21st October 2022:
Friday Fun Fact Faction: 3 shark facts!
• Sharks don't have bones! Their skeletons are made up of cartilage, this helps them float easier and swim faster as they are much lighter. Despite not being bone these skeletons can still be fossilised much like human teeth can be (teeth are not made of cartilage though). Other sea creatures share this feature with sharks, for example rays and sawfish.
• The two biggest species of shark in the world (the basking shark and the whale shark) are both filter feeders! Despite their massive size (up to 8 meters and 10 meters long respectively) they do not hunt, instead they swim slowly with their mouths agape capturing microplankton or "inhale" a large cloud of plankton at once. The water in their mouths is then filtered past large gill rakers (which prevent food from escaping) and through their large gills.
• Most sharks have eight fins but some may have less! These consist of two pectoral fins, two pelvic fins, two dorsal fins, a caudal fin, and an anal fin. Though an order of sharks exists known as "hexanchiformes", they are primitive sharks and therefore have some undeveloped features such as having only one dorsal fin resulting in a total of seven fins. There are only seven extant (currently existing) species of hexanchiformes because of this, in this list are the frilled shark and the cow shark.
