Fact-checked by Grok 2 weeks ago

Yangtze giant softshell turtle

The Yangtze giant softshell turtle (Rafetus swinhoei), also known as Swinhoe's softshell turtle, is a large-bodied freshwater species of the family Trionychidae, endemic to the lower Yangtze River floodplain in China and the Red River drainage in Vietnam and southern China.^[1] Adults typically exhibit a carapace length exceeding 100 cm, a width up to 70 cm, and body weights ranging from 70 to 100 kg, with a recorded maximum of 169 kg, making it one of the world's largest softshell turtles.^[2] The turtle inhabits deep river channels, lakes, and floodplains, where it spends much of its time buried in sediment, emerging to forage on fish, mollusks, and crustaceans.^[1] Classified as critically endangered by the IUCN, the species has undergone drastic declines due to overexploitation for food and medicine, habitat degradation from dams and pollution, and incidental capture, reducing its population to potentially just two confirmed individuals as of 2024—one captive male in Suzhou Zoo, China, and one wild individual in Xuan Khanh Lake, Vietnam.^[2]^[2] Environmental DNA surveys have suggested the possible presence of additional specimens, raising cautious optimism for locating breeding pairs, though repeated captive breeding attempts have failed, underscoring the species' functional extinction risk.^[3]^[4] Conservation initiatives emphasize habitat restoration, anti-poaching measures, and advanced detection technologies like portable eDNA kits to avert total extinction.^[5]

Taxonomy and systematics

Scientific classification

The Yangtze giant softshell turtle (Rafetus swinhoei) is a species in the family Trionychidae, the softshell turtles, within the order Testudines.^[6]^[7] The binomial name was established by John Edward Gray in 1873, originally under the genus Trionyx, but later reclassified into Rafetus based on morphological and phylogenetic distinctions from related genera like Pelochelys.^[6]^[8]

Rank	Classification
Kingdom	Animalia
Phylum	Chordata
Class	Reptilia
Order	Testudines
Suborder	Cryptodira
Superfamily	Trionychoidea
Family	Trionychidae
Subfamily	Trionychinae
Genus	Rafetus
Species	R. swinhoei

This placement reflects its shared traits with other trionychid turtles, including a leathery carapace and aquatic adaptations, supported by anatomical studies and genetic data distinguishing it from Asian softshells in Pelochelys.^[9]^[8] No subspecies are currently recognized, though historical records note synonyms like Trionyx sinensis and Pelochelys swinhoei, now synonymized under Rafetus swinhoei.^[6]

Evolutionary history and relations

The Yangtze giant softshell turtle, Rafetus swinhoei, belongs to the family Trionychidae, a group of softshell turtles characterized by leathery shells and adaptations for aquatic lifestyles, with a fossil record extending to the Late Cretaceous but modern diversification occurring in the Paleogene.^[10] Within Trionychidae, R. swinhoei is placed in the subfamily Trionychinae, which includes other Asian and African softshell genera, and phylogenetic analyses using mitochondrial and nuclear DNA support Trionychidae as the sister taxon to Carettochelyidae (pig-nosed turtles).^[11] Genus-level relations position Rafetus as monophyletic, with R. swinhoei forming a clade with the Euphrates softshell turtle (R. euphraticus), diverging from other trionychines; molecular clock estimates date this intraspecific split to the late Miocene, approximately 5–10 million years ago, reflecting vicariance driven by tectonic and climatic changes in Eurasia.^[12]^[13] A 2022 genomic study further indicates a close phylogenetic affinity between R. swinhoei and the Chinese softshell turtle (Pelodiscus sinensis), sharing a common ancestor around 19.8 million years ago (95% highest posterior density: 13.5–27.0 million years ago), consistent with Oligo-Miocene radiations in East Asian freshwater systems.^[14] Fossil evidence for the genus Rafetus includes R. bohemicus from the Miocene of central Europe (Czech Republic), redescribed in 2023 as a valid trionychine species with morphological traits akin to extant Rafetus, suggesting a historically broader Eurasian distribution before range contraction due to post-Miocene cooling and habitat fragmentation.^[13] Contemporary R. swinhoei exhibits extremely low genetic diversity across remnant populations, indicative of a prolonged effective population size reduction or ancient bottleneck, potentially tracing to Pleistocene glacial cycles that isolated Yangtze Basin refugia.^[15]^[16] This genetic pattern underscores the species' deep evolutionary lineage within Trionychidae, with no evidence of recent hybridization inflating variability.^[14]

Physical description

Size and morphology

The Yangtze giant softshell turtle (Rafetus swinhoei) attains one of the largest sizes among freshwater turtle species, with the carapace typically exceeding 50 cm in straight length and reaching up to 86 cm in documented specimens, while curved measurements can surpass 100 cm.^[17] Overall body length often exceeds 100 cm, and widths approach 70 cm, with weights ranging from 70 to 100 kg in adults, though larger individuals have been reported at 170-247 kg.^[17]^[18] One rescued specimen measured 90 cm in length and weighed 69 kg.^[19] These dimensions reflect observations from limited live and historical captures, as the species' extreme rarity constrains comprehensive measurement data.^[20] Morphologically, the turtle features a characteristic softshell structure with a leathery, flexible carapace lacking rigid scutes, adapted for a flattened, streamlined body suited to aquatic environments.^[17] The head is notably large, exceeding 20 cm in length and 10 cm in width, with a proboscis-like snout and dorsally positioned eyes facilitating ambush predation.^[17] Limbs are paddle-like with webbing for swimming, and the neck is elongated for striking. Sexual dimorphism is evident, with females generally larger than males, the latter distinguished by a longer, thicker tail.^[17] Coloration includes an olive-gray carapace, often with subtle spotting in juveniles that fades in adults.^[21] Cranial morphology, including broader skulls in some populations, has been noted in comparative studies, though variation requires further verification due to taxonomic debates.^[20]

