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Salangidae
Salangidae
from Wikipedia

Salangidae
Protosalanx hyalocranius
Salanx chinensis
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Osmeriformes
Suborder: Osmeroidei
Family: Salangidae
Genera

Salangidae, the icefishes or noodlefishes, are a family of small osmeriform fish, related to the smelts. They are found in Eastern Asia, ranging from the Russian Far East in the north to Vietnam in the south, with the highest species richness in China. Some species are widespread and common, but others have relatively small ranges and are threatened.[1] Depending on species, they inhabit coastal marine, brackish or fresh water habitats, and some are anadromous, only visiting fresh water to spawn.[2]

Appearance and life cycle

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They are slender, have translucent or transparent bodies and almost no scales (females are entirely scale-less, while males have a few). The head is strongly depressed and has numerous teeth. The adults are believed to be neotenic, retaining some larval features. For example, the skeleton is not fully ossified, consisting largely of cartilage.[3] They are small fish, typically around 8 cm (3.1 in) long; only a few reach 16 cm (6.3 in),[4] and the largest species no more than 22.5 cm (8.9 in).[5]

Icefish rapidly reach maturity, have a high fecundity and typically only live one year.[1][6] Some species live in the same habitat throughout their lives, but other visit specific habitats, like rivers, estuaries or the surf zone, to lay their eggs. In at least Salangichthys microdon there are both populations that are resident and populations that are anadromous.[2]

As food and introduced species

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Japanese sushi with Salangichthys microdon (shirauo)

Icefish support important fisheries and are eaten in East Asia, often after being dried or cooked. They are also exported to southern Europe for use as a replacement for the more expensive transparent goby, a Mediterranean species used in the local cuisine.[7]

Because of their value as food fish, there have been many attempts of introducing icefish (especially certain Neosalanx and Protosalanx) to regions in East Asia where not native. Most attempts failed, but several were successful, and in some cases the icefish rapidly multiplied and became the most common fish in their new habitat. Feeding on planktonic crustaceans and tiny fish, they have outcompeted certain native fish like Anabarilius grahami, which have become rare and threatened.[8][9][10]

See also

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  • Sundasalanx, the Sundaland noodlefish, which formerly were included in Salangidae, but now are placed in their own family

References

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Revisions and contributorsEdit on WikipediaRead on Wikipedia
from Grokipedia
Salangidae, known as icefishes or noodlefishes, is a family of small osmeriform characterized by transparent or translucent bodies, scaleless skin, and poorly ossified skeletons, which confer a neotenic appearance retaining larval traits into adulthood. These , reaching a maximum length of about 15 cm, primarily inhabit freshwater, brackish, and coastal marine environments across eastern , with some species exhibiting anadromous migrations for spawning. The family encompasses 7 genera and approximately 20 species, many endemic to and originating from the region, where they feed on and complete annual life cycles of roughly . Salangids hold commercial importance as food in , though populations of several species have declined due to , habitat , , and ecological disruptions from species introductions. Diagnostic features include a strongly depressed head with toothed maxillae, 6-8 pelvic rays, and 48-79 vertebrae, distinguishing them from related smelts.

Taxonomy and phylogeny

Classification and genera

Salangidae is a family of small osmeriform fishes classified within the order Osmeriformes, suborder Osmeroidei, superorder Protacanthopterygii, and class Teleostei. The family was established by Pieter Bleeker in 1859, with Salanx designated as the type genus. Members exhibit primitive characteristics relative to other osmeriforms, such as reduced scales and translucent bodies adapted to freshwater and brackish environments in East and Southeast Asia. Current taxonomy recognizes seven genera within Salangidae, encompassing around 20 valid as cataloged in like FishBase and Eschmeyer's Catalog of Fishes. These genera include:
  • Hemisalanx , 1908 (monotypic, with H. brachyrostralis)
  • Neosalangichthys Fu, Li, Xia & Lei, 2012 (monotypic, N. ishikawae; elevated from Salangichthys based on morphological distinctions)
  • Neosalanx Wakiya & Takahashi, 1937 (multiple , e.g., N. brevirostris, N. taihuensis)
  • Parasalanx , 1908 (monotypic, P. cuvieri)
  • Protosalanx , 1908 (monotypic, P. chinensis; considered basal within the family)
  • Salangichthys Bleeker, 1860 (monotypic, S. microdon)
  • Salanx Cuvier, 1816 (; multiple , e.g., S. ariakensis, S. chinensis; includes synonyms like Leucosoma)
Some classifications, such as those in older references, synonymize Leucosoma (e.g., L. reevesii) under Salanx, reflecting ongoing taxonomic refinements based on morphological and molecular data. Multilocus phylogenetic analyses support the of Salangidae but highlight potential in certain genera like Neosalanx, warranting further revision.

