Mycale grandis is an orange-red brightly coloured sponge. The colouring is both internal and external. It can grow as thickly encrusting to lobate-massive cushions up to 1 metre diameter and 0.5m thick or larger. The upper surfaces of large sponges show large ostia or \"keyholes\", hence the common name. The sponge's surface is uneven. The texture is fibrous and firm but compressible, and can be torn easily. The interior is cavernous, and often packed with small ophiuroids (Ophiactis cf. savignyi) (Eldredge and Smith 2001).
Mycale grandis is typically restricted to shallow-water fouling communities (i.e. pier pilings, floating docks) in major harbours or on associated disturbed habitats (i.e. dredged channels and artificial lagoons). This species has also been found over-growing native coral communities in areas of Hawaii like Kane‘ohe'ohe Bay, where it grows on patch reefs in the southeast corner of the bay as well as artificial structures (Eldredge and Smith 2001; Coles and Bolick 2006).
Like most sponges, Mycale grandis is probably capable of asexual reproduction by fragmentation but specific details regarding sexual reproduction of this species are unstudied (Eldredge and Smith 2001).
Mycale grandis is a filter feeder, continuously circulating water through its body. Microscopic food particles are removed from the water by specialised collar cells. Digestion is intracellular (Eldredge and Smith 2001).
Principal source: Dr. Steve Coles, Bishop Museum.
Coles, S. L and Bolick, H. 2006. Assessment of invasiveness of the orange keyhole sponge Mycale armata in Kane`ohe Bay, O`ahu, Hawai`i.
Compiler: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Review: Steve Coles
Bishop Museum Hawai'i USA
Publication date: 2006-03-23
Recommended citation: Global Invasive Species Database (2019) Species profile: Mycale grandis. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=953 on 22-02-2019.