THE STEINHART AQUARIUM - Gulf of Guinea Science ...

164 A Docent Field Guide to the Species of the Steinhart Aquarium
Common Clownfish
Amphiprion percula (Pomacentridae)
Damselfishes
Distribution: Solomon Islands, Vanuatu, New
Guinea and Great Barrier Reef, Australia.
Habitat: Lagoon and seaward reefs, including
turbid coastal locations at depths 1–15 m.
Symbiotic groups of this clown occur with
three anemone species (Heteractis magnifica, H.
crispa and Stichodactyla gigantea). Each group of
orange clownfish consists of a breeding pair
and up to 4 non-breeders.
Appearance: Orange with three horizontal
white bars, middle bar sideways T-shaped,
variable amount of black edging on bars and
fins. Length to 11 cm.
Diet: Primarily zooplankton.
Reproduction and Development: Each group
of clown anemonefish consists of a breeding
pair and 0 –4 non-breeders. Within each group
there is a size-based hierarchy: the female is
largest, the male is second largest, and the
non-breeders get progressively smaller as
the hierarchy descends. If the female dies, the
male changes sex and becomes the breeding
female, while the largest non-breeder becomes
the breeding male. The maintenance of size
differences may avoid conflicts, because
subordinates do not become a threat to the
dominant breeders.
Remarks: Clownfishes and anemones display a
classic case of mutualism. Clownfish gradually
(matter of minutes to days) acquires a covering
of mucus by brushing against the tentacles of
its host. The mucus provides a blanket of chemosensory
camouflage that prevents firing of
the host anemone’s nematocysts.
The symbiotic trade off: The clownfish actively
discourages other anemone-nibbling fishes
from approaching and also provides the
anemone with bits of food from its sloppy
eating habits. The clownfish gains protection
among the anemone’s nematocysts.
Pink Anemonefish
Amphiprion perideraion (Pomacentridae)
Damselfishes
Distribution: Eastern Indian Ocean to western
Pacific Ocean; Indonesia to Marshall Is. In
eastern Micronesia. Southwest Japan to
northwest Australia, New Caledonia.
Habitat: Reefs from 3–30 m. Pursue a symbiotic
life with at least 4 anemone species, but most
commonly with the typically large (to 1 m
diameter) mature magnificent sea anemone,
Heteractis magnifica. Also associates with
Heteractis crispa, Macrodactyla doreensis and
Stichodactyla gigantea.
Appearance: Pinkish-orange coloration varies
in saturation of color by individual. Distinctive
narrow white head bar, narrow white dorsal
stripe from eyes to tail. To 10 cm length.
Diet: Zooplankton, primarily copepods, as
well as filamentous algae.
Reproduction and Development: Protandrous
hermaphrodites. Like all anemonefishes, sex
and growth are controlled by the dominant
female. Elliptical eggs are laid on rocks close
under the host anemone’s mantle. The male
fish guards the eggs. Upon hatching the larvae
drift in the plankton.
Blue Chromis
Chromis cyanea (Pomacentridae)
Damselfishes
Distribution: Florida, Bahamas, Bermuda,
Caribbean, Gulf of Mexico.
Habitat: Outer reef slopes and exposed patch
reefs from 3–60 m.
Appearance: Length to 15 cm. Body is brilliant
blue, nape and back often dark. Slender tail is
deeply forked and has dark borders.
Diet: Zooplankton, primarily copepods.
Reproduction and Development: Female lays
demersal eggs, which are guarded by the male.
Mortality/Longevity: Preyed upon by other
fishes such as groupers and trumpetfishes.
Remarks: Often found in large aggregations.
Bicolor Chromis
Chromis dimidiata (Pomacentridae)
Damselfishes
Distribution: Indian Ocean: Red Sea, Kenya,
Tanzania, South Africa, Mauritius, Réunion,
Sri Lanka, Thailand, and Christmas Island.
Habitat: Lagoon and seaward reefs, 1–36 m
depth. Occur in large aggregations near shore,
over reef tops and upper edges of slopes.
Appearance: Length to 9 cm. Brown or black
head and forebody; white rear body and tail.
Diet: Zooplankton, plants.