Adaptations

The Yangtze giant softshell turtle exhibits morphological adaptations typical of the Trionychidae family, including a leathery carapace composed of reduced bony elements covered in tough skin rather than keratinized scutes, which minimizes hydrodynamic drag and facilitates burial in riverbed sediments for ambush predation and predator avoidance.^[13]^[22] This soft, flexible shell, combined with a dorsoventrally flattened body, enhances maneuverability in fast-flowing rivers and allows the turtle to compress into shallow substrates during periods of environmental stress, such as low oxygen levels or seasonal drying.^[23] The species features a tubular, proboscis-like snout formed by elongated nostrils, enabling it to breathe while the majority of its body remains submerged or buried, an adaptation suited to its primarily aquatic lifestyle in turbid, oxygen-poor waters.^[24] Its forelimbs and hindlimbs bear fully webbed feet with strong claws, providing powerful propulsion for swimming and digging into mud, where individuals spend much of their time concealed.^[23] These traits support a carnivorous diet reliant on stealthy ambushes of fish and invertebrates from cover. Attaining a carapace length exceeding 1 meter and weights over 100 kg in adults, the turtle's massive size confers protection from most predators once mature, positioning it as a potential apex predator in its riverine habitats and reducing intraspecific competition through spatial dominance.^[25] Such gigantism likely evolved in response to abundant prey resources in large Asian river systems, though direct physiological data on metabolic efficiencies remain limited due to the species' rarity.^[26]

Distribution and habitat

Historical geographic range

The Yangtze giant softshell turtle (Rafetus swinhoei) was historically distributed across large river systems in eastern and southern China, primarily the Yangtze River basin, including the lower Yangtze floodplain, Lake Taihu, and areas around Shanghai.^[6] Specimens were recorded from Yunnan Province in the south, indicating a broader range extending into subtropical riverine habitats suitable for large-bodied aquatic turtles.^[6]^[27] In northern Vietnam, the species occupied the Red River drainage system and associated lakes, such as Hoan Kiem Lake in Hanoi, where a subspecies (R. s. vietnamensis) was described based on local specimens.^[6]^[19] Historical accounts and surveys confirm occurrences in other major rivers like the Xam and Ma Rivers, suggesting connectivity between Chinese and Vietnamese populations via shared drainage basins prior to modern habitat fragmentation.^[28]^[19] Fossil and subfossil evidence supports a prehistoric presence in these regions dating back millennia, with the species adapted to deep, slow-moving waters in lowland floodplains; however, post-20th-century declines have restricted verifiable historical records to these core areas without confirmed extensions into more distant Southeast Asian or Indian river systems.^[16]

Current known locations

As of 2024, only two living individuals of the Yangtze giant softshell turtle (Rafetus swinhoei) are confirmed, with no verified populations in their historical Yangtze River range in China.^[4] One male resides in captivity at Suzhou Shangfangshan Forest Animal World (also referred to as Suzhou Zoo) in Jiangsu Province, eastern China, where it has been held since the early 2000s following rescue from the wild.^[29] This facility represents the sole known captive site, with conservation efforts including past artificial insemination attempts, though unsuccessful due to the absence of a viable female partner.^[30] The second confirmed individual inhabits Xuan Khanh Lake, a reservoir near Hanoi in northern Vietnam, verified through environmental DNA analysis of water samples in 2018, indicating at least one adult presence.^[4] This lake, part of the Red River Delta system, supports the turtle's preference for deep, slow-moving freshwater bodies with muddy substrates.^[19] The sex of this wild specimen remains unconfirmed but is presumed male following the 2023 death of the last known female in nearby Dong Mo Lake, which had been documented since 2008 and died on April 21 of undetermined causes, leaving the species functionally extinct without natural reproduction possible.^[30]^[31] Ongoing surveys using portable eDNA kits, developed and field-tested in 2024–2025, target potential undetected individuals in Vietnamese river systems like the Red, Da, and Chu, but no additional confirmations have been reported as of early 2025.^[5] These efforts underscore the absence of verified wild populations elsewhere, with historical sightings in China's Yangtze Basin unconfirmed since the 1990s due to extensive habitat loss and exploitation.^[32]

Ecology and behavior

Diet and foraging

The Yangtze giant softshell turtle (Rafetus swinhoei) maintains an omnivorous diet, with stomach contents from captured specimens revealing a mix of animal prey including fish, crabs, snails, birds such as moorhens (Amaurornis spp.) and pond herons (Ardeola spp.), rats, insects, carrion, and reportedly ducks, alongside plant matter like lotus roots, grasses, water hyacinth, water lily roots, and green rice leaves.^[33]^[21]^[34] Dissections by hunters indicate variability, with some individuals containing solely fish and others exclusively vegetation such as grass and water lily roots, underscoring opportunistic feeding habits.^[33] Primarily carnivorous, the species targets aquatic and semi-aquatic prey, consistent with reports of fish, crustaceans, mollusks, amphibians like frogs, and occasional vertebrates.^[21]^[34] In captivity, individuals have been sustained on pieces of fresh fish, reflecting a focus on protein-rich foods. Foraging occurs in deep riverine and lacustrine habitats where the turtle remains largely submerged, emerging periodically to breathe; it employs ambush predation by burying in benthic sediments to intercept passing prey, though hunters have observed active consumption of floating plants, suggesting behavioral flexibility.^[33]^[21] Due to the species' extreme rarity, detailed foraging observations are limited to anecdotal accounts from fishermen and incidental captures, with no systematic studies available.^[33]

Reproduction

Females reach sexual maturity at an advanced age, estimated at over 20 years, contributing to their slow reproductive rates and vulnerability to population declines.^[35] Mating involves courtship displays, including neck abrasions from aggressive interactions observed in captive pairs following hibernation periods.^[36] Egg-laying occurs on sandy riverbanks during suitable seasonal conditions, with females excavating nests to deposit clutches.^[37] Clutch sizes range from 20 to over 80 eggs, with documented instances of 89 eggs across two clutches in a single season.^[17] Females may produce three to four clutches annually under optimal conditions.^[35]^[37] In captivity, breeding trials since 2008 at Suzhou Zoo paired a female with the sole known fertile male, resulting in repeated egg-laying totaling hundreds of eggs, but none have hatched due to suspected male infertility or suboptimal incubation conditions.^[38]^[39] Artificial insemination was attempted in 2015 as a final measure for this pair, but the female died in 2019 without producing viable offspring.^[40] No successful reproduction has been recorded in recent decades, underscoring the species' intrinsic reproductive limitations amid critically low population numbers.^[41]

