heterocercal การใช้

• The caudal fin is heterocercal, but approaches a functional homocercal condition.
• Most Palaeozoic fishes had a diphycercal heterocercal tail.
• One of the primary characteristics present in most sharks is the heterocercal tail, which aids in locomotion.
• In sharks, the heterocercal tail shape drives water downward, creating a counteracting upward force while thrusting the shark forward.
• During the initial stages of development from embryo to fry, paddlefish have no heterocercal tail, and small poorly developed eyes.
• The common smooth-hound has two dorsal fins, an anal fin, a pair of pectoral fins, a pair of pelvic fins and a heterocercal tail.
• Some of their primitive characteristics include a skeleton composed primarily of cartilage, and a deeply forked heterocercal caudal fin similar to that of sharks, although they are not closely related.
• The dorsal and anal fins are supposed to be near the caudal fin, and the caudal fin itself heterocercal, with the upper lobe narrow, the lower lobe rounded and " three times as wide as the upper blade " whatever that means.
• Like many antiarchs, " B . canadensis " also had narrow pectoral fins, a heterocercal caudal fin ( meaning the notochord extends into the upper lobe of the caudal tail ) and a large dorsal fin which likely didn t play an important role in propulsion but instead acted more as a stabilizer
• Bowfin are often referred to as " living fossils ", or " primitive fishes " because they retained some of the primitive characters common to their ancestral predecessors, including a modified ( rounded externally ) heterocercal caudal fin, a highly vascularized gas bladder lung, vestiges of a spiral valve, and a bony gular plate.