Harlequin Tuskfish (Choerodon fasciatus)QuestionTwo weeks ago, I added a harlequin tuskfish to my 90-gallon reef tank with the understanding that it’s a peaceful fish. Then this morning, the stupid thing ate my skunk cleaner shrimp right in front of me! Was I misinformed about this fish’s temperament? Eating tankmates whole seems like pretty aggressive behavior to me. Also, I was under the impression that predatory fish usually leave cleaner shrimp alone because they recognize that they’re helpful. Is that not the case?” – Submitted by Jen Answer I don’t know that I’d say you’ve been misinformed about this species’ temperament exactly, but it may be that you’ve misinterpreted or misapplied a few terms here.
Astraea snail chowing down on nuisance algaeThis past year, I rediscovered how great an army of snails can be. At Tidal Gardens, we go pretty light on cleanup crews in general. For example, there really aren’t any hermit crabs to speak of in our systems. In 5,000 gallons of reef tanks, there may be only one or two hermit crabs. Most likely they arrived as refugees from local customers taking their tanks down who needed to re-home some of their inhabitants. I am not a fan of crabs because there is always a risk they might kill something they should not be killing, like another member of the cleanup crew or a coral. Long story short, I don’t trust them. I don’t have the same level of distrust for snails
Blue-legged hermit crabs (Clibanarius tricolor)Clibanarius tricolor, the blue-legged hermit crab, is very commonly introduced to marine aquaria, either in conspecific groups or as part of a multi-species “reef janitor” package or “cleanup crew” (aka “CUC” for those who just can’t get enough of those marine aquarium acronyms), for the purpose of aiding in detritus and algae control. But does this little hermit really perform as advertised and is it truly reef safe? Based on my personal experience with keeping blue-legged hermits, I would answer both of these questions with a resounding “maybe.” Before adding C. tricolor to your aquarium—especially in large numbers—consider the following four caveats:1. It’s an opportunistic omnivore What this point should tell you is, C. tricolor won’t necessarily limit its menu to the algae, detritus, and uneaten food you want it to consume.
The smooth giant clam (Tridacna derasa)Of all the Tridacna spp. clams available to hobbyists, perhaps the hardiest and easiest to maintain of them all is Tridacna derasa, the so-called smooth giant clam. This species is so smooth, in fact, that amorous, gold-chain-wearing male specimens have been overhead in bars making comments like, “Say, did it hurt when you fell from heaven?” and “If I could rearrange the alphabet, I’d put ‘U’ and ‘I’ together.” Okay, maybe T. derasa isn’t that kind of smooth, but its shell does lack pronounced ridges or scutes, making it relatively smooth to the touch. So, that’s probably where the name actually came from (though you have to admit my explanation is much more fun). It’s a fast-growing species when given proper conditions and a great choice for first-time clam keepers who have the tank space to spare.Physical traits T. derasa is the second largest of the Tridacna clams, potentially reaching 18 inches to upwards of 2 feet in length.
Green brittle star (Ophiarachna incrassata)“Voracious predator” is not a term one commonly associates with brittle stars—that is, of course, unless the brittle star in question happens to be Ophiarachna incrassata, or the green brittle star (aka “the green death”). This bold species has a well-earned reputation for not merely scavenging deceased small fish and motile invertebrates, as one might assume, but also for actively hunting and capturing these animals while they’re still alive and kicking. Physical appearanceO. incrassata, as its common name implies, is muted green overall with lighter colored dots forming a radial pattern on the central disc. Whitish to yellowish spines line either side of each arm. Specimens can reach a rather prodigious size of around 20 inches in diameter (arm tip to arm tip, that is). Feeding This brittle star is not a finicky eater. It will accept pretty much any foods offered to fish as well as consume detritus