General behavior and physiology

The Yangtze giant softshell turtle (Rafetus swinhoei) displays physiological traits characteristic of the Trionychidae family, adapted for a fully aquatic existence in large river systems. Its carapace consists of tough, leathery skin rather than rigid bony plates, reducing hydrodynamic resistance and enabling burrowing into soft substrates for concealment and ambush foraging. The head morphology includes a tubular, proboscis-like snout with valvular nostrils, facilitating respiration while the body remains submerged or embedded in sediment, and dorsally positioned eyes that enhance surveillance of the surface environment.^[42] These features support extended periods of apnea, with the turtle capable of remaining underwater for prolonged durations, supplemented by occasional surfacing for air.^[25] Behaviorally, R. swinhoei is predominantly solitary and cryptic, spending the majority of its time buried in riverbed mud or sand, emerging primarily during nocturnal or crepuscular hours to forage or bask. Limited field observations suggest an ambush predatory strategy, where the turtle lies in wait partially concealed before striking at passing prey with rapid extension of its long neck. In captivity, individuals exhibit territorial aggression, including snapping at conspecifics or handlers, and have demonstrated courtship behaviors such as mutual circling and mounting attempts between males and females during breeding trials conducted in 2015.^[43] Due to the species' extreme rarity, with fewer than four confirmed individuals as of 2023, comprehensive data on social interactions or daily activity cycles remain scarce, inferred partly from congeners in the genus Rafetus.^[25]

Population status

Historical population declines

The population of the Rafetus swinhoei underwent a precipitous decline exceeding 99% over the past century, rendering it functionally extinct in the wild by the early 21st century.^[44] Historical records indicate the species was already scarce in the Yangtze River basin and Taihu Lake region of China during the 1870s, when naturalist Pierre-Marie Heude collected specimens, suggesting it may never have been highly abundant but was present in sufficient numbers to support local documentation.^[16] Intensification of human activities in the 20th century, including widespread hunting for meat and use in traditional medicine, accelerated the reduction, as demand from growing populations in China and Vietnam outpaced the turtle's low reproductive rates and long generation times.^[19] Habitat fragmentation from large-scale infrastructure projects further compounded the losses, particularly in China, where the construction of the Gezhouba Dam in 1981 blocked upstream migration routes and inundated sandy nesting beaches essential for egg-laying.^[45] This barrier, combined with pollution from industrial runoff and agricultural expansion, disrupted the species' reliance on deep river channels and lake systems for foraging and shelter, leading to localized extirpations in the Yangtze system by the 1990s.^[46] In northern Vietnam's Red River drainage, similar declines were noted from the 1980s onward, with fishermen reporting fewer sightings amid ongoing exploitation and hydrological alterations, though unconfirmed reports persisted into the early 2000s.^[45] Genomic analyses corroborate a protracted bottleneck, revealing the lowest heterozygosity levels among turtle species examined, indicative of sustained small population sizes and genetic erosion over recent generations rather than a sudden crash.^[26] By the late 20th century, verified wild encounters had dwindled to isolated captures, transitioning the species from rarity to near-absence across its former range.^[16]

Current known individuals and estimates

As of 2024, only two confirmed living individuals of the Yangtze giant softshell turtle (Rafetus swinhoei) persist, both males, which precludes natural reproduction and classifies the species as functionally extinct. One male, estimated to be over 100 years old, is maintained in captivity at Suzhou Shangfangshan Forest Zoo in Jiangsu Province, China, where it has participated in unsuccessful artificial insemination attempts with deceased females.^[47]^[48] The second male inhabits Xuan Khanh Lake near Hanoi, Vietnam, confirmed through visual sightings and environmental DNA (eDNA) detection, though its exact status remains semi-wild amid urban pressures.^[30]^[19] The death of the last known female occurred on April 22, 2023, at Dong Mo Lake, Vietnam, from complications including a tumor and shell infection, leaving no fertile females globally.^[49]^[30] Prior to this, breeding trials between the Suzhou male and imported females from Vietnam yielded infertile eggs, attributed to advanced age, genetic incompatibility, or physiological factors.^[48] Population estimates beyond these individuals are negligible, with extensive river and lake surveys in China and Vietnam since the 1990s yielding no additional confirmed sightings. Recent eDNA protocols, including portable kits deployed in 2024–2025, aim to detect trace genetic material in potential habitats like the Yangtze River basin and Red River delta, but have not verified further specimens as of early 2025.^[5]^[32] Conservationists assess the wild population at near zero, citing habitat fragmentation and historical poaching as barriers to undetected survivors.^[19]^[30]

Threats to survival

Habitat alteration from development

Habitat alteration from development has profoundly impacted the Yangtze giant softshell turtle (Rafetus swinhoei) through river damming, infrastructure expansion, and land conversion, fragmenting its preferred deep riverine and lacustrine environments in the Yangtze and Red River basins. Hydropower dams disrupt natural flow regimes, reduce sediment deposition essential for nesting banks, and inundate suitable habitats; for example, proposed cascades of dams along the Red River in China could permanently flood 73% of potential nesting areas, exacerbating isolation of remaining populations.^[50]^[1] Urbanization and associated settlements drive direct conversion of wetlands and riverine floodplains into residential or agricultural land, diminishing sandy nesting sites and foraging grounds critical for the species' burrowing and ambush predation behaviors. In northern Vietnam's Red River system, infrastructure projects including dams and navigation improvements have degraded over 80% of historical wetland extents through fragmentation and erosion, limiting access to deep-water refugia.^[45]^[51] Sand mining, often tied to construction booms, further erodes riverbanks and alters substrate stability, compounding dam-induced hydrological changes and rendering habitats unsuitable for egg-laying, which requires loose, sandy substrates above high-water lines. These developmental pressures, intensified since the mid-20th century, have confined surviving individuals to isolated remnants like Dong Mo Lake in Vietnam, where ongoing encroachment continues to shrink viable areas.^[51]^[52]

