Short-term continuous cultures of Gammarus sp., Tigriopus californicus, and Nannochloropsis sp.

Abstract

The key components of my Honors College thesis addressed the following questions: can stacked rectangles of corrugated plastic sheeting make suitable habitat for a continuous culture of amphipods (Gammarus sp.), can a small scale semi-continuous culture of Nannochloropsis sp. be reliably maintained in the laboratory for a 3-month period, and can a commercial, non-viable microalgae (Nannochloropsis sp.) be used as an alternative to laboratory-grown microalgae to feed and maintain a continuous culture of copepods (Tigriopus californicus)? There has been ample research and practice of long-term commercial culturing of these organisms, however my research will address the short-term culturing of Gammarus sp., Nannochloropsis sp., and Tigriopus californicus for use in a laboratory employing a more practical and simplified approach for use in the laboratory. Amphipods were reared in a standard 38 L aquarium, copepods were cultured in two 19 L plastic buckets, and the phytoplankton was grown in three inverted 2 L clear plastic bottles. These organisms are intended for short-term use by students in a prospective fall 2020 marine biology laboratory at Oakland University. The results of my investigation established protocols for the practical maintenance of these three different cultures over a stipulated 3-month trial period. Amphipods were successfully maintained, and the initial population actually increased by more than 73% by the end of the trial period. I was successful in maintaining a continuous culture of copepods. Although copepod populations underwent cyclic oscillations, by maintaining two separate cultures, there were always sufficient numbers of copepods available. I was also successful in developing techniques for sustainable cultures of microalgae in optimal densities over the same trial period.