxa Born) obtained from the Cross River, Nigeria were subjected to live storage for 7 days in or outside of water. The objective was to study the effects of storage method and duration on mortality, weight changes and selected physical and physicochemical properties of the clams. Overall, 62 or 35% of the stored clams died over the 7-day duration under wet (potable water) or dry storage, respectively. No deaths were recorded in day 1 (wet storage) or in days 1–3 (dry storage). Regression analysis showed linear relationships between storage duration and each of the dependent-quality variables of weight change, density, pH and electrical conductivity (EC) evaluated under both storage methods. The regression coefficients (β1, β2) for assayed quality parameters in wet or dry storage were significantly different (P ≤ 0.05). R2were generally larger for dry storage than for wet storage. Initial clam weights did not significantly (P ≥ 0.05) affect weight change during storage, indicating that weight loss during dry storage was statistically invariant with clam weight. The study concludes that priority should be given to prompt sale and utilization (<3 days) of clams, particularly large clams. The use of dry storage to reduce postharvest mortality and weight losses will potentially increase the profitability of the clam industry.