THE STEINHART AQUARIUM - Gulf of Guinea Science ...

152 A Docent Field Guide to the Species of the Steinhart Aquarium
blue; no bars; two prominent black, forking
stripes in caudal fin.
Diet: Primarily zooplankton, supplemented
with benthic invertebrates and algae.
Reproduction and Development: Spawn at
sunset. Mating activity is less if there are no
currents to disperse the spawn.
Remarks: Genicanthus spp. are the only angelfishes
in which the sexes are distinctly colored.
Elongated tail that ends in two filaments bequeaths
the swallowtail its name.
Queen Angelfish
Holacanthus ciliaris (Pomacanthidae)
Angelfishes
Distribution: Bermuda, Florida, Bahamas,
Caribbean, Gulf of Mexico to Brazil.
Habitat: Offshore reefs, 2–70+ m. Travel solitarily
or in pairs among sea fans, sea whips and
corals.
Appearance: Deep-bodied and strongly
compressed. Length to 45 cm, weight to 1.6 kg.
Dorsal and anal fins trail. Adults have blue to
greenish-blue ground color, yellow edges on
scales. Tail and pectoral fins bordered in yellow.
Dark blue lips.
Diet: Adults feed primarily on sponges; also
algae, tunicates, hydroids and bryozoans. Juveniles
glean ectoparasites from other fishes.
Reproduction and Development: Juveniles
have vertical blue bands on an orange-red
body. As the fish grows, the bars increase in
number before gradually disappearing.
King Angelfish
Holacanthus passer (Pomacanthidae)
Angelfishes
Distribution: Tropical reefs of the eastern
Pacific from the coast of Peru north to the Gulf
of California and as far west as the Galapagos
Islands.
Habitat: Commonly found around shallow
rocky and coral reefs at depths of 3 to 27 m.
Juveniles are generally found in shallower
water
Appearance: Bodies of both males and females
are a dark blue with a vertical band of white
behind the pectoral fins, and yellow tails. The
pelvic fins of the male are white while the
females are yellow. Juveniles are primarily
yellow with iridescent blue edged fins, blue
stripes toward the posterior of the body with
orange around the eyes. Rays of the dorsal and
anal fins taper down and end in long filaments.
Max size: 30–35 cm.
Like all angelfish, have a blunt snout and a
large strong spike at the anterior most bone of
the operculum.
Diet: Sponges, tunicates, sessile invertebrates,
zooplankton and graze on benthic microalgae.
Feed during the day, are lethargic at night.
Reproduction and Development: Form
monogamous pairs. During the late summer
spawning cycle the females become more
territorial and the pair will mate daily. A pair
can produce millions of fertilized eggs which
will drift in the water column for about 20
hours at which time those that survive hatch
as finless fry living off their yolk sac until it is
completely absorbed. The fry then eat small
zooplankton until their size requires larger
prey. Some juveniles display cleaning behavior.
Conservation Status: One of the most abundant
fish in the Sea of Cortez and not considered to
be threatened.
Remarks: King Angelfish are popular aquarium
fish but are difficult to keep.
Emperor Angelfish
Pomacanthus imperator (Pomacanthidae)
Angelfishes
Distribution: Indo-Pacific.
Habitat: Juveniles solitary under ledges and
holes of outer lagoon patch reefs or semiprotected
areas of exposed channels and outer
reef flats. Subadults occupy reef front holes or
surge channels. Adults occur near ledges and
caves in regions of robust coral growth on clear
lagoon, channel or seaward reefs 3–70 m. Adults
typically in male/female pair or solitary.
Appearance: Length to 40 cm. Juvenile with
concentric white circles, also distinguished
by a white dorsal fin margin; adult pattern
emerges at about 10 cm: vivid, alternating
yellow and blue stripes and yellow tail; blueedged
eye mask, broad blue-edged black bar
behind head.
Diet: Sponges and other encrusting organisms
such as tunicates. Young and adults may
clean much larger fishes such as sunfish.
Reproduction and Development: Haremic.
Form pairs.