Hadromerids are one of only a couple of marine sponge groups with a lifestage (a gemmule) that can go dormant during rough conditions. A gemmule is produced asexually (without sexual reproduction). The sponge makes a bunch of cells on a stalk (like an undersea flower bud). These buds then break off and may float around for a bit before settling on the sea bottom. The gemmule is packed with some extra nutrients, and its compact, enclosed structure means a gemmule might survive where an adult sponge would not. When conditions are favorable, gemmules anchor on the substrate and grow into new sponges. The gemmules of a hadromerid sponge may survive cold or other stresses such as damage to the reef it lives on.

With the exception of one group of carnivorous sponges, all sponges are filter-feeders. The design of their bodies is mostly about filtering food, and does not include a mouth or stomach. A sponge body is basically a tube or sack with lots of small pores (ostia) for water to come in and other, larger pores (oscula) for water to get out. What happens in between varies. In the simplest sponge bodies, the water enters the ostia pores and then dumps into a large, central area called the atrium. The most complex sponge bodies have a whole system of canals leading to smaller chambers where water gets filtered. In any case, the filtering is done by little hair-like flagella that trap bacteria and tiny ocean organisms (plankton) before the water gets expelled from the sponge. Sponge wastewater may be flushed out forcefully enough to travel 10 feet.