Cyanobacteria-shrimp colonies in the Mariana Islands.

Cyanobacteria have multifaceted ecological roles on coral reefs. , a chemically rich filamentous cyanobacterium, has been characterized as a pathogenic organism with an unusual ability to overgrow gorgonian corals, but little has been done to study its general growth habits or its unique association with the snapping shrimp . Quantitative benthic surveys, and field and photographic observations were utilized to develop a better understanding of the ecology of these species, while growth experiments and nutrient analysis were performed to examine how this cyanobacterium may be benefiting from its shrimp symbiont. Colonies of and displayed considerable habitat specificity in terms of occupied substrate. Although found to vary in abundance and density across survey sites and transects, was consistently found to be thriving with within interstitial spaces on the reef. Removal of from cyanobacterial colonies in a laboratory experiment altered pigmentation, whereas cyanobacteria-shrimp colonies in the field exhibited elevated nutrient levels compared to the surrounding seawater.