Ask the WWM Crew
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Like all commercial hunters, when fish collectors are out "doing their thing" their eyes are fixed on the principal prize... Money... Collecting the most of the species that will generate the most revenue. In Hawai'i', the list of such target species is more than a handful... Dragon Morays (Enchelycore pardalis), Tinker's Butterflies (Chaetodon tinkeri), the equally deep-water Holo Holo/Bandit Angel (Apolemichthys arcuatus) and a few others are big pay days per specimen... A "medium" income animal is the topic of this article, the Chevron, or in the trade more commonly termed the "Chevy" Tang.
As a good stock in trade member of the Bristlemouth genus Ctenochaetus, the Chevy is a great fish for most all types of marine systems... Fish Only to full blown Reef systems will find this fish getting along with all other fishes, sessile invertebrates, including of course the stinging-celled animals called corals, anemones, sea fans...
Bristlemouth tangs are of great utility as aquarium specimens, tirelessly picking at micro-algae and smaller fleshy algal species from hard substrates, resting only during the night.
What is more to recommend the Chevy for your aquarium? It's a relatively hardy, disease free species... and quite beautiful, particularly as a juvenile; though it's less colorful vermiculate markings as an adult and nice fan-shape to the overall body with growth are equally distinctive IMO.
The Chevron tang occurs widely in the tropical
Pacific; from Micronesia and the Wake Islands, Hawaii's principal
chain, to Pitcairn Island. Almost all specimens for the trade are
collected from the U.S.'s 50th State. Like all Ctenochaetus
species, the hawaiiensis is found on sloping reef fronts, picking on
algae... Adults can be found in as little as a few tens of feet of
water; most juveniles are encountered between 60-100 feet of depth,
though I have seen adults in as shallow as 15 feet and juveniles much
Most all Chevron tangs are collected from Hawaii for the ornamental trade... the vast majority from the Kona coast of the Big Island... and are well-taken care of from the point of collection, processing, holding, bagging/boxing... and this species ships well. However, there are some general things to look for in assessing specimens for purchase. Chief of which are:
1) Activity. This tang should be out and about picking on hard surfaces, including the systems walls, for micro-algae...
2) Feeding... in addition to nibbling on what's available, ask the dealer to feed the fish in front of you.
3) A lack of damage to the mouth... Tied in with the previous two
characteristics to check for, like all Tangs, this Ctenochaetus has an
apical mouth... it points out at the front of the animal. And is
unfortunately the area most likely to suffer damage in collection and
handling. Specimens with such traumas often will not feed... and the
antithesis of a "fish that feeds, lives"... applies.
This Surgeonfish lives in constant semi-contact with the stony rocks that make up the reefs in its distribution, searching and picking by day for algae, and nestling twixt rocks at night sleeping. Chevrons are always found in "open" areas of good water movement... and need space, circulation, high dissolved oxygen in your care. Though one can be crammed into a small space when it's small, I strongly advise a minimum tank of 80 gallons or four feet length to give this species room to move around, space to culture small algae for its consumption.
Live rock and live sand should be "fresh" enough to produce green and diatom algae that this species consumes. Do bear in mind that this material needs periodic replenishment, replacement or supplanting to steadily produce such fodder. A good ten percent or more should be switched out and/or added after a year or so in place, and this amount moved again every six months or so following.
Very small juveniles... 2 inch, 5 cm. in length
or so, are found in and amongst finger-like Porites growing upright on
the bottom. Most individuals sold in the trade are larger than this,
and small specimens adapt readily to unfamiliar settings, as long as
there are spaces to get out of sight.
The Chevy gets along with all
sessile invertebrates and most all fishes, though it may spar for a
while with dwarf angels of the genus Centropyge and other similarly
shaped fishes that utilize small encrusting algae as food, and it may
in turn be picked on by more aggressive surgeons. It is a loner in the
wild unless very small. Keep this species one to a tank.
This Tang is largely an herbivore, relying on
micro-algae in the wild, and secondarily a detritivore. Almost all
specimens readily adapt to all sorts of prepared foods offered near the
bottom or on the rock. Vegetable material should make up a good
proportion of a prepared diet, though my usual statement here re
source: Avoid terrestrial greens... these are too often largely
un-digestible, of little food value, and often a source of algal-growing
pollution and toxins. The best foods are ones you culture yourself, or
bought, collected or processed from marine environments.
It is my long-standing opinion that most losses of this fish are due to "hobbyist neglect"; principally through either unsuitable habitat and/or insufficient nutrition. Please, don't be one of these causes. Keeping a healthy Chevron for years is actually quite simple. Plenty of room, consistent, high water quality (simple filtration, skimming, regular water changes...), and a good deal of live rock, a dearth of competing micro-algal herbivores, perhaps some supplement soaked algae-based foods occasionally... is all this species requires.
Specimens that develop HLLE have been exposed continuously to toxins like copper or allowed to suffer avitaminoses... These can be corrected with the use of "mud" in their filters/refugiums/sumps, food supplementation, and proffering live algae that's palatable. Again, I'm compelled to praise friend Pablo Tepoot's Spectrum Foods here for their ready complete nutrition and avid acceptance.
As with all acanthurids, the Chevron cannot be
sexually differentiated externally. This species has not been spawned
in captivity, but can be seen doing so in the wild, in apparently mated
Some other authors, resources state that the
Chevron is difficult to care for, even quarrelsome. This runs counter
to all my experience with this fish. The Chevron Tang is a great
aquarium species. It is hardy, undemanding, gets along with most
everything but algae, and in turn most all other
non-territorial/piscivorous sealife leaves it alone. If you have room
for a medium sized showpiece, do consider Ctenochaetus hawaiiensis.
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Campbell, Douglas G. 1979. Fishes for the beginner, A guide for the new marine hobbyist, Parts three and four, Tangs. FAMA 1,2/79.
Debelius, Helmut. Undated. Interesting information about surgeon (sic) fisch- III The Ctenochaetus genus. Aquarium Digest International #31.
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