Wednesday, August 25, 2010
August 25, 2010 : Sea Robin
Sea robins, also known as gurnard, are bottom-feeding scorpaeniform fishes in the family Triglidae. They get their name from their large pectoral fins, which, when swimming, open and close like a bird's wings in flight.
They are bottom dwelling fish, living at depths of up to 200 m (660 ft). Most species are around 30 to 40 cm (12 to 16 in) in length. They have an unusually solid skull, and many species also possess armored plates on the body. Another distinctive feature is the presence of a "drumming muscle" that makes sounds by beating against the swim bladder. When caught, they make a croaking noise similar to a frog.
Sea robins have six spiny "legs," three on each side. These legs are actually flexible spines that were once part of the pectoral fin. Over time, the spines separated themselves from the rest of the fin, developing into feeler-like "forelegs." The pelvic fins have been thought to let the fish "walk" on the bottom, but are really used to stir up food. The first three rays of the pectoral fins are membrane free and used for chemoreception.
Sea robins have sharp spines on their gill plates and dorsal fins that inject a mild poison, causing slight pain for two to three days.