Species group: Sponges
Other common names: Elephant Ear Sponge
Scientific name: Halichondria japonica
The Beadcrumb Sponge is not recommended for novices, but has done well for aquarists experienced in the care of delicate filter-feeders.
The Breadcrumb Sponge is found in the coastal waters of Korea and Japan, where it lives on rocks in the inter-tidal zone.
Appearance / health:
The Breadcrumb Sponge is a rock-encrusting species, taking on the size and shape of its anchoring site. The thick, dense body is red, orange, yellow or tan in color.
Exposure to air, inadequate lighting, starvation, and a lack of suitably-strong currents are the most common causes of sponge deaths. Air trapped within the cells prevents food and oxygen from circulating, while low light levels inhibit the growth of symbiotic algae and bacteria.
Behavior / temperament:
Sponges are stationary and feed continuously by filtering water through their bodies.
They are aggressive towards one another, corals, anemones and other sessile invertebrates, and may poison fish which attempt to eat them.
The Breadcrumb Sponge requires moderately-strong lighting so that the symbiotic algae and bacteria which provide it with important nutrients can thrive. The water should be well-oxygenated, ammonia and nitrite-free, and in the range of 22-23.8 C (72-75 F). It is critical that Sponges be positioned such that they receive indirect flow from moderate to strong water currents. The aquarium should be provisioned with live sand and live rock, which will provide supplementary food in the form of micro-organisms.
The following water quality parameters should be maintained in order to assure long-term health: Specific Gravity (Salinity): 1.023-1.025; pH: 8.1-8.4; Alkalinity 8-12 dKH.
In addition to the nutrients provided by symbiotic algae and bacteria, Breadcrumb Sponges require daily feedings of commercial liquid plankton preparations…products that provide the smallest particle size should be selected. Important supplements include calcium, magnesium and marine trace elements.
Reproduction in the aquarium, if it occurs, will most often be by asexual budding. Free-living Sponges can also reproduce sexually.
Written by Frank Indiviglio