Direct exploitation

The Yangtze giant softshell turtle (Rafetus swinhoei) has faced intense direct exploitation, primarily through hunting for its meat—regarded as a delicacy in regional cuisines—and eggs, with the carapace harvested for use in traditional Chinese medicine.^[53] This subsistence and commercial harvesting occurred historically across its range in the Yangtze River basin in China and the Red River in Vietnam, where local fishers targeted the species opportunistically during foraging or nesting periods.^[19] Overexploitation intensified in the 20th century, reducing once-abundant populations to critically low levels, as evidenced by the near-absence of sightings in the wild by the late 1900s despite earlier records of common occurrence.^[54] Legal protections, including national bans on hunting in China and Vietnam and inclusion in CITES Appendix I (prohibiting international commercial trade), were implemented to curb this pressure, yet illegal poaching persists as a latent threat due to the species' high value on black markets for food and purported medicinal benefits.^[55] Documented poaching incidents are scarce in recent decades, attributable to the turtle's extreme rarity—fewer than four confirmed individuals remain globally—but surveys indicate ongoing vulnerability to opportunistic capture by fishers, who historically contributed to local extirpations through direct harvesting rather than bycatch alone.^[56]^[45] The case exemplifies softshell turtles' susceptibility to overexploitation, where even moderate hunting rates can precipitate functional extinction in large-bodied, low-reproductive species.^[55]^[57]

Intrinsic vulnerabilities

The Yangtze giant softshell turtle (Rafetus swinhoei) possesses life history traits typical of many long-lived chelonians, including slow somatic growth, delayed sexual maturity, and an extended lifespan often surpassing 100 years, with females documented as fertile beyond 90 years of age.^[35] ^[21] These characteristics result in prolonged generation times, estimated at several decades, which severely limit the species' capacity for demographic recovery following population bottlenecks.^[21] Reproductive output is inherently low, with females producing clutches of 20 to 80 eggs, typically once per breeding season, though nest success and early-life survival rates remain poorly quantified but are inferred to be minimal based on the absence of confirmed wild recruitment in recent decades.^[58] ^[35] High juvenile mortality, combined with the species' reliance on specific deep-water habitats for development, exacerbates this vulnerability, as even small perturbations can prevent cohort replacement.^[21] In captivity, breeding attempts have repeatedly failed despite interventions like artificial insemination, with evidence suggesting male infertility or age-related reproductive senescence in known individuals, further underscoring physiological constraints on propagation.^[40] ^[41] Low genetic diversity, stemming from historical bottlenecks, compounds these issues by increasing susceptibility to inbreeding depression and reducing adaptive potential, though this interacts with extrinsic factors.^[16] Overall, these intrinsic attributes render the species functionally incapable of sustaining populations below critical thresholds without intensive human intervention.^[44]

Conservation measures

Captive management and breeding trials

In 2008, a male and female Rafetus swinhoei—both estimated to be over 100 years old—were paired at Suzhou Zoo in China as part of a captive breeding program coordinated by the Turtle Survival Alliance and Wildlife Conservation Society to prevent extinction.^[19]^[43] Natural mating attempts failed due to behavioral incompatibilities and the turtles' advanced age, prompting exploration of artificial insemination techniques.^[39] In May 2015, the first artificial insemination of the species was performed on the female using sperm collected from the male, under veterinary oversight to address reproductive challenges in this long-lived taxon.^[40] No viable eggs or offspring resulted from this or subsequent efforts, highlighting difficulties in captive reproduction for such rare, geriatric specimens.^[38] The Suzhou female died on April 23, 2019, from a gastrointestinal obstruction, leaving the resident male as the only confirmed captive individual worldwide and effectively halting the program's immediate breeding prospects.^[59] Captive management at Suzhou has since emphasized health monitoring, enclosure optimization with large aquatic habitats mimicking riverine conditions, and dietary provision of fish and invertebrates to sustain the male's condition.^[38] Conservationists have advocated genetic banking of the male's semen for future use, though viability remains unproven without a viable female partner.^[39] A potential female discovered in Dong Mo Lake, Vietnam, in October 2020 was genetically confirmed as R. swinhoei in December 2020, raising hopes for relocation to a breeding facility.^[60] However, capture attempts to integrate her into a captive program have failed due to her wariness and the lake's open environment, with non-invasive monitoring preferred to avoid stress-induced mortality.^[61] As of 2024, no successful captive breeding has occurred, underscoring the species' intrinsic reproductive hurdles, including low fertility in remnant populations and logistical barriers to pairing distant individuals.^[4] Ongoing trials prioritize semen cryopreservation and eDNA-assisted mate sourcing over unproven translocation risks.^[5]

