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Chinese softshell turtle

The Chinese softshell turtle (Pelodiscus sinensis), a medium-sized freshwater turtle in the family Trionychidae, is distinguished by its soft, leathery, olive-gray to greenish-brown carapace lacking the hard scutes typical of most turtles, with juveniles often featuring yellow-bordered black spots that fade in adults.^[1] Females grow larger than males, reaching carapace lengths of up to 250 mm, while males exhibit longer tails and necks; both sexes have a snorkel-like proboscis for breathing at the water's surface.^[1]^[2] Native to East Asia, including eastern China, Taiwan, Korea, Japan, extreme southeastern Russia, and northern Vietnam, this species prefers lowland freshwater habitats such as rivers, lakes, ponds, and wetlands, where it burrows into mud or sand for concealment and thermoregulation.^[1]^[3] It has been introduced to regions like Hawaii, the Philippines, and parts of Europe through the pet and food trades, establishing feral populations in some areas due to its adaptability to disturbed waterways.^[1] As an opportunistic carnivore, it preys on fish, insects, crustaceans, and mollusks, using its tubular snout and expansive mouth to ambush prey while largely aquatic; it occasionally basks on land or riverbanks to regulate body temperature.^[1]^[2] Reproductively prolific, females lay multiple clutches of 10–30 eggs per year in sandy or gravelly nests during the warmer months following heavy rains, with incubation occurring at temperatures of 25–32°C; the species is widely farmed in Asia for its meat and medicinal uses, supporting a significant aquaculture industry.^[1] However, wild populations face severe declines from overexploitation, habitat degradation, pollution, and collection for the pet trade, leading to its classification as Vulnerable on the IUCN Red List.^[3] Conservation efforts include habitat protection, though challenges persist due to the species' cultural and economic value.^[3]

Taxonomy and nomenclature

Classification

The Chinese softshell turtle (Pelodiscus sinensis) belongs to the kingdom Animalia, phylum Chordata, class Reptilia, order Testudines, suborder Cryptodira, superfamily Trionychoidea, family Trionychidae, subfamily Trionychinae, genus Pelodiscus, and species sinensis.^[4] This placement situates it among the hidden-necked turtles, characterized by their ability to retract the head into the shell in a vertical S-shaped curve.^[5] The Trionychidae family, encompassing softshell turtles like P. sinensis, represents an ancient lineage with fossil records extending to the Early Cretaceous, originating likely in Asia before dispersing across Laurasia.^[6] Pan-trionychids, the broader clade including modern Trionychidae, dominated turtle faunas from the Late Cretaceous onward, highlighting the family's evolutionary persistence amid major geological changes.^[7] Within the genus Pelodiscus, P. sinensis is differentiated from congeners such as P. axenaria and P. maackii through distinct morphological traits, including shell patterns and osteological features, corroborated by genetic evidence from mitochondrial DNA sequences that reveal deep phylogenetic divergences. These analyses confirm P. axenaria and P. maackii as valid species, separate from the P. sinensis complex, based on diagnosable cytochrome b haplotypes and nuclear markers.^[8] Subsequent studies have further refined the complex, describing additional species including P. variegatus (2019), P. huangshanensis (2021), and P. shipian (2022).^[9]

Synonyms and etymology

The scientific name Pelodiscus sinensis reflects the turtle's ecological adaptations and geographic origin. The genus name Pelodiscus is derived from the Greek pēlos (mud or mire) and diskos (disc), alluding to the species' habit of dwelling in muddy substrates and its flattened, disc-like carapace.^[4] The specific epithet sinensis is Latin for "Chinese," denoting the turtle's native range in China.^[4] The species was first described by Arend Friedrich August Wiegmann in 1835 under the name Trionyx (Aspidonectes) sinensis, based on a specimen from a small island in the Xi Jiang (Pearl River) near Macao, China.^[10] In the same year, Leopold Fitzinger established the genus Pelodiscus with P. sinensis as the type species, marking an early taxonomic separation from the broader Trionyx genus. Subsequent revisions in the 20th century, including synonymizations by Friedrich Siebenrock in 1907, consolidated many junior synonyms under Pelodiscus sinensis to address the species' morphological variability across its range. Key synonyms include:

Trionyx sinensis Wiegmann, 1835^[10]
Potamochelys novemcostata Gray, 1864^[4]
Amyda sinensis (Wiegmann, 1835)^[4]

These names arose from early descriptions of regional variants, but phylogenetic studies in the 21st century have prompted further refinements, restricting P. sinensis to specific lineages while elevating others to species status.^[11]

Physical characteristics

Morphology

The Chinese softshell turtle (Pelodiscus sinensis) exhibits a distinctive morphology adapted to its semiaquatic lifestyle, featuring a soft, leathery carapace and plastron devoid of the keratinous scutes found in hard-shelled turtles. The carapace is round to oval in shape, typically olive-gray to greenish-brown in coloration, often marked with dark vermiculations or spots that provide camouflage against muddy substrates; juveniles display more prominent yellow-bordered black spots, which fade in adults. The plastron is similarly flexible and leathery, pale white to yellowish underneath, with well-developed buttresses that articulate with the carapace for structural support.^[1]^[12]^[13] The head and neck are elongated and highly retractable, enabling the turtle to withdraw into the shell for protection. A prominent tubular snout, or proboscis, extends from the head, functioning like a snorkel to allow respiration at the water surface while the body remains submerged or buried in sediment. The eyes are small and laterally positioned, suited to low-light aquatic environments, complemented by a well-developed olfactory system with over 1,000 odorant receptor genes^[14] and numerous olfactory receptor neurons (up to 23 million in the lower chamber epithelium), enhancing chemosensory detection in turbid waters.^[15] The limbs are robust with fully webbed feet, facilitating efficient propulsion through water, while the overall body lacks rigid bony plates, prioritizing flexibility and rapid movement over armored defense.^[4]^[13] Internally, P. sinensis relies on pulmonary respiration via lungs but supplements this with accessory mechanisms during prolonged submersion or burial, including buccopharyngeal respiration—pumping water over vascularized pharyngeal tissues—and cutaneous respiration through the permeable leathery skin, which accounts for a significant portion of oxygen uptake.^[16] These adaptations allow the turtle to remain active underwater for extended periods without surfacing, particularly when ambushing prey or evading threats by burrowing into mud. While cloacal structures are present, P. sinensis primarily relies on pharyngeal and dermal exchange rather than cloacal respiration during burial.^[16]

