Hello, Jason here. Working in the fishroom at That Fish Place, I have a great opportunity to learn and discover new things about the fish and inverts so many people love to keep in their aquariums. My co-workers (being science majors and marine bio graduates) are able to work closely with these animals, observing captive behaviors and sometimes having the time to experiment with how they can keep the fish happier while they are held at our facility. Recently, we’ve been experimenting in our holding tanks – I thought might share one of our recent tests, if for no other reason than to explain what you might see if you visit.
As you can guess, the tanks in the fish room are left rather stark. The tanks are for holding the fish for the short time they are here before being purchased by our customers. As you can imagine, it is much easier to catch a fish from a tank if there aren’t too many obstructions. Our tanks are each furnished with plain lengths of pvc pipe to provide cover for the fish so they can feel secure. There is a down side to having bare and minimal furnishings in the tanks. After a day or two, the brilliant colors the fish should display fade, as they try to blend with thier surroundings, so they don’t always look as good in our tanks as they will when you get them home to a rocky reef or otherwise well-decorated environment.
We’ve been trying to test whether livestock adapts better to our tanks if they have artificial corals or even colored tubes as opposed to the plain white PVC. After placing some various imitation corals into the tanks, we noticed that the fish in those aquariums were keeping their color better than the fish that were put into tanks with plain white pvc. The obvious conclusion was the shape and/or color of the imitation coral made the fish feel safer and more at home in the aquarium. Is it the darker colors or the more life-like shapes that made the difference? We took a few of our standard white PVC pipes and painted them with random blotches of red, blue, black, and green to see if the tubes would appeal more to the fish. Now, we’re watching the fish in those tanks to see if the experiment is having any effect.
Some of the tangs, specifically, have shown us that they are attracted to the black blotches, in particular. Presumably they are drawn to the dark spots since they resemble the dark algaes that grow on reef rock (since they seem to want to chew the black coloration off of the pipes). These results were especially apparent in tanks housing Powder Blue Tangs (Acanthurus leucosternon). Interesting to see that these fish may rely not only on smell and taste to find food, but they may also seek out specific shades that they associate with food items. That may be something in mind if you have a finnicky tang that won’t eat lighter spirulina based foods – they may be more enticed by sea veggies or algae sheets. It could be that the algae they eat in their natural habitat is a darker in color so it seems more recognizable to them. (Not something we expected to see, but an interesting tidbit anyway.)
Anyway, if you visit our fishroom and wonder why we would have such hideous decor, now you’ll know why. We’re still trying to see how the colored tubes will benefit the fish, but hopefully our theories pan out.