Field surveys and detection methods

Field surveys for the Yangtze giant softshell turtle (Rafetus swinhoei) have traditionally involved interview-based assessments with local fishers and hunters, direct visual searches, and collection of physical evidence such as shells or skulls. Since 2003, the Asian Turtle Program has conducted interview surveys across eight provinces in northern Vietnam, yielding seven deceased specimens and one photographed live individual, with confirmations of wild presence at Dong Mo Lake in 2007 and Xuan Khanh Lake in 2016.^[19] These methods prioritize areas based on presence probability (scored from confirmed evidence to low-likelihood reports), habitat alteration (from natural to severely modified), and fishing intensity (low to high), as applied in 80 interviews along Vietnam's Da River system in November 2019, identifying 13 potential sites with recent sightings up to 2019.^[62] Ongoing visual and interview surveys in China's Yangtze River and other systems have not confirmed additional wild individuals.^[63] Detection challenges stem from the turtle's cryptic behavior, as it remains submerged in deep water for extended periods, surfacing only briefly to breathe, which limits reliable visual identification.^[63] To address this, environmental DNA (eDNA) analysis has emerged as a key non-invasive method, detecting genetic material shed into water. The Asian Turtle Program, in collaboration with Washington State University, initiated eDNA development in 2013, deploying a portable quantitative PCR (qPCR) platform in 2018 that targets the species' cytochrome b and CO1 genes using onsite water filtration, DNA extraction kits, and a field thermocycler.^[4] Field applications of eDNA include pilot testing at Dong Mo and Xuan Khanh Lakes in 2018, followed by 113 samples from Dong Mo (145 ha) in 2019–2020 yielding no positives, and 62 samples from a 28-ha penned area at Xuan Khanh in 2021 detecting six positives (9.7% rate) with cycle thresholds of 34.0–38.7, confirmed via sequencing.^[4] The assay achieves 98–109% efficiency and sensitivity to 10–50 DNA copies per reaction, with pooled filters enabling cost-effective scanning of larger areas; eDNA confirmed a second wild individual at Xuan Khanh in April 2018.^[19]^[4] Separately, the Wildlife Conservation Society is validating a hand-held eDNA kit for field use, targeting R. swinhoei and similar species in river systems.^[63] These molecular tools enhance survey efficacy for ultra-rare aquatic species by enabling rapid, broad-scale detection without direct observation.^[4]

Policy and habitat protection efforts

In China, the Yangtze giant softshell turtle (Rafetus swinhoei) is classified as a national Class I key protected wild animal under the country's Wildlife Protection Law, which prohibits hunting, killing, trading, and consumption of the species, with violations punishable by fines and criminal penalties.^[64] This status has been in place since the species' inclusion on the national protected list in the late 1980s, aiming to curb direct exploitation amid ongoing illegal trade despite enforcement challenges.^[65] In Vietnam, where the species is known as Swinhoe's softshell turtle, legal protections were formalized in 2013, elevating it to a prohibited species under wildlife regulations to prevent capture and communal consumption that previously occurred upon incidental encounters.^[53] These were strengthened by Decree No. 06/2019/ND-CP, effective February 2019, which explicitly bans all commercial exploitation and trade of R. swinhoei among 13 critically endangered turtle species, imposing strict penalties for violations as part of broader national wildlife conservation policy.^[66] Internationally, R. swinhoei is listed as Critically Endangered on the IUCN Red List, reflecting severe population decline and habitat threats, which informs global conservation priorities including bans on international trade under CITES Appendix II.^[67]^[68] Habitat protection efforts emphasize monitoring and advocacy against riverine development; for instance, organizations like the Wildlife Conservation Society collaborate with Chinese and Vietnamese authorities to safeguard riverine habitats in the Yangtze and Red River basins, including calls to delay hydropower dams that could inundate nesting sites.^[69] In Vietnam, surveys in lakes such as Dong Mo and Xuan Khanh include habitat enrichment and visual monitoring to support potential wild individuals, while studies in China's upper Red River recommend establishing protected areas, enhancing public education on threats, and restricting trade to preserve suitable deep-water and sandy nesting habitats.^[70]^[71]

Cultural and historical context

Discovery and early records

The Yangtze giant softshell turtle (Rafetus swinhoei) appears in ancient Chinese records dating back over 3,000 years, with archaeological and textual evidence suggesting its use in cultural artifacts such as the bixi, large stone turtles supporting imperial stelae, which morphologically resemble the species' elongated form and softshell structure.^[72] These depictions, common from the Zhou Dynasty onward, indicate the turtle's historical abundance in the Yangtze River basin and associated wetlands, where it was harvested for medicinal and ornamental purposes.^[23] The species remained locally known in eastern China and northern Vietnam through the early modern period but received its formal scientific description in 1873 by British zoologist John Edward Gray, based on a specimen collected near Shanghai and forwarded to the British Museum by naturalist Robert Swinhoe.^[6] Gray initially classified it as Oscaria swinhoei within the Trionychidae family, praising its distinctive markings and size as among the most striking of Chinese mud turtles, with the type locality specified as Shanghai.^[73] Subsequent taxonomic revisions in the 20th century reassigned it to the genus Rafetus, confirming its distinction from related softshell species through shell morphology and geographic distribution limited to the Yangtze and Red River systems.^[74] Early post-description records were sparse, primarily from museum specimens and anecdotal reports of large softshell turtles in the Yangtze floodplain and Lake Tai, where the species was once commercially exploited for its meat and shell but declined sharply by the mid-20th century due to overharvesting and habitat changes.^[23] Vietnamese records from the Red River delta, including Tonkin specimens archived in European collections, further corroborated its presence but highlighted taxonomic confusion with other trionychids until genetic and morphological analyses in the late 20th century.^[20]

Mythological associations

In Vietnamese folklore, the Yangtze giant softshell turtle (Rafetus swinhoei) is closely associated with the legendary figure of Kim Qui, the Great Turtle God, who symbolizes divine intervention and national sovereignty. According to the 15th-century legend, during the reign of Emperor Lê Lợi (r. 1428–1433), a giant golden turtle emerged from Hoàn Kiếm Lake in Hanoi and presented him with a magical sword, known as the Heaven Bestowed Sword, to lead the Vietnamese forces against Ming Chinese invaders. After victory, the turtle reappeared to reclaim the blade, signifying the return of power to the heavens.^[54]^[49] This narrative has elevated the species to a status of cultural reverence, with turtles in Hoàn Kiếm Lake regarded as living embodiments of Kim Qui, representing longevity, wisdom, and good fortune in broader Vietnamese traditions. Historical sightings of large softshell turtles in the lake, persisting until the death of the last known individual in 2016, reinforced this connection, as genetic and morphological analyses confirmed them as R. swinhoei.^[30]^[75] The mythological linkage extends to the turtle's role as a guardian spirit, with temples and pagodas around Hoàn Kiếm Lake dedicated to commemorating the event, including the Turtle Tower (Tháp Rùa), constructed in 1886 to honor the divine creature. Despite the species' rarity—fewer than four wild individuals remain as of 2023—the legend underscores a tension between cultural symbolism and ecological peril, where historical veneration did not prevent overhunting and habitat loss.^[76]^[30]

