The nomenclatural history of the species is somewhat complicated. The name Stegostoma fasciatum (Hermann, 1783) has been the standard name used, however Dahl et al. (2019) concluded that the original name Stegostoma tigrinum Forster, 1781 is the correct senior synonym.

The Indo-Pacific Leopard Shark (Stegostoma tigrinum) is a medium-sized (to 266 cm total length) shark that occurs across the Indo-West Pacific Oceans. It is found on continental and insular shelves from inshore to a depth of 90 m and is associated with coral and rocky reefs, and inshore mudflats, mangroves and seagrass beds. The species has strong site fidelity to reefs when mature and can occur in aggregations, both of which make it more susceptible to targeted fishing. It is captured in a wide range of inshore fisheries including incidentally in demersal gillnet and trawl fisheries. It is sometimes retained for its meat and fins or released alive in some areas. There are two genetically distinct subpopulations: Western Indian Ocean-Southeast Asian and Eastern Indonesian-Oceania. Significant declines in the Western Indian Ocean-Southeast Asian subpopulation are apparent due to overfishing and significant inshore habitat degradation and loss. It is now locally extinct in some areas such as parts of Indonesia. It is suspected the subpopulation has undergone a population reduction of >80% over the past three generation lengths (57–72 years) and it is assessed as Critically Endangered. The Eastern Indonesian-Oceania subpopulation is exposed to minimal threats in eastern Australia where it has been stable over the past two decades and the Indo-Pacific Leopard Shark in Australian waters is considered Least Concern. However, there is likely movement between Australia and Eastern Indonesia where fishing is intense and unregulated and pressure has increased since the 1980s. Thus, the Eastern Indonesian-Oceania subpopulation is suspected to have undergone a population reduction of 20–29% over the past three generation lengths (57–72 years) and it is assessed as Near Threatened. To estimate a global population trend, the estimated three generation population trends for each subpopulation were weighted according to the relative size of each region. Thus, it is suspected that the species has undergone a population reduction of 50–79% over the past three generation lengths (57–72 years) due to levels of exploitation and habitat degradation, and the Indo-Pacific Leopard Shark is assessed as Endangered A2bcd.

The Indo-Pacific Leopard Shark occurs across the Indian and Western Central Pacific Oceans from South Africa to Samoa and north to Japan (Ebert et al. 2021). Since the previous assessment (Dudgeon et al. 2019), the distribution map has been refined to map this species to its known bathymetric range.

Based on population genetic analysis, the Indo-Pacific Leopard Shark comprises two distinct subpopulations: Western Indian Ocean-Southeast Asian and Eastern Indonesian-Oceania (Dudgeon et al. 2009).

Western Indian Ocean-Southeast Asian subpopulation

In Eastern Africa, a photo identification study in Mozambique from 2010–2018 identified 90 individuals with a low but stable population estimate of <100 individuals (Pottie et al. 2021). The most recent number of identified individuals is 114 and sightings-per-unit-effort has remained relatively stable in recent years (S. Venables unpub. data). Fishers interviewed in the same area caught the Indo-Pacific Leopard Shark incidentally in gillnets but reported much lower encounter rates than those in diver surveys (Pottie et al. 2021). There was an apparent decline in landings at fishing ports in Sudan from the early 2000s (I. Elhassan pers. comm. 2017). In the Arabian Sea and adjacent waters, the Indo-Pacific Leopard Shark is generally rare, partially due to its habitat specificity and therefore somewhat localised occurrence. This species comprised less than 1% of total elasmobranch landings by number in the Saudi Arabian Red Sea (Spaet and Berumen 2015) but has been observed on Baited Remote Underwater Surveys (BRUVS) in the southern Red Sea (Spaet et al. 2016). The species used to be commonly seen by divers off the United Arab Emirates (UAE) east coast and Oman, particularly around the Daymaniyat Islands but sightings have now become sporadic. In those countries, the species is rarely landed due to low commercial value (R.W. Jabado pers. comm. 2017). In the UAE, it represented less than 1% of sharks by number landed from the local fishery and of those traded from Oman and the UAE (Jabado et al. 2015, 2016). The species was not observed in market surveys of elasmobranchs in Kuwait and Bahrain (Moore et al. 2012, Moore and Peirce 2013), although there are historic records of individuals from Kuwait and Bahrain (Goubanov and Shleib 1980, Randall 1986). It has been observed in the Al Shaheen area of Qatari waters (D. Robinson unpub. data). Data from Iran indicates the species was commonly recorded in trawls from 2005–2006 but by 2015–2016, much smaller numbers were caught (Owfi et al. 2017, F. Owfi pers. comm. 2017). In Pakistan, catches of the species have declined as it was previously a commonly landed species from gillnet and trawl fisheries but is now seldom landed (Osmany and Khan 2022). In the Maldives, where there is no fishing pressure on the species, Indo-Pacific Leopard Sharks are occasionally observed by divers (Sattar et al. 2014).

