The two-toed amphiuma (Amphiuma means) is an aquatic salamander widely distributed in the southeastern United States. It is commonly, but incorrectly, called "congo snake", "conger eel" or the "blind eel". Two-toed amphiumas are some of the largest extant amphibians in the world.
Two-toed amphiumas can grow from 39 to 1,042 g (1.4 to 36.8 oz) in mass and from 34.8 to 116 cm (13.7 to 45.7 in) in length.[3][4][5] They have four vestigial legs that end in two toes; the number of toes is one of the primary differences between Amphiuma means and its relatives, the one-toed and three-toed amphiumas. Additional genetic studies have been conducted on the three species, which indicated genetic distance estimates suggest that there is high levels of similarity between Two-toed amphiumas and three-toed amphiumas, and much greater dissimilarity between the one-toed amphiuma and the two-toed amphiuma[6] The head is pointed and wedge-shaped, and the eyes are small. Adults retain a single gill slit on each side of the head. They are black, dark grey or dark brown in color.[4]
Behavior
Two-toed amphiumas are nocturnal, and are often difficult to handle because of their slippery skins. They may leave water temporarily if weather is wet enough. They dig burrows in muddy stream bottoms, or may invade the burrows of other aquatic creatures. They are primarily found in the littoral zones where fish and crayfish are most abundant and vegetation is floating, on logs, or submerged.[7]
They are harmless to humans when left alone, but, when disturbed, they can deliver a tough bite, which may lead to a severe infection. Unlike other salamanders, which are mute, A. means gives a clear whistle when disturbed.[citation needed] It has been studied that two-toed amphiumas utilize acoustic signals during social interactions for communications at short distances, as the species did not express these acoustics when housed individually.[8] These acoustic signals can be described as "clicks". There are three discernable clicks produced, ranging in frequencies.[3]
Reproduction
Amphiumas breed from June to July in North Carolina and northern Florida. Females lay about 200 eggs in a damp cavity beneath debris, close to standing water, and they remain coiled around them during incubation (which lasts around five months). These eggs are laid in strings.[9]Hatchlings are about 2 in (51 mm) long with three pairs of light-colored external gills soon lost after hatching.[10] In some conditions offspring can exhibit direct development and hatch without external gills.[11] In a series of three studies conducted in northern Florida, two-toed amphiuma eggs hatched in response to inundation with water, can stand without feeding for 125 days by using resources from their yolk reserves, and the eggs can retain a period of no growth and still survive after 110 days on a moist substrate.[12]
A study depicted seasonal lipid storage increases in males' testicular region and females' liver.[5]
^Geoffrey Hammerson (2004). "Amphiuma means". IUCN Red List of Threatened Species. 2004: e.T59074A11879454. doi:10.2305/IUCN.UK.2004.RLTS.T59074A11879454.en. Retrieved 20 November 2021.
^ abHeisler, N.; Forcht, G.; Ultsch, G.R.; Anderson, J.F. (1982). "Acid-base regulation in response to environmental hypercapnia in two aquatic salamanders, Siren lacertina and Amphiuma means". Respiration Physiology. 49 (2): 141–58. doi:10.1016/0034-5687(82)90070-6. PMID 6815749.
^ abCaudata Culture Species Entry – Amphiuma. Caudata.org. Retrieved on 2013-01-03.
^ abDeyle, Anna C. (2011) Population Genetics of Amphiuma means and Siren lacertina in Central Florida. M.S. Thesis, University of South Florida
^Karlin, Alvan A.; Means, D. Bruce (1994). "Genetic variation in the Aquatic Salamander genus Amphiuma". The American Midland Naturalist. 132 (1): 1. doi:10.2307/2426195.
^Luhring; Crawford, B.; Schalk, C. (2010). "Summer microhabitat use of the Greater Siren (Siren lacertina) and Two-toed Amphiuma (Amphiuma means) in an isolated wetland". Amphibia-Reptilia. 2010 (2): 251-256. doi:10.1163/156853810791069155.
^Crovo, J. A., Zeyl, J. N., & Johnston, C. E. (2016). Hearing and sound production in the aquatic salamander, Amphiuma means. Herpetologica, 72(3), 167-173.
^ Gunzburger, M., S. (2003). Evaluation of the Hatching Trigger and Larval Ecology of the Salamander Amphiuma means. Herpetologica, 59(4), 459–468. https://doi.org/10.1655/02-82
^ abc"Amphiuma means". amphibiaweb.org. AmphibiaWeb. Retrieved 26 December 2018.
^ Gunzburger, M., S. (2003). Evaluation of the Hatching Trigger and Larval Ecology of the Salamander Amphiuma means. Herpetologica, 59(4), 459–468. https://doi.org/10.1655/02-82
^Gunzburger, Margaret S. (1 December 2003). "Evaluation of the Hatching Trigger and Larval Ecology of the Salamander Amphiuma Means". Herpetologica. 59 (4): 459. doi:10.1655/02-82.
^Montaña, C. G. (2014). New vertebrate prey for the aquatic salamander Amphiuma means (Caudata: Amphiumidae). Herpetology Notes, 7, 755-756.
^"Amphiuma means". amphibiaweb.org. AmphibiaWeb. Retrieved 26 December 2018.
Wikimedia Commons has media related to Amphiuma means.
March 04, 2023
toed, amphiuma, this, article, includes, list, general, references, lacks, sufficient, corresponding, inline, citations, please, help, improve, this, article, introducing, more, precise, citations, february, 2016, learn, when, remove, this, template, message, . This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations February 2016 Learn how and when to remove this template message The two toed amphiuma Amphiuma means is an aquatic salamander widely distributed in the southeastern United States It is commonly but incorrectly called congo snake conger eel or the blind eel Two toed amphiumas are some of the largest extant amphibians in the world Two toed amphiumaTemporal range Pleistocene present PreꞒ Ꞓ O S D C P T J K Pg N 1 Conservation statusLeast Concern IUCN 3 1 2 Scientific classificationKingdom AnimaliaPhylum ChordataClass AmphibiaOrder UrodelaFamily AmphiumidaeGenus AmphiumaSpecies A meansBinomial nameAmphiuma meansGarden in Smith 1821 Contents 1 Description 2 Behavior 2 1 Reproduction 2 2 Feeding 3 Habitat and range 4 ReferencesDescription EditTwo toed amphiumas can grow from 39 to 1 042 g 1 4 to 36 8 oz in mass and from 34 8 to 116 cm 13 7 to 45 7 in in length 3 4 5 They have four vestigial legs that end in two toes the number of toes is one of the primary differences between Amphiuma means and its relatives the one toed and three toed amphiumas Additional genetic studies have been conducted on the three species which indicated genetic distance estimates suggest that there is high levels of similarity between Two toed amphiumas and three toed amphiumas and much greater dissimilarity between the one toed amphiuma and the two toed amphiuma 6 The head is pointed and wedge shaped and the eyes are small Adults retain a single gill slit on each side of the head They are black dark grey or dark brown in color 4 Behavior EditTwo toed amphiumas are nocturnal and are often difficult to handle because of their slippery skins They may leave water temporarily if weather is wet enough They dig burrows in muddy stream bottoms or may invade the burrows of other aquatic creatures They are primarily found in the littoral zones where fish and crayfish are most abundant and vegetation is floating on logs or submerged 7 They are harmless to humans when left alone but when disturbed they can deliver a tough bite which may lead to a severe infection Unlike other salamanders which are mute A means gives a clear whistle when disturbed citation needed It has been studied that two toed amphiumas utilize acoustic signals during social interactions for communications at short distances as the species did not express these acoustics when housed individually 8 These acoustic signals can be described as clicks There are three discernable clicks produced ranging in frequencies 3 Reproduction Edit Amphiumas breed from June to July in North Carolina and northern Florida Females lay about 200 eggs in a damp cavity beneath debris close to standing water and they remain coiled around them during incubation which lasts around five months These eggs are laid in strings 9 Hatchlings are about 2 in 51 mm long with three pairs of light colored external gills soon lost after hatching 10 In some conditions offspring can exhibit direct development and hatch without external gills 11 In a series of three studies conducted in northern Florida two toed amphiuma eggs hatched in response to inundation with water can stand without feeding for 125 days by using resources from their yolk reserves and the eggs can retain a period of no growth and still survive after 110 days on a moist substrate 12 A study depicted seasonal lipid storage increases in males testicular region and females liver 5 Feeding Edit Two toed amphiumas feed on small fish tadpoles crawfish insects and insect larvae They are also recorded to prey on reptiles and amphibians such as southern cricket frogs southern leopard frogs greater sirens peninsula newts water snakes of the genus Nerodia and small mud turtles Their hunting behavior is not thoroughly understood but they are believed to forage actively for food and to wait under debris and in burrows for prey to approach them They likely detect prey through olfaction 10 Habitat and range EditAmphiumas live in areas of shallow heavily vegetated water in swamps bayous lakes and ponds as well as wet prairies 10 It has been found that their microhabitats largely coincide with high prey availability 13 Their range includes southeastern Virginia eastern North Carolina South Carolina southern Georgia and Alabama Florida south Mississippi Arkansas Louisiana and southeastern Texas 14 References Edit Fossilworks Geoffrey Hammerson 2004 Amphiuma means IUCN Red List of Threatened Species 2004 e T59074A11879454 doi 10 2305 IUCN UK 2004 RLTS T59074A11879454 en Retrieved 20 November 2021 a b Heisler N Forcht G Ultsch G R Anderson J F 1982 Acid base regulation in response to environmental hypercapnia in two aquatic salamanders Siren lacertina and Amphiuma means Respiration Physiology 49 2 141 58 doi 10 1016 0034 5687 82 90070 6 PMID 6815749 a b Caudata Culture Species Entry Amphiuma Caudata org Retrieved on 2013 01 03 a b Deyle Anna C 2011 Population Genetics of Amphiuma means and Siren lacertina in Central Florida M S Thesis University of South Florida Karlin Alvan A Means D Bruce 1994 Genetic variation in the Aquatic Salamander genus Amphiuma The American Midland Naturalist 132 1 1 doi 10 2307 2426195 Luhring Crawford B Schalk C 2010 Summer microhabitat use of the Greater Siren Siren lacertina and Two toed Amphiuma Amphiuma means in an isolated wetland Amphibia Reptilia 2010 2 251 256 doi 10 1163 156853810791069155 Crovo J A Zeyl J N amp Johnston C E 2016 Hearing and sound production in the aquatic salamander Amphiuma means Herpetologica 72 3 167 173 Gunzburger M S 2003 Evaluation of the Hatching Trigger and Larval Ecology of the Salamander Amphiuma means Herpetologica 59 4 459 468 https doi org 10 1655 02 82 a b c Amphiuma means amphibiaweb org AmphibiaWeb Retrieved 26 December 2018 Gunzburger M S 2003 Evaluation of the Hatching Trigger and Larval Ecology of the Salamander Amphiuma means Herpetologica 59 4 459 468 https doi org 10 1655 02 82 Gunzburger Margaret S 1 December 2003 Evaluation of the Hatching Trigger and Larval Ecology of the Salamander Amphiuma Means Herpetologica 59 4 459 doi 10 1655 02 82 Montana C G 2014 New vertebrate prey for the aquatic salamander Amphiuma means Caudata Amphiumidae Herpetology Notes 7 755 756 Amphiuma means amphibiaweb org AmphibiaWeb Retrieved 26 December 2018 Wikimedia Commons has media related to Amphiuma means Retrieved from https en wikipedia org w index php title Two toed amphiuma amp oldid 1136092964, wikipedia, wiki, book, books, library,
