Salinity Preference of Two Diatoms and Their Growth Performance in Three Prepared and Two Alternative On-Farm Media Sources

ABSTRACT

Salinity and preferred nutrient composition of Chaetoceros affinis and Skeletonema costatum were tested. Salinity was tested at 12, 16, 23, 28, and 32 ppt. Three compositions of nitrogen (N), phosphorus (P), and potassium (K) and two on-farm low-cost alternative media sources, cow urine (CU) and hatchery waste water (HWW), were tested to find the suitable NPK ratio and to determine the efficacy of the on-farm media respectively. Chaetoceros affinis preferred 23 ppt salinity, while Skeletonema costatum preferred both 28 and 32 ppt. Among the NPK treatments, higher cell density was observed in 4:1:1 followed by 4:2:1 ratios. Significant differences in maximum cell density of both species were observed in the NPK treatments while only S. costatum showed significant difference in CU and HWW.

KEYWORDS:

• Chaetoceros affinis
• Skeletonema costatum
• salinity preference
• NPK ratio
• cow urine
• hatchery waste water

ACKNOWLDGMENTS

The authors thank the personnel of the IDA hatchery and the Kalataly hatchery of Cox's Bazar district for their support and guidance during the study. Thanks also to the two anonymous reviewers for their comments and suggestions. The study was partially supported by the Bangladesh Agricultural Research Council (BARC).