Search results
Results from the WOW.Com Content Network
Fins allow the sharks to be able to guide and lift themselves. Most sharks have eight fins: a pair of pectoral fins, a pair of pelvic fins, two dorsal fins, an anal fin, and a caudal fin. Pectoral fins are stiff, which enables downward movement, lift, and guidance. The members of the order Hexanchiformes have only a single
Dorsal fin of a shark. A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom.Many species of animals possessing dorsal fins are not particularly closely related to each other, though through convergent evolution they have independently evolved external superficial fish-like body plans adapted to their marine environments ...
External anatomy of a bony fish (Hector's lanternfish): 1. operculum (gill cover), 2. lateral line, 3. dorsal fin, 4. adipose fin, 5. caudal peduncle, 6. caudal fin, 7. anal fin, 8. photophores, 9. pelvic fins (paired), 10. pectoral fins (paired) Internal anatomy of a bony fish. Fish anatomy is the study of the form or morphology of fish.
In the 1990s, the sharks of the species from the same area averaged only 56.1 kg (124 lb). [11] The species is grey-bronze dorsally and white ventrally. [6] As its name suggests, most of its fins (dorsal, pectoral, pelvic and caudal) have white tips. Along with white tips, the fins may be mottled, and young specimens can have black marks.
Vision is an important sensory system for most species of fish. Fish eyes are similar to those of terrestrial vertebrates like birds and mammals, but have a more spherical lens. Their retinas generally have both rod cells and cone cells (for scotopic and photopic vision), and most species have colour vision.
The first dorsal fin is positioned closer to the pelvic than the pectoral fins. The second dorsal fin, nearly equal to the first in size, is located over or slightly forward of the anal fin. No ridge is seen between the dorsal fins. The pectoral fins are long and broad, originating below the space between the third and fourth gill slits.
Carcharhiniformes / kɑːrkəˈraɪnɪfɔːrmiːz /, the ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and requiem sharks. Members of this order are characterized by the presence of a nictitating membrane over the eye, two dorsal fins, an anal fin ...
The second dorsal fin is relatively large and originates over the anal fin. No ridge runs between the dorsal fins. The pectoral fins are small and sickle-shaped, with pointed tips. [2] The dermal denticles are small and overlapping, each bearing three horizontal ridges leading to marginal teeth. Living finetooth sharks are a distinctive dark ...