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Spiracle of a bluespotted ribbontail ray, Taeniura lymma. Spiracles (/ ˈ s p ɪr ə k əl, ˈ s p aɪ-/ [1] [2]) are openings on the surface of some animals, which usually lead to respiratory systems. Spiracle of a shark (bighead spurdog, Squalus bucephalus) The spiracle is a small hole behind each eye that opens to the mouth in some fish.
Shark Anatomy (50693674756) The gill slits of a whale shark flaring as it expels water from its pharyngeal cavity. In the shark anatomy image, it depicts the beginning half of the shark, including the gills. The shark gills are especially important and were evolved from the chordate pharyngeal gill slits synapomorphy.
Shark gill slits lie in a row behind the head. The anterior edge of a gill slit is motile, moving outward to allow water to exit, but closing to prevent reverse flow. A modified slit, called a spiracle , lies just behind the eye , which assists the shark with taking in water during respiration and plays a major role in bottom–dwelling sharks.
The shark is able to breathe with these gills by swimming or staying in a current. The Pacific spiny dogfish also has a special feature called a spiracle. These are gills that are behind the eyes of the shark that give oxygen to the eyes and brain. It is also used to breathe while resting or eating. [20]
A spiracle is a small hole found behind each eye. These can be tiny and circular, such as found on the nurse shark (Ginglymostoma cirratum), to extended and slit-like, such as found on the wobbegongs (Orectolobidae). Many larger, pelagic species, such as the mackerel sharks (Lamnidae) and the thresher sharks (Alopiidae), no longer possess them.
The spiral valve of a nurse shark (Ginglymostoma cirratum).. A spiral valve or scroll valve is the corkscrew-shaped lower portion of the intestine of some sharks, Acipenseriformes (sturgeon and paddlefish), rays, skates, bichirs, Lepisosteiformes (gars), and lungfishes.
Here are some facts about the top shark attack countries in the world to get you ready for Shark Week: 1. South Africa Since 1905, there have been 239 confirmed shark attacks in South Africa. 53 ...
Batoid gill slits lie under the pectoral fins on the underside, whereas a shark's are on the sides of the head. Most batoids have a flat, disk-like body, with the exception of the guitarfishes and sawfishes, while most sharks have a spindle-shaped body. Many species of batoid have developed their pectoral fins into broad flat wing-like appendages.