Black tunicate / Sea SquirtPhallusia nigra
Sea Squirts are another name for the members of the class tunicate . While some tunicate s are "Threatened species", like this one, other species are exploding in population and causing problems. Sea Squirts are thought to be a precursor to the human heart! According to 'Science Daily" Scientists are working to develop better diagnostics and therapies to manage heart defects in newborns. An obscure filter-feeding sea animal holds the promise of helping them unravel the complex mechanisms underlying heart formation and develop new diagnostics for congenital heart defects. Black tunicate s are found in the mangroves, on wall faces, in between rocks and just about any where else and in water as shallow as a couple of feet. They are the largest tunicate of all the ones I've photographed snorkeling in St. John waters. The tallest siphon (incurrent) may be 2 inches tall.