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What Are Stingrays?

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Reproduction Mating season usually occurs during the winter. During the breeding seasons, males of various stingrays use their “ampullae of lorenzini” to sense certain electrical signals given off by other female counterparts before potential copulation. When the female is found within site, the male courts the female until he is able to bite at her pectoral disc (pre-copulatory biting). In this process the male bites off the female’s pectoral fins and in process, replaces one of his two claspers into her valve or cloaca. The clasper then transfers the sperm into the female’s oviduct where the egg is fertilized until the birth of the babies. All female Stingrays are internal fertilizers and therefore undergo a process called ovoviviparity. …show more content…

This includes all 800 species of rays, skates, sharks and chimaeras (Katie Birkett, 2014). Based on fossil remains, it has been known that this class of fish have been around since the Paleozoic period (approximately 250 million years ago), however theories have accumulated that the adaption of the flattered bodies (alike stingrays) had only occurred around 100 million years ago (approximately around the Lower Jurassic Period). Before the stingray’s existence, stingrays had in fact been evolved from sharks. This process took nearly 150 to 250 million years to complete for the first ever rays came upon this earth and also the reason why stingrays and sharks share a common ancestor within elasmobranch fishes. As this occurred, the development of their body shape and the loss of body area enabled early rays to hide and camouflage very discreetly against predators and to its pray. In addition, the process of their evolution introduced a new convergent evolution adding the additional venom stingers we all see in stingrays today and altering the way they reproduction from laying eggs to live birth. Currently there are two types of stingrays: ones in the family dasyatidae (stingrays) and ones in the family potamotrygonidae (river

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