THE STEINHART AQUARIUM - Gulf of Guinea Science ...

there is an advantage to mimicking an angelfish
which possesses a sharp, preopercular spine
when this young surgeonfish and its peduncular
spines are quite small.
Convict Tang aka Convict Surgeonfish
Acanthurus triostegus (Acanthuridae)
Surgeonfishes, Tangs and Unicornfishes
Distribution: Indo-Pacific.
Habitat: Juveniles in tide pools. Adults in
lagoon and seaward reefs in areas of hard
substrates from sea level to 90 m; typically
occur in shallows to 5 m.
Appearance: Length to 27 cm. White with 5–6
black bars on head and body.
Diet: Filamentous algae.
Reproduction and Development: Spawn at
sunset within small groups that break away
from a huge milling aggregation of conspecifics
at a reef edge or channel entrance. Pelagic eggs.
Larvae drift ~75 days. Post-larvae settle in
intertidal areas of benches and reef flats.
Mortality/Longevity: Eggs and sperm are
preyed upon by eagle rays, which are often
present during spawning.
Remarks: Ubiquitous, one of the most
widespread coral reef species. May be solitary,
in small groups or in schools of 1,000 or more.
This black-barred fish’s common name
presumably alludes to the coloration of many
prison uniforms of the previous century.
This species has a very small caudal spine and
therefore is near the gutter of the “acanthurid
pecking order.” Thus they usually feed in large,
roving aggregations which overwhelm the
defenses of territorial herbivores.
Goldring Bristletooth aka Spotted Surgeonfish
Ctenochaetus strigosus (Acanthuridae)
Surgeonfishes, Tangs, and Unicornfishes
Distribution: Central Pacific.
Habitat: Coral-rich areas of deep lagoon and
seaward reefs.
Appearance: Brown with pale yellow spots
on head and pale yellow pinstripes on body.
Conspicuous, broad yellow ring around the
eye. Max. length: 15 cm.
Diet: Feeds on algae and detritus using its
comb-like teeth.
Reproduction and Development: Pelagic
spawner.
California Academy of Sciences
R e m a r k s : T h e g e n u s C t e n o c h a e t u s
(bristletooths) have differently shaped
mouths than Acanthurus species. The latter
group have lips and dentition suitable for
snipping off the tips and branches of algae.
Bristletooths feed on detritus and unicellular
algae from the surfaces of dead coral, rock,
seagrasses, or other algae, using specialized
bristle-like teeth to scrape off their meal and
then suck it into the mouth. Both groups are
favorites of aquarists for their tank-cleaning
services.
Their diet may contain high concentrations
of the dinoflagellates that produces ciguatera
toxin, and so bristletooths and their predators
are known to sometimes concentrate sufficient
toxin to cause illness in humans.
Tomini Tang
Ctenochaetus tominiensis (Acanthuridae)
Surgeonfishes, Tangs, and Unicornfishes
Distribution: Western Central Pacific,
including Indonesia, Philippines, to northern
Great Barrier Reef.
Habitat: Steep coral drop-offs of sheltered coasts.
Appearance: Brown with pale lower head. The
only species of Ctenochaetus (bristletooths) with
angular dorsal and anal fins; outer portion of
these fins is a bright orange. Caudal fin white.
Max length: 15 cm.
Diet: See Goldring Bristletooth remarks above.
Reproduction and Development: Pelagic
spawner.
Spotted Unicornfish
Naso brevirostris (Acanthuridae)
Surgeonfishes, Tangs, and Unicornfishes
Distribution: Indo-Pacific: East Africa to the
Hawaiian Islands, north to southern Japan,
south to Australia.
Habitat: Mid-waters along steep outer lagoon
and seaward reef drop-offs, from 4–45 m.
Appearance: Olive-brown to blue-grey with
dark spots on head and vertical rows of spots
and lines on sides. Tail whitish with dark area at
base. Long, tapering horn on forehead of adults
is lacking in juveniles. Max length: 60 cm.
Diet: Juveniles: benthic algae; adults: mainly
zooplankton.
Reproduction and Development: Pelagic
spawners.
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