Size and sexual dimorphism

The Chinese softshell turtle (Pelodiscus sinensis) exhibits marked sexual dimorphism, with females generally larger and more robust than males to support egg production and overall reproductive capacity. Adult females can attain a maximum carapace length of 25 cm (250 mm), while males reach up to 20 cm; large females may weigh up to 5 kg, reflecting their greater body mass and structural development.^[1]^[17] In addition to size differences, males possess thicker tails for reproductive functions and a slightly concave plastron that facilitates mounting during mating, contrasting with the flatter plastron of females. These morphological traits become evident as individuals approach sexual maturity, typically at around 18-19 cm carapace length for both sexes, though females continue growing more substantially thereafter.^[12]^[1] Growth in P. sinensis is rapid during the juvenile phase, with annual carapace length increases of up to 10 cm in the first few years under optimal aquaculture conditions, before slowing considerably in adults to rates of approximately 0.2–0.5 cm per month. This pattern is influenced by environmental factors such as water temperature, which optimally ranges from 25-30°C for maximal growth, and food availability, with nutrient-rich diets accelerating development in captive populations.^[18]^[19]

Distribution and habitat

Native range

The Chinese softshell turtle (Pelodiscus sinensis) is native to central and eastern China, including provinces such as Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hong Kong, Hubei, Hunan, Jiangsu, Jiangxi, Zhejiang, Yunnan, and Sichuan, as well as Taiwan and northern Vietnam.^[4]^[1]^[20] This distribution reflects its adaptation to diverse freshwater systems across these regions. Note that populations in northern China (e.g., Inner Mongolia, Heilongjiang) are now classified as a separate species, Pelodiscus maackii. Historical range contraction has occurred due to human activities, particularly overharvesting for food and traditional medicine as well as habitat degradation, leading to sharp declines in wild populations—over 95% in some areas—with core remaining populations concentrated in the Yangtze River basin.^[21]^[22]^[23]

Introduced populations

The Chinese softshell turtle (Pelodiscus sinensis) has been introduced to various regions outside its native range in East Asia primarily through the pet trade, aquaculture for food and traditional medicine, and intentional releases by immigrants. These human-mediated translocations have led to established wild populations in select areas, while many introductions remain sporadic or unestablished. In the United States, the species was first introduced to Hawaii in the 1800s by Asian immigrants seeking a food source, resulting in self-sustaining populations on islands such as Kauai and Oahu.^[1] Introductions to the mainland, including Maryland via the pet trade and food cultivation attempts, have occurred but have not led to widespread establishment, with only isolated records reported.^[1]^[4] In Europe, P. sinensis has been introduced mainly through releases of pet turtles that outgrow captivity or prove difficult to manage due to their aggressive behavior and size. Established populations exist in the marshes of the Guadalquivir River in southern Spain, while recent records indicate introductions in Germany (e.g., near Weil am Rhein along the Rhine) and Switzerland (e.g., Quellsee near Basel and Gübsensee near St. Gallen), often in ponds connected to river systems.^[1]^[24] In the United Kingdom, sporadic sightings from pet releases have been documented, though no breeding populations are confirmed.^[25] Southeast Asian countries beyond the native range, such as the Philippines (including Luzon and other islands) and Indonesia (Kalimantan, Sumatra, and Timor), host introduced populations stemming from aquaculture escapes and food farming initiatives dating back to the mid-20th century.^[1]^[4] In Brazil, introductions to the state of Pará in the Amazon region have been recorded, potentially establishing in local wetlands through releases from ornamental or food trades, though confirmation of reproduction remains limited.^[1] These non-native distributions contrast with the species' indigenous occurrence in rivers and lakes of China and Taiwan, highlighting the role of global trade in facilitating spread.^[1]

Habitat preferences

The Chinese softshell turtle (Pelodiscus sinensis) inhabits primarily slow-moving or stagnant freshwater environments, including lowland rivers, lakes, ponds, canals, marshes, and rice paddies, where soft, muddy substrates predominate. These conditions allow the species to exploit shallow, vegetated waters with low flow rates, which support its sedentary lifestyle and foraging needs.^[1]^[26]^[21] While predominantly a freshwater species, P. sinensis exhibits tolerance for brackish conditions up to 15 ppt salinity for short durations, enabling occasional incursions into estuarine or coastal habitats, though it actively avoids fast-flowing currents and deep, open waters that exceed its physiological limits.^[27]^[28] In microhabitats, individuals burrow into loose sediment at the water bottom, a behavior essential for ambush predation on passing prey and for thermoregulation by maintaining stable body temperatures in fluctuating aquatic environments. Females further require accessible sandy or muddy banks with sparse vegetation for nesting, where they excavate shallow cavities to deposit eggs during the reproductive season.^[1]^[29]^[30]