Species diversity and molecular insights

The family Salangidae encompasses approximately 20 species across 6 to 7 genera, with genera including Salanx, Leucosoma, Salangichthys, Protosalanx, and Neosalanx. is concentrated in , particularly , where 15 of the approximately 17 recognized global species occur, including 6 endemics restricted to coastal, riverine, and estuarine habitats. This regional hotspot reflects adaptive radiations in freshwater and brackish environments, though some taxa exhibit low , potentially due to historical bottlenecks or limited . Molecular phylogenetic studies have clarified intra-familial relationships and evolutionary history. A 2007 analysis of complete mitochondrial sequences (1141 bp) from 15 species resolved major s, supporting of Salangidae within Argentinoidea and highlighting estuarine adaptations as a derived trait in certain lineages. Subsequent multilocus approaches, incorporating seven nuclear genes and one mitochondrial marker with full taxon sampling, refined genus-level topologies, revealing Salangichthys as basal and potential in Neosalanx, while underscoring reticulate evolution via hybridization in polyploid forms. These findings align with osmeroid affinities, positioning Salangidae as a Southern Hemisphere-derived within Protacanthopterygii. Genomic insights further illuminate and ecological specializations. Chromosome-level assemblies, such as for Neosalanx taihuensis, reveal expanded gene families linked to and transparency, traits enabling larval-like retention into adulthood across the family. Phylogeographic analyses indicate complex demographic histories, with low nucleotide diversity in Chinese populations suggesting post-glacial expansions from refugia, though has reduced effective population sizes in exploited . Such challenge earlier morphological classifications and emphasize molecular evidence for conservation prioritization amid .

Physical description

Morphology and external features

Members of the Salangidae family possess slender, elongate bodies that are typically transparent or translucent, facilitating in their aquatic environments. This body shape is characterized by a compressed form, with lengths generally ranging from 5 to 15 cm in total length, though some species like Neosalanx pseudotaihuensis reach a maximum of 70 mm. The skin is scaleless in females and most individuals, while adult males may exhibit a single row of scales above the anal fin base; this reduction in scales contributes to their soft, gelatinous texture. The head is strongly depressed, often featuring large eyes suited for low-light conditions in rivers and lakes. Fins are positioned posteriorly, with dorsal and anal fins located toward the rear of the body, and pelvic fins inserted at mid-body with 6-8 rays. An adipose fin is present between the dorsal and caudal fins, consistent with their osmeriform affinities. Coloration is predominantly or silvery, enhancing transparency and reducing visibility to predators.

Anatomy and adaptations

Salangid fishes exhibit a highly specialized characterized by an elongate, slender body form typically reaching a maximum length of 15–21 cm, with a nearly scaleless, translucent that enhances in clear aquatic environments. The body is streamlined, lacking prominent scales except occasionally in a single row along the dorsal midline or bases in mature males, and features a strongly depressed head equipped with numerous small teeth adapted for capturing planktonic prey. This morphology reflects neotenic retention of larval traits, including a poorly ossified composed largely of rather than , which contributes to their lightweight, flexible structure and reduced requirements in nutrient-limited habitats. Internally, Salangidae display remarkable physiological adaptations, notably the independent evolutionary loss of functional and deterioration of associated oxygen-transport genes, resulting in colorless, hemoglobin-free and absence of red blood cells across most . This neotenic-derived trait, stemming from pseudogenization of α- and β-globin genes in their common , limits oxygen-carrying capacity but is viable in well-oxygenated, normoxic waters where suffices for metabolic demands, potentially reducing energy costs for . Complementing this, the complete loss of the gene further streamlines oxygen storage, aligning with their small size and low metabolic rates. Many are , exhibiting osmotic plasticity via changes in ionoregulatory pathways, enabling tolerance of brackish to freshwater transitions during migratory life histories. These adaptations collectively favor rapid growth, early maturation (often within 7 months), and exploitation of ephemeral blooms in dynamic estuarine systems.

