Which are the most suitable sponges?
Those aquariophiles who have already tried to keep in their tanks those bigger sized sponges available on the market, often have the impression that these organisms may represent an almost unsustainable animal group. For many sponges this can effectively be true, particularly if, during yield, transport and maintenance, they have been treated in a wrong way. Sponges, for example, shall never be extracted from water, since in this case air could actually infiltrate the canals and the internal chambers. It is then very difficult for the sponge to get rid of this air by forcing it towards the outside and the tissue area in question usually ends up degenerating. Those sponges evidencing pale areas should not be purchased. It should also be considered that bigger sized sponges have a naturally pronounced necessity of dissolved organic substances, bacteria and phytoplankton. Without a spot-on supplementary administration of ailment, these sponges can only be fed in aquariums with a certain organic charge, and with n0 skimming in place. Those who would like to employ sponges in aquariums as living filters, should be better off using the smallest specimens. These kinds of sponges are way less susceptible to transport they are also found as clandestine on the coral’s rocky sublayer. Furthermore, these sponges are usually transported underwater and cannot get dry. It is then more promising for the aquariophile to “sow” these small sponges in the reef tank. In the USA my company already commercializes and ships these sponge packs for the “sowing” of many species, as natural filters for a reef tank. Many small sponge species develop nicely in the aquarium, and are able to grow in a surprisingly quick manner. If an aquarium has matured for over a year, then sponges will also develop in crepuscular spots between decorative rocks. Many surprised aquariophiles have reported to me of many sponges that they found in their aquariums under or behind rocks. The best solution would be to search for them with a pocket lamp, illuminating between rocks.
To this purpose, however, it is necessary to scan deeply in the rocky construction. In any case, even in maintenance tanks for living rocks belonging to many specialized dealers, it can be possible to find many of these sponges. The best result can be obtained if a little deeper “digging” is operated in said containers, reaching those rocks which have stationed there for a longer time and with their covering organisms well reestablished. It is often necessary to scan thoroughly, but it is definitely possible to also find pieces who have developed healthy sponges on top of them. If the objective is filtration in the aquarium through the use of living sponges, then the best solution would be the use of a great number of small specimens of different species. With such a specific variety, there will be notable chances of making it through difficult phases with diseases or sponge predators, in regards to what would happen with the use of only one species and probably with a few big individuals too. In the range of five years I have been able, using this method, to obtain an effective sponge filtering in ten different reef aquariums, and I never experienced problems related to diseases or sponge predation damage. A healthy and species rich population is very helpful, to recreate in the aquarium the natural regulation cycle of the coral reef. Over the last few years the offering of dried or frozen phytoplankton for feeding of aquarium animals has sensibly improved, and said nourishment can prove itself as extremely useful for lively sponges. In tropical reefs, sponges are the dominant group in phytoplankton users, and they capture said vegetable organisms in the water very effectively. Anyway, for an aquarium administration it is preferable to use living phytoplankton, because the inert kind (frozen or lyophilized) can, in case of excessive distribution, accumulate in the tank more quickly.