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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:
A second, shorter pair of keels are present below the main keels. The caudal fin is large and crescent-shaped, with the lower lobe almost as long as the upper; both dorsal and ventral depressions (precaudal pits) are at the caudal fin base, and a deep ventral notch is near the tip of the upper caudal fin lobe. [7]
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 is characteristic of threshers, measuring about as long as the rest of the shark; the thin, gently curving lobe is held at a steep upward angle and has a notch in the trailing margin near ...
Chondrichthye (cartilaginous fish) – jawed fish with paired fins, paired nares, scales, two-chambered hearts, and skeletons made of cartilage rather than bone. Elasmobranch – member of the subclass Elasmobranchii, which includes sharks, rays, and skates. Predator – organism that attacks and feeds on prey (the organism that is attacked). [2]
The anal fin is low and positioned just in front of the caudal fin. The caudal fin has only an upper lobe, which contains a prominent ventral notch near the tip and is angled almost horizontally relative to the body. Adult epaulette sharks are beige to brownish above with many widely spaced brown spots and subtle darker bands.
An example of a Rhinopristiform, the guitarfish relies on undulation of its caudal fin for propulsion Rhinopristiformes are an intermediate group between sharks and rays. There has been little study into their swimming characteristics but it can be assumed from their morphological similarity to sharks that they rely primarily on body caudal fin ...
The second dorsal fin is positioned opposite the anal fin and is relatively large and high. There is no ridge between the dorsal fins. A crescent-shaped notch is present on the caudal peduncle just before the upper caudal fin origin. The caudal fin is asymmetrical, with a strong lower lobe and a longer upper lobe with a ventral notch near the tip.
The bones to which the pectoral fin is attached. peduncle Usually referred to as the caudal peduncle, the region of the body between the end of the anal fin and the base of the caudal fin. pelagic Living on or in the open seas. pelvic girdle The bones to which the ventral fins are attached. pelvic fins Paired fins behind or below the pectoral fins.