Distribution and ecology

Native geographic range

Salangidae, commonly known as icefishes or noodlefishes, are endemic to eastern , with their native range extending from the southward through , the Korean Peninsula, and to . This distribution encompasses coastal marine, brackish estuarine, riverine, and lacustrine habitats in the northwest Pacific region. The family originated in the vicinity of the Chinese , from which it radiated into adjacent freshwater and brackish systems. China hosts the greatest species diversity, with 15 of the roughly 17 recognized species occurring naturally within its river basins, lakes, and coastal waters, including the , , Huai, and systems. In the northern extent of the range, species such as Salangichthys microdon are found in waters off eastern , , and Korea, often exhibiting anadromous behavior between marine and freshwater environments. Southern populations extend into subtropical and tropical zones of and adjacent Southeast Asian drainages, though records there may reflect natural limits or early dispersals rather than widespread . While primarily freshwater-oriented, several species tolerate or preferentially occupy brackish and nearshore marine conditions, contributing to their broad latitudinal spread across temperate to subtropical climates. No native populations are documented outside this East Asian corridor, distinguishing Salangidae from more cosmopolitan osmeriform families.

Habitat preferences and environmental tolerances

Salangidae species predominantly occupy freshwater habitats such as rivers, lakes, and reservoirs across East and , with many exhibiting preferences for slow-flowing or lentic waters where they occur as demersal or pelagic forms. Certain genera, including Protosalanx and Salangichthys, frequently utilize estuarine zones and coastal shallows, reflecting adaptations to transitional environments that support their transparent, neotenic morphology suited for low-light or turbid conditions. Habitat selection varies intraspecifically; for example, Protosalanx chinensis populations thrive in both riverine systems like the Basin and adjacent lakes such as Taihu, often favoring depths and substrates that align with zooplankton-rich foraging grounds. The family demonstrates broad salinity tolerances, qualifying many members as , with capabilities spanning freshwater (near 0 ppt) to full marine salinities (up to approximately 35 ppt). Anadromous behaviors are common in species like Salanx ariakensis and Protosalanx hyalocranius, involving migrations between marine feeding grounds and freshwater spawning sites, while others such as Neosalanx tangkahkeii display facultative shifts without obligatory patterns. This plasticity has facilitated successful introductions to diverse systems, including saline and alkaline lakes in northern , where species like Protosalanx chinensis establish viable populations despite varying ionic compositions. Sympatric species often partition microhabitats by salinity gradients, minimizing competition in shared estuaries. Environmental tolerances extend to temperate climatic zones, with distributions confined to regions supporting cooler water regimes typical of their native ranges, though specific thermal limits remain understudied. Sensitivity to hypoxia and air exposure constrains handling during capture, as evidenced by rapid mortality in Protosalanx chinensis under oxygen deprivation, underscoring physiological vulnerabilities despite overall adaptability.

Life history and behavior

Reproduction and development

Salangid fishes are semelparous, completing their annual life cycle with a single reproductive event followed by death. This strategy allocates maximal energy to gonadal development at the expense of somatic growth cessation, resulting in paedomorphic adults that retain larval traits such as unpigmented bodies, absent scales, and a persistent larval finfold. is achieved rapidly, often within months; for example, female Protosalanx chinensis reach maturity by early after hatching in spring. Spawning seasons differ across genera and populations, generally aligning with cooler periods to match slow embryonic development in low temperatures. Most species spawn in spring, though some, like Neosalanx taihuensis, do so from October to December, with introduced populations shifting from multiple to single spawning bouts. Protosalanx chinensis spawns once in early following asynchronous oocyte development that synchronizes prior to release. Many salangids are amphidromous or anadromous, ascending rivers or estuaries for spawning in freshwater or brackish substrates. Fertilization is external, with demersal eggs adhering to sand or gravel via filaments or chorionic membranes. Egg characteristics vary; in Salangichthys microdon, populations exhibit a trade-off between fecundity and quality, with brackish-water types producing more but smaller eggs compared to riverine ones. Gonadosomatic indices exceed 20 in ripe individuals, reflecting high reproductive investment. Spawning behavior in S. microdon involves female mate choice, with pairs forming after male competition; the male attaches his gonopore to the female's using anal fin scales as a sucker, followed by body shaking and ascent for egg release in small batches, though success is low due to frequent female rejection. Embryonic development proceeds slowly in cold water, optimizing survival in oligotrophic habitats. In Protosalanx hyalocranius, fertilized eggs with thread-like chorionic filaments hatch after 33 days, 18 hours, and 54 minutes at 0.9–10.1°C, producing larvae of 5.74 mm total length bearing 66 myomeres (44 preanal + 22 postanal). Key milestones include mouth opening and air bladder inflation on day 6, with yolk sac absorption by day 18 at approximately 6.5 mm; larvae succumb at 7.2°C, underscoring thermal sensitivity. Post-hatching, larvae exhibit neotenic retention of features like straight digestive tracts and larval otoliths into adulthood, supporting rapid maturation without full .

