Are sponges plants or animals?
Until the late 1800's, sponges were considered "animalplants" (zoophytes). more advanced methods of microscopy revealed however that sponges have the cell structure and reproduction of typical animals and cholorophyll pigments found in many species belong to symbiotic (associated) plants (e.g., dinoflagellate zooxanthellae) or photosynthetic bacteria (cyanobacteria)
How many species of sponges are there?
Approximately 10,000 sponge names are recorded in the literature but not all represent distinct species and some species have been named more than once. Scientists estimate that about 6,000 species names are valid. Because new species are found during most new surveys it has been estimated (from the rate of discovery by area) that nearly 10,000 species of sponges actually exist, circa 4,000 yet to be discovered and described.
Are sponges colonies?
Each sponge is an integrated organism bound by a simple cell layer (pinacoderm); it should be referred to as an individual. Larvae produced by one parent sponge may fuse into one organism but larvae from different parents develop into distinct individuals even if they settled in close vicinity.
Can you use a sponge for bathing right out of the ocean?
No. There are about half a dozen species of commercial (bath) sponges (of some 6,000 sponge species known) and they belong to one family (Spongiidae). This family is distinguished by a very dense and elastic skeleton of a proteinic substance called spongin, and there are no mineral component (siliceous or calcareous spicules) as in most other sponges. In the sea the live bath sponge appears blackish in color resulting from a pigmented outer cell layer, the pinacoderm. The cellular "tissue" (all living cells needed for a functioning and reproducing sponge) is suspended among the spongin network. Sponge fishermen macerate the freshly collected animal by squeezing and kneading it in buckets of water. The remaining elastic skeleton is decalcified in mild acid (to eliminate incorporated sand grains), then rinsed and often bleached to eliminate "rusty" color caused by an iron mineral.Staff | History | Research & Collections | IZ FAQs | Newsletters | Scientific Visits | Home