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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:
Sharks possess a heterocercal caudal fin in which the dorsal portion is usually noticeably larger than the ventral portion. This is because the shark's vertebral column extends into that dorsal portion, providing a greater surface area for muscle attachment.
It has three dorsal and two anal fins. Types of caudal fin: heterocercal (A), protocercal (B), homocercal (C), and diphycercal (D) Sharks possess a heterocercal caudal fin. The dorsal portion is usually larger than the ventral portion. The high performance [definition needed] bigeye tuna is equipped with a homocercal caudal fin, finlets and keels.
Named for their exceptionally long, thresher-like heterocercal tail or caudal fins (which can be as long as the total body length), thresher sharks are active predators; the tail is used as a weapon to stun prey. [12] [13] The thresher shark has a short head and a cone-shaped nose.
Their gill openings are short and their second dorsal fin, the fin located closer to the tail, is about twice the size of the first dorsal fin, which is located closer to the head. Like all shark species, they have heterocercal caudal fins, where the upper part is longer than the lower.
The spiny dogfish has dorsal fins, no anal fin, and white spot along its back. The caudal fin has asymmetrical lobes, forming a heterocercal tail. The species name acanthias refers to the shark's two spines. These are used defensively. If captured, the shark can arch its back to pierce its captor with spines near the dorsal fins that secrete a ...
The shark has two dorsal fins set relatively far back on the body, a pair of pectoral fins, a pair of pelvic fins and a single medial anal fin. The caudal fin has a larger upper lobe than the lower lobe (heterocercal). Whale sharks have been found to possess dermal denticles on the surface of their eyeballs that are structured differently from ...
The caudal fin is elongated with a long upper lobe (i.e. strongly heterocercal). They have two large, broad-based grey dorsal fins set back beyond the pectoral fins. [2] The sand tiger shark has a grey-brown back and pale underside. Adults tend to have reddish-brown spots scattered, mostly on the hind part of the body. [6]