The Atlantic spotted dolphin (Stenella frontalis) is a dolphin found in warm temperate and tropical waters of the Atlantic Ocean. Older members of the species have a very distinctive spotted coloration all over their bodies.
The Atlantic spotted dolphin was first described by Cuvier in 1828. Considerable variation in the physical form of individuals occurs in the species, and specialists have long been uncertain as to the correct taxonomic classification. Currently, just one species is recognised, but a large, particularly spotty variant commonly found near Florida quite possibly may be classified as a formal subspecies or indeed a species in its own right.
Atlantic spotted dolphins in the Bahamas have been observed mating with bottlenose dolphins.[4] Rich LeDuc has published data that suggest the Atlantic spotted dolphin may be more closely related to the bottlenose dolphins (genus Tursiops) than to other members of the genus Stenella.[4] More recent studies in the 2020's indicate that this is a consequence of reticulate evolution (such as past hybridization between Stenella (spotted dolphins) and ancestral Tursiops (bottlenose dolphins)) and incomplete lineage sorting, and thus support T. truncatus and T. aduncus belonging to the same genus. This likely explains why Atlantic spotted dolphins can mate with both species of bottlenose dolphins.[5]
Description
Stenella frontalis, La GomeraNear South Caicos, Turks and Caicos IslandsA juvenile swimming in the blue water
The coloring of the Atlantic spotted dolphin varies enormously as it grows, and is usually classified into age-dependent phases known as two-tone, speckled, mottled, and fused. Calves are a fairly uniform gray-white, with one or no spots. When they are weaned, speckling occurs, typically between 3 and 4 years and lasting for an average of 5 years. A juvenile is considered mottled when it develops merging gray and white spots on the dorsal surface and black spots on the ventral surface. This usually happens between age 8 or 9. A fused pattern is reached when dark and white spots are on both the ventral and dorsal sides. As the animal matures, the spots become denser and spread until the body appears black with white spots at full maturation.[6]
In comparison to other dolphin species, the Atlantic spotted dolphin is medium-sized. Newborn calves are about 35–43 in (89–109 cm) long, while adults can reach a length of 2.26 m (7 ft 5 in) and a weight of 140 kg (310 lb) in males, and 2.29 m (7 ft 6 in) and 130 kg (290 lb) in females. Compared to the much smaller pantropical spotted dolphin, the Atlantic spotted dolphin is more robust. It shares its habitat with the pantropical spotted dolphin and the bottlenose dolphin.
The species exhibits a range of about ten different vocalizations, including whistles, buzzes, squawks and barks, each corresponding with different behaviors.[7]
Behavior
Atlantic spotted dolphins are extremely gregarious animals, which gather in complex social groups of 5-15, often in mixed groups with common bottlenose dolphins. They are fast swimmers and known for their bow-riding and long, shallow leaping behaviors. Their mating system consists of one male mating with several females, and the pod is highly protective over pregnant females. The dolphin’s gestational period is ~11 months, and the mother cares for its calf for up to 5 years, with the help of the rest of her group.[8]
These animals are cooperative hunters that hunt in groups at night. They strategically encircle their prey, which consists mostly of small fish, benthic invertebrates, and cephalopods such as squid. They can dive to depths of up to 60 m (200 ft) and can stay beneath the surface for up to 10 minutes at a time.[citation needed] When showing aggression towards other species, these dolphins make use of more contact behaviors such as biting and chasing than when being aggressive towards members of their species, in which they usually rely on display behaviors. [9]
Population and distribution
The species is endemic to the temperate and tropical areas of the Atlantic Ocean. It has been widely observed in the western end of the Gulf Stream, between Florida and Bermuda. Off the Bahamas, tourism industries to swim with dolphins are available.[10] It is also present in the Gulf of Mexico. More infrequent sightings have been made further east, off the Azores and Canary Islands. Northerly sightings have been made as far north as Cape Cod across to the southwestern tip of Spain. They are certainly present further south, too, as far as Rio Grande do Sul in Brazil and across to west Africa, but their distribution is poorly understood in these areas.
About 20 years ago, only about 80 dolphins were in the Bahamas. Now, almost 200 dolphins are found there. On account of their similar appearance to other dolphins in their range, it is difficult to be sure of the Atlantic spotted dolphin's population. A conservative estimate is around 100,000 individuals.[citation needed]
Human interaction
Some Atlantic spotted dolphins, particularly some of those are around the Bahamas, have become habituated to human contact. In these areas, cruises to watch and even swim with the dolphins are common. They are usually not held in captivity.
