THE STEINHART AQUARIUM - Gulf of Guinea Science ...

174 A Docent Field Guide to the Species of the Steinhart Aquarium
last two saddling the tail. The head has a
distinct ‘daisy’ print around the eyes made
of a few different pastel colors (e.g., pink
bands radiating from the eye) in larger adults.
Terminal males are gaudier than primary
males. Max length: 20 cm.
Diet: Carnivore on benthic and planktonic
crustaceans, other motile invertebrates and
small fishes.
Reproduction/Development: Protogynous
hermaphrodite; pelagic spawner.
Remarks. Occur in small, loose groups.
Rainbow Wrasse
Thalassoma lucasanum (Labridae)
Wrasses
Distribution: Tropical marine waters from
the central Gulf of California to the Galapagos
Islands.
Habitat: Shallow reefs at depths of about 48 m
as well as near-bottom substrate.
Appearance: Distinctive yellow and red lateral
stripes with the less common larger males
displaying a blue head with a broad yellow
vertical stripe behind the head. Like most
wrasses, is cigar-shaped with a pointed snout,
thick lips, a protractile mouth and protruding
canine teeth. Max. length: 15 cm.
Diet: An efficient carnivore that congregates
during the day in groups to feed on a wide
variety of small crustaceans, algae and egg
masses.
Reproduction and Development: Rainbow
wrasses utilize two types of reproduction and
two types of males. Those displaying the red
and yellow striped pattern are both males
and females, and reproduce by broadcast
spawning. They rise in large numbers to the
top of the water column, release eggs and
sperm, and quickly return to the safety of
deeper water..
Terminal males are those identified with blue
heads and yellow vertical stripe. This male
forms a harem and selects each female with
which to spawn. Normally each population
of these wrasses has only one sexually mature
terminal male. Should that male be removed,
a female newly transformed into a terminal
male will quickly take its place.
Remarks: Not fished commercially.
Moon Wrasse
Thalassoma lunare (Labridae)
Wrasses
Distribution: Indo-Pacific; Red Sea to East
Africa to the Line Islands, northwest to
southern Japan, and southwest to northern
New Zealand.
Habitat: Marine reefs to a depth of 20 m. Also
lagoons, coastal reefs, protected seaward reefs,
and estuaries.
Appearance: Adult’s caudal fin is a large
yellow crescent edged in purple and blue, the
source of the species common name. Body
dark green to blue with vertical red lines on
scales; pectoral fins a bright pink surrounded
by neon blue. The head is distinctive for its
bright irregular pink and violet bands radiating
from the mouth towards the body, a kind of
fluorescent camouflage. Terminal males most
colorful. Max. length: 25 cm.
Diet: Crustaceans, snails, and other small
benthic invertebrates; also fish and snail eggs.
Reproduction/Development: Protogynous
hermaphrodites. The terminal male has
priority access to food and spawning females.
Because eggs are fertilized externally during
mass spawning, some lesser males may mix
their gametes into the spawning cloud.
Remarks: Typically a peaceful fish with only
the dominant males becoming aggressive in
territorial or mating disputes.
When frightened this fish will hide in the reef
or bury itself in the sand; also buries in sand
to sleep.
SUBORDER ZOARCOIDEI
Northern Ronquil
Ronquilus jordani (Bathymasteridae)
Ronquils
Distribution: Bering Sea to Monterey Bay.
Habitat: On bottom, usually among rocks,
3–165 m.
Appearance: Males orange above, with vague
dark bars on side; olive-green below. Females
olive-green above, paler below. Like all
ronquils, body elongate, dorsal and anal fins
long, caudal and pectoral fins rounded. Max.
size: 18 cm.
Diet: Small invertebrates of the plankton and
benthos.