Ecology and behavior

Diet and foraging

The Chinese softshell turtle (Pelodiscus sinensis) is primarily carnivorous but omnivorous in practice, with its diet consisting mainly of aquatic prey such as fish, crustaceans including crayfish and crabs, insects, mollusks, and other invertebrates like zooplankton.^[1] It occasionally consumes amphibians such as frogs and plant matter, including seeds of marsh plants; analyses of stomach contents indicate plant material occurs in at least 50% of samples.^[31] As an ambush predator, P. sinensis typically buries itself in the soft substrate of rivers, lakes, or marshes, protruding only its eyes and elongated, proboscis-like snout to breathe and detect prey.^[1] It remains largely sedentary and buried for most of the day, striking rapidly with its long neck to capture passing prey, and also engages in opportunistic scavenging of carrion when available.^[1] This bottom-dwelling strategy allows it to conserve energy while exploiting abundant aquatic resources in its habitat.^[18] Dietary preferences exhibit ontogenetic shifts, with juveniles focusing more on smaller invertebrates such as insects and zooplankton due to their size limitations, while adults incorporate larger vertebrate prey like fish and amphibians into their diet. These shifts reflect developmental changes in body size and digestive capabilities, enabling adults to handle more diverse and substantial food items without a major transition to herbivory.

Locomotion and daily activity

The Chinese softshell turtle (Pelodiscus sinensis) is predominantly aquatic, relying on its fully webbed limbs to generate powerful paddling propulsion for swimming through rivers, lakes, and other freshwater habitats.^[32] These adaptations enable efficient movement in water, where the turtle spends most of its time foraging and resting.^[1] On land, locomotion is limited to short distances, primarily for sunbathing to regulate body temperature or nesting, after which individuals quickly return to water.^[33] Daily activity patterns vary with environmental conditions; the species exhibits both diurnal and nocturnal behaviors, with foraging and other activities observed during day and night in warm periods. To avoid excessive heat and predation in hot climates, turtles often burrow into the substrate or remain buried at the bottom of their aquatic habitat for much of the day, emerging more actively at dawn or dusk.^[1] Seasonal movements are limited, with higher daily distances (up to 59 m on average in peak months like May) correlating positively with warmer water temperatures, while activity drops sharply in winter (to about 0.4 m per day).^[34] Individuals maintain a home range typically spanning several hundred meters along river channels, up to approximately 1 km in linear extent, shifting to deeper waters during colder periods for protection.^[34]^[21]

Reproduction and life cycle

The breeding season for the Chinese softshell turtle (Pelodiscus sinensis) typically spans from spring to late autumn in its native range, with mating occurring in aquatic environments at the water surface or underwater.^[1] Males may exhibit courtship behaviors involving physical contact, such as biting or grasping the female's head, though detailed observations of these interactions remain limited in wild populations.^[4] Females can store viable sperm for up to six months after copulation (and longer in the oviduct), enabling delayed fertilization and multiple clutches without repeated mating.^[35] Nesting occurs primarily during periods of heavy rainfall, when females excavate burrows in sandy or muddy riverbanks, creating flask-shaped nests approximately 10-15 cm deep and 4-5 cm in diameter at the entrance.^[1] Each clutch contains 3-28 eggs, with a mean of around 20, and eggs are spherical, measuring 17-20 mm in diameter and weighing approximately 5.4–6.5 g.^[36]^[37]^[18] Females produce 2-5 clutches per season, with larger individuals (4,000-5,000 g body weight) capable of up to 4-5 clutches annually, and they are ready to mate again 5-7 days after laying.^[18]^[36] Eggs incubate for 48-68 days, with the duration influenced by environmental temperature; optimal hatching occurs at 28-33°C, where higher temperatures accelerate development and result in larger hatchlings, though incubation temperature does not determine sex, as P. sinensis follows a genetic ZZ/ZW system.^[36]^[38] Hatchlings emerge at approximately 3 cm in carapace length, measuring about 2.5-3 cm across, and are independent immediately upon hatching, feeding on small invertebrates.^[39] Sexual maturity is reached at 5-6 years of age, with females maturing slightly later than males, often at a carapace length of 15-20 cm.^[36] In the wild, individuals typically live 25-30 years, though lifespan can vary based on habitat quality and predation pressure.^[40]

Hibernation and seasonal adaptations

The Chinese softshell turtle (Pelodiscus sinensis) enters a state of hibernation, also known as overwintering or brumation, typically from late October or November to March or early April, lasting approximately four months in its native range.^[41] During this period, the turtle buries itself in mud or soil burrows along riverbanks or in aquatic substrates to conserve energy amid cold temperatures and food scarcity.^[21] Hibernation sites are selected for stability, with individuals preferring moist, vegetated areas such as dense stands of Acorus calamus near water bodies, where the dorsal carapace is buried about 5 cm deep.^[21] These locations maintain soil or water temperatures above freezing (typically >0°C to 8°C) and humidity levels exceeding 30%, protecting against desiccation and extreme cold.^[21] Physiological adaptations enable survival during hibernation, including a drastic reduction in metabolic rate, heart rate, and respiratory frequency to minimize energy expenditure.^[42] Oxygen uptake shifts primarily to cutaneous (skin) respiration, supplemented by pharyngeal breathing in terrestrial burrows where the neck may protrude slightly for air access.^[43] Pre-hibernation fat accumulation in the liver and adipose tissue provides essential energy reserves, with lipid breakdown via lipolysis sustaining the turtle through the dormant phase.^[44] Studies indicate that hepatic lipid droplets decrease significantly during hibernation, reflecting efficient mobilization of stored fats.^[45] Emergence from hibernation is triggered by rising ambient temperatures and warming waters in spring, often occurring around late March when conditions support active foraging.^[21] Recent research highlights selective habitat use for microenvironments with high humidity and stable thermal profiles, underscoring the turtle's adaptations to seasonal variability for overwintering success.^[46] These strategies allow P. sinensis to endure prolonged low-oxygen and hypothermic conditions without feeding.^[47]

