The naupliar stage represents the first larval stage and its quality is a direct reflection of broodstock condition, because at this stage there is still a strong dependence on the nutrients transferred from the female. Besides nutrition, also broodstock age, environment (e.g. temperature), health status and genetics have an influence on nauplii quality. How nauplii condition or nauplii “quality” relates to performance during further larval stages is barely described in literature, but most hatcheries do can attempt to predict larviculture performance in order to stock larval rearing tanks yes or no, by looking at nauplii deformities or nauplii color.
At the INVE Tropical Aquaculture Research Center (ITARC) in Thailand, a set of parameters is routinely measured on nauplii and zoea 1 stages and used to calculate a Nauplii Quality Index (NQI) (Table 1). In the NQI formula, a weight factor is assigned to each parameter in accordance to its estimated predictive value for further successful larviculture.
This presentation summarizes our findings related to nauplii quality criteria and correlations with performance during the larval rearing cycle. Advantages and limitations of using a calculated Nauplii Quality Index as cut-off for larval tank stocking will be discussed.