THE STEINHART AQUARIUM - Gulf of Guinea Science ...

186 A Docent Field Guide to the Species of the Steinhart Aquarium
to blue horizontal lines. Yellow dorsal fin,
upper lip and band across eyes.
Diet: Group grazer upon plankton.
Reproduction and Development: Form
resident spawning aggregations mid-water.
Conservation Status: IUCN: Not Evaluated.
Reported to be moderately to highly vulnerable
to extinction in the scientific press.
Remarks: Marketed as a food fish.
Whitecheek Surgeonfish aka Goldrim Tang
Acanthurus nigricans (Acanthuridae)
Surgeonfishes and Unicornfishes
Distribution: Eastern Indian Ocean and
throughout the tropical Pacific, including
Indonesia and the Philippines, eastward as
far as Hawaii, Galapagos and coast of Mexico.
Habitat: Hard substrates of clear lagoon and
especially exposed reefs to 67 m.
Appearance: Length to 21 cm. Body dark
brown, navy-blue or black. Tail white with
yellow bar; white patch below eye, white ring
behind mouth; yellow line at base of anal and
dorsal fins; yellow tail spine.
Diet: Filamentous algae.
Reproduction and Development: Monogamous.
Following external fertilization, female
scatters eggs over substrate. Hatched larvae
join the plankton.
Remarks: Territorial.
Bluelined Surgeonfish
Acanthurus nigroris (Acanthuridae)
Distribution: Indo-Pacific: East Africa to
Hawaiian Islands.
Habitat: Clear lagoons and outward reefs to
90 m.
Appearance: Dark brown body with numerous
blue stripes in scroll patterns on face and chest,
more horizontal on body. Dark peduncular
spine and tail. Small but distinctive black spots
on rear base of both dorsal and anal fins. A
small surgeonfish; max. size: 25 cm.
Diet: Filamentous algae, diatoms, fine algal
film.
Reproduction and Development: Pelagic
spawner.
Remarks: Solitary or forms small groups.
Orangeband Surgeonfish aka Orange Shoulder
Tang
Acanthurus olivaceus (Acanthuridae)
Surgeonfishes, Tangs and Unicornfishes
Distribution: Eastern Indo-Pacific.
Habitat: Near reefs over sand, bare rock and
rubble substrates, 3–45 m. Juveniles inhabit
protected bays and lagoons in depths as shallow
as 3 m. Adults occur singly or in schools.
Appearance: Juveniles less than 6 cm are
yellow, subadults become a dirty yellowishbrown.
At 12 cm have the adult coloration: light
gray head and forebody, dark gray behind;
blue-edged elliptical orange band behind upper
gill cover. Length to 35 cm.
Diet: Diurnal feeder on surface film of detritus,
diatoms and filamentous algae covering sand
and rocks.
Reproduction and Development: Spawn,
typically at dusk.
Mortality/Longevity: An important food fish.
Mimic Surgeonfish
Acanthurus pyroferus (Acanthuridae)
Surgeonfishes and Unicornfishes
Distribution: Indonesia, Philippines,
Micronesia to French Polynesia; southwest
Japan to New Caledonia and the Great Barrier
Reef.
Habitat: Lagoon and seaward reefs from 4–60
m. Prefers areas of mixed coral, rock or sand
near base of reefs. Often observed on silty reefs.
Appearance: Length to 25 cm. Adults have a
purplish-black to brown body; curving black
band from chin to upper edge of the operculum;
orange patch above base of pectoral fin. Front of
juvenile’s body (“face”) is gray; body is white
anteriorly and dark posteriorly. Dark-colored
caudal fin rounded in juveniles.
Diet: Algae.
Reproduction and Development: Following
external fertilization female scatters eggs over
open water substrate; eggs not guarded.
Remarks: The common name “mimic” is based
on the juvenile coloration; juveniles exhibit three
different color patterns mimicking angelfish in
the Centropyge genus. Coloration of juveniles
mimics these angelfishes until they achieve the
largest size attained by the angelfishes; then
their appearance transforms to the appropriate
adult coloration for A. pyroferus. Presumably