Abstract
Phaeodactylum tricornutum , a diatom identified as having superior survival and growth rates during South Texas winters compared to various commercially cultivated species, was assessed for its potential as a nutritional supplement for Crassostrea virginica spat. Oysters were collected from the Laguna Madre (Corpus Christi, TX, USA) and spawned to produce the spat used in this study. Spat were subject to five feeding treatments that involved replacing a standard microalgal diet with P. tricornutum to various degrees (0–100%). Water quality parameters were maintained at optimal levels for growth and survival. Comparison of growth metrics of the spat revealed no significant differences for the 0–50% feed replacements, indicating that up to 50% of the standard hatchery–produced juvenile oyster diet can be replaced with P. tricornutum with minimal effects on growth and survival. This information is important in that it could provide a more cost-effective and less labor-intensive solution for microalgae production in Texas, particularly in the southern region where natural phytoplankton supply may be seasonally limited.