Common sea sponge cleans up
The old Boca Grande railroad runs along the north end of Gasparilla Island over a shallow sandbar that is a popular hangout for boaters and paddlers. It is also where I take my guests on eco-tours, because the shallow waters are a perfect place to get out of the kayaks and look for different marine species.
Some species pass through, and some get washed up and stranded from currents created by wind and tide exchanges. Because it is growing popular as a hangout, it is also common to find lots of trash – from sunglasses and shoes to beer cans, coolers and anything else that people lose.
In early January, the skies were gray. It was pretty chilly, with an incoming tide and a bit of a breeze blowing that made the water a little cloudy, but still shallow enough for my guest and I to do some exploring.
While we were walking back to the kayaks, I noticed something bright red close to the tracks. Assuming it was trash because of its vibrant color, I walked over to pick it up. When I got up close, I noticed that it was not trash, but rather a red-bearded sponge. Sponges are a very common find, but most that I find here in our estuary are yellow, orange or grayish in color. Even the red-bearded sponges I find are more of an orange color.
Clathria prolifera, the red-bearded sponge, is of the demosponge species in the family microcionidae and is common in the shallow waters of Florida, as well as other shallow areas of the western Atlantic from Prince Edward Island to Mexico.
As plankton, they swim around the sea for about three days before they begin to show settling behavior. When they are about to settle, the larvae will have a two- to three-hour period in which they switch between floating and swimming before finally attaching to a hard substate where they begin to grow into an adult sponge.
Adult red-bearded sponges will have thick, intertwining branches in shades of red to orange, and they will grow to be 8 inches tall and 12 inches wide. Because sponges are sessile animals (meaning that they live their life stuck to substrates such as oysters, rocks and anything else hard on the shallow sea floor), by the time most people see them they have been broken off by wind, current or a predator. They are not consumed by a lot of marine life, but a few species that do like to snack on them are sea stars, sea slugs and turtles.
Red-bearded sponges may be simple animals, but they are a very important part of our marine ecosystems, aside from being food. They are filter feeders that help with regulating the exchange of energy, mass and nutrients between habitats. They also support diverse seafloor communities by transforming carbon, while serving as a structural habitat that provides fish and crustaceans with shelter from predators.
The red-bearded sponge also holds an important place in modern medical science. This spong could help determine why organs are rejected in humans, according to research out of the University of Barcelona. The red-bearded sponge has a cell-to-cell recognition system that, on a basic level, is similar to that of humans but much simpler.
While it might be tempting in our shallow estuary, never take one of these red- bearded sponges home to clean and to use as a sponge for your skin. This is not the species for that, as you will end up with a nasty case of dermatitis.