Health and threats

Diseases and parasites

The Chinese softshell turtle (Pelodiscus sinensis) is susceptible to various bacterial infections, particularly in aquaculture settings with poor water quality. Shell rot, characterized by ulceration and decay of the carapace or plastron, is commonly caused by Aeromonas sobria and A. caviae, leading to necrotic lesions and high mortality if untreated.^[48] Other bacterial pathogens, such as Aeromonas hydrophila, induce hemorrhagic septicemia and red spot disease, manifesting as skin ulcers, red discoloration, and internal organ enlargement, often exacerbated by high stocking densities and polluted environments.^[48] Fungal infections, such as saprolegniasis caused by Saprolegnia spp., can also affect stressed individuals in cool, damp conditions.^[48] Viral infections pose significant threats, with the soft-shelled turtle iridovirus (STIV), a member of the Ranavirus genus, causing red neck disease and systemic septicemia in farmed populations. Symptoms include hyperemia of the neck and limbs, lethargy, and hemorrhaging, resulting in mass die-offs with mortality rates exceeding 80% during outbreaks.^[49]^[50] Ranavirus infections, including STIV, are associated with the international trade in live animals, which can facilitate pathogen spread.^[51] Parasitic infestations are prevalent, especially in polluted habitats where intermediate hosts proliferate. Trematodes such as Coeuritrema platti and Leurosoma baiyangdiensis infect the blood vessels and intestines, causing anemia, tissue damage, and reduced growth rates.^[52]^[48] Protozoans like Haemogregarina species parasitize erythrocytes, leading to hemolytic anemia, while trypanosomes (Trypanosoma spp.) affect the bloodstream.^[53] Leeches may occasionally attach externally in wild populations, potentially causing wounds and secondary infections in contaminated waters.^[54] Emerging challenges include antibiotic resistance in cultured populations, where bacterial isolates like Escherichia coli and Aeromonas spp. exhibit multidrug resistance to common treatments such as ampicillin and tetracycline, complicating disease management in intensive farming.^[55]^[56] These health issues contribute to economic losses in aquaculture and pose risks to wild populations through escaped infected individuals.

Natural predators

The eggs and hatchlings of the Chinese softshell turtle (Pelodiscus sinensis) are vulnerable to predation by birds such as herons and crows, as well as reptiles like monitor lizards in native Asian habitats, which dig up nests. Mammals including otters may also target nests and young turtles. Adult Chinese softshell turtles experience rarer predation due to their effective camouflage and defensive behaviors, but they can occasionally fall victim to large aquatic predators like catfish, avian hunters such as eagles, and terrestrial mammals including foxes and feral dogs. These encounters are infrequent, as adults inhabit muddy substrates that provide natural cover for concealment.^[57] To counter these threats, Chinese softshell turtles employ several anti-predator strategies across life stages. They rapidly bury themselves in mud or sand for camouflage, retracting their tubular snorkel-like snout to remain hidden while breathing through small openings. When directly threatened, individuals display aggressive behavior, including lunging bites capable of inflicting serious injury. These adaptations, combined with their flattened, leathery shell, enhance survival in predator-rich freshwater environments.^[57]^[58]

Conservation

Status and threats

The Chinese softshell turtle (Pelodiscus sinensis) is classified as Vulnerable on the IUCN Red List (as of 2025), a status assigned in 2000 by the Asian Turtle Trade Working Group; the assessment requires updating due to an estimated population decline exceeding 30% over three generations resulting from ongoing anthropogenic pressures.^[3] This decline is inferred from observed reductions in wild densities across its native range in East Asia, particularly in riverine and lacustrine habitats, where mature individuals face intensified exploitation and environmental degradation. Habitat loss represents a primary threat, driven by dam construction, river channelization, and urbanization that fragment and degrade essential freshwater ecosystems. Overcollection for commercial trade exacerbates this vulnerability, with wild populations heavily targeted despite extensive aquaculture; the trade volume is met largely by farming, but continued unsustainable harvesting of wild individuals occurs due to preferences for wild-caught specimens that command premium prices.^[59] Pollution further compounds these risks, as heavy metals like copper and pesticides accumulate in the turtles' tissues through their aquatic diet and permeable skin, causing physiological stress, reduced reproduction, and increased mortality. Bioaccumulation studies indicate elevated levels of such contaminants in P. sinensis from polluted rivers, impairing immune function and overall fitness.^[60] Climate change poses an emerging threat to freshwater turtle habitats by altering environmental conditions. Diseases, including bacterial and viral infections, can exacerbate these declines by increasing mortality in weakened populations exposed to polluted or fragmented environments.^[48]

Conservation measures

The Chinese softshell turtle (Pelodiscus sinensis) is classified as a Class II nationally protected wild animal under China's Wildlife Protection Law, prohibiting unauthorized capture, trade, and transport of wild individuals to safeguard declining populations.^[61] This legal framework supports broader aquatic wildlife management regulations, emphasizing sustainable practices amid threats like habitat degradation.^[62] It is also listed on CITES Appendix II, which regulates international trade to prevent overexploitation.^[3] Captive breeding programs in China have achieved large-scale success, with annual production surpassing 300,000 tons since 2011, primarily to fulfill commercial demand while alleviating pressure on wild stocks.^[62] These efforts include government-backed farms and reserves that propagate individuals for potential release to bolster natural populations; however, post-release tracking remains limited, hindering evaluation of long-term viability. Habitat restoration efforts focus on wetland preservation in core ranges like the Yellow River Delta, where rehydration projects aim to maintain suitable hibernation and foraging sites critical for overwintering adults.^[21] Monitoring integrates radio telemetry for tracking movements and genetic analyses to assess population structure and diversity, informing targeted interventions such as site-specific protections against seasonal flooding alterations.^[63] These measures collectively prioritize wild population recovery while leveraging aquaculture to mitigate overexploitation.

