Phytoplankton Feeding Trials


Feeding trials have been used to test various aspects concerning the quality of phytoplankton products that are marketed in the aquarium trade in two published studies.

For over 10 years the various companies that are producing or repackaging phytoplankton based feeds have made strong claims of their effectiveness for feeding various captive reef inhabitants.

Virtually any kind of small particles or many chemical additives can cause a coral to react by expanding its polyps. Unfortunately, this phenomenon alone has influenced many hobbyists to feed to their corals products that provide no real benefit as coral food. It is almost impossible for hobbyists to determine the immediate and most long term effects to aquarium animals, do to any products that are added to the aquarium.

Phytoplankton often causes coral polyps to extend, but it does not directly feed most stony corals. The benefit provided to stony corals by phytoplankton is to increase the amount of zooplankton available for the corals to feed on.  Although copepods do not need to feed on live phytoplankton, the fats that they store are determined by the fats that they consume (in other words, they are what they eat). Therefore, higher quality phytoplankton will produce more nutritious copepods.

How effective phytoplankton is as a food is determined not only by nutritional value, but also by it being accepted as a food by the animals it is intended to feed. Two studies that have tested phytoplankton products in the aquarium trade have been published.

View Feeding Trial Study #1

Marine Fish & Reef USA 2002 Annual

This study was conducted by Dr. Robert Toonen, Kelly Batchelor & Thien Mai at the University of California, Davis. This study looked at the effectiveness of phytoplankton products that were stored in various ways with feeding trials on invertebrate larvae. It is notable that the shelf life of SA’s Live Marine Phytoplankton was determined in this study.


Pales Espinosa E., Allam B. Comparative growth and survival of juvenile hard clams, Mercenaria mercenaria, fed commercially available diets. Zoo Biology 25: 513-525.

View Peer-Reviewed Feeding Trial

Marine Sciences research Center, Stony Brook University, Stony Brook, NY.
This study was conducted by researchers:

Dr. Bassem Allam and Dr. Emmanuelle Pales Espinosa


The objective of this research was to compare the nutritional value among several commercially available diets for juvenile hard clams, Mercenaria mercenaria. This study also assessed the effects of refrigeration on the nutritional value of Isochrysis, Pavlovaand Tetraselmis Growth and mortality rates provide a good estimate of the nutritional value of each product or species of algae tested.