Migration patterns and feeding ecology

Salangid icefishes (family Salangidae) exhibit diverse migratory patterns, with many species displaying anadromous behavior where adults reside in brackish or coastal marine environments before ascending rivers for spawning. Sr/Ca ratio analyses reveal that species such as Salangichthys microdon (Japanese icefish or shirauo) undertake upstream migrations into freshwater systems like the Kuji River in , often as juveniles or subadults with body lengths ranging from 6.4 mm to 39.8 mm during ascent, followed by seaward migration after spawning or growth. In Protosalanx chinensis (clearhead icefish), migrations occur into rivers connected to estuaries like the , transitioning from brackish ( up to 0.01–several ppt) to freshwater habitats for reproduction, though populations can persist in lentic freshwater systems such as lakes and reservoirs post-introduction. Coexisting strategies within species include non-migratory residency in brackish or freshwater, as observed in some S. microdon cohorts that remain estuarine without full anadromy. Feeding ecology in Salangidae is predominantly zooplanktivorous, centered on small planktonic crustaceans that support their short lifespan of approximately . Juveniles of species like Neosalanx pseudotaihuensis rely almost exclusively on copepods and other planktonic crustaceans, while adults incorporate small fishes into their diet, reflecting an ontogenetic shift that enhances energy intake for reproduction. In estuarine and coastal habitats, prey availability—such as abundant in oligohaline zones—drives foraging success, with turbidity maxima in upper estuaries like the Chikugo providing optimal conditions for feeding on diatoms, mysids, and conspecific eggs in related taxa. Exotic introductions, such as Neosalanx taihuensis in Chinese lakes, demonstrate competitive diet overlap with native fishes through shared planktivory on cladocerans and copepods, contributing to declines in endemic like Anabarilius grahami.

Evolutionary origins

Phylogenetic relationships

Salangidae is classified within the order , part of the superorder Protacanthopterygii, with molecular evidence supporting its as a distinct family closely related to Osmeridae (true smelts) and Plecoglossidae (ayu). Phylogenetic analyses using mitochondrial and nuclear DNA sequences place Salangidae as a to these families within a restricted , excluding more distant taxa like . Within Salangidae, a multilocus study analyzing seven nuclear loci (4099 bp) and the mitochondrial gene (1099 bp) across 12 resolved intergeneric relationships using a coalescence-based -tree method, confirming family and each as monophyletic. This analysis identified two major subfamilies based on pectoral-fin ray counts: Protosalanginae (≥20 rays), comprising Protosalanx and Neosalanx as sister genera; and Salanginae (≤19 rays), including Salanx, Salangichthys, Leucosoma, and the newly erected Neosalangichthys (for the former Salangichthys ishikawae, distinguished by unique fin-ray and tooth morphology). The study proposed a revised redefining subfamilies with synapomorphies like fin-ray counts and gill-raker structures, superseding earlier morphology-based arrangements. Earlier studies, such as a 2007 analysis of complete sequences (1141 bp) from 15 species, corroborated and key sister relationships, including ProtosalanxNeosalanx and SalanxHemisalanx, though with less resolution for basal genera like Leucosoma. Subsequent mitochondrial phylogenies using multiple genes (e.g., four mt genes) reinforced Leucosoma as basal, with Protosalanx + Neosalanx forming one and Hemisalanx + Salanx another within Salanginae. These findings highlight adaptive convergence in translucent body forms but underscore genetic divergence driven by estuarine and freshwater habitats in .