Human relations

Culinary and medicinal uses

The Chinese softshell turtle (Pelodiscus sinensis) is highly valued in Chinese cuisine for its tender, mild-flavored meat, often compared to chicken in texture, with a surrounding layer of gelatinous skin that enhances dishes. It is commonly prepared as turtle soup or stew, simmered with herbs and spices to create rich, nourishing broths that incorporate the meat, skin, and innards for a no-waste approach. These preparations are staples in Cantonese and southern Chinese cooking, where the turtle is consumed fresh to preserve its delicate qualities, though dried meat is also used in some preserved forms.^[64]^[65]^[66] In traditional Chinese medicine (TCM), the turtle's shell, known as biejia or carapax, is a key ingredient prized for its ability to clear heat, nourish yin, and soften hard masses or accumulations, making it a component in formulas like Biejiajian pills traditionally used to treat conditions such as liver cancer. The turtle's blood is employed in tonics and wines believed to invigorate energy, replenish vital proteins, and promote overall vitality, often added to herbal mixtures for restorative purposes. These medicinal applications stem from ancient texts describing the turtle as a health-strengthening agent capable of warding off diseases.^[67]^[68]^[69]^[70]^[71] The demand for both culinary and medicinal uses has driven extensive commercial farming in China, with hundreds of millions of individuals produced annually to supply domestic markets. To safeguard declining wild populations, China has enforced export restrictions on wild softshell turtles since the late 1990s, including import bans on contaminated farmed stock in 1999 and broader trade regulations under national protection laws.^[59]^[72]

Cultural significance

In Chinese mythology, the softshell turtle holds symbolic value as an emblem of longevity and resilience, often depicted as a creature capable of enduring extreme conditions by burrowing into mud, reflecting its adaptive nature as a mud-dweller.^[73] This association stems from ancient beliefs attributing to it a lifespan exceeding 10,000 years, positioning it as a semi-mythical being that embodies auspicious progress, as it is said to "only climb forward, not backward."^[73] In folklore, such as accounts from classical texts, the softshell turtle appears as the zhū biē yú, a pearl-spitting entity resembling dried meat with multiple eyes and legs, symbolizing the harmony of Heaven, Earth, and Man, though its utility ironically led to its frequent exploitation.^[74] Traditional practices incorporate the softshell turtle into rituals tied to prosperity and health, particularly during the Chinese New Year, where consuming middle-aged specimens is believed to invoke strength and longevity due to the animal's symbolic endurance.^[75] Certain taboos persist, such as prohibiting pregnant women from eating softshell turtles, viewed as a "cold" food that could harm the fetus, underscoring broader cultural cautions around its potent, yin-natured properties in traditional Chinese medicine.^[76] In contemporary representations, the Chinese softshell turtle serves as an emblem of wetland ecosystems and environmental fragility in literature and media, highlighting threats to aquatic habitats amid rapid development.^[77] Wildlife documentaries and conservation narratives often feature it to underscore biodiversity loss in China's rivers and lakes, reinforcing its role as a symbol of ecological resilience under duress.^[78]

Aquaculture and invasive potential

The Chinese softshell turtle (Pelodiscus sinensis) is the dominant species in global turtle aquaculture, with China producing nearly all of the world's supply through intensive pond farming systems.^[79] Annual production in China reached 497,536 metric tons in 2023.^[80] Farming practices originated over 2,400 years ago but intensified in the 1970s with the adoption of polyculture techniques, where turtles are co-reared with fish species to optimize stocking densities, enhance resource utilization, and control waste through complementary feeding habits. However, recent challenges including urbanization, disease outbreaks, and shifting markets have led to declines in farming in some southern regions as of 2024.^[73] These systems typically involve concrete or earthen ponds stocked at densities of 10–20 individuals per square meter, with supplemental feeding of commercial diets at 1–4% of body weight daily, achieving growth from juveniles (around 400–600 g) to market size (700–1,800 g) in 5–12 months.^[81] Yields in polyculture setups, including rice-turtle or fish-turtle combinations, commonly range from 1–3 tons per hectare after one to four years, with survival rates of 89–96% and feed conversion ratios of 2.6–3.1.^[82] Beyond its native range in East Asia, P. sinensis has been introduced to regions like the United States and Europe primarily through the pet and food trades, posing risks as an invasive species due to its adaptability and predatory behavior.^[1] In the contiguous U.S., the species exhibits a high climate match (score of 0.347), indicating suitable conditions for establishment, while it is already reproducing in Hawaii (e.g., on Oahu and Kauai), where it competes with native aquatic invertebrates and fish for resources and may alter local food webs.^[1] European assessments classify P. sinensis as having moderate establishment potential (risk score of 0.32), with isolated records in countries like the Czech Republic and potential to outcompete native freshwater turtles such as Emys orbicularis for basking sites, foraging areas, and nesting habitats in warmer wetlands.^[83]^[20] Although direct hybridization with native softshell turtles like Apalone spinifera remains undocumented, the species' broad environmental tolerance heightens concerns for genetic introgression in overlapping habitats. Management of non-native P. sinensis populations focuses on prevention through trade regulations and public education, as eradication efforts are rare due to the species' cryptic nature and limited documented impacts.^[84] In the U.S., importation to Hawaii has been banned since 1999 to curb further spread, with ongoing surveys recommended to monitor populations and assess ecological effects before targeted removals.^[85] European Union Regulation 1143/2014 lists invasive alien species and mandates risk assessments, prohibiting releases of pets like P. sinensis while emphasizing early detection and rapid response in affected wetlands.^[84] These measures aim to mitigate invasion risks from pet trade releases, though enforcement challenges persist in both regions.^[86]

