Immune response activation in channel catfish ictaluras punctatus fed
spirulina enriched artemia. by B. Portoni et al. 1996.
American Fisheries Society Fish Health Section. USA.
The following is a summary of the article referenced.
The cyanobacteria spirulina is commercially produced for human consumption
as well as agricultural feed ingredients. Recently, whole spirulina and
cell extracts were found to enhance immunity in animals by increasing
phagocytic activity. The purpose of this study was to determine the effect
of spirulina enhanced diet on the nonspecific immune response of channel
catfish, ictaluras punctatus. The sample population consisted of "young of
the year" channel catfish obtained from Fish Producers, Niland, CA. Fish
(50/tank) were maintained in glass aquaria equiped with undergravel filters.
All fish were fed a diet of Trout Starter Diet (Rangen, Inc) for a month
until they were large enough to ingest adult brine shrimp (artemia franciscana).
The control diet consisted of adult brine shrimp. The test diet consisted
of adult brine shrimp biencapsulated with spirulina. Adult brine shrimp
were allowed to feed on dried spirulina powder for 3-4 hours to maximize
bioencapsulation. Preliminary studies indicated that channel catfish fed
spirulina had an increase in the number of splenic macrophages determined
by esterase staining compared to controls. Not only were more macrophages
present in the spleen, but also the macrophages appeared activated.
Activation determined by morphology on scanning electron microscopy, was
characterized by the presence of numerous folds and ruffles. This research
was performed on a single population of catfish over a period of months.
While data suggests nonspecific immunostimulation elicited by spirulina
in the diet, further study on different populations of fish is underway
to confirm the preliminary data.