Adaptive radiation and historical biogeography

The Salangidae family is believed to have originated in the inshore coastal waters of the East China Sea, from which ancestral populations dispersed into diverse inland and estuarine habitats across eastern Asia through multiple unrelated founding events, particularly during Pleistocene interglacial periods. Genetic evidence from species like Neosalanx taihuensis reveals three distinct subclades emerging approximately 0.35 million years ago (Clade 1), 0.145 million years ago (Clade 3), and 0.12 million years ago (Clade 2), with population expansions following the Last Glacial Maximum around 0.02 million years ago. This pattern of stepwise colonization reflects a broader phylogeographic model for inshore-oriented freshwater fishes, involving repeated marine-to-freshwater transitions rather than vicariance. Molecular phylogenetic reconstructions, based on complete mitochondrial cytochrome b sequences (1141 bp) across 15 species, confirm the monophyly of Salangidae and identify four principal lineages: (I) Protosalanx and Neosalanx spp.; (II) additional Neosalanx spp.; (III) Hemisalanx, Salanx, Leucosoma, and Salangichthys ishikawae; and (IV) Salangichthys microdon as basal. Divergence among these lineages initiated in the early approximately 21 million years ago, with subsequent speciation events spanning 1.05 to 9.90 million years ago. Although is common among species, suggesting secondary contact rather than or strict geographical isolation as primary drivers, ecological opportunities in varied salinities facilitated lineage sorting. Adaptive radiation within Salangidae, occurring from the mid-Miocene to , involved extensive habitat invasions, especially into freshwater systems, paralleled by the evolution of —a paedomorphic retention of larval traits in adults, including body transparency, (adults typically 5–10 cm), and a predominantly cartilaginous . Genomic analyses of Protosalanx chinensis highlight genetic underpinnings of this , such as losses in EDAR, SCPP1, four Hox proteins, and impaired FGF5 function, which likely enhanced survival in oligotrophic, low-oxygen, and aquatic niches across rivers, lakes, estuaries, and coastal zones. High enables tolerance of broad ranges (e.g., Sr/Ca ratios <5.0 × 10⁻³ in freshwater to >20.0 × 10⁻³ in marine settings), supporting facultative anadromy in some taxa like Salanx ariakensis and residency in others like Protosalanx chinensis. This radiation, nested within the Protacanthopterygii order (diverging from salmonid ancestors ~185 million years ago), underscores as a key innovation driving diversification in a lineage otherwise characterized by conserved morphology.

Human utilization and impacts

Economic importance as food

Species of the family Salangidae, particularly those in the genera Protosalanx and Neosalanx, are commercially harvested for in , where they support significant inland production through wild capture and stock enhancement. These small, translucent fishes have been widely introduced into lakes and reservoirs since the to boost yields, with Protosalanx hyalocranius noted for its high economic value and role in expansion. Traditional exploitation targets their delicate flavor, and they are processed for domestic markets or exported to and despite limited individual size. In , Salangichthys microdon (known as shirauo) forms the basis of a targeted commercial in brackish and coastal waters, yielding catches valued as a seasonal often consumed raw or alive in dishes like . Harvesting occurs in regions such as and , where the species' abundance in estuaries supports local economies, though production remains modest compared to larger fisheries due to its 5-9 cm body length. Overall, Salangidae contribute to regional and cultural cuisine in , with introductions driving output gains but prompting concerns over long-term sustainability in enhanced systems.

