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The tail of a shark consists of the caudal peduncle and the caudal fin, which provide the main source of thrust for the shark. Most sharks have heterocercal caudal fins, meaning that the backbone extends into the (usually longer) upper lobe. The shape of the caudal fin reflects the shark's lifestyle, and can be broadly divided into five categories:
• Measuring a shark's total length can be challenging due to the natural angle at which the caudal lobes are positioned relative to the rest of the shark's body. Some reports calculate the total length by adding the caudal fin to the pre-caudal length, or by stretching the caudal fin to the maximum possible (sometimes referred to as stretched ...
For example, the whale shark reported by Kaikini et al. (1959) was reported at 12.1 m in total length, the precaudal length was reported at 9.84 m, and the upper caudal fin was 2.31 m. Reaching the reported total length of 12.1 m would require the upper caudal fin to be illustrated at a very shallow angle.
The pelvic fins are almost as large as the first dorsal fin and bear long, thin claspers in males. The second dorsal and anal fins are tiny, with the former positioned ahead of the latter. Crescent-shaped notches occur on the caudal peduncle at the upper and lower origins of the caudal fin. The upper caudal fin lobe is enormously elongated as ...
Caudal/Tail fins: Also called the tail fins, caudal fins are attached to the end of the caudal peduncle and used for propulsion. The caudal peduncle is the narrow part of the fish's body. The hypural joint is the joint between the caudal fin and the last of the vertebrae. The hypural is often fan-shaped.
Behind the pelvic fins, the body rapidly tapers to the short caudal peduncle. The anal fin originates behind the midpoint of the second dorsal fin and is no more than half its size. The caudal fin is short, with no lower lobe and an upper lobe bearing a strong ventral notch near the tip.
A shark, also called a "selachimorph", can be described as all of the following: Animal – multicellular, eukaryotic organism of the kingdom Animalia or Metazoa. An animal's body plan eventually becomes fixed as it develops, although some types of animal undergo a process of metamorphosis later on in their life.
The second dorsal and anal fins are minute. The caudal peduncle has a few or less distinct keels. The teeth are gigantic. The fifth gill opening is in front of the pectoral fin and spiracles are sometimes absent. They are heavily built sharks, sometimes weighing nearly twice as much as sharks of comparable length from other families.