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Jan 17, 2025 · This study investigates the hibernation habitat selection and overwintering environment of Chinese softshell turtle (Pelodiscus sinensis) in ...Missing: cloacal pharyngeal
[20]
Nesting Activity of the Chinese Softshell Turtle, Pelodiscus sinensis ...
Dec 3, 2021 · Wild populations of P. sinensis have suffered a continuous decline in recent decades because of overharvesting and habitat destruction (Kong ...
[21]
Establishment and population genetic analysis of SNP fingerprinting ...
Chinese soft-shelled turtle (Pelodiscus sinensis) is an important aquaculture species in China. ... sinensis is included in the IUCN Red List of Threatened ...
[22]
[PDF] The Chinese Soft-shelled Turtle Pelodiscus sinensis (Testudines
Oct 5, 2021 · Soft-shelled turtles (Trionychidae) comprise 33 species and are distributed from North America to Africa and. Asia (Uetz et al., 2021).<|control11|><|separator|>
[23]
TURTLE TALLY - Issuu
Turtle Tally UK was established in 2018 to help document the introduced turtle species that inhabit the UK's waterbodies. ... (Pelodiscus sinensis) have been ...
[24]
Pelodiscus sinensis - Invasive Species of Japan
The populations of mainland of Japan and Taiwan are sometimes classified to different subspecies, P. s. japonicus and P. s. sinensis respectively.<|control11|><|separator|>
[25]
None
### Summary of Pelodiscus sinensis Salinity Tolerance, Brackish Water Use, and Habitat Preferences
[26]
Effect of acclimation temperature and substrate type on selected ...
These factors may be particularly important for softshell turtles that are highly aquatic and often thermoregulate by burying in the substrate in shallow water ...Missing: burrowing | Show results with:burrowing
[27]
Nesting Activity of the Chinese Softshell Turtle, Pelodiscus sinensis ...
Dec 3, 2021 · The sparsely vegetated sandbanks of these wetlands and ponds provide ideal nesting sites for P. sinensis (Kong 2020).Missing: banks | Show results with:banks
[28]
https://toddlab.ucdavis.edu/publications/agha%20et%20al.%202018%20biol%20rev.pdf
[29]
Analysis of Thrust Performance for Paddling Locomotion - J-Stage
Paddling is used by many swimming creatures as a primary propulsive device such as webbed feet of ... The other is a soft-shelled turtle (Pelodiscus sinensis), ...
[30]
https://meridian.allenpress.com/ccb/article/20/2/290/474692/Nesting-Activity-of-the-Chinese-Softshell-Turtle
[31]
Daily and Seasonal Activity Rhythms of Wild Reeves' Turtles ...
Apr 15, 2024 · The Chinese softshell turtle (Pelodiscus sinensis) is also diurnal and nocturnal, and both foraging and spawning are observed during the day and ...Missing: crepuscular | Show results with:crepuscular
[32]
Home Ranges and Movement Patterns of the Chinese Softshell ...
May 13, 2021 · Daily movements of P. sinensis averaged 35 ± 18 m SD for males and 43 ± 18 m SD for females, and there was no significant difference between ...<|control11|><|separator|>
[33]
Pelodiscus sinensis - NatureServe Explorer
Conservation Biology of Freshwater Turtles and Tortoises: A Compilation Project of the IUCN/SSC Tortoise and Freshwater Turtle Specialist Group. Chelonian ...
[34]
Incubation temperature affects the immune function of hatchling soft ...
Jun 1, 2015 · From May to August, female P. sinensis individuals lay multiple clutches of eggs (mean clutch size = 20). Incubation temperatures significantly ...
[35]
Incubation temperature affects hatchling growth but not sexual ...
Feb 28, 2006 · Incubation temperature affects hatchling growth but not sexual phenotype in the Chinese soft-shelled turtle, Pelodiscus sinensis (Trionychidae).
[36]
Chinese softshell turtle (Pelodiscus sinensis) - Thai National Parks
Conservation status. Vulnerable (IUCN2.3). Photos. Please help us review our species pages if wrong photos are used or any other details ...
[37]
Softshell Turtles: Leathery Shell, Habitat, Behavior, Diet & Pictures
Sep 17, 2025 · In an extraordinary feat of biology, the Chinese softshell turtle (Pelodiscus sinensis) can exchange oxygen and carbon dioxide through its mouth ...
[38]
Liver transcriptome analysis reveals the molecular response to ...
In P. sinensis, the up-regulation of DLL4 during the pre-hibernation and arousal phases may represent an adaptive strategy to mediate the equilibrium between ...
[39]
Antioxidant responses in hibernating Chinese soft-shelled turtle ...
Liu et al. (2002) reported decreased respiratory frequency, oxygen consumption, and heart rate in hibernating P. sinensis. During the arousal stage, oxidative ...
[40]
The effect of hibernation on the morphological structure and ...
The intestinal function of hibernating animals undergoes seasonal changes, during which they are in a fasting state, which also affects the morphology, ...
[41]
Analysis of Lipid Metabolism in Adipose Tissue and Liver of Chinese ...
Hibernation serves as an energy-conserving strategy that enables animals to withstand harsh environments by reducing their metabolic rate significantly.
[42]
Hepatic lipid droplet breakdown through lipolysis during hibernation ...
