Tang Fish
A surgeonfish: the name comes from a blade at the base of the tail that it can raise. Marine grazers that want length of tank more than volume.
Photo by Lexi Amico, CC BY 4.0
Overview
Tangs are surgeonfish, and the name is literal. There is a blade at the base of the tail, set in a groove, and in the blue tang it sits with a venom gland. It is a defensive weapon, it is sharp, and it is the reason a tang is netted and handled with more care than its manner suggests.
They are also large and active. The blue tang reaches 31 cm and the yellow tang 20 cm, and both come from clear, current swept reef terraces where they cover a lot of ground.
Temperament
Busy all day and territorial towards their own kind. A tang patrols, grazes and keeps moving, and it does not settle into a corner the way a goby or a clownfish does.
Two tangs of similar shape in one tank usually fight, which is why one to a tank is the standard arrangement outside very large systems. Towards fish of other shapes they are generally indifferent. Blue tangs feed on zooplankton and occasionally on algae, and yellow tangs are mainly herbivores browsing filamentous algae.
Care and grooming
Algae is the staple for the grazing species. Dried algae sheets on a clip, marine greens and a prepared herbivore food, offered continuously rather than in one meal, because these are fish that graze all day.
Marine parameters held steady, around 75 to 82 F and pH 8.1 to 8.4. Tangs are notably prone to white spot when stressed or newly moved, and the parasite's free swimming stage is the only one treatment reaches, so quarantining a new fish before it enters a display tank is standard practice rather than a precaution.
Living and exercise
A hundred gallons upwards, and long rather than tall, because the fish needs distance to swim rather than height. Rock work with swim throughs suits how they use a reef.
Algae growth in the tank is a feature rather than a fault here, since it gives them something to graze between feeds. A tang added last to an established system settles better than one added early, because it enters a tank where the territories are already someone else's problem.
Something here wrong or out of date?