The undulate ray features a disc-shaped body, triangular in the front and near-circular in the rear, and dermal denticles developed as spines for protection. Median spines are scattered in adults, regular on young. The males have one lateral row each side, whereas the females have three.[2] The eyes are medium-sized and followed by spiracles. The mouth is on the ventral surface and is slightly arched, followed by the five pairs of small gill slits. Tail is as long as body, and has two well separated dorsal fins near its end, usually with two spines between them. The colouring of the dorsal surface varies from light brown to citrine or grey, with darker waved bands and numerous small white patches. Snout and margins are frequently clearer with dark spots.[3] The underside is creamy-white with a greyish margin. It typically weighs about 10 lb (4.5 kg), but can reach to as much as 22.13 lb (10.04 kg) and 100 cm (39 in) in length.[4]
Distribution and habitatedit
This species has a patchy and discontinuous distribution in northeastern Atlantic. It is found from southern Ireland and England to Senegal, and in the western Mediterranean. It is uncommon overall but can be locally abundant, mainly around the north-west of Ireland, in the eastern side of the English Channel, and near the south coast of Portugal.[5] It is also present sporadically across the northern Mediterranean Sea.[6] It is usually found on sandy, muddy or detrital bottoms, at depths of 50–200 m from coastal regions to the upper continental slope, even if it's sometimes possible to find it in shallower water.[7]
There are few data about biology of this species. Using vertebrae as growth markers, maximum lifespan was supposed to be 21–23 years.[8] It's an oviparous cartilaginous fish. The females lay their eggs from March to September.[9] Each egg is a leathery black eggcase with horny corners, known by the common name "mermaid's purse" (as are the eggcases of other rays, skates and sharks). They usually are 72– 90 mm long and 42– 52 mm wide. These "purses" often wash up on beaches after rough weather, although usually they wash up empty, the young ray having already hatched out.[10]
Like other benthonic species of similar size this ray is caught incidentally or intentionally by commercial fisheries using trawls, gillnets, and line gears.[5] It is a common host in public aquariums as fares relatively well.
Protectionedit
Because of its late sexual maturity and low rate of population growth, undulate ray is extremely vulnerable to exploitation by fisheries.[11] In the north Atlantic, populations have declined severely from the Irish area, and there are no longer records of catches of this species in the English Channel. Since 2009 it has been illegal to keep Undulate Rays fished in EU waters due to concerns over the decreasing size of stocks. They must be returned unharmed if possible.[12]
Reproductionedit
During a study it was found that the gonadosomatic index for the females was higher in the winter, which means that this specie reproduces during this season. Females also matured at significantly larger sized and older ages than males.[13]
Referencesedit
^ abcdCoelho, R.; Bertozzi, M.,Ungaro. N.; Ellis, J. (2009). "Raja undulata". IUCN Red List of Threatened Species. 2009: e.T161425A5420694. doi:10.2305/IUCN.UK.2009-2.RLTS.T161425A5420694.en. Retrieved 20 November 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ abHurst, Richard. "Undulate ray Raja undulata" (PDF). Shark Trust. Retrieved 4 January 2015.
^"Undulate ray (Raja undulata)". Marine Species Identification Portal. KeyToNature Project Consortium. Retrieved 4 January 2015.
^"Undulate Ray (RAJA UNDULATA)". the European Federation Of Sea Anglers. Retrieved 4 January 2015.
^ ab"Raja undulata Undulate Ray". Encyclopedia of Life. Retrieved 4 January 2015.
^Ellis JR, McCully SR, Brown MJ (April 2012). "An overview of the biology and status of undulate ray Raja undulata in the north-east Atlantic Ocean". J Fish Biol. 80 (5): 1057–74. doi:10.1111/j.1095-8649.2011.03211.x. PMID 22497373.
^Coelho R, et al. (September 2002). Fisheries Biology of the Undulate Ray, Raja undulata , in the Algarve ( Southern Portugal)(PDF). Northwest Atlantic Fisheries Organization Scientific council meeting. Retrieved 4 January 2015.
^"Skate and Ray Eggcase Identification Guide" (PDF). Marine Conservation Society. Retrieved 4 January 2015.
^Coelho R, Erzini K (October 2006). "Reproductive aspects of the undulate ray, Raja undulata, from the south coast of Portugal". Fisheries Research. 81 (1): 80–85. doi:10.1016/j.fishres.2006.05.017.
^Rossell, Robert. "Raja undulata – undulate ray". National Museums Northern Ireland. Retrieved 4 January 2015.
^Universidade do Algarve, Faculdade de Ciências do Mar e Ambiente/Centro de Ciências do Mar, Campus de Gambelas, 8000 Faro, Portugal
External linksedit
Wikimedia Commons has media related to Raja undulata.
Wikispecies has information related to Raja undulata.
