Monday, May 4, 2015


 A gorgeous Australian harlequin tuskfish. This species is displaying towards a tankmate.

Reef Tectonic's clients love the harlequin tusk (Choerodon fasciatus)! And why wouldn’t they? They are indeed one of the most beautiful fish inhabiting the reefs of the western Pacific. The tuskfishes are members of the wrasse family Labridae and is the only member of the genus Choerodon that is found in the aquarium trade with any regularity.Let's take a closer look at the biology and husbandry requirements of this fish.

This harlequin tuskfish is grayish to baby blue overall, with up from five to nine bars on the head and body. In juveniles, the bars are coppery orange or brown and there are two eyes spots on the dorsal fin and one on the anal fin. The pelvic fins are black. As the fish ages, the head and body bars become brighter orange with blue trim and the ocelli on the fins disappear. The rear portion of the body becomes darker and in some individuals the posterior body bars become paler. In adults, the dorsal, anal and pelvic fins are also red, while the tail is pale (often with a red rear edge) These fish have a somewhat viscous look because of the enlarged canine teeth at the front of the jaws. But rather than being white in color, their teeth are sky blue! These dental pigments typically become more intense as the fish gets larger.

There are apparently two distinct populations of harlequin tuskfish in the western Pacific. There is a northern population, which ranges from southern Japan to Taiwan (including the Philippines and Micronesia). Many of the individuals in the aquarium trade come from the Philippines. There is also a southern population, which ranges from Vanuatu and New Caledonia to Queensland, Australia. Individuals from the southern population often exhibit a more striking color pattern. For this reason, and the fact that fishes from this region are just more expensive, those individuals from Australia command a higher price. I should point out that paying more for individuals from Australia is worth it. Not only are they more attractive, they have better long-term survival rates than those from the Philippines. No doubt this is a function of how the fish are collected and handled prior to arriving at marine fish wholesalers. This medium-sized wrasse attains a maximum of 12 inches in length (reports in the aquarium literature that this fish attains  24 inches are erroneous).

This blue-toothed beast has a reputation for being rather pugnacious. However, I think some of this reputation is based more on its fearsome "grin" than a true desire to inflict harm. It has been my experience that this fish is usually not overly aggressive toward similar sized or larger fish tankmates. You can even keep it with small fish in a large tank with plenty of nooks and crannies that its more diminutive tankmates can seek shelter in if threatened. Obviously, a harlequin tuskfish is more likely to cause problems in a smaller tank and if they get the chance, they may prey on fish tankmates that are small enough to subdue. One other note, they are a greater threat to their aquarium tankmates as they get larger. There can also be differences between individuals - an occasional individual may be more ill-tempered than other members of its species. 

In most cases, these fish are not picky about what they consume. However it is not unusual for a new tuskfish to refuse food for several days after it is introduced to its new home. When it settles in, it will eat with gusto! Feed them a varied diet (e.g., fresh seafood, prepared foods for carnivores – we love the Rod’s Food!) and make sure you include those foods with added pigments to facilitate color fidelity.

There are two things that make the harlequin tuskfish a bit of a husbandry challenge. First of all, it is imperative you start with a good specimen to begin with. Individuals that arrive in rough shape and never acclimate to captive living. The other problem is resident bullies. If your tuskfish is picked on, it will never adjust to its new home, will start skulking behind the aquarium décor and stop feeding. I will give you an example of the latter – we added a beautiful adult harlequin to an aquarium that was in excess of 300 gallons. As soon as the tuskfish was added, it was harried by a smaller adult Symphorichthys spilurus – the threadfin snapper. This later fish is rarely aggressive in my experience, but this snapper hated the harlequin tuskfish! Eventually, we removed the tuskfish but it was too late. It had gone too long without eating and eventually perished.

The harlequin tuskfish feeds on mollusks, crustaceans, worms and echinoderms. However, they do not eat coral (they may move coral colonies when looking for hidden prey). You will have to make a decision if you want to keep snails, small clams, ornamental shrimps, sea urchins or sea stars. If you want to house these inverts in your reef aquarium than you better stay away from a harlequin tuskfish. Note, these fish are much less destructive as juveniles than they are as adults. Also, it would be fool hardy to place more than one in the same tank, unless the aquarium is huge. Unlike some wrasses, be aware that tuskfishes do not bury under the substrate at night or when threatened.

©  Scott W. Michael- Reef Tectonics

Reef Tectonics Aquarium Maintenance and Design - Omaha, Lincoln, Des Moines, Kansas City

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