THE STEINHART AQUARIUM - Gulf of Guinea Science ...

Diet: Microcarnivore of plankton; may also
possess zooxanthellae.
Reproduction and Development: Sexual and
asexual, mostly through budding and pedal
laceration.
Remarks: Aquarists commonly use the generic
term Actinodiscus.
Rhodactis
Rhodactis spp. (Discosomatidae)
Distribution: Tropical marine.
Habitat: Tropical coral reefs.
Appearance: 10 cm diameter. Numerous small
branched tentacles on the central portion of the
oral disc. Rim is covered with small, unbranched
tentacles and is greatly expanded nocturnally.
Diet: Mostly photosynthetic; also takes microplankton.
Reproduction and Development: Sexual and
asexual, mostly through budding and pedal
laceration.
Remarks: Like other species in this order, lacks
a hard skeleton.
Bullseye Mushroom
Rhodactis inchoata (Discosomatidae)
Distribution: Indo-Pacific.
Habitat: Areas of tropical reef with moderate
light and low-energy water movement.
Appearance: Varied colors, most often a violet
to blue; mouth often red or pink. Tentacles form
cauliflower-like clusters on the central disk.
The area around the mouth is typically bare,
giving the species its common name. Usually
4–5 cm, but may grow to 8 cm.
Diet: Feeds primarily on nutrients provided
by zooxanthellae. Also snares zooplankton
with its tentacles or occasionally captures
even larger food items by folding the oral disc
around them.
Reproduction and Development: Reproduce
primarily by longitudinal fission,
Remarks: Like most Rhodactis species, R.
inchoata is semi-aggressive and placed some
distance from other species.
Ricordea Mushroom
Ricordea spp. (Ricordeidae)
Distribution: Pan-Pacific. Found in both Philippines
and Caribbean.
California Academy of Sciences
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Habitat: Often hundreds of polyps of a species,
all genetically identical, cover rocky substrates
and coral rubble on reefs to 30 m. May also live
as solitary individuals.
Appearance: Spherical; short, non-retractile,
knob-like tentacles cover oral surface. Colors
vary within species (tentacles greenish,
greenish-brown, blue-gray with base often a
different color). Colors may fluoresce. Mouth
and outer row of tentacles may be colored
differently than other tentacles.
Diet: Most if not all nutrition provided by zooxanthellae;
may also consume plankton, food
particles, and small invertebrates.
Reproduction and Development: Sexually
and asexually (by longitudinal fission, pedal
laceration, or budding).File
Conservation Status: Have become locally
abundant (Monterey Bay peninsula, California)
during the past 50 years due to rising ocean
temperature.
Remarks: Ricordea spp. cannot retract the
tentacles that cover the disc.
Florida Ricordea
Ricordea florida (Ricordeidae)
Distribution: Tropical western Atlantic Ocean,
southern Florida south to Brazil; also in the
Caribbean and Gulf of Mexico.
Habitat: Shallow, turbid waters in large
colonial aggregations, also solitary in deeper
waters on hard substrates.
Appearance: Rounded, grape-like tentacles
on the oral disc. Color intensities may vary
from white to near black; others exhibit bright,
even florescent colors including orange, green,
yellow, blue, and purple with some having
blue, purple, or orange rings surrounding
a contrasting middle color. Max. diameter:
5–7.5 cm.
Diet: Most nutrition from symbiotic algae.
Also feed on small particulate matter.
Reproduction and Development: Reproduce
by fission.
Remarks: Genetic material that produces R.
floridas’s fluorescent colors has been isolated,
introduced into the freshwater zebrafish (Danio
rerio). Under blue light they fluoresce brilliant
green, orange, or blue, like the Ricordea polyps
from which the pigments were derived.
Perhaps parents of on-the-move teenagers will