Specimens of Raja undulata collected by scientific institutions
Genetic records of Raja undulata stored into scientific institutions
Photos of Undulate ray on Sealife Collection
April 14, 2024
undulate, undulate, raja, undulata, species, cartilaginous, fish, found, mediterranean, east, atlantic, from, southern, ireland, england, gulf, guinea, found, areas, with, sand, occur, deep, though, prefers, shallower, depths, considered, endangered, overfishi. The undulate ray Raja undulata is a species of ray and cartilaginous fish found in the Mediterranean and East Atlantic from southern Ireland and England to the Gulf of Guinea 1 It is found in areas with mud or sand and may occur as deep as 200 m 660 ft though it prefers shallower depths 1 It is considered endangered due to overfishing 1 Undulate rayConservation statusEndangered IUCN 3 1 1 Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass ChondrichthyesSubclass ElasmobranchiiSuperorder BatoideaOrder RajiformesFamily RajidaeGenus RajaSpecies R undulataBinomial nameRaja undulataLacepede 1802 Contents 1 Description 2 Distribution and habitat 3 Biology 4 Diet 5 Human interactions 6 Protection 7 Reproduction 8 References 9 External linksDescription editThe undulate ray features a disc shaped body triangular in the front and near circular in the rear and dermal denticles developed as spines for protection Median spines are scattered in adults regular on young The males have one lateral row each side whereas the females have three 2 The eyes are medium sized and followed by spiracles The mouth is on the ventral surface and is slightly arched followed by the five pairs of small gill slits Tail is as long as body and has two well separated dorsal fins near its end usually with two spines between them The colouring of the dorsal surface varies from light brown to citrine or grey with darker waved bands and numerous small white patches Snout and margins are frequently clearer with dark spots 3 The underside is creamy white with a greyish margin It typically weighs about 10 lb 4 5 kg but can reach to as much as 22 13 lb 10 04 kg and 100 cm 39 in in length 4 Distribution and habitat editThis species has a patchy and discontinuous distribution in northeastern Atlantic It is found from southern Ireland and England to Senegal and in the western Mediterranean It is uncommon overall but can be locally abundant mainly around the north west of Ireland in the eastern side of the English Channel and near the south coast of Portugal 5 It is also present sporadically across the northern Mediterranean Sea 6 It is usually found on sandy muddy or detrital bottoms at depths of 50 200 m from coastal regions to the upper continental slope even if it s sometimes possible to find it in shallower water 7 Biology edit nbsp Young Raja undulata at the Aquarium of GenoaThere are few data about biology of this species Using vertebrae as growth markers maximum lifespan was supposed to be 21 23 years 8 It s an oviparous cartilaginous fish The females lay their eggs from March to September 9 Each egg is a leathery black eggcase with horny corners known by the common name mermaid s purse as are the eggcases of other rays skates and sharks They usually are 72 90 mm long and 42 52 mm wide These purses often wash up on beaches after rough weather although usually they wash up empty the young ray having already hatched out 10 Diet editThe ray eats small fish crustaceans molluscs and other macrobenthos 2 Human interactions editLike other benthonic species of similar size this ray is caught incidentally or intentionally by commercial fisheries using trawls gillnets and line gears 5 It is a common host in public aquariums as fares relatively well Protection editBecause of its late sexual maturity and low rate of population growth undulate ray is extremely vulnerable to exploitation by fisheries 11 In the north Atlantic populations have declined severely from the Irish area and there are no longer records of catches of this species in the English Channel Since 2009 it has been illegal to keep Undulate Rays fished in EU waters due to concerns over the decreasing size of stocks They must be returned unharmed if possible 12 Reproduction editDuring a study it was found that the gonadosomatic index for the females was higher in the winter which means that this specie reproduces during this season Females also matured at significantly larger sized and older ages than males 13 References edit a b c d Coelho R Bertozzi M Ungaro N Ellis J 2009 Raja undulata IUCN Red List of Threatened Species 2009 e T161425A5420694 doi 10 2305 IUCN UK 2009 2 RLTS T161425A5420694 en Retrieved 20 November 2021 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint multiple names authors list link a b Hurst Richard Undulate ray Raja undulata PDF Shark Trust Retrieved 4 January 2015 Undulate ray Raja undulata Marine Species Identification Portal KeyToNature Project Consortium Retrieved 4 January 2015 Undulate Ray RAJA UNDULATA the European Federation Of Sea Anglers Retrieved 4 January 2015 a b Raja undulata Undulate Ray Encyclopedia of Life Retrieved 4 January 2015 Guide of Mediterranean Skates and Rays Raja undulata Oct 2022 Mendez L Bacquet A and F Briand http www ciesm org Guide skatesandrays raja undulata Ellis JR McCully SR Brown MJ April 2012 An overview of the biology and status of undulate ray Raja undulata in the north east Atlantic Ocean J Fish Biol 80 5 1057 74 doi 10 1111 j 1095 8649 2011 03211 x PMID 22497373 Coelho R et al September 2002 Fisheries Biology of the Undulate Ray Raja undulata in the Algarve Southern Portugal PDF Northwest Atlantic Fisheries Organization Scientific council meeting Retrieved 4 January 2015 Pollerspock Jurgen Raja undulata LACEPEDE 1802 www shark references com Retrieved 4 January 2015 Skate and Ray Eggcase Identification Guide PDF Marine Conservation Society Retrieved 4 January 2015 Coelho R Erzini K October 2006 Reproductive aspects of the undulate ray Raja undulata from the south coast of Portugal Fisheries Research 81 1 80 85 doi 10 1016 j fishres 2006 05 017 Rossell Robert Raja undulata undulate ray National Museums Northern Ireland Retrieved 4 January 2015 Universidade do Algarve Faculdade de Ciencias do Mar e Ambiente Centro de Ciencias do Mar Campus de Gambelas 8000 Faro PortugalExternal links edit nbsp Wikimedia Commons has media related to Raja undulata nbsp Wikispecies has information related to Raja undulata Raja undulata in Fishbase Specimens of Raja undulata collected by scientific institutions Genetic records of Raja undulata stored into scientific institutions Photos of Undulate ray on Sealife Collection Retrieved from https en wikipedia org w index php title Undulate ray amp oldid 1194543410, wikipedia, wiki, book, books, library,