Atlantic spotted dolphins are an occasional target of harpoon fishermen, and every year some creatures are trapped and killed in gill nets, but these activities are not currently believed to be threatening the survival of the species. This species lives in the mesopelagic layer of the ocean. These dolphins are not threatened by extinction, however, commercial trade may affect their evolution and sustainability. Sometimes they are killed by harpoons off St. Vincent.
Conservation
The Atlantic spotted dolphin is included in the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia.[11] They are also marked as Least Concern of the Conservation Action Plan for the World's Cetaceans.[12]
^Mead, J. G.; Brownell, R. L. Jr. (2005). "Order Cetacea". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 723–743. ISBN978-0-8018-8221-0. OCLC 62265494.
^Braulik, G.; Jefferson, T.A. (2018). "Stenella frontalis". IUCN Red List of Threatened Species. 2018: e.T20732A50375312. doi:10.2305/IUCN.UK.2018-2.RLTS.T20732A50375312.en. Retrieved 18 November 2021.
^ abHerzing, D. (2011). Dolphin Diaries: My 25 Years with Spotted Dolphins in the Bahamas. Macmillan. pp. 132–147. ISBN978-0-312-60896-5.
^Moura, Andre E.; Shreves, Kypher; Pilot, Małgorzata; Andrews, Kimberly R.; Moore, Daniel M.; Kishida, Takushi; Möller, Luciana; Natoli, Ada; Gaspari, Stefania; McGowen, Michael; Chen, Ing; Gray, Howard; Gore, Mauvis; Culloch, Ross M.; Kiani, Muhammad S.; Willson, Maia Sarrouf; Bulushi, Asma; Collins, Tim; Baldwin, Robert; Willson, Andrew; Minton, Gianna; Ponnampalam, Louisa; Hoelzel, A. Rus (2020-05-01). "Phylogenomics of the genus Tursiops and closely related Delphininae reveals extensive reticulation among lineages and provides inference about eco-evolutionary drivers". Molecular Phylogenetics and Evolution. 146: 106756. doi:10.1016/j.ympev.2020.106756. hdl:2164/16438. ISSN 1055-7903. PMID 32028032. S2CID 211048062.
^Herzing, Denise L. (October 1997). "The life history of free-ranging Atlantic Spotted Dolphins (Stenella frontalis): Age classes, color phases, and female reproduction". Marine Mammal Science. 13 (4): 576–595. doi:10.1111/j.1748-7692.1997.tb00085.x.
^Herzing, Denise L. (1996). "Vocalizations and associated underwater behavior of free-ranging Atlantic Spotted dolphins, Stenella frontalis and bottlenose dolphins, Tursiops truncatus". Aquatic Mammals. 22 (2): 61–79.
^Myers, Alyson J.; Herzing, Denise L.; Bjorklund, David F. (2017-05-03). "Synchrony during aggression in adult male Atlantic spotted dolphins (Stenella frontalis)". Acta Ethologica. 20 (2): 175–185. doi:10.1007/s10211-017-0262-7. ISSN 0873-9749. S2CID 254164529.
^. Archived from the original on 2014-04-07. Retrieved 3 April 2014.
^Western African Aquatic Mammals MoU, Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia
^Reeves, Randall R.; Smith, Brian D.; Crespo, Enrique A.; di Sciara, Giuseppe Notarbartolo (2003). "Dolphins, Whales and Porpoises". 2002-2010 Conservation Action Plan for the World's Cetaceans.
Whales Dolphins and Porpoises, Mark Carwardine, Dorling Kindersley Handbooks, ISBN0-7513-2781-6
National Audubon Society Guide to Marine Mammals of the World, Reeves, Stewart, Clapham and Powell, and there is no characteristics for survival. ISBN0-375-41141-0
Perrin, William F. (2002). "". Mammalian Species (702):1–6.
External links
Voices in the Sea - Sounds of the Atlantic Spotted Dolphin
Whale and Dolphin Conservation Society
Wikimedia Commons has media related to Stenella frontalis (Atlantic spotted dolphin).