References

[1]
Habitat Selection and Conservation Suggestions for the Yangtze ...
Aug 7, 2025 · Swinhoe's softshell turtle is known only from the Red River basin in China and Vietnam, and from China's lower Yangtze River floodplain (Jian, ...
[2]
What we have learned from Yangtze giant soft-shell turtle Rafetus ...
Aug 10, 2025 · As of 2024, only two individuals have been confirmed to remain alive, one at the Suzhou Zoo in China and one in Xuan Khanh Lake, Viet Nam. The ...
[3]
Some Good News for the Rarest Turtle in the World
A new Swinhoe's Softshell Turtle was found using eDNA, bringing the total known population to four, and there is hope for captive breeding.
[4]
Development and Application of a Portable Environmental DNA Test ...
Oct 3, 2024 · Ex situ conservation efforts for R. swinhoei have, to date, failed. Repeated attempts to breed a pair at the Suzhou Zoo in China proved ...
[5]
Can a new DNA test save the world's rarest turtle? - Mongabay
Feb 19, 2025 · Scientists have developed and tested a portable environmental DNA kit to help detect the presence of the Yangtze softshell turtle (Rafetus swinhoei) in large ...Missing: size | Show results with:size
[6]
Rafetus swinhoei (GRAY, 1873) - The Reptile Database
Higher Taxa, Trionychidae (Trionychinae), Trionychoidea, Testudines (turtles) ; Subspecies ; Common Names, E: Shanghai Softshell Turtle, Swinhoe's Soft-shelled ...
[7]
Taxonomy browser (Rafetus swinhoei) - NCBI
Genbank common name: Swinhoes soft-shelled turtle. NCBI BLAST name: turtles. Rank: species. Genetic code: Translation table 1 (Standard)
[8]
Shanghai Softshell Turtle - Explore the Taxonomic Tree | FWS.gov
Location in Taxonomic Tree ; Suborder, Cryptodira ; Superfamily, Trionychoidea ; Family, Trionychidae ; Subfamily, Trionychinae ; Genus, Rafetus.
[9]
Rafetus swinhoei (Gray, 1873) | Trionychidae - MyBIS
Taxonomy ; Kingdom. Animalia ; Phylum. Chordata ; Class. Reptilia Reptiles ; Order. Testudines Turtles ; Family. Trionychidae Softshell Turtles and Terrapins.
[10]
Multiple Data Sets, High Homoplasy, and the Phylogeny of Softshell ...
Tissues were not available for Rafetus swinhoei, Aspideretes nigricans ... evolutionary history is rejected in favor of the shorter unconstrained topology ...
[11]
Phylogenetic relationships and divergence dates of softshell turtles ...
Our phylogenetic analyses indicate that Trionychidae is the sister taxon of Carettochelyidae, and support the monophyly of Trionychinae and Cyclanorbinae ...
[12]
A phylogeny of softshell turtles (Testudines: Trionychidae) with ...
Mar 6, 2014 · However, to date the taxonomic status of the critically endangered Shanghai Softshell Turtle, Rafetus swinhoei, is still a matter of debate (Le ...
[13]
Redescription of the soft-shell turtle Rafetus bohemicus (Testudines ...
Jul 27, 2023 · Phylogenetic analyses performed by Le et al. (2014, Fig. 5) dated the divergence between extant Rafetus species (R. swinhoei and R. euphraticus) ...
[14]
Genomic insights into the evolution of the critically endangered soft ...
Feb 13, 2022 · Phylogeny and divergence time analyses indicated that R. swinhoei has a close relationship with Pelodiscus sinensis, and they shared a common ...
[15]
A phylogeny of softshell turtles (Testudines: Trionychidae) with ...
Aug 6, 2025 · ly evolved lineages. Low genetic diversity among different populations of. Rafetus swinhoei suggests that this large softshell species.
[16]
[PDF] Genetic Variability of the Critically Endangered Softshell Turtle ...
ABSTRACT. The critically endangered softshell turtle, Rafetus swinhoei, is on the verge of extinction due to anthropogenic threats.
[17]
Yangtze giant softshell turtle - Facts, Diet, Habitat & Pictures on ...
Following the deaths of a wild individual in Vietnam in January 2016 and a captive individual in China in 2019, the species is listed as critically endangered ...
[18]
Preparation of the World's Largest Freshwater Turtle
With a total length of about 2 meters and a weight of about 170 kilograms, it is the largest known specimen of its nearly extinct species.
[19]
Rafetus project - Asian Turtle Program
As such, it is listed as Critically Endangered on IUCN's Red List of Threatened Species (2019), as well as in the Turtle Conservation Coalition's 25+ Most ...
[20]
[PDF] Comparative morphological and DNA analysis of specimens of giant ...
Apr 23, 1993 · The total body length from the muzzle to the end of tail is estimated at about 1500 – 2000 mm and body weight about at 170-220 kg at the adult ...
[21]
Yangtze Giant Softshell Turtle Facts - ThoughtCo
Oct 28, 2019 · Yangtze giant softshell turtles are designated as Critically Endangered by the International Union for Conservation of Nature (IUCN). They are ...<|separator|>
[22]
[PDF] A phylogeny of softshell turtles (Testudines: Trionychidae ... - GfBS
Mar 6, 2014 · However, to date the taxonomic status of the critically endangered Shanghai Softshell Turtle, Rafetus swinhoei, is still a matter of debate (Le ...
[23]
World's Largest Freshwater Turtle Nearly Extinct | National Geographic
Jul 4, 2013 · In June, the last known pair of the near-extinct Yangtze giant softshell turtle mated again—and, scientists hope, made babies.Missing: record relations
[24]
https://reptilesmagazine.com/softshell-turtles-around-the-world/
[25]
A new locality of presence for the world's rarest turtle (Rafetus ...
Rafetus swinhoei is the world's most threatened turtle with only two known specimens remaining, with high probability both males. The species is therefore ...Missing: morphology | Show results with:morphology
[26]
Genomic insights into the evolution of the critically endangered soft ...
