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Pelvic fin of a Java barb, a ray-finned fish The short fin spines on a coelacanth, a lobe-finned fish A lionfish, with venomous spines The stinger on a stingray's tail. Spines are found in the fins of most bony fishes, particularly actinopterygians (ray-finned fishes), who have folding fan-like fin made of spreading bony spines called lepidotrichia or "rays" covered by thin stretches of skin.
Sea urchin injuries are puncture wounds inflicted by the animal's brittle, fragile spines. [59] These are a common source of injury to ocean swimmers, especially along coastal surfaces where coral with stationary sea urchins are present. Their stings vary in severity depending on the species. Their spines can be venomous or cause infection.
Unlike other Cambrian animals, these groups had the basic vertebrate body plan: a notochord, rudimentary vertebrae, and a well-defined head and tail, but lacked jaws. [29] A vertebrate group of uncertain phylogeny, small eel-like conodonts , are known from microfossils of their paired tooth segments from the late Cambrian to the end of the ...
The word porcupine comes from the Latin porcus ' pig ' + spina ' spine, quill ', from Old Italian porcospino, ' thorn-pig '. [4] [5] A regional American name for the animal is quill-pig. [6] A baby porcupine is a porcupette. When born, a porcupette's quills are soft hair; they harden within a few days, forming the sharp quills of adults. [7]
This is called "quilling". Spines can also shed when the animal is diseased or under extreme stress. Hedgehogs are usually brown, with pale tips to the spines, though blonde hedgehogs are found on the Channel Island of Alderney. A skin-skeletal preparation Close-up of the last 5 millimetres (0.20 in) of a hedgehog spine (SEM microscopy) A ...
They are the only known living animals that have a skull but no vertebral column. Lampreys form a superclass containing 38 known extant species of jawless fish . [ 3 ] The adult lamprey is characterized by a toothed, funnel-like sucking mouth.
They were living inside cavities within the Earth's crust at an ocean-floor site where the Pacific is 1.56 miles (2,515 meters) deep. All the species were previously known to have lived near such ...
Hatching takes place after 10 days of gestation; the young echidna, called a puggle, [23] [24] born larval and fetus-like, then sucks milk from the pores of the two milk patches (monotremes have no teats) and remains in the pouch for 45 to 55 days, [25] at which time it starts to develop spines. The mother digs a nursery burrow and deposits the ...