ISOLATION AND GROWTH OF DINOFLAGELLATE, Scrippsiella sp. AND DIATOM, Melosira cf. moniliformis IN CONTROLLED CONDITIONS
Abstract: The growth of the
dinoflagellate, Scrippsiella sp. from Narragansett Bay, USA and the
chain-forming benthic diatom, Melosira cf. moniliformis from Kendari Bay,
Indonesia was evaluated under optimized laboratory conditions to investigate
potential new candidates for shrimp aquaculture hatchery feeds. Isolation of
microalgae was performed using capillary pipets in f/8-Si for Scrippsiella sp.
and f/2 for M. cf. moniliformis. Isolated cells were placed in an incubator
with a photoperiod of 12:12 hour (light : dark cycle), at light intensities of
62-89 μmol photons.m-2.s and at temperature of 20oC. Microalgae cells were
cultured in 150-mL Erlenmeyer flasks containing 100 mL of f/2-Si medium for
Scrippsiella spin triplicates and in 50-mL culture tubes containing 20 mL of
f/2 medium for M. cf. moniliformis in four replicates. The cells in culture
flasks were used in cell counting experiments while those in tubes were for
fluorometer trials. Growth evaluation was conducted every 2-3 days. The diatom,
M. cf. moniliformis was in logarithmic phase when observed at 2 to 7 days after
inoculation and showed a high growth rate (μ = 0.52 day-1) and high division rate
(k = 0.76 day-1, 1 division every 1.3 days). Logarithmic phase of Scrippsiella
in culture flasks was started on day 7 to 30 (μ = 0.17 day-1 and k = 0.25 day-1
or 1 division every 4 days). In culture tubes, Scrippsiella sp. reached
logarithmic phase at day 21 to 47 (μ = 0.12 day-1 and k = 0.18 day-1, 1
division every 5.65 days). This study indicates that M. cf. moniliformis can be
used for aquaculture hatcheries feed but further study for the nutrition
composition is needed. Scrippsiella sp. is potentially toxic for aquaculture at
high densities, therefore they should be assessed carefully if used for
aquaculture feeds.
Keywords: white shrimp;
microalga; Scrippsiella sp. and Melosira cf. monoliformis
Author: Wa Iba
Journal Code: jpperikanangg140063