Feb 13, 2022 · This study not only provides a genomic resource for scientists to study the species using the strategy of comparative genomics, but also provides a data basis
[27]
[PDF] prioritizing areas where Rafetus swinhoei may persist in the wild
(2013) Habitat selection and conservation suggestions for the Yangtze giant softshell turtle. (Rafetus swinhoei) in the Upper Red River, China. Chelonian.
[28]
An Interview-Based Survey to Investigate the Occurrence of ...
Our interview data indicates that a species of large softshell turtle – most likely Rafetus swinhoei – formerly occurred in the Xam and Ma Rivers.Missing: adaptations | Show results with:adaptations
[29]
Shell Game: In China, a $14K Reward for a Turtle That May Be Extinct
Jun 17, 2025 · Only one Yangtze giant softshell turtle is known to exist in China. Nicknamed Susu, the turtle is at Suzhou Shangfangshan Forest Animal World, ...Missing: current | Show results with:current
[30]
Death of last female Yangtze softshell turtle signals end for 'god' turtle
May 9, 2023 · The last known female Yangtze giant softshell turtle died in April of unknown causes, leaving only two males as the final known living ...
[31]
Last Female of Endangered Turtle Species Dies - Explorersweb »
May 7, 2023 · On April 21, the last-known female washed up dead in Dong Mo Lake, Vietnam. The cause of death is unknown. The species is now functionally extinct.
[32]
"Time is ticking" for world's rarest turtle – this new DNA test could ...
Jan 15, 2025 · “Swinhoe's softshell turtle is considered functionally extinct, meaning their population density is too low to reproduce naturally. Their future ...Missing: size | Show results with:size
[33]
[PDF] Hunters' structured questionnaires enhance ecological knowledge ...
Rafetus swinhoei, a giant softshell turtle from southern China and northern Viet- nam, is the rarest turtle species on Earth, and only two individuals are ...Missing: behavioral | Show results with:behavioral
[34]
Popular questions about the Hoan Kiem Turtle
Mar 15, 2010 · What do they eat? These large softshells are mostly carnivorous, eating ... Hoan Kiem turtleRafetus swinhoei · Facebook · PreviousTesting the Sedi ...
[35]
Yangtze giant softshell turtle - IGB Berlin
It is assessed as Critically Endangered on the IUCN Red List.
[36]
Rafetus Breeding Attempt 2011 – Turtle Survival Alliance
Sep 12, 2022 · ... (Rafetus swinhoei) have roamed together in both the small and the ... The turtles' diet in 2011 consisted of pieces of fresh fish with ...
[37]
The Hidden World of the Yangtze Giant Softshell Turtles
Apr 5, 2023 · One approach involves collecting environmental DNA (eDNA) to locate more individuals in the wild. Additionally, the Turtle Survival Alliance has ...
[38]
One Day in Suzhou for the Yangtze Giant Softshell Turtle
Jan 13, 2015 · The Yangtze giant softshell turtle Rafetus swinhoei is one of the world's most critically endangered species. Housed together at China's Suzhou Zoo.Missing: adaptations | Show results with:adaptations
[39]
Swinhoe's Softshell Turtle: Captive Breeding Program Update
Oct 2, 2014 · The news this fall from the Suzhou Zoo's captive breeding program that their male may be infertile has forced researchers to reconsider the program's future.
[40]
First artificial insemination of Yangtze giant softshell turtle
May 28, 2015 · "It now appears that artificial insemination is the only possible option for the pair of Rafetus swinhoei in Suzhou Zoo to reproduce ...
[41]
Swinhoe's Softshell Turtle: Captive Breeding Program 2016 Update
Aug 1, 2016 · But despite repeated bouts of courtship displays and mating between the pair in the years since, the resulting eggs have failed to hatch.
[42]
The phylogeny of softshell turtles and the ... - SerpentResearch.Com
May 19, 2014 · The fossil record supports the family's former presence in Australia, Europe, and South America. Trionychid phylogenetic relationships are a ...
[43]
100-Year-Old Turtle Given Last Chance to Breed; Only 4 Left of ...
May 24, 2015 · There are four Yangtze giant softshell turtles remaining in existence - two in Vietnam (both thought to be males) and two in China at the Suzhou ...
[44]
Swinhoe's Giant Softshell Turtle - Turtle Survival Alliance
No readable text found in the HTML.<|separator|>
[45]
A threat analysis for the world's most threatened turtle (Rafetus ...
We conducted a comprehensive threat analysis of the Swinhoe's softshell turtle (Rafetus swinhoei), the most endangered freshwater turtle in the world.<|control11|><|separator|>
[46]
The Most Endangered Turtle in the World - International Rivers
Sep 13, 2017 · With only three known individuals still alive, the Yangtze giant softshell turtle (Rafetus swinhoei) is the most endangered species of turtle in the world.
[47]
Feature: Earth's last two Swinhoe's turtles, yet both male - Xinhua
Jun 25, 2023 · One is in Vietnam, while the other is in the Suzhou Zoo, east China's Jiangsu Province.
[48]
Incentive offer to find endangered turtle raises concern - China Daily
one in Suzhou Shangfangshan Forest Zoo, formerly known as Suzhou ...
[49]
Rare, Revered Reptile on Brink of Extinction After Last Female Dies
Apr 28, 2023 · A female Giant Yangtze Softshell Turtle, which died in 2023, in Hanoi in 2008.Courtesy of Tim McCormack—Asian Turtle Program.Missing: Dong | Show results with:Dong
[50]
Impacts of Dams on Freshwater Turtles: A Global Review to Identify ...
Jun 8, 2022 · A decrease in the abundance of fish and absence of the Yangtze giant softshell turtle R. swinhoei was recorded after the installation of the Hoa ...
[51]
Remote Sensing Data Reveal a Significant Reduction in the Area of ...
Dec 16, 2024 · The models indicate that, compared to 2018, the occurrence of sandbanks—assumed to be crucial nesting habitat for this species—was reduced by 41 ...
