Bacterial Flora of Cultured Swimming Crab (Portunus trituberculatus) Larvae

Abstract

The aerobic bacterial flora of larval swimming crabs (Zoea-I to Crab-I) cultured in three hatcheries were investigated in relation to the microflora of rearing pond water and diets. The external and internal bacterial counts of the crab on ZoBell's 2216 e agar ranged from 10² to 10⁴ and 10¹ to 10⁴ CFU/animal, respectively. The number of the bacterial counts increased as the developmental stages progressed. In respect of constitution, Vibrio and Pseudomonas predominated both in external and internal bacterial flora.
The total bacterial counts for rearing pond water, live diets (rotifer and brine shrimp) and minced/artificial foods ranged 10⁴10⁵, 10⁶10⁸, and 10³10⁵ CFU/ml or g, respectively. The bacterial flora of rearing pond water and live diets consisted of mainly Vibrio and Pseudomonas, while from the minced food and artificial food only Pseudomonas was predominantly isolated.