In India, there is no species-specific trend information for the Indo-Pacific Leopard Shark, although across India, landings of elasmobranchs have declined by 44% from 1998–2018 despite increasing fishing pressure and the elasmobranch component of the annual marine fish landings in India declined from 3.4% to et al. 2020, Akhilesh et al. 2023). In Bangladesh, the Indo-Pacific Leopard Shark was previously reported to be a minor component of fisheries accounting for <1% of elasmobranch catches (Hoq et al. 2014) but has not been noted in more recent fishery reports (e.g., Haque et al. 2018, Haque et al. 2019). Similarly, in Myanmar, it was reported from fisheries in the early 2000s but by 2015–2016 was not noted in fishery surveys (SEAFDEC 2004, 2020). In Thailand, a photo-identification program identified 339 individual Indo-Pacific Leopard Sharks from 2012–2015 in the Krabi Province in the Andaman Sea, though there has been no recent systematic data collection (C. Dudgeon, Spot the Leopard Shark Thailand, unpub. data). Dive sightings in Krabi Province from 2012–2016 noted Indo-Pacific Leopard Sharks as among the most frequently encountered shark species (Ward-Paige et al. 2018), though over the past four years, dive operators anecdotally reported a decline in numbers (C. Dudgeon unpub. data). Landing site surveys of Thai commercial fishers from the Andaman Sea revealed a potential significant decline in Indo-Pacific Leopard Shark landings from 30 to three individuals between 2005–2015 (Arunrugstichai et al. 2018) although without standardisation between the surveys, the actual level of decline is difficult to determine. Fish market surveys support substantial population declines in the Gulf of Thailand as the Indo-Pacific Leopard Shark was not sighted at landing sites in the region, though it was noted as occurring there in a subsequent report but not whether it was seen at landing sites or sighted by divers (Krajangdara 2014, 2019). Surveys of SCUBA dive schools operating in the Gulf of Thailand also recorded a significant reduction in Indo-Pacific Leopard Shark sightings between the 1990s and 2000s from an average of one shark sighted per dive to <0.25 sharks sighted per dive (Ward-Paige and Lotze 2011).

In Indonesia, the Indo-Pacific Leopard Shark is likely to be locally extinct from several locations (Dudgeon et al. 2019). In particular, extensive SCUBA surveys for fish diversity assessments at sites across the Indonesian Archipelago recorded none (Bali, Anambas Archipelago, Timor-Leste, Triton Bay and Cenderawasih Bay in West Papua) or very few Indo-Pacific Leopard Sharks (Southwest Sulawesi, North Sulawesi, Raja Ampat) (Dudgeon et al. 2019. M. Erdmann pers. comm. 23 March 2015). The Indo-Pacific Leopard Shark was observed regularly (3–7 animals per dive) on dive sites at Berau Archipelago off East Kalimantan during surveys in 1997 but none were observed on subsequent surveys in 2002 and 2004 (M. Erdmann pers. comm. 23 March 2015). Previous fish market surveys in Indonesia during April 2001–March 2006 recorded 77 Indo-Pacific Leopard Sharks with almost all coming from trawl fishery incidental catch landed in Jakarta (Dharmadi et al. 2015). Anecdotal and fishery reports note it is still regularly captured in northern Java waters and Kalimantan, though declines have been noted over the past two decades (Fahmi 2021, N. Ichida pers. comm. 2023). Documented large declines in shark and ray catches associated with corresponding increases in fishing effort in the Java Sea from 1976–1997 (Blaber et al. 2009) are likely to have had a significant impact on the Indo-Pacific Leopard Shark in Indonesian waters and may be representative of fishing impacts across the region. In Taiwan, the species was previously but not commonly reported from fisheries and has not been observed in fish markets since the late 2000s (Chen et al. 1997, Ebert et al. 2013). Anecdotally, recent sightings of the species have been reported in Taiwan (L. Hoopes pers. comm. 2023).

