The Caribbean reef shark was originally described from off the coast of Cuba as Platypodon perezi by Poey in 1876. Bigelow and Schroeder later described the same species as Carcharhinus springeri in 1944 and the reef shark appears in much literature under this scientific name. The genus name Carcharhinus is derived from the Greek “karcharos” = sharpen and “rhinos” = nose. The currently accepted valid name is C. perezi (Poey 1876).
Cyanobacteria do not have skeletons and individuals are microscopic. Cyanobacteria can encourage the precipitation or accumulation of calcium carbonate to produce distinct sediment bodies in composition that have relief on the seafloor. Cyanobacterial mounds were most abundant before the evolution of shelly macroscopic organisms, but they still exist today (stromatolites are microbial mounds with a laminated internal structure). Bryozoans and crinoids, common contributors to marine sediments during the Mississippian (for example), produced a very different kind of mound. Bryozoans are small and the skeletons of crinoids disintegrate. However, bryozoan and crinoid meadows can persist over time and produce compositionally distinct bodies of sediment with depositional relief.
While scientists are still trying to determine exactly how many of theses species exist, we do know that many of these sharks lose their lives from getting caught in fishing nets. Not only does it significantly reduce their population, it compromises the fragile ecosystem around coral reefs. Many new laws and regulations are being put into place to protect this ever important fish.
A reef is a bar of rock, sand, coral or similar material, lying beneath the surface of water. Many reefs result from abiotic processes (i.e. deposition of sand, wave erosion planing down rock outcrops, and other natural processes), but the best known reefs are the coral reefs of tropical waters developed through biotic processes dominated by corals and coralline algae.