August 21, 2023
atlantic, spotted, dolphin, stenella, frontalis, dolphin, found, warm, temperate, tropical, waters, atlantic, ocean, older, members, species, have, very, distinctive, spotted, coloration, over, their, bodies, conservation, statusleast, concern, iucn, cites, ap. The Atlantic spotted dolphin Stenella frontalis is a dolphin found in warm temperate and tropical waters of the Atlantic Ocean Older members of the species have a very distinctive spotted coloration all over their bodies Atlantic spotted dolphin 1 Conservation statusLeast Concern IUCN 3 1 2 CITES Appendix II CITES 3 Scientific classificationDomain EukaryotaKingdom AnimaliaPhylum ChordataClass MammaliaOrder ArtiodactylaInfraorder CetaceaFamily DelphinidaeGenus StenellaSpecies S frontalisBinomial nameStenella frontalisCuvier 1829Atlantic Spotted Dolphin rangeSynonymsStenella plagiodon Cope 1866 Spilodelphis frontalis Contents 1 Taxonomy 2 Description 3 Behavior 4 Population and distribution 5 Human interaction 6 Conservation 7 See also 8 References 9 External linksTaxonomy EditThe Atlantic spotted dolphin was first described by Cuvier in 1828 Considerable variation in the physical form of individuals occurs in the species and specialists have long been uncertain as to the correct taxonomic classification Currently just one species is recognised but a large particularly spotty variant commonly found near Florida quite possibly may be classified as a formal subspecies or indeed a species in its own right Atlantic spotted dolphins in the Bahamas have been observed mating with bottlenose dolphins 4 Rich LeDuc has published data that suggest the Atlantic spotted dolphin may be more closely related to the bottlenose dolphins genus Tursiops than to other members of the genus Stenella 4 More recent studies in the 2020 s indicate that this is a consequence of reticulate evolution such as past hybridization between Stenella spotted dolphins and ancestral Tursiops bottlenose dolphins and incomplete lineage sorting and thus support T truncatus and T aduncus belonging to the same genus This likely explains why Atlantic spotted dolphins can mate with both species of bottlenose dolphins 5 Description Edit Stenella frontalis La Gomera Near South Caicos Turks and Caicos Islands A juvenile swimming in the blue waterThe coloring of the Atlantic spotted dolphin varies enormously as it grows and is usually classified into age dependent phases known as two tone speckled mottled and fused Calves are a fairly uniform gray white with one or no spots When they are weaned speckling occurs typically between 3 and 4 years and lasting for an average of 5 years A juvenile is considered mottled when it develops merging gray and white spots on the dorsal surface and black spots on the ventral surface This usually happens between age 8 or 9 A fused pattern is reached when dark and white spots are on both the ventral and dorsal sides As the animal matures the spots become denser and spread until the body appears black with white spots at full maturation 6 In comparison to other dolphin species the Atlantic spotted dolphin is medium sized Newborn calves are about 35 43 in 89 109 cm long while adults can reach a length of 2 26 m 7 ft 5 in and a weight of 140 kg 310 lb in males and 2 29 m 7 ft 6 in and 130 kg 290 lb in females Compared to the much smaller pantropical spotted dolphin the Atlantic spotted dolphin is more robust It shares its habitat with the pantropical spotted dolphin and the bottlenose dolphin The species exhibits a range of about ten different vocalizations including whistles buzzes squawks and barks each corresponding with different behaviors 7 Behavior EditAtlantic spotted dolphins are extremely gregarious animals which gather in complex social groups of 5 15 often in mixed groups with common bottlenose dolphins They are fast swimmers and known for their bow riding and long shallow leaping behaviors Their mating system consists of one male mating with several females and the pod is highly protective over pregnant females The dolphin s gestational period is 11 months and the mother cares for its calf for up to 5 years with the help of the rest of her group 8 These animals are cooperative hunters that hunt in groups at night They strategically encircle their prey which consists mostly of small fish benthic invertebrates and cephalopods such as squid They can dive to depths of up to 60 m 200 ft and can stay beneath the surface for up to 10 minutes at a time citation needed When showing aggression towards other species these dolphins make use of more contact behaviors such as biting and chasing than when being aggressive towards members of their species in which they usually rely on display behaviors 9 Population and distribution EditThe species is endemic to the temperate and tropical areas of the Atlantic Ocean It has been widely observed