[52]
Last known female Yangtze giant softshell turtle dies in China
Apr 16, 2019 · But the loss of wetland habitats from infrastructure development and river damming, poaching for meat and eggs, as well as capture for the pet ...Missing: destruction | Show results with:destruction
[53]
Hopes for most endangered turtle after discovery of female in ...
Jan 1, 2021 · DNA tests have now confirmed the animal is a Swinhoe's softshell turtle, (Rafetus swinhoei), the most endangered turtle in the world.<|separator|>
[54]
Killing gods: The last hope for the world's rarest reptile - Mongabay
almost twice the size of any known Yangtze softshell turtle. It got away ...Missing: measurements length
[55]
[PDF] CoP 16 Prop. 38 – p. 1 Original language - CITES
The example of Rafetus swinhoei demonstrates the vulnerability of softshell turtles to overexploitation. With the exploitation of Rafetus swinhoei no longer ...
[56]
Last known Rafetus swinhoei female dies, leaving rare turtle species ...
May 2, 2023 · These giant turtles were once abundant in the Yangtze River, but due to habitat loss, pollution, overfishing, and illegal poaching, their
[57]
[PDF] TURTLES IN TROUBLE - IUCN Portal
Recent intensive surveys in Yunnan, China, and in Vietnam have not yet confirmed additional wild specimens, although sight- ings were reported until a decade ...
[58]
Yangtze giant softshell turtle facts, distribution & population - BioDB
Also known as the Red river turtle or the Swinhoe's Softshell turtle, it stands as an emblem of the dire conservation status faced by many freshwater species.
[59]
Biggest freshwater turtle nears extinction in Southeast Asia
May 1, 2019 · The death of the last known female Yangtze giant softshell turtle has pushed scientists to search for wild specimens in China and Vietnam.Missing: exploitation meat
[60]
World's Most Endangered Turtle Gets Some Good News In 2020
Dec 18, 2020 · Scientists release genetic results confirming a female turtle captured in October 2020 in Viet Nam is definitively the near extinct Swinhoe's softshell turtle.
[61]
[PDF] Investigating the occurrence of the Yangtze Giant Softshell Turtle ...
Feb 6, 2024 · In collaboration with the Kunming Institute of Zoology (KIZ), we investigated the current status of Rafetus swinhoei in the Madushan Reservoir ...Missing: diet foraging behavior
[62]
prioritizing areas where Rafetus swinhoei may persist in the wild
Oct 20, 2021 · The Yangtze giant softshell turtle Rafetus swinhoei is the rarest turtle species, with just two individuals known to be surviving.
[63]
Wildlife Yangtze Giant Softshell Turtle - WCS One Health
No turtle is more critically endangered than the Yangtze giant softshell turtle – with sad news that the last known (at the time) female of the species died.Missing: scientific habitat
[64]
Say goodbye to giant softshell turtle - Chinadaily.com.cn
Apr 15, 2019 · For the Yangtze giant softshell turtle, it is probably too late. But for all protected species, anyone found buying the meat, parts or products ...
[65]
Strict laws fail to deter illegal trade of China's largest and most ...
Apr 21, 2022 · Despite being a protected species for 32 years, the turtle is still illegally traded due to low public awareness, ineffective reserves, and ...Missing: Yangtze | Show results with:Yangtze
[66]
Vietnam passes new law protecting endangered turtles – 13 species ...
Feb 15, 2019 · (Rafetus swinhoei). These species are highly endangered and commercial use or exploitation is strictly prohibited. The other 17 species are ...
[67]
There are Only 2 of These Turtles Left in the Wild - A-Z Animals
May 23, 2025 · About Yangtze Giant Softshell Turtle. This turtle is native to northern Vietnam, and southern and eastern China. It's named after the Yangtze ...Missing: current | Show results with:current
[68]
Rafetus swinhoei - Turtle Sanctuary Conservation Center
Apr 10, 2020 · Distribution : One captive specimen male in the Suzhou zoo in China and one specimen at Dong Mo Lake, Hanoi (Vietnam).
[69]
Concerning Efforts to Prevent the Extinction of the Giant Yangtze ...
Apr 15, 2019 · Scientists hope that this species can still be saved by working in conjunction with partners in China and with the Vietnamese government where ...
[70]
https://turtlesurvival.org/programs/vietnam/
[71]
Habitat Selection and Conservation Suggestions for the Yangtze ...
Jul 1, 2013 · Further conservation efforts require monitoring of the hunting and trade of turtles in this region, public education, delaying the building of ...
[72]
Last known female Yangtze giant softshell turtle dies, species ...
Apr 16, 2019 · Though the earliest record of the Yangtze giant softshell turtle dates back over 3,000 years ago, and the image of Bi Xi is commonly seen ...Missing: historical mentions
[73]
Rafetus swinhoei (Yangtze giant softshell turtle, Red River giant ...
Functionally extinct. IUCN status (2000): Critically Endangered. Only three individuals (two males, one sex unknown), of Rafetus swinhoei are known to exist.
[74]
(PDF) Rafetus swinhoei (Gray) 1873, a Valid Species of Living Soft ...
Aug 6, 2025 · The Euphrates Softshell Turtle, Rafetus euphraticus (Family Trionychidae), is a medium-sized (maximum recorded carapace length 680 mm), ...
[75]
The Life and Legacy of Vietnam's Sacred Giant Turtle - Atlas Obscura
Jan 10, 2019 · The legend of the Hoàn Kiếm turtle is so enduring that some Hanoians have suggested that authorities move one of the Vietnamese softshells ...
[76]
Hoan Kiem turtle: a symbolic creature of Hanoi's history - Vinpearl
Rating 5.0 (999) 1. Legend of Hoan Kiem turtle. In Vietnamese culture, turtles are considered sacred creatures that symbolize longevity, wisdom, and good fortune. This belief ...