By Bob Goemans
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Aquarium Systems (Instant Ocean) 

Family Discosomatidae

Amplexidiscus fenestrafer

Dunn & Hamner, 1980

Elephant Ear Coral, Giant Cup Mushroom

Likely Reef Tank Suitable

Likely Fish-Only Tank Suitable

Range: Indo-West Pacific Ocean

Natural Environment: Inhabits shallow turbid areas in lagoons and tidepools receiving little to moderate water movement and generally solitary creatures, sometimes attached vertically on substrates, and may be found in small groups.

General Husbandry: These mostly photosynthetic corals, which can attain a diameter of 12 - 14 inches (30 - 35 cm), are among the easiest of all large polyped soft (LPS) corals to maintain since they do better in somewhat nutrient rich surroundings with medium light intensity and gentle water movement.

Generally a tan color, but depending upon where collected, may be an ivory, dark brown, or gray color, with the central oral area possibly a dark orange.

Has small stinging tentacles that are capable of capturing small fishes and invertebrates, which usually occurs during evening hours.

Requires occasional feedings of small pieces of fresh fish flesh/clam/shrimp.


    Kingdom: Animalia

    Phylum: Cnidaria

    Class: Anthozoa

    Subclass: Hexacorallia

    Order: Corallimorpharia

    Family: Discosomatidae

    Genus: Amplexidiscus

FYI: Only one species in this genus.

Placement in the aquarium can be wherever conditions favor it, but keep in mind to provide enough space between it and its neighbors!

Experience Level: Intermediate

Diet: Photosynthetic/Carnivore

Temperament: Semi-aggressive

Aquarium Environment: Reef or fish-only aquarium

Coral Safe:With caution

Fish Safe: With caution

Invertebrate Safe: With caution

Acclimation Time: 30 minutes+

Aquarium Hardiness: Hardy

Calcium (Ca): 380 - 430 mg/l

Alkalinity: 2.5 - 3.0 meq/l

Phosphate (PO4): <0.05 mg/l

Magnesium (Mg): approx. 1350 mg/l (relate to specific gravity)

Strontium (Sr) 8 - 10 mg/l

Temperature Range: 72 - 83°F (22 - 28°C)

Minimum Tank Size: 100 gallons

Lighting: PAR 300 - 400+

Water Movement: WM 1 - 2

Specific Gravity: 1.023 - 1.025

pH: 8.0 - 8.4

Iodine/Trace Elements Monitor/as necessary to maintain quality seawater.

 Amplexidiscus fenestrafer (Elephant Ear Coral, Giant Cup Mushroom)
Photo © Bob Goemans
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