in the western end of the Gulf Stream between Florida and Bermuda Off the Bahamas tourism industries to swim with dolphins are available 10 It is also present in the Gulf of Mexico More infrequent sightings have been made further east off the Azores and Canary Islands Northerly sightings have been made as far north as Cape Cod across to the southwestern tip of Spain They are certainly present further south too as far as Rio Grande do Sul in Brazil and across to west Africa but their distribution is poorly understood in these areas About 20 years ago only about 80 dolphins were in the Bahamas Now almost 200 dolphins are found there On account of their similar appearance to other dolphins in their range it is difficult to be sure of the Atlantic spotted dolphin s population A conservative estimate is around 100 000 individuals citation needed Human interaction EditSome Atlantic spotted dolphins particularly some of those are around the Bahamas have become habituated to human contact In these areas cruises to watch and even swim with the dolphins are common They are usually not held in captivity Atlantic spotted dolphins are an occasional target of harpoon fishermen and every year some creatures are trapped and killed in gill nets but these activities are not currently believed to be threatening the survival of the species This species lives in the mesopelagic layer of the ocean These dolphins are not threatened by extinction however commercial trade may affect their evolution and sustainability Sometimes they are killed by harpoons off St Vincent Conservation EditThe Atlantic spotted dolphin is included in the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia 11 They are also marked as Least Concern of the Conservation Action Plan for the World s Cetaceans 12 See also Edit Cetaceans portal Mammals portal Marine life portalList of cetaceans Marine biologyReferences Edit Mead J G Brownell R L Jr 2005 Order Cetacea In Wilson D E Reeder D M eds Mammal Species of the World A Taxonomic and Geographic Reference 3rd ed Johns Hopkins University Press pp 723 743 ISBN 978 0 8018 8221 0 OCLC 62265494 Braulik G Jefferson T A 2018 Stenella frontalis IUCN Red List of Threatened Species 2018 e T20732A50375312 doi 10 2305 IUCN UK 2018 2 RLTS T20732A50375312 en Retrieved 18 November 2021 Appendices CITES cites org Retrieved 2022 01 14 a b Herzing D 2011 Dolphin Diaries My 25 Years with Spotted Dolphins in the Bahamas Macmillan pp 132 147 ISBN 978 0 312 60896 5 Moura Andre E Shreves Kypher Pilot Malgorzata Andrews Kimberly R Moore Daniel M Kishida Takushi Moller Luciana Natoli Ada Gaspari Stefania McGowen Michael Chen Ing Gray Howard Gore Mauvis Culloch Ross M Kiani Muhammad S Willson Maia Sarrouf Bulushi Asma Collins Tim Baldwin Robert Willson Andrew Minton Gianna Ponnampalam Louisa Hoelzel A Rus 2020 05 01 Phylogenomics of the genus Tursiops and closely related Delphininae reveals extensive reticulation among lineages and provides inference about eco evolutionary drivers Molecular Phylogenetics and Evolution 146 106756 doi 10 1016 j ympev 2020 106756 hdl 2164 16438 ISSN 1055 7903 PMID 32028032 S2CID 211048062 Herzing Denise L October 1997 The life history of free ranging Atlantic Spotted Dolphins Stenella frontalis Age classes color phases and female reproduction Marine Mammal Science 13 4 576 595 doi 10 1111 j 1748 7692 1997 tb00085 x Herzing Denise L 1996 Vocalizations and associated underwater behavior of free ranging Atlantic Spotted dolphins Stenella frontalis and bottlenose dolphins Tursiops truncatus Aquatic Mammals 22 2 61 79 Atlantic spotted dolphin Whales org Myers Alyson J Herzing Denise L Bjorklund David F 2017 05 03 Synchrony during aggression in adult male Atlantic spotted dolphins Stenella frontalis Acta Ethologica 20 2 175 185 doi 10 1007 s10211 017 0262 7 ISSN 0873 9749 S2CID 254164529 Bimini Dolphin Discovery Archived from the original on 2014 04 07 Retrieved 3 April 2014 Western African Aquatic Mammals MoU Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia Reeves Randall R Smith Brian D Crespo Enrique A di Sciara Giuseppe Notarbartolo 2003 Dolphins Whales and Porpoises 2002 2010 Conservation Action Plan for the World s Cetaceans Whales Dolphins and Porpoises Mark Carwardine Dorling Kindersley Handbooks ISBN 0 7513 2781 6 National Audubon Society Guide to Marine Mammals of the World Reeves Stewart Clapham and Powell and there is no characteristics for survival ISBN 0 375 41141 0 Perrin William F 2002 Stenella frontalis Mammalian Species 702 1 6 External links EditVoices in the Sea Sounds of the Atlantic Spotted Dolphin Whale and Dolphin Conservation Society Wikimedia Commons has media related to Stenella frontalis Atlantic spotted dolphin Retrieved from https en wikipedia org w index php title Atlantic spotted dolphin amp oldid 1161509668, wikipedia, wiki, book, books, library,