When they encounter a cold and food-limited winter, hibernating animals will drastically reduce their body temperature, heart rate, metabolic rate, and other ...Missing: respiration | Show results with:respiration
[43]
Hibernation Habitat Selection by the Threatened Chinese Softshell ...
Jan 17, 2025 · Our results suggest that P. sinensis has selectivity toward hibernation habitats with specific microenvironmental characteristics.
[44]
Induction of Hibernation and Changes in Physiological and ... - NIH
May 15, 2023 · Pelodiscus sinensis (P. sinensis) is a hibernating reptile that can tolerate extreme environments of low temperature and low oxygen. The ...Missing: strategies | Show results with:strategies
[45]
Infectious diseases of the Chinese soft-shelled turtle (Pelodiscus ...
But, due to diminishing wild populations, the CSST has been included in the red list of endangered species by the International Union of Conservation of Nature ...
[46]
A new iridovirus isolated from soft-shelled turtle - PubMed
A virus was isolated from soft-shelled turtle (Trionyx sinensis) with 'red neck disease' on a farm in Shenzhen, China, the virus multiplied and caused a ...Missing: Pelodiscus | Show results with:Pelodiscus
[47]
Complete sequence determination of a novel reptile iridovirus ...
May 14, 2009 · Soft-shelled turtle iridovirus (STIV) is the causative agent of severe systemic diseases in cultured soft-shelled turtles (Trionyx sinensis).<|separator|>
[48]
(PDF) Ranavirus-associated morbidity and mortality in a group of ...
Aug 9, 2025 · In Asia, only three cases of ranavirus infection in turtles have been reported: in farmed soft-shelled turtles [Pelodiscus (Trionyx) sinensis], ...<|control11|><|separator|>
[49]
Blood flukes of Asiatic softshell turtles: revision of Coeuritrema ...
Coeuritrema platti sp. n. infects the blood of Chinese softshell turtles, Pelodiscus sinensis (Wiegmann), cultured in the Da Rang River Basin (Phu Yen Province, ...Missing: leeches protozoans
[50]
Six new species of Haemogregarina from Chinese turtles.
Aug 9, 2025 · PDF | On Apr 25, 1990, Chen C Chai J published Six new species of Haemogregarina from Chinese turtles. | Find, read and cite all the ...
[51]
Identification and antibiotic resistance profiling of bacterial isolates ...
Mar 31, 2017 · The present study sought to identify pathogens associated with septicaemia in the Chinese soft-shelled turtle (Pelodiscus sinensis) and to ...Missing: Ranavirus | Show results with:Ranavirus
[52]
A Multidrug-Resistant Escherichia coli Caused the Death of the ...
May 14, 2025 · A multidrug-resistant Escherichia coli caused the death of the Chinese soft-shelled turtle (Pelodiscus sinensis)Missing: Ranavirus | Show results with:Ranavirus
[53]
Softshell turtle | Description & Facts - Britannica
Oct 27, 2025 · Form and function. The turtle's shell is an adaptation that protects it from predators, which compensates for the reptile's slow crawling speed ...
[54]
Turtle Predators: What Eats Turtles? - A-Z Animals
Oct 14, 2024 · In fact, most carnivorous lizards enjoy eating turtle eggs. On the other hand, crocodiles have a strong jaw and can break through turtle shells ...What Eats Turtles? · Turtle Predators: Snakes · Turtle Predators: Other...
[55]
Apalone mutica : Smooth Softshell | Rare Species Guide | Minnesota ...
The main predators of smooth softshell turtle eggs are skunks and raccoons, while the main predators of hatchlings are fish, turtles, snakes, wading birds, and ...
[56]
Are Softshell Turtles Dangerous?
Feb 9, 2024 · The softshell turtle is one of the more aggressive than most turtles, perhaps to make up for their lack of a hard shell. These freshwater ...
[57]
Evidence for the massive scale of turtle farming in China | Oryx
Jan 31, 2008 · USD 750 million. Although the bulk of these figures comprise the common Chinese softshell turtle Pelodiscus sinensis many other species are ...
[58]
Toxicological effects of copper on bioaccumulation and mRNA ... - NIH
Nov 9, 2023 · These results explain that copper toxicity causes bioaccumulation, promotes oxidative stress, obstructs immunity, and induces inflammation and ...Missing: pesticides | Show results with:pesticides
[59]
Turtles and Tortoises Are in Trouble - ScienceDirect.com
Jun 22, 2020 · This commercial overexploitation for meat has drastically reduced populations in parts of their range. In some areas where nesting beaches have ...
[60]
A mixed black and whitelist approach for wildlife trade regulation in ...
Jan 17, 2024 · ... class II protected species, respectively. While aquatic species ... Chinese softshell turtle, Pelodiscus sinensis, 16 small rodents and 12 bats.
[61]
Status and Analysis of Artificial Breeding and Management of ...
Sep 17, 2022 · This paper presents the current situation and problems of aquaculture and conservation of aquatic turtles in major provinces of China
[62]
Spotted softshell turtle release boosts reptile conservation in Vietnam
Apr 4, 2024 · Described by scientists as recently as 2019, the species is considered critically endangered throughout its range in China and Southeast Asia ...
[63]
Genetic diversity and population differentiation of the Chinese soft ...