Introductions, aquaculture, and ecological consequences

Salangidae species, particularly Neosalanx taihuensis and Protosalanx hyalocranius, native to eastern waters such as Lake Taihu and the River basin, have been widely introduced to inland lakes, reservoirs, and rivers across since 1979 to enhance fisheries production. These translocations involved fingerlings from source populations into over 100 water bodies, including plateau lakes in Province and northern systems like the River basin, aiming to exploit the fishes' high —up to 10,000 eggs per female—and rapid growth to boost yields in oligotrophic or underutilized habitats. By the , such introductions had established self-sustaining populations in recipients like and Erhai Lake, contributing to national icefish catches exceeding 100,000 metric tons annually in peak years. Aquaculture of Salangidae emphasizes stock enhancement over intensive closed-cycle farming, with hatcheries producing larvae and juveniles from wild or semi-wild for release into open waters. In , facilities in provinces like and rear N. taihuensis through artificial spawning induced by temperature shifts and hormone injections, achieving survival rates of 20-50% to stocking size (20-30 mm total length) before transfer to lakes. P. hyalocranius farming remains developmental, with experimental pond and cage systems yielding 1-2 kg/m³ but challenged by the species' semelparous life cycle and sensitivity to high densities, limiting full ; live transport for market remains rare despite economic value exceeding 10 yuan/kg in fresh sales. Overall, these practices have supported a output valued at hundreds of millions of yuan annually, though reliance on natural recruitment post-stocking reduces predictability. Ecological consequences of Salangidae introductions include predation on and competition with native planktivores, leading to trophic shifts and declines. In plateau lakes, N. taihuensis invasions correlated with 50-90% reductions in endemic cyprinid populations, such as Cyprinus carpio variants and Schizothorax species, between 1980 and 2000, attributed to icefish numerical dominance (densities >1,000 individuals/ha) and voracious feeding on shared prey like copepods and cladocerans. Hybridization with local congeners, as observed in basin P. hyalocranius populations via mtDNA recombination, further erodes genetic integrity of natives. While short-term boosts in total biomass occurred, long-term losses—evidenced by extirpations in Erhai Lake—outweigh gains, prompting calls for containment over expansion; no successful eradications have been reported, exacerbating risks in connected basins.

Conservation status

Population threats and declines

Populations of Salangidae species across their native East Asian ranges, particularly in , have undergone marked declines since the mid-20th century, driven primarily by , , and . Annual commercial yields of icefishes in the Yangtze River basin peaked at approximately 4,000 metric tons before falling to under 1,300 metric tons by the early , reflecting sustained exploitation that exceeded reproductive capacity. In Lake Nanyi, eastern , catch per unit effort (CPUE) has serially declined across fishing seasons, with population models indicating depensatory effects where low densities further impair per capita reproductive success. Habitat loss from anthropogenic activities has compounded these pressures, including reclamation for , dyke fragmenting riverine systems, and hydroelectric disrupting spawning migrations and larval drift. For instance, in the and basins, such alterations have reduced available spawning grounds for species like Neosalanx taihuensis, contributing to localized extirpations and overall erosion within the family. Water from industrial effluents and agricultural runoff has further degraded water quality, impairing egg viability and juvenile survival, as evidenced by correlations between loads and failures in affected lakes. Specific to Protosalanx chinensis (formerly classified under P. hyalocranius), wild stocks have collapsed in native rivers due to intensified amid economic growth, coupled with hydroproject-induced flow regime changes and ; genetic analyses reveal bottlenecks traceable to 1980s episodes. Similar dynamics affect other genera, such as Salanx, where has halved biomasses in exploited inland waters since the 1990s. These threats interact causally—habitat fragmentation amplifies vulnerability to harvesting, while reduces resilience—leading to range contractions and, in some cases, reliance on to offset shortfalls, though wild recoveries remain elusive without targeted interventions.

Current assessments and management strategies

Many Salangidae species remain unassessed or on the , with limited formal evaluations reflecting gaps in monitoring despite evident population declines from , habitat degradation, and . For instance, Neosalanx regani was assessed as Vulnerable in 1996 due to restricted range and threats in , while Neosalanx brevirostris is currently . Fisheries data from the River basin indicate severe degradation, with icefish yields falling from a maximum of 4,000 metric tons annually to under 1,300 metric tons, attributed primarily to excessive exploitation across affiliated lakes. In response, enacted a 10-year commercial fishing moratorium in the River and key tributaries effective 2021, aiming to rebuild stocks of diadromous like Protosalanx hyalocranius through enforced closures and resource protection. Complementary measures include basin-wide restoration via strategic fish releases from lakes to rivers, sluice gate management for migration support, and a compensation framework for displaced fishermen to ensure compliance. Ecosystem-based approaches emphasize spawning ground preservation and pollution controls, though implementation varies by locality. In , management for species such as Salangichthys microdon relies on localized catch monitoring and otolith strontium-calcium ratio analysis to track migratory life histories and assess riverine population viability, informing adaptive regulations amid observed declines in rivers like the Yoshii and . These efforts prioritize sustainable harvest levels, with resilience estimates suggesting medium recovery potential (minimum 1.4–4.4 years) under reduced pressure. Overall, strategies across ranges stress integrated monitoring and enforcement, yet persistent challenges like illegal and interactions necessitate enhanced international coordination for transboundary populations.

References

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