Chaetomorpha is a diverse genus of macroalgae featuring an a array of over fifty species. Much like the genus, Caulerpa, members of the Chaetomorpha genus come in many shapes and sizes, some with round cells so large that they bare a likeness to a string of pearls, others sporting a holdfast and filaments so fine that you’d call it “green hair algae” if it showed up in your reef aquarium. However, there seems to be three main species that are cultivated in the refugiums of reef aquariums for the purpose of “nutrient export,” and unfortunately, they’re not so easy to identify.
Learn MoreChaetomorpha spiralis seems to be the most readily available species offered for sale both in our local, Orlando area fish stores and and on other macroalgae specialized websites. Aptly coined “Brillo” by the late Jake Adams, C. spiralis is characterized by it’s densely growing, coarse, tightly curled filaments, reminiscent of a green Brillo pad. We’ve found C. spiralis to be the slowest growing, least versatile, and least forgiving of the three species. C. spiralis thrives under low to moderate lighting in systems with moderate to high nutrient levels, however it seems to be the least aggressive at consuming nutrients. C. spiralis does not like intense lighting or low nutrients; both conditions may cause it to die, and melt away. Samples of any given Chaetomorpha species often vary in color based on the intensity of the lighting it was cultivated in, however C. spiralis seems to vary the least, this may be linked to its narrower preferences for lighting intensity. One positive characteristic of C. Spiralis is that it seems to be more resistant to having common pest types of microalgaes grow on its filaments when these pest algaes bloom in aquaria.
Having relatively fine filaments compared to C. spiralis, the hallmark of Chaetomorpha linum is its very straight filaments. A mass of C. linum strongly resembles a plate of angel hair pasta in structure. Despite coming in varying shades, C. linum can often be seen in very dark, almost black, shades of green. C. linum grows significantly faster than C. spiralis, and consumes nutrients more aggressively as well. However, C. linum seems to be the most sensitive to high PH and alkalinity caused by the supplements commonly dosed for coral growth can be prone to sudden die-offs in seemingly ideal conditions, this is thought to be linked to its reproductive cycle like many Caulerpa species.
Chaetomorpha crassa seems to be the species best suited for cultivation in the refugiums of reef aquaria. C. crassa can be identified by its relatively fine (similar to C. linum), moderately curled filaments. We at ChaetoFarm.com have found it to be the hardiest, “hungriest,” fastest growing, and most versatile species; which is why it was chosen as the species we culture. We’ve found that C. crassa is extremely tolerant of varying water parameters, lighting, and flow. C. crassa aggressively consumes nutrients in our systems but we’ve also seen it continue to grow under ~700PAR in an ultra-low nutrient system (0.0 NO3, 0.02 PO4) where Chaetomorpha spiralis had simply melted away. C. crassa also seems to thrive under dimmer lighting with restricted schedules where less aggressive nutrient export is desired. In addition to C. crassa’s excellent characteristics for cultivation, it also is the clear winner in our tangs’ eyes as well. Therefore, we at ChaetoFarm.com have concluded that Chaetomorpha crassa is the best species for all types of marine aquaria.