The greatest levels of exploitation, ongoing intense and unregulated fishing pressure, and habitat degradation and loss for this species occurs in the Western Indian Ocean and Southeast Asia, particularly Thailand through to Indonesia, and the species is suspected to be locally extinct in parts of this range. The species has no refuge from fishing pressure across these regions. Given little or no genetic exchange from unexploited areas it is suspected that this subpopulation has undergone at least an 80% reduction over the past three generations (57–72 years). Thus, the Western Indian Ocean-Southeast Asian subpopulation is assessed as Critically Endangered.

Eastern Indonesian-Oceania subpopulation

The Indo-Pacific Leopard Shark occurs in large aggregations (20–50 animals) over sand near reef systems in parts of its Australian range which are likely the largest known aggregations for the species (Pillans and Simpfendorfer 2003, Dudgeon et al. 2008). Population estimates are based on mark-recapture analysis of photo-identification surveys of mature individuals over two decades from North Stradbroke Island, Queensland to Julian Rocks, New South Wales from 2003–2023. These indicate a stable population with a mean estimate of 582 individuals sighted per year from 2003–2006 and 621 individuals sighted per year from 2020–2023 (Dudgeon et al. 2008, D. Robinson unpub. data). The Eastern Indonesian-Oceania subpopulation occurs across regions with minimal exploitation of this species as well as regions of greater fishing pressure and habitat threats. In particular, across the Pacific Islands, the low human population numbers result in much lower fishing pressure than elsewhere and in Australia, there are the relatively minimal impacts from fishing and habitat loss and the Indo-Pacific Leopard Shark has recently been categorised in an Australian National Red List assessment as Least Concern (Kyne et al. 2021). However, population genetic and tracking studies suggest there is likely to be exchange between Australian waters and the Arafura Sea in Eastern Indonesian waters. Extensive trawl fishing occurs in the Arafura Sea region and has been increasing in intensity since the 1980s, with a reported 43% decrease in shark catches from 2015–2021 indicating decreasing shark stocks (Jaiteh et al. 2017, Nurdin et al. 2023). In Raja Ampat, the Indo-Pacific Leopard Shark is extremely rare with only three individuals sighted in >15,000 person-hour surveys since 2001 (Traylor-Holzer 2021). Based on the ongoing fishing threats posed by these trawl fisheries in Eastern Indonesia and the potential impacts on Indo-Pacific Leopard Sharks migrating from adjacent Australian waters, it is suspected the subpopulation has undergone a reduction of at least 20% over the past three generation lengths (57–72 years), and the Eastern Indonesian-Oceania subpopulation is assessed as Near Threatened.

To estimate a global population trend, the estimated three generation population trends for each subpopulation were weighted according to the relative size of each region. The Western Indian Ocean-Southeast Asian subpopulation represents approximately 70% of the species range and the Eastern Indonesian-Oceania approximately 30% of the species range. Thus, across its global range, it is suspected that the Indo-Pacific Leopard Shark has undergone a population reduction of 50–79% over the past three generation lengths (57–72 years) due to levels of exploitation and habitat degradation and loss, and it is assessed as Endangered A2bcd.

The Indo-Pacific Leopard Shark occurs in tropical and subtropical waters on continental and insular shelves at depths of 0–90 m, though it mostly occurs to 60 m depth with one individual recorded to 142 m depth (Yano 1999, Weigmann 2016, Ebert et al. 2021). It occurs around coral and rocky reefs and on sandy plateaus near coral, and in inshore mudflats, mangroves and seagrass beds, and is often observed resting on the bottom as well as swimming near the surface as both juveniles and adults. The species has strong site fidelity to particular reefs when mature but can also seasonally migrate up to 2,300 km (Dudgeon et al. 2013, Pottie et al. 2021, C. Dudgeon unpub. data). While mostly solitary, it can occur in aggregations of up to 50 individuals (C. Dudgeon and D. Robinson unpub. data). The Indo-Pacific Leopard Shark reaches a maximum size of 266 cm total length (TL), males mature at 147–183 cm TL and females mature at 169–171 cm TL (Ebert et al. 2021, Osmany and Khan 2022). Reproduction is oviparous with a likely annual reproductive cycle. Captive aquaria animals lay egg cases for a period of up to three months with 40–80 egg cases laid per year and up to 25% of egg cases resulting in hatchlings with a size-at-birth of 20–36 cm TL (Robinson et al. 2011, Ebert et al. 2021, L. Squire Jnr. pers. comm. 2014). Females exhibit parthenogenesis, i.e, can produce viable egg cases without the need for male fertilization. Age-at-maturity of captive female sharks is approximately 6–8 years with maximum age of male sharks in captivity of at least 40 years and maximum age of male sharks observed in the wild of at least 31 years (D. Robinson and S. Thomas pers. comm. 2015). This results in a generation length of 19–24 years.

