Ircinia strobilina
Ircinia strobilina
''Ircinia strobilina'' is a species of sponge in the family Irciniidae. It is grey or shiny black in colour, with spiny structures dotting the surface. The spiny structures are interconnected by ridges, though not arranged in an orderly lattice. This species is globular and massive in shape, but usually no more than 0.3 metres across. ''I. strobilina'' is lobed and spherical and has a tough consistency. The large excurrent pores are located in depressions at the top of the sponge. Many smaller incurrent pores are scattered across the surface, more densely at the sides.
''I. strobilina'' inhabits marine waters, specifically those of the Caribbean Sea including off the coast of Florida, the Virgin Islands, and Cuba. It is found in warm, shallow water, anchored to a substrate. This species is the most abundant sponge in the Abrolhos reef, where it grows exposed to many predatory fishes. The predatory fishes avoid ''I. strobilina'', for reasons discussed below.
''I. strobilina'' has been found to have chemical defences against predation by fishes: when force-fed with it in a study of three sponge species, the fish ''Holacanthus tricolor'' was temporarily paralysed and exhibited a loss of balance. The chemicals involved in repelling predators have been extracted and identified as the metabolite and sesterterpene variabilin, and its isomer strobilin. The same study concluded that ''I. strobilina'' forms scar tissue over lesions more quickly than the other species studied, ''Neofibularia nolitangere'' and ''Agelas clathrodes''.
''I. strobilina'' inhabits marine waters, specifically those of the Caribbean Sea including off the coast of Florida, the Virgin Islands, and Cuba. It is found in warm, shallow water, anchored to a substrate. This species is the most abundant sponge in the Abrolhos reef, where it grows exposed to many predatory fishes. The predatory fishes avoid ''I. strobilina'', for reasons discussed below.
''I. strobilina'' has been found to have chemical defences against predation by fishes: when force-fed with it in a study of three sponge species, the fish ''Holacanthus tricolor'' was temporarily paralysed and exhibited a loss of balance. The chemicals involved in repelling predators have been extracted and identified as the metabolite and sesterterpene variabilin, and its isomer strobilin. The same study concluded that ''I. strobilina'' forms scar tissue over lesions more quickly than the other species studied, ''Neofibularia nolitangere'' and ''Agelas clathrodes''.