Bentfin Devil Ray
Bentfin Devil Ray
Fishes · Rays · Manta ray

Bentfin Devil Ray

Mobula thurstoni (Lloyd, