View source for Hickatee

{{Short description|Genus of turtles}}
{{Redirect|River turtle|}}
{{Use dmy dates|date=June 2021}}
{{Speciesbox
| image = Dlouhohlávka mexická 9243u.jpg
| image_caption = In the [[Prague Zoo]]
| status = CR
| status_system = IUCN3.1
| status_ref = <ref name="iucn">{{Cite iucn|author=[[Richard Vogt (herpetologist)|Vogt RC]], Gonzalez-Porter GP, Van Dijk PP|title=''Dermatemys mawii'' |year=2006 |errata =2016 |article-number= e.T6493A97409830|doi=10.2305/IUCN.UK.2006.RLTS.T6493A12783921.en|access-date=27 October 2022}}</ref>
| status2 = CITES_A2 
| status2_system = CITES 
| status2_ref = <ref name="CITES">{{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}</ref>
| genus = Dermatemys
| parent_authority = [[John Edward Gray|Gray]], 1847<ref name=gray1847>[[John Edward Gray|Gray JE]] (1847). "Description of a new Genus of Emydæ". ''Proceedings of the Zoological Society of London'' '''1847''': 55–56. (''Dermatemys'', new genus, p. 55; ''Dermatemys Mawii'', new species, p. 56).</ref>
| species = mawii
| authority = [[John Edward Gray|Gray]], 1847<ref name=gray1847 />
| synonyms = *''Dermatemys mawii'' <br/>{{small|Gray, 1847: 56}}<ref name=gray1847 />
*''Emys berardii'' <br/>{{small|[[André Marie Constant Duméril|A.M.C. Duméril]] & [[Gabriel Bibron|Bibron]], 1851: 11}}<ref name=dum&dum1851>[[André Marie Constant Duméril|Duméril AMC]], [[Gabriel Bibron|Bibron G]] (1851). "''Emys areolata'', ''Emys berardii'', ''Cinosternon leucostomum'', ''Cinosternon cruentatum'' ". '''''In'':''' Duméril AMC, [[Auguste Duméril|Duméril AHA]] (1851). ''Catalogue Methodique de la Collection des Reptiles'' (''Museum d'Histoire Naturelle de Paris''). Paris: Gide and Baudry. 224 pp. (in French).</ref>
*''Dermatemys abnormis'' <br/>{{small|[[Edward Drinker Cope|Cope]], 1868: 120}}<ref name=cope1868>[[Edward Drinker Cope|Cope ED]] (1868). "An examination of the Reptilia and Batrachia obtained by the Orton expedition to Equador [sic] and the upper Amazon, with notes on other species". ''Proceedings of the Academy of Natural Sciences of Philadelphia'' '''20''': 96–140.</ref>
*''Dermatemys salvinii'' <br/>{{small|Gray, 1870: 50}}<ref name=gray1870b>Gray JE (1870). ''Supplement to the Catalogue of Shield Reptiles in the Collection of the British Museum. Part I. Testudinata (Tortoises)''. London: British Museum. 120 pp.</ref>
*''Limnochelone micrura'' <br/>{{small|[[Franz Werner|F. Werner]], 1901: 298}}<ref name=wern1901>[[Franz Werner|Werner F]] (1901). "''Neue Reptilien des Königsberger zoologischen Museums'' ". ''Zoologischer Anzeiger'' '''24''': 297–301. (in German).</ref>
| synonyms_ref = <ref name="ttwg">[[Turtle Taxonomy Working Group]] [van Dijk PP, Iverson JB, Shaffer HB, Bour R, Rhodin AGJ] (2012). "Turtles of the World, 2012 update: annotated checklist of taxonomy, synonymy, distribution, and conservation status". ''Chelonian Research Monographs'' (5):, 000.243–000.328, doi:10.3854/crm.5.000.checklist.v5.2012, [http://www.iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_000_checklist_v5_2012.pdf].</ref>
}}

The '''hickatee''' ('''''Dermatemys mawii''')'' or in Spanish '''''tortuga blanca''''' ("white turtle"), also called the '''Central American river turtle''',<ref name=vogtetal>{{cite journal |last1=Vogt |first1=RC |author-link1=Richard Vogt (herpetologist) |last2=Polisar |first2=J. R. |last3=Moll |first3=Don |last4=Gonzalez-Porter |first4=Gracia |date=2011 |title=''Dermatemys mawii'' Gray 1847 – Central American River Turtle, Tortuga Blanca, Hickatee, ''in'' Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group |url=https://iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_058_mawii_v1_2011.pdf |editor1-last=Rhodin |editor1-first=AGJ |editor2-last=Pritchard |editor2-first=P. C. H. |editor2-link=Peter Pritchard |editor3-last=van Dijk |editor3-first=P. P. |editor4-last=Samure |editor4-first=R. A. |editor5-last=Buhlmann |editor5-first=K. A. |editor6-last=Iverson |editor6-first=J. B. |editor7-last=Mittermeier |editor7-first=R. A. |editor7-link=Russell Mittermeier |journal=Chelonian Research Monographs |volume=5 |issue=58 |pages=1–11 |doi=10.3854/crm.5.058.mawii.v1.2011}}</ref> is the only living [[species]] in the [[Family (biology)|family]] [[Dermatemydidae]]. The species is found in the Atlantic drainages of [[Central America]], specifically [[Belize]], [[Guatemala]], southern [[Mexico]], and probably [[Honduras]]. It is a relatively large-bodied species, with records of {{convert|60|cm|in|abbr=on}} straight [[carapace]] length and weights of {{convert|22|kg|lb|abbr=on}}; although most individuals are smaller. This is a [[herbivorous]] and almost completely aquatic turtle that does not surface to bask. Bizarrely for reptiles, the eggs can remain viable even after being underwater for weeks -in the recent past, some scientists mistakenly claimed it nests underwater, likely due to visiting Central America during a frequent flood, when nests are often submerged.

In the culture of the [[Ancient Maya]]n civilisation this species and turtles in general had numerous uses such as being used in warfare, as musical instruments and as food, with this species likely being consumed by the elites during feasts. The Maya probably exported these turtles to areas where they do not occur, based on their shell remains in kitchen middens. There is genetic evidence that the Mayans and other ancient peoples may have hunted the turtle to [[local extinction]] in areas it now occurs in, and that some modern turtle populations stem from turtles introduced into waterways from elsewhere. The turtle also had mythological symbolism, although the true nature of Ancient Mayan myth has been largely obscured by time. Among the modern communities inheriting this land the turtle continues to be eagerly sought as a dish eaten during important cultural events. The meat of this turtle is said to be very tasty. It has thus had a long history of exploitation.

This has prompted Western conservationists to declare this use unsustainable, and that the turtle is now '[[critically endangered]]', especially singling out the people of [[Tabasco]] as the culprits. In Belize, the only country where it is still legal to hunt these animals, it is still common in some areas, but populations are devastated in areas where people live. In Mexico, the state of the population is unclear. It was said to be almost extirpated from Mexico in 2006 based on an entry in a book from the 1970s, but reasonable amounts are still caught in areas such as Tabasco and [[Quintana Roo]]. In Guatemala the species is abundant in some areas, but uncommon elsewhere.

Although in the 1990s scientists dismissed breeding this species as impracticable, it is now known they can reproduce in poor waters, and as a generalist herbivorous species [[fodder]] costs are low. Much has been discovered regarding their [[animal husbandry]], with some US scientists now musing that commercial breeding might be cost effective using experimental [[polyculture]] systems with the turtles as a secondary income source. The Mexican government already stimulated the farming of this species in the 2000s, there are now likely a few thousand kept in captivity there. The health of these captive animals is not ideal, and the success of these operations is unclear.

==Taxonomy==
''Dermatemys mawii'' is the only living [[species]] in the [[Family (biology)|family]] [[Dermatemydidae]].<ref>{{cite journal |url=http://www.iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_000_checklist_v4_2011.pdf |title=Turtles of the world, 2011 update: Annotated checklist of taxonomy, synonymy, distribution and conservation status |journal=Chelonian Research Monographs |volume=5 |date=2011-12-31 |author1=Rhodin, Anders G.J. |author2=van Dijk, Peter Paul |author3=Inverson, John B. |author4=Shaffer, H. Bradley |author5=Roger, Bour |archive-url=https://web.archive.org/web/20120131102839/http://www.iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_000_checklist_v4_2011.pdf |archive-date=2012-01-31 }}</ref> Its closest relatives are only known from [[fossil]]s with some 19 genera described from a worldwide distribution in the [[Jurassic]] and [[Cretaceous]].{{citation needed|date=November 2021}}

===Etymology===
The [[Specific name (zoology)|specific name]], ''mawii'', is in honour of the collector of the [[Holotype|type specimen]], Lieutenant Mawe of the British Navy.<ref>{{EponymDictionaryReptiles}}</ref>{{rp|171}}

This species is usually vernacularly called ''tortuga blanca'' in Spanish, because it can be readily distinguished when prepared as food. When the meat of this turtle is cooked, it turns a white colour, unlike the more common turtle meat (''[[Trachemys scripta]]''), which colours dark.<ref name=Campbell1998>{{cite book |last=Campbell |first=Jonathan A. |date=1998 |title=Amphibians and Reptiles of Northern Guatemala, the Yucatán and Belize |url=https://books.google.com/books?id=orUl8Ezs1iQC&pg=PA111 |location=Norman, Oklahoma |publisher=University of Oklahoma Press |pages=111–113 |isbn=0-8061-3066-0}}</ref>

===Genetics===
Many species sharing a similar distribution have [[Phylogeography|phylogeographic]] structure revealed in their [[genome]]s, with the population often being split into at least three subgroups representing the three main Atlantic hydrological basins of this region, the [[Papaloapan]], [[Coatzacoalcos River|Coatzacoalcos]] and [[Grijalva River|Grijalva]]-[[Usumacinta River|Usumacinta]]. A 2011 study of the [[mitochondrial DNA]] (mtDNA) of extant populations throughout the range of this species, however, revealed a less clear differentiation. Although some genetic structure was evident, most locations showed a high rate of mixing of different lineages, with two main closely related mitochondrial [[haplotype]]s dominating the population. Three divergent mitochondrial lineages were found: an extremely rare one dubbed '1D' only found in four samples from [[Sarstoon River|Sarstún]] and [[Salinas River (Mexico)|Salinas]] on the southeast edge of the Grijalva-Usumacinta basin, a second northernmost 'Papaloapan' lineage restricted to the Papaloapan basin in the state of [[Veracruz]], to the west of the [[Sierra de Santa Marta]] and the [[Isthmus of Tehuantepec]], and a third widespread 'central' lineage that was found in all studied localities. It appeared as if a formerly clear [[Phylogeography|phylogeographical pattern]] had been obscured by transport and introductions of turtle populations from one waterway to another, i.e. secondary blurring by large-scale [[gene flow]] between populations. Low haplotype diversity at some localities indicated prehistoric [[population bottleneck]]s, possibly after a drastic cull from over-harvesting, followed by population expansions. As it is almost certain the [[Ancient Maya]] were engaged in long distance trade in this turtle species and consumed large amounts, it was deemed most probable that the Maya were responsible for this (see section on interaction with humans below).<ref name=González2011>{{cite journal |last1=González Porter |first1=Gracia P. |last2=Hailer |first2=Frank |last3=Flores Villela |first3=Oscar |last4=García Anleu |first4=Rony |last5=Maldonado |first5=Jesús E. |date=17 May 2011 |title=Patterns of genetic diversity in the critically endangered Central American river turtle: human influence since the Mayan age? |journal=Conservation Genetics |volume=12 |issue=5 |pages=1229–1242 |doi=10.1007/s10592-011-0225-x|s2cid=39768099 }}</ref> Even today, turtles have been found trapped in small isolated ponds (called ''aguadas'' in Guatemala) where they would be unlikely to naturally disperse to, or in areas they do not naturally occur, likely moved there by people in order to harvest them at a later date.<ref name=vogtetal/><ref name=Campbell1998/>

Although most haplotypes were relatively closely related, there was one highly divergent haplotype which only showed up in four samples from Sarstún and Salinas, divergent enough to represent a possible new hyper-critically endangered [[cryptic species]]. Hydrological reproductive barriers between populations may have led to the main lineages splitting in the [[Pliocene]] to [[Pleistocene]] (3.73–0.227 million years ago), generally enough time to accumulate the genetic divergences for [[speciation]] to occur. The sampling locations, however, also contained the common central haplotypes.<ref name=González2011/> The existence of such divergent genes led Vogt ''et al''. to recommended splitting up the taxon into three [[evolutionary significant unit]]s, corresponding to the Sarstun, Salinas, and Papaloapan populations, and something called a 'management unit'{{efn|unexplained, but most likely ''sensu'' Moritz C (1999) ''Conservation units and translocations: strategies for conserving evolutionary processes''. Hereditas 30: 217–228. ''fide'' González (2013).<ref name=González2013/>}} for the locations where all of the 238 turtles tested in 2011 had the more common central mitochondria, for conservation purposes.<ref name=vogtetal/> Although mtDNA can reveal deep genetic structure in populations, as it is only inherited via the mother, it does not show insofar different subpopulations are independently evolving units, because different populations may interbreed without this showing in the mtDNA of individuals. A subsequent 2013 study of eight [[Locus (genetics)|loci]] of the [[nuclear DNA]] aimed to resolve this.<ref name=González2013>{{cite journal |last1=González Porter |first1=Gracia P. |last2=Maldonado |first2=Jesús E. |last3=Flores Villela |first3=Oscar |last4=Vogt |first4=Richard C. |author-link4=Richard Vogt (herpetologist) |last5=Janke |first5=Axel |last6=Fleischer |first6=Robert C. |last7=Hailer |first7=Frank |date=25 September 2013 |title=Cryptic Population Structuring and the Role of the Isthmus of Tehuantepec as a Gene Flow Barrier in the Critically Endangered Central American River Turtle |journal=PLOS ONE |volume=8 |issue=9 |article-number=e71668 |pmid=24086253 |doi=10.1371/journal.pone.0071668|pmc=3783458|bibcode=2013PLoSO...871668G |doi-access=free }}</ref>

This 2013 study found no sign of a recent bottleneck in the fifteen locations sampled, indicating that harvesting going for the past half century had not yet had an effect on genomic diversity, possibly a long generation time and delayed sexual maturity of ''D. mawii'' buffering against loss of genetic diversity despite population size reduction. The Sarstún and Salinas populations in general were not strongly differentiated from the neighbouring populations, but the four individuals from Sarstún and Salinas with divergent mitochondria did have divergent [[microsatellite]] loci sequences in varying amounts according to the individual, with three rare alleles only found in this [[subpopulation]] of four. The samples from Papaloapan locations were highly differentiated compared to almost all other populations, and also were rich in unique alleles. However, individuals carrying Papaloapan-type mtDNA haplotypes did not appear differentiated from the central type individuals, and these individuals occurred at relatively low frequencies amongst the central type haplotypes shared with adjacent populations to the east of the isthmus, indicating significant gene flow of mitochondrial lineages westwards across the isthmus. At the same time nuclear microsatellites appear to show gene flow in the other direction. Such conflicting signals could be caused by different episodes, or be due to a sex bias in dispersal. Also the populations from [[Sibun River]], [[Lake Salpetén]] and [[Cultural Triangle Yaxha-Nakum-Naranjo National Park|Laguna Sacnab]], all near the eastern edge of the distribution, were relatively well-differentiated from the remaining populations. This was thought to be due to losses of genetic variability from recent [[genetic drift]] and/or demographic isolation. All the other populations had high levels of gene flow, even between areas separated by geographic distances of more than 300&nbsp;km. The study found that this suggests likely thousands of years of human-mediated trade, but that it might also just mean that this species is capable of moving great distances during its life. Besides microsatellite regions another part of the nuclear DNA was looked at, a 779 [[base pair|bp]] fragment of first [[intron]] of the [[RNA]] [[protein]] R35, with four haplotypes found. This revealed no phylogeographic structure: the main haplotype was common across the distribution, and the four individuals from Sarstún and Salinas all had this haplotype.<ref name=González2013/>

The overall pattern is completely different in the alligator snapping turtle (''[[Macrochelys temminckii]]''), which is also often caught, but in which gene flow between populations is very low, but the mixed lineages are somewhat similar to the diamondback terrapin (''[[Malaclemys terrapin]]''), with translocations during the early twentieth century, or the radiated tortoise (''[[Geochelone radiata]]'') and gopher tortoises (''[[Gopherus polyphemus]]''), which show contemporary population structuring influenced by recent releases.<ref name=González2013/>

The 2013 study concluded that as there was evidence of substantial genetic mingling the species was best regarded as a single cohesive 'management unit' for conservation purposes,<ref name=González2013/> as opposed to Vogt ''et al''. in 2011.<ref name=vogtetal/> The sample size of the individuals with the 1D mitochondria was too small to calculate insofar they represent a taxonomically relevant cryptic species.<ref name=González2013/>

==Description==
[[File:EmysBerardii.jpg|thumb]]
''Dermatemys mawii''  It is a relatively large-bodied species, with historical records of {{convert|60|cm|in|abbr=on}} straight [[carapace]] length and weights of {{convert|22|kg|lb|abbr=on}}; however, more recent records have found few individuals over {{convert|14|kg|lb|abbr=on}} in Mexico or {{convert|11|kg|lb|abbr=on}} in Guatemala. It has a low, flattened, smooth [[Turtle Shell#Carapace|carapace]] with a median keel present in juveniles, it is usually a uniform brown, almost black, grey or olive in colour.<ref name=vogtetal /> The [[Turtle Shell#Plastron|plastron]] is usually white to yellow, though may acquire substrate staining in some areas. In juveniles, a distinctive keel is found down the centre of the carapace,<ref name=vogtetal /> and the outer edges have serrations. These features are lost as the turtle ages. Its skin is predominantly the same colour as the shell, with reddish or peach-coloured markings around the neck and underside.

Adult males can often be differentiated from females by yellow (although sometimes cream or reddish-brown) markings on the top of their heads, as opposed to the uniformly dull-coloured heads of females,<ref name=tsa2010>{{cite magazine |last1=Rainwater |first1=T. |last2=Pop |first2=T. |last3=Cal |first3=O. |last4=Platt |first4=S. |last5=Hudson |first5=R. |date=August 2010 |title=Catalyzing Conservation in Belize for Central America's Imperiled River Turtle |url=http://www.turtlesurvival.org/storage/documents/magazines/TSA_August_2010_final-compressed.pdf |magazine=Turtle Survival Alliance Magazine |page= |publisher=Turtle Survival Alliance |pages=79–82 |access-date=22 November 2021 |archive-url=https://web.archive.org/web/20101221195057/http://turtlesurvival.org/storage/documents/magazines/TSA_August_2010_final-compressed.pdf |archive-date=21 December 2010}}</ref> and longer, thicker tails.

==Distribution==
[[File:Tortuga blanca.jpg|thumb]]
[[File:Dlouhohlávka mexická 7157u.jpg|thumbnail|right|Central American river turtle in Prague Zoo]]
''Dermatemys mawii'' lives in Atlantic-draining larger rivers and lakes in Central America, from southern [[Mexico]] through [[Belize]] to the [[Guatemala]]n-[[Honduras|Honduran]] border.<ref name=vogtetal /> In Mexico it occurs in the states of [[Veracruz]], [[Tabasco]], [[Campeche]], the north of [[Oaxaca]], the north of [[Chiapas]] and the south of [[Quintana Roo]], primarily in the hydrological basins of the [[Papaloapan]], [[Coatzacoalcos River|Coatzacoalcos]] and [[Grijalva River|Grijalva]]-[[Usumacinta River]] systems.<ref>{{cite report |last1=Vázquez Sánchez |first1=Marta Minerva |last2=Antaño Diaz |first2=Laura Aleida |last3=Balderas Acata |first3=Salvador |date=April 2012 |title=Plan de Manejo Tipo para Tortuga Blanca |url=https://www.yumpu.com/es/document/read/14828412/plan-de-manejo-tipo-para-tortuga-blanca-semarnat |publisher=[[SEMARNAT|Secretaría del Medio Ambiente y Recursos Naturales]], Subsecretaría de Gestión para la Protección Ambiental, Dirección General de Vida Silvestre |pages=1–42 |language=es |access-date=25 November 2021}}</ref>

In Guatemala the species occurs from southern and central [[Petén Department]], south to [[Lago de Izabal]] and the rivers which drain into it.<ref name=Campbell1998/> The presence and status in the [[Río Motagua]] bordering Honduras was unknown in 2011.<ref name=vogtetal /> It is reasonably common in the [[Pasión River]] and its tributaries as well as several lakes in Petén as of 1998. It was once common in [[Lake Petén Itzá]], but by 1998 had become rarer there.<ref name=Campbell1998/> It is well protected in [[Yaxhá Lake]].<ref name=vogtetal /> In 2007 it was found to occur throughout northern Petén in the area corresponding to the [[Maya Biosphere Reserve]], with the researchers reporting that it was quite common almost everywhere, and extending the known distribution somewhat with the [[Blue Creek (Belize)|Río Azul]] in [[Mirador-Río Azul National Park]] and Playa Grande, Quiche. Based on an extrapolation of the turtle densities obtained in this survey, 4,081 turtles are estimated to currently exist within this area. This number is clearly an extreme underestimate, as only the surface area of large water bodies and rivers was taken into account, and the lowest densities found in the area were used in the calculations in order to be conservative.<ref name=García2007>{{cite report |last1=García Anleu |first1=Rony |last2=McNab |first2=Roan Balas |last3=Soto Shoender |first3=José |last4=Espejel |first4=Verónica |last5=Moreira |first5=José |last6=Ponce |first6=Gabriela |last7=Ramos |first7=Víctor H. |last8=Oliva |first8=Francisco |last9=González |first9=Eleazar |last10=Tut |first10=Henry |last11=Tut |first11=Kender |last12=Xol |first12=Tono |last13=Xoc |first13=Pedro |last14=Córdova |first14=Marcial |last15=Córdova |first15=Francisco |last16=Morales |first16=Luis |date=2007 |title=Distribution and ecology of the Central America River Turtle (''Dermatemys mawii'': Dermatemidae) in the lowland Maya forest, Guatemala |url=https://www.researchgate.net/publication/284733460 |publisher=Wildlife Conservation Society–Guatemala Program Internal Report |pages=1–28 |access-date=25 November 2021}}</ref> Very high turtle densities were captured in [[Laguna Peru]] in 2007 and 2009.<ref name=vogtetal /><ref name=García2007/>

==Ecology==
''Dermatemys mawii'' is a [[nocturnal animal|nocturnal]], completely aquatic turtle<ref name=vogtetal /> that does not bask or leave the water, except to lay eggs.

The most significant predator is the otter (''[[Lontra longicaudis]]'').<ref name=vogtetal /><ref name=Campbell1998/> [[Richard Vogt (herpetologist)|Vogt]] ''et al''. stated in 2011 that these otters are known to be able to keep turtle populations low in some cases by hindering [[Recruitment (biology)|recruitment]],<ref name=vogtetal /> whereas Platt and Rainwater in 2011 claim that they are the first to register otter predation in this species, and note that because other otter species in Canada or Europe are not significant predators of other species of turtles and turtles are not believed to form a major part of the otter diets, they hypothesise that otter predation is not significant, and also state that while there was ample evidence for otter predation in one part of Belize, this was the only place they had seen it occur.<ref name=Platt2011>{{cite journal |last1=Platt |first1=Steven G. |last2=Rainwater |first2=Thomas R. |date=2011 |title=Predation by Neotropical Otters (''Lontra longicaudis'') on Turtles in Belize |url=https://www.iucnosgbull.org/Volume28/Platt_Rainwater2011.html |journal=IUCN Otter Specialist Group Bulletin |volume=28 |issue=1 |pages=4–10 |access-date=22 November 2021}}</ref> Campbell in 1998 notes that the otter is itself not common enough for this to be an issue.<ref name=Campbell1998/> Especially large juveniles and subadults are preyed upon by otters in Belize. Otter predation can be recognised by the manner by which they typically chew off the heads, tail and limbs, sometimes slurping out the entrails, but leave the shell intact.<ref name=Platt2011/>

The crocodiles ''[[Crocodylus moreletii]]'' and [[Crocodylus acutus|''C. acutus'']] usually feed on juveniles and hatchlings, or intermediate-sized turtles.<ref name=vogtetal /><ref name=Zenteno2011>{{cite thesis |last=Zenteno Ruiz |first=Claudia Elena |date=2011 |title=Análisis espacio-temporal del hábitat y presencia de ''Dermatemys mawii'' (Gray, 1847) en la Reserva de la Biosfera Pantanos de Centla |type=Doctorate |publisher=El Colegio de la Frontera Sur, Villahermosa, Tabasco, México |docket=TE/597.92097263/Z4  |url=https://www.researchgate.net/publication/234004647 |access-date=25 November 2021}}</ref> Crocodiles crush the shell and swallow the turtle whole.<ref name=Platt2011/> The indigo snake ''[[Drymarchon melanurus]]'' preys on the eggs and hatchlings.<ref name=Zenteno2011/> According to one report raccoons (''[[Procyon lotor]]'') have a similar feeding strategy as otters, and typically target nesting females,<ref name=Platt2011/> other reports has them as predators of the eggs and hatchlings. Other predators of the eggs and hatchlings are coati (''[[Nasua narica]]'')<ref name=vogtetal /><ref name=Zenteno2011/> and birds are also known to eat the eggs and hatchlings, namely the rails ''[[Aramides cajanea]]'' and ''[[Rallus longirostris]]'', limpkins (''[[Aramus guarauna]]'') and the herons ''[[Butorides virescens]]'', ''[[Nycticorax nycticorax]]'' and ''[[Nyctanassa violacea]]''.<ref name=vogtetal /> A possible predator is the jaguar (''[[Panthera onca]]''), which feeds on turtles in general by cracking the shell open to scoop out the contents.<ref name=Platt2011/>

''D. mawii'' hosts a number of specialised [[parasite]]s. The [[Fluke (flatworm)|fluke]] ''[[Caballerodiscus resupinatus]]'' is found in the intestine and [[Caballerodiscus tabascensis|''C. tabascensis'']] in the intestine and stomach, both have been found in Tabasco and Veracruz, ''[[Parachiorchis parviacetabulatus]]'' recorded from the intestine was only found once in Veracruz, ''[[Pseudocleptodiscus margaritae]]'' recorded from the intestine was only found twice in Tabasco, ''[[Dermatemytrema trifoliatum]]'' in the intestine and stomach from Oaxaca, Tabasco and Veracruz, ''[[Octangioides skrjabini]]'' was recorded from the intestine and only found once in Tabasco, whereas [[Octangioides tlacotalpensis|''O. tlacotalpensis'']] was recorded from the intestine and only found in two localities in Veracruz, and lastly ''[[Choanophorus rovirosai]]'' was recorded from the intestine in Tabasco and Veracruz. All of these eight fluke species are only known to be [[Host (biology)|hosted]] by ''D. mawii''. ''[[Serpinema trispinosum]]'' is a parasitic [[nematode]] (also see entry on diet below) which has been recovered from a wide variety of freshwater turtles in North and Central America. Species of ''[[Placobdella]]'', a type of leech, have been Chiapas found to suck blood from the skin of these turtles, as well as a number of other ''[[Kinosternon]]'' mud turtles in other parts of southern Mexico.<ref>{{cite journal |last1=Paredes León |first1=Ricardo |last2=Garcia Prieto |first2=Luis |last3=Guzmán Cornejo |first3=Carmen |last4=León Règagnon |first4=Virginia |last5=Pérez |first5=Tila M. |date=15 October 2008 |title=Metazoan parasites of Mexican amphibians and reptiles |url=https://www.researchgate.net/publication/282355986 |journal=Zootaxa |volume=1904 |issue=1904 |pages=9, 10, 12, 21, 24, 42, 69, 70, 114, 115 |doi=10.11646/zootaxa.1904.1.1 |access-date=26 November 2021}}</ref><ref>{{cite journal |last1=Thatcher |first1=Vernon E. |date=October 1963 |title=Trematodes of Turtles from Tabasco, Mexico, with a Description of a New Species of ''Dadaytrema'' (Trematoda: Paramphistomidae) |journal=The American Midland Naturalist |volume=70 |issue=2 |pages=347–355 |doi=10.2307/2423063|jstor=2423063 }}</ref> A study on the blood of turtles collected in the wild in [[Pantanos de Centla Biosphere Reserve]] and a turtle breeding farm, both located in Tabasco, found 100% of the wild turtles were infected with a species of ''[[Haemogregarina]]'', a protozoan parasite inhabiting the red blood cells of turtles and spread by leeches. The protozoan was more prevalent during the [[rainy season]]. 27% of the wild turtles had leeches feeding off them, with no apparent detrimental effect on the hosts. The captive turtles were uninfected by both, but more unhealthy in other ways, wild turtles were better fed, bigger, and exhibited no real damage to the shell or major wounds.<ref name=Rangel2009>{{cite journal |last1=Rangel Mendoza |first1=Judith |last2=Weber |first2=Manuel |last3=Zenteno Ruiz |first3=Claudia E. |last4=López Luna |first4=Marco A. |last5=Barba Macías |first5=Everardo |date=October 2009 |title=Hematology and serum biochemistry comparison in wild and captive Central American river turtles (''Dermatemys mawii'') in Tabasco, Mexico |url=https://www.academia.edu/4126786 |journal=Research in Veterinary Science |volume=87 |issue=2 |pages=313–318 |doi=10.1016/j.rvsc.2009.03.006 |pmid=19380155 |access-date=28 November 2021}}</ref>

On a turtle farm in Veracruz it was noticed that turtles kept out of water for any period were highly susceptible to a bacterial lung infection.<ref name=vogtetal />

===Diet===
''Dermatemys mawii'' is [[herbivorous]]; it is a generalist, feeding on [[aquatic plant]]s, floating plants, shoreline emergents, bank vegetation and grasses depending on the habitat. Typically, these include Russell river grass (''[[Paspalum]] paniculatum''), among others.<ref name="animaldiversity.org">{{cite web | url=https://animaldiversity.org/accounts/Dermatemys_mawii/ | title=Dermatemys mawii (Central American River Turtle) | website=[[Animal Diversity Web]] }}</ref> It will also eat fruit and flowers opportunistically. During the [[rainy season]] the waters rise a few metres, sometimes many, in some places this brings the leaves and branches of terrestrial trees within the jaws of this turtle and it will largely [[Browsing (herbivory)|browse]] on this during this season, in other places the water floods pastures, and the turtle will primarily [[grazing|graze]] upon the submerged grass. The habitat appears to be the main factor impacting diet -in many rivers the water is too strong or the waters to muddy to sustain aquatic plant-life, and in these waters the turtles feed on plants growing on the banks. Where the banks are too steep for such plants, here the turtles feed on leaves of overhanging branches.<ref name=vogtetal />

It feeds during the night, spending most of the day underwater, generally in the deepest parts, usually near or under large branches and likewise, and often half-buried in the mud.<ref name=vogtetal />

Because leafy vegetables are low-energy foods requiring extensive digestion, and reptiles are [[Ectothermy|cold-blooded]], herbivorous reptiles usually try to speed things up by [[Sunning (behaviour)|basking]] in the sun -water turtles plopping back into the water as one walks past a lake is a common experience in tropical and subtropical climates. This species does not bask, maintaining the same body temperature as the waters which surround it. Thus this means that it likely has a specialised gut flora to help it break down its food, but the particulars of this have not adequately been explored. One experiment found that symbiotic microorganisms must aid in digestion -when eggs from the same nest were incubated and separated into two groups, with the hatchlings in one group being fed adult faeces and other group lacking this [[food additive]], found that the young which snacked on excrement grew much faster than their peers. In [[green iguana]]s the behaviour of young feeding on adult dung is known to be important, but it is unknown if this means that turtle hatchlings also exhibit this behaviour in the wild. The intestines of these turtles are commonly swarming with [[nematode]]s-again, in iguanas of the ''[[Cyclura]]'' genus similar worms appear to aid in digestion, but in this case it is unknown if they are parasites, [[commensal]]s or [[symbiont]]s.<ref name=vogtetal />

Captured ''D. mawii'' will occasionally, however, eat [[fish]]. Juveniles in captivity tend to more readily accept animal matter as food which may show that young ''D. mawii'' are more apt to be carnivorous.<ref name="animaldiversity.org"/>

===Reproduction===
The exact reproductive season for this species, ''Dermatemys mawii'', has been confused in the literature.<ref name=lee96>Lee JC (1996). ''The Amphibians and Reptiles of the Yucatán Peninsula''. Ithaca, New York: Comstock Publishing Associates, a Division of Cornell University Press. 500 pp. {{ISBN|978-0801424502}}.</ref> However, it is possible that a combination of a diapause and variable local reproductive cues is responsible for this. There appears to be a primary breeding season timed with the later part of the rainy season (September to December)<ref name=pol1996>{{cite journal |last1=Polisar |first1=John |date=1996 |title=Reproductive biology of a flood-season nesting freshwater turtle of the northern neotropics: ''Dermatemys mawii'' in Belize |url=http://library.bfreebz.org/Reptiles-Amphibians/John%20Polisar,%20Reproductive%20Biology%20of%20a%20Flood-Season%20Nesting%20Freshwater%20Turtle%20of%20the%20Northern%20Neotropics_%20Dermatemys%20mawii%20in%20Belize,%201996.pdf |journal=Chelonian Conservation and Biology |volume=2 |issue=1 |pages=13–15 |access-date=25 November 2021}}</ref> and a secondary one at the beginning of the dry season (January to February).<ref name=vogtetal /> The species can lay up to 4 clutches per year with an average of 2–20 eggs per clutch; clutch sizes over 15, however, were not common.<ref name=vogtetal /><ref name=pol1996 />

As this species often buries its eggs in more than one nests with a rather random spatial distribution within one to three metres along a constantly shifting shoreline, the nests are extremely difficult to locate for humans, and finding eggs is very uncommon.<ref name=vogtetal /> In 1989 and 1990, despite nightly searches by a team during two seasons, only two nests were located. Polisar was never able to witness nesting himself, but three accounts from local hunters had the animals nesting within 1.5 metres from the shoreline.<ref name=pol1996/>

In 1996 Polisar published that it was quite possible that the turtles nest underwater like the Australian ''[[Chelodina rugosa]]'',<ref name=pol1996/> a claim repeated as a certainty in later works,<ref name=Platt2011/> but in 2011 Vogt ''et al''. dismiss the claim as invented by 'locals' confused by the constantly rising and falling waters of their homeland.<ref name=vogtetal />

==Interaction with humans==
''Dermatemys mawii'' has been hunted for food for millennia. Archaeologists have recovered the remains of what appear to be [[Maya civilization|Ancient Mayan]] feasts, wherein large numbers of turtles were roasted.<ref name=Guevara2017>{{cite journal |last1=Guevara Chumacero |first1=Miguel |last2=Pichardo Fragoso |first2=Alejandra |last3=Martínez Cornelio |first3=Monserrat |date=2017 |title=La tortuga en Tabasco: comida, identidad y representación |trans-title=The Turtle in Tabasco: Food, Identity and Representation |url=http://www.scielo.org.mx/pdf/ecm/v49/0185-2574-ecm-49-00097.pdf |journal=Estudios de Cultura Maya |volume=xlix |pages=97–122 |language=es |doi=10.19130/iifl.ecm.2017.49.758 |access-date=23 November 2021}}</ref> Such remains are also found in areas, such as the eastern and northern [[Yucatán]], where the species is not believed to occur today. This could be due to import during Mayan times, or represent a distribution it is now [[extirpated]] from, or modern scientists simply have not looked properly here.{{citation needed|date=January 2022}} A 2011 study of the [[mtDNA]] of extant populations throughout the range of this species indicated that the population was likely highly impacted during Mayan times, and may have even been extirpated from certain areas, only to be restocked from other waterways. The [[mitochondria]]l divergences likely represent hydrological reproductive barriers between populations that may have existed for up to three million years, but there is an absence of a clear [[Phylogeography|phylogeographical pattern]] between the lineages and the collection localities, with different mitochondrial lineages interspersed amongst each other, which shows probable large-scale [[gene flow]] between populations. This can be explained by colonisation of the area by imported animals. Haplotype diversity was furthermore found to be quite low in some populations, which was explained as likely the result of [[population bottleneck|bottlenecks]] resulting from over-harvesting during Mayan followed by population expansions.<ref name=González2011/> A later genetic study refined this story and largely supported it, but proposed alternate explanations. Bottlenecks were not found to be caused by ''recent'' hunting pressure in this study (see genetics section above).<ref name=González2013/> According to a study by Götz which looked at the contents of different kitchen middens in the Yucatán, it is clear that although all species of turtles were eaten, ''D. mawii'' was a luxury product of the elites. Some time later, in the mid-16th century, Spanish explorers of the Gulf Coast of Mexico relate that turtles were a common meal for them there.<ref name=Guevara2017/>

The turtles were also used for warfare by the Mayans, the carapace being used as a shield by Mayan warriors.<ref name=Guevara2017/>

Today the turtle remains much loved as a traditional feast food in the Tabasco community, where it is considered a mark of cultural identity. ''D. mawii'' is primarily prepared for the religious festivities of [[Lent]] and [[Holy Week|''Semana Santa'']].<ref name=Guevara2017/>

In Belize these turtles are a culturally important food and popularly served as a traditional dish especially around the festivities of Easter, Christmas and La Ruta Maya, which is a canoe race in March attended by many people.<ref>{{cite web |url=https://tidebelize.org/wp-content/uploads/2021/08/Requena-Lord-2014-Raising-national-awareness-of-the-hicatee-Dermatemys-mawii-and-public-support-for-its-protection-in-Belize_0.pdf |title=Raising national awareness of the hicatee (''Dermatemys mawii'') and public support for its protection in Belize |last1=Requena |first1=E. |last2=Lord |first2=J. |last3=Tricone |first3=F. |date=2017 |website= |publisher=Toledo Institute for Development and Environment |access-date=23 November 2021}}</ref> A recipe from the 1950s or 1960s advises pouring boiling water over the chopped pieces of hickatee to remove the thin skin, seasoning the meat with thyme, black pepper, onion, garlic and vinegar and letting it marinate overnight, cooking in hot oil, mixing with coconut cream and serving with rice.<ref>{{cite web |url=https://ambergriscaye.com/forum/ubbthreads.php/topics/548941/hicatee.html |title=Hicatee |author=Marty |date=19 March 2021 |website=Ambergris Caye Forums - Culture- Food & Recipes |publisher=Ambergris Caye Message Board |access-date=23 November 2021}}</ref>

In the Petén highlands of Guatemala it is the most esteemed turtle because of its delicious flesh.<ref name=Campbell1998/>

==Conservation==
''Dermatemys mawii'' is a heavily exploited turtle; it is primarily harvested for its meat, exploitation of nesting females and their eggs is inconsequential because the nests are extremely hard to find.<ref name=pol97>Polisar, J. (1997) [http://nytts.org/proceedings/polisar.htm Effects of exploitation on ''Dermatemys mawii'' populations in northern Belize and conservation strategies for rural riverside villages]. ''in'' J.V. Abbema (Ed.) Proceedings of the Conservation, Restoration, and Management of Tortoises and Turtles: An International Conference, pp.&nbsp;441–443</ref> The species has been overhunted because it is valued by local people as a food, thus the meat fetches good prices.<ref name=vogtetal />

The turtle is now uncommon from much of its former range in southern Mexico.<ref name=vogtetal /> It was assessed by the IUCN as being a [[critically endangered species]] in 2006<ref name="iucn"/> and is listed as endangered under the [[Endangered Species Act|US Endangered Species Act]]. It is listed in Appendix II of the [[Convention on International Trade in Endangered Species]] (CITES) meaning international trade is regulated by the CITES permit system,<ref name="CITES"/> and local laws are in place to control hunting.

===Conservation efforts in Belize===
The non-governmental conservation organisation the Turtle Survival Alliance (TSA) has conducted at least two hickatee workshops in Belize in the early 2010s where attendees were taught net capture techniques, measuring captured turtles and recording the information on standard collection sheets.<ref>{{cite web|last=Rainwater|first=Thomas|title=Finishing up the Hicatee Workshops in Belize|url=http://www.turtlesurvival.org/blog/1/129|work=Turtle Survival Alliance blog|access-date=12 June 2011|archive-url=https://web.archive.org/web/20110721205818/http://www.turtlesurvival.org/blog/1/129|archive-date=21 July 2011}}</ref>

A countrywide survey of the population in Belize in 1983 and 1984 found that the species was common and abundant in some areas, but declining in population in more human-populated areas. Research in north-central Belize from 1989 through 1991 determined that harvesting rates in human-populated areas were unsustainable. As such, in 1993 the government of Belize instituted a number of new laws meant to control hunting and forbid trade. Hunting was forbidden in a certain closed season, hunters were allowed to bag no more than three turtles, and females above a certain size have to be released. A series of protected zones were established in a number of the major waterways in northern Belize. A 1998 and 1999 survey in north-central Belize found that the species was still common in remote areas, but was also still declining in more populated areas. A 2010 countrywide survey indicated that the population was much the same as in the previous surveys, depressed in human-populated areas, but healthy populations continue to exist in more remote areas. Although there was not much difference between the situation of the population in 2010 compared to the 1980s, there was a general decrease in overall numbers and sighting localities. Interviews with locals indicate the 1993 laws are largely ineffective, hunting continues to be performed with in some areas with hundreds of turtles being caught in small parts of the [[Belize River]], and the traditional Easter dish of the country continues to be served in rural restaurants.<ref name=tsa2010/>

=== Captive breeding ===
In 1997 Polisar claimed it was rarely found in [[Captivity (animal)|captivity]], and that breeding would probably be impractical because he thought the nesting behaviour was complicated in this species.<ref name=pol97/> He seems to be somewhat wrong in this. The first turtle farm in Mexico has been operating in [[Nacajuca]], Tabasco, since the 1980s when it began as a rescue centre. It is the largest captive breeding facility for ''Dermatemys'' today, with a population of about 700 individuals in 2006,<ref name=Rangel2009/> and 800 in 2011.<ref name=vogtetal /> The turtles were three times a week fed with commercial pellets for [[tilapia]] fish, ''[[Melampodium divaricatum]]'' and ''[[Eichhornia crassipes]]'', sometimes with the odd vegetable. The reproductive adult females were injected with [[calcium]] supplements twice a year (March, after the end of the [[oviposition]] period, and June–July at the beginning of the courtship period).<ref name=Rangel2009/> The Mexican government has stimulated the breeding of this species in captivity, and as of 2009 fourteen farms were officially registered with the [[SEMARNAT|Secretaría del Medio Ambiente y Recursos Naturales]], holding a few dozen to a few hundred turtles each.<ref>{{cite journal |last1=Rangel Mendoza |first1=Judith A. |last2=Weber |first2=Manuel |date=15 August 2015 |title=Evaluación del Estado Físico de la Tortuga blanca, ''Dermatemys mawii'', bajo Condiciones de Cautiverio en Tabasco, México |trans-title=Physical Examination of Central American River Turtle, ''Dermatemys mawii'', in Captivity in Tabasco, Mexico |url=http://www.scielo.org.mx/pdf/agro/v49n5/v49n5a3.pdf |journal=Agrociencia |volume=49 |issue= |pages=499–511 |language=es, en |access-date=24 November 2021}}</ref>

As a generalist herbivore [[fodder]] costs are low. However, growth rates are low. In 2011 some US scientists mused that commercial breeding might be cost effective using experimental aquatic [[polyculture]] systems with the turtles as a secondary income source, and shrimp as the main crop. The turtles could graze on weeds and grasses, and do not harm the shrimp. A three year pilot study was done in Veracruz, after the pond weeds were consumed the turtles were fed grass clippings, and the turtles reproduced each year.<ref name=vogtetal />

A project conducted by TSA on Belize Foundation for Research and Environmental Education property began in early 2011 focused on generating food plants and exploring husbandry details, such as egg laying and incubation. Located in southern Belize along the Bladen River, the {{convert|1200|acre|km2|abbr=on}} property is situated among four protected areas ([[Bladen Nature Reserve]], [[Cockscomb Basin Wildlife Sanctuary|Cockscomb Basin Jaguar Reserve]], Deep River Forest Reserve and Maya Mountain Forest Reserve). The goal of the program was to generate hatchlings and release them for stocking purposes.<ref name=tsa2010/>

As of 2006 it was kept at the following zoos: [[Veracruz Aquarium]], [[Chicago Zoo]], [[Detroit Zoo]], [[Philadelphia Zoo]] (with the most specimens), and the [[Guatemala City Zoo]] (with only one).<ref name="iucn"/>

==Notes==
{{notelist}}

==References==
{{Reflist|30em}}

{{Commons category|Dermatemys mawii}}
{{Wikispecies|Dermatemys mawii}}
{{Dermatemydidae}}
{{Taxonbar |from=Q301044}}

[[Category:Dermatemys]]
[[Category:Fauna of Southern Mexico]]
[[Category:Reptiles of Belize]]
[[Category:Reptiles of Guatemala]]
[[Category:Reptiles of Honduras]]
<!-- [[Category:Monotypic reptile genera]] moved to genus redirect -->
[[Category:Reptiles described in 1847]]
[[Category:Taxa named by John Edward Gray]]
[[Category:Critically endangered fauna of North America]]