Sharks and rays are usually easy to tell apart. Usually. By and large, sharks are *roughly* cylindrical in cross section, have tall dorsal fins and caudal fins (tails), have pectoral fins separated from their heads and have gill slits on the sides of their bodies, whereas rays usually have flattened bodies, reduced dorsal and caudal fins, have pectoral fins continuous with their heads and have gill slits on the underside of their body. This animal is actually a ray -- a kind of guitarfish called a shark ray (Rhina ancylostoma) -- but morphologically resembles a shark in several respects (although it does satisfy the last two criteria regarding the pectoral fins and position of gill slits). It demonstrates that Chondrichthyans are incredibly diverse creatures, even if we do not consider their spectacularly diverse extinct representatives. oceanwideimages/images/13831/large/shark-ray-43M2740-15.jpg
Posted on: Mon, 09 Jun 2014 07:29:05 +0000
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