The Chinese soft-shelled turtle Pelodiscus sinensis is favored for its medicinal and nutritional value and has been consumed as food for a long period of time ( ...Missing: juveniles | Show results with:juveniles<|control11|><|separator|>
[64]
Steamed Softshell Turtle Is A No-Waste Delicacy - Food Republic
Sep 10, 2023 · In China, common ways to enjoy softshell turtles include steaming them whole, creating a soup with Chinese medicinal herbs, and stir frying.
[65]
Softshell Turtle - Asian Bestiary |
A common method of consuming the Chinese softshell turtle is as turtle soup, which contains the turtle's meat, skin and innards. · The softshell turtle is widely ...Missing: culinary | Show results with:culinary
[66]
Snake soup, softshell turtle stew... The end of traditional Cantonese ...
Feb 28, 2020 · In Guangdong, softshell turtles and snakes are considered nourishing ingredients. The consumption of bullfrogs is also a common practice. Luo ...
[67]
Bie Jia (Softshell turtle shells) in Chinese Medicine - Me & Qi
Free delivery over $35 30-day returnsIn Traditional Chinese Medicine (TCM), Bie Jia belongs to the 'Tonic herbs for Yin Deficiency' category. Tonic herbs are used for patterns of Deficiency, when ...
[68]
Tortoise Shell: with Brief Reports on Treating Aplastic Anemia and ...
Turtle shell (biejia): nourishes yin, clears heat, disperses blood, softens hard lumps, disperses accumulations. • Tortoise shell (guiban): nourishes yin, ...
[69]
Biejiajian Pill Inhibits Carcinogenesis and Metastasis via the Akt ...
Mar 8, 2021 · In China, Biejiajian pill (BJJP), Traditional Chinese Medicine clinical prescription, is broadly utilized for the prevention and therapy of HCC.
[70]
Turtles threatened by medical myths | New Scientist
Jul 29, 1995 · Turtle eggs are thought to be an aphrodisiac, and turtle blood is believed to increase a person's energy and protein supply. The shells of ...
[71]
Effect of chinese softshell turtle egg powder on immune functions in ...
In ancient Chinese medical books, soft-shell turtle has been described as a drug for strengthening health, and they believed that it could ward off diseases ...
[72]
ENDANGERED SPECIES ISSUES AFFECTING
... Pelodiscus sinensis and Chinemys reevesii) was suspended in June 2000. Since June 2001, the importation of CITES-listed tortoises and freshwater turtles has ...
[73]
The Decline of Softshell Turtle Farms in South China
Jun 21, 2024 · They are an especially popular delicacy in southern China. Several of Humen's folk recipes include the stomach shell of a female hardshell ...<|control11|><|separator|>
[74]
Zhubieyu | A Book of Creatures
Jul 17, 2015 · Embodying Heaven, Earth, and Man”, and found irony in the fact that their own usefulness doomed them. They appear to be softshell turtles.
[75]
Entrée: Soft-shell Turtle | Dartmouth Folklore Archive
Nov 29, 2020 · The soft-shell turtles eaten during the Chinese New Year are often the middle-aged ones since they represent strength and health. The elders ...
[76]
https://www.chinese-showcase.com/blogs/chinese-culture/73-folk-taboos-in-chinese-culture
[77]
China's Turtles, Emblems of a Crisis - The New York Times
Dec 5, 2007 · Since 1998, China has banned the domestic timber trade and ... China in hopes of finding another Yangtze giant soft-shell in the wild.
[78]
Chinese Softshell Turtle. Wildlife Films Vietnam - YouTube
Jan 16, 2024 · Chinese Softshell Turtle - Vietnam's Aquatic Life in Lakes & Ponds - Peter Scheid is a wildlife filmmaker & dop/cameraman based in Ho Chi ...Missing: literature media wetland emblem
[79]
https://www.cites.org/sites/default/files/eng/com/ac/19/E19-15-2.doc
[80]
Effects of stocking density of Chinese soft‐shelled turtle and ...
Nov 11, 2019 · The results suggest that an appropriate stocking density (10 turtles/m 2 ) of turtles in the coculture system can effectively increase the yield of turtles.
[81]
None
### Summary of Monoculture and Polyculture Techniques, Yields for Pelodiscus sinensis Farming
[82]
Establishment risk from pet-trade freshwater turtles in the European ...
Pelodiscus sinensis. Trionychidae. 0.32 moderate. Kinosternon baurii ... risk for freshwater turtle species introduced into EU. Several non-native ...
[83]
Genetically verified record of non-indigenous turtle, Pelodiscus ...
Aug 31, 2023 · Here we report the first and genetically verified record of Chinese soft-shelled turtle (Pelodiscus sinensis) from the eastern part of the Czech Republic.Missing: synonyms etymology<|control11|><|separator|>
[84]
Effectiveness of legislative tools to stop biological invasions - NeoBiota
Oct 7, 2025 · Invasive species pose significant threats to biodiversity, human health, and economic systems. Freshwater turtles are popular as pets, ...
[85]
[PDF] origins of softshell turtles in hawaii with implications for - ScholarSpace
In their native ranges, wild populations of both Pelodiscus and Palea have been depleted by high levels of exploitation for food and medicinal uses, compounded ...
[86]
(PDF) Establishment risk from pet-trade freshwater turtles in the ...
Aug 7, 2025 · Urgent public education and additional legal regulations are needed for the pet trade to prevent the further spread of invasive turtle species ...