The Indo-Pacific Leopard Shark is susceptible to capture in a wide range of inshore fisheries and is targeted and caught incidentally mainly in demersal gillnet and trawl fisheries. The species' strong site fidelity to reefs and its occurrence in aggregations make it more susceptible to targeted fishing with the rapid capture of large numbers of individuals possible and evident in some fisheries, for e.g., in India (D. Robinson unpub. data). Fisheries across the Western Indian Ocean and Southeast Asia have experienced increased demand for sharks since the 1970s due to the shark fin trade (the fins of the Indo-Pacific Leopard Shark are not valuable but the species can be taken incidentally) and as a result, effort is increasing in traditional shark fisheries in many areas (Jabado et al. 2015, Obura et al. 2017, Karnad et al. 2019). Simultaneously, there has been a significant increase in coastal fishing effort and power leading to a reduction in the number of shark catches across the regions (e.g., Spaet and Berumen 2015, Bennet et al. 2023).

In Mozambique, Indo-Pacific Leopard Sharks are opportunistically targeted by spear fishers if they are seen and Praia do Tofo, southern Mozambique appears to be a hotspot for the Indo-Pacific Leopard Shark (Pierce et al. 2008, Pottie et al. 2021). In Madagascar, the species is targeted in artisanal gillnet fisheries and it is taken by artisanal fishers within the Antongil Bay Shark Sanctuary (Bennett et al. 2023). In Kenya, it is also taken by artisanal gillnet and in prawn trawl fisheries (Bennett et al. 2023). Across the Arabian Sea and adjacent waters, the Indo-Pacific Leopard Shark is caught in the Arabian/Persian Gulf (including Iran; R. Jababo pers. comm. 2017), the Sea of Oman (Valinassab et al. 2006, Henderson et al. 2007), and India (Theivasigamani and Subbiah 2014). It is now rarely caught in Pakistan (Osmany and Khan 2022). In some other areas, it is considered low value and is not generally landed. For example, in the Saudi Red Sea, the species is not targeted and is released alive (J. Spaet pers. comm. 2017). The Indo-Pacific Leopard Shark was reported from fisheries in Thailand, where it was previously (2004–2012) landed regularly at fish markets from the Andaman Sea but was not recorded from the Gulf of Thailand (Krajandara 2014). In Papua New Guinea, the Indo-Pacific Leopard Shark is incidentally caught in a prawn trawl fishery that operates in the Gulf of Papua where it represents a minor part of the elasmobranch catch (0.5%) and was assessed as at medium risk from the fishery based on susceptibility to capture and recovery ability (Baje et al. 2021).

In Eastern Indonesia, legal and illegal fishing pressure has increased substantially in the Arafura Sea since the 1980s (Resosudarmo et al. 2009). Trawling was banned in 1980 in all waters of the Indonesian 200-mile Exclusive Economic Zone west of longitude 130˚E. This resulted in concentrated trawling pressure in the eastern part of the Timor Sea and the Arafura Sea. Indo-Pacific Leopard Sharks likely comprised part of this catch given their presence as bycatch in trawl surveys from neighbouring regions (e.g., Zhou and Griffiths 2008, Baje et al. 2021). Threats within Australia are likely to be relatively minimal. It is not targeted and small numbers are captured incidentally and released in the Queensland East Coast Inshore Finfish Fishery (Harry et al. 2011), the Northern Prawn Fishery (Zhou and Griffiths 2008), the Pilbara Trawl fishery (Western Australia Department of Fisheries 2010, M. Braccini pers. comm. 2023), and in nets deployed by the Queensland Shark Control program (Queensland Government 2023). However, the species has a high post-release survival rate of 80–100% from these fisheries. Its behaviour of swimming at the surface in aggregations in eastern Australia exposes it to the threat of boat strikes and severe wounds from boat propellers have been observed. The species occurs across the Pacific Islands in low numbers and due to lower human population numbers, fishing is far less intensive than in other parts of its range.

The Indo-Pacific Leopard Shark's preference for inshore coastal waters including mudflats, mangroves and seagrass beds, and coral reefs as well as its inshore egg laying means it is also threatened by habitat loss and degradation, including pollution, clearing, coastal developments, and climate change. Threats to these key habitats occur in the Western Indian Ocean and Southeast Asia. For example, marine habitats in the Arabian/Persian Gulf have experienced high levels of disturbance and rapid deterioration due to major impacts from development activities (including dredging and reclamation), industrial activities, habitat destruction through the removal of shallow productive areas and major shipping lanes (Sheppard et al. 2010). In Southeast Asia, large coastal areas, in particular mangroves, have been lost through land conversion for urban development, mining, aquaculture, and agriculture. For example, across Myanmar, Malaysia, and Cambodia from 1970–2020, 44% of the mangrove area was lost (Baltezar et al. 2023). Global climate change has already resulted in large-scale coral bleaching events with increasing frequency causing worldwide reef degradation since 1997. Almost all warm-water coral reefs are projected to suffer significant losses of area and local extinctions, even if global warming is limited to 1.5°C (IPCC 2019). The Indo-Pacific Leopard Shark is also a popular public aquarium species and is targeted for these aquaria.

Indo-Pacific Leopard Sharks are landed whole and used for their fins, skin (dried), meat and cartilage (White et al. 2006). In some regions, such as the Arabian Sea and adjacent waters, small specimens (<1 m total length, TL) are usually discarded in fisheries, except in India where they are more frequently retained whole for local consumption (R. Jabado pers. comm. 2017). Indo-Pacific Leopard Sharks have been historically targeted by spear fishers for sport (D. Robinson unpub. data). In Pakistan, the species is released or retained and processed into fish meal (Osmany and Khan 2022). Large specimens (>1 m TL) have been traded from Oman to the United Arab Emirates where their meat is cut into small cubes, dried and exported to Sri Lanka. The fins are not considered valuable but are still traded internationally in small quantities, accounting for 0.01–0.02% of fins sampled in Hong Kong (Fields et al. 2018, Cardeñosa et al. 2020). Indo-Pacific Leopard Sharks are targeted for aquaria around the world; they breed well in aquaria and egg-cases and adults are also taken from the wild for aquaria stock. They are valuable within the recreational SCUBA diving industry, particularly in Mozambique (Pottie et al. 2021), Thailand (Ward-Paige et al. 2018), and eastern Australia (C. Dudgeon. unpub. data).

There are few species-specific conservation regulations in place. The Indo-Pacific Leopard Shark is specifically protected in a few countries such as Malaysia (Last et al. 2010) and is protected in countries that protect all sharks and rays, such as Maldives and Israel. There are many general management measures that contribute to conserving this species in several range states. Marine Protected Areas that incorporate >20 km of coral reef can provide significant protections because of the species strong site fidelity to reefs (Dwyer et al. 2020). Marine Protected Areas are common in coral reef areas throughout its range, but only those that are sufficiently large and well enforced provide refuge (MacNeil et al. 2020). In 2020, the Stegostoma tigrinum Augmentation and Recovery (StAR) project was initiated which aims to re-establish wild and genetically diverse populations of Indo-Pacific Leopard Shark, beginning with Raja Ampat, Indonesia (Traylor-Holzer 2021). Four individuals were released into the wild in 2022. Apart from directly increasing numbers in the wild, the aim of the program is to raise awareness and the profile of the Indo-Pacific Leopard Shark in the country to encourage increased protections for the species and critical habitats. In New Caledonia, to mitigate Indo-Pacific Leopard Shark egg case predation by snails, egg cases are harvested from the wild, hatched and released back into the wild (H. Lassauce unpub. data).

To conserve the population and to permit recovery, a suite of measures will be required which may include species protection, spatial management, bycatch mitigation, and harvest and trade management measures (including international trade measures). Effective enforcement of measures will require ongoing training and capacity-building (including in the area of species identification). Catch monitoring is needed to help understand population trends and inform management.