Learn & Explore/Species/Introduced & Invasive/Keyhole Sponge

Orange Keyhole Sponge

Category: Invasive

Rapidly spreading sponge known to overgrow native corals and sponges on patch reefs

Orange Keyhole Sponge (Mycale armata)​

  • Bright orange encrusting sponge 

  • Can grow up to one meter in diameter

  • Firm but compresses and tears easily

  • Large oscules spread evenly across body

Habitat

  • Typically found in fouling communities such as floating docks, piers, and jetties 

  • Found on shallow patch reefs in Kāne‘ohe

Impacts & Concern

  • Overgrows native corals and sponges on patch reefs 3

Orange Keyhole Sponge

Introduction

  • First reported in Pearl Harbor in 1996 

  • Unintentionally introduced, most likely through hull fouling 

Distribution in Hawai’i

  • Kauaʻi: Not documented

  • O‘ahu: Pearl Harbor, Honolulu Harbor, Ke‘ehi Lagoon, Barbers Point Harbor, Kāne‘ohe Bay

  • Molokaʻi: Not documented

  • Lānaʻi: Not documented

  • Maui: Kahului Harbor

  • Hawaiʻi Island: Not documented

References

  1. Eldredge, L. G., & Smith, C. M. (2001). A guidebook of introduced marine species in Hawai’i. Honolulu: Bishop Museum and the Univ. of Hawai’i.

  2. Bolick, H., & Coles, S. (2007). Invasive introduced sponge Mycale grandis overgrows reef corals in Kāne‘ohe Bay, O‘ahu, Hawai‘i. Coral Reefs, 26(4), 911. DOI: 10.1007/s00338-007-0295-x

  3. Hawai’i Biological Survey (2001). Mycale armata. Introduced marine species of Hawai’iGuidebook. https://www2.bishopmuseum.org/HBS/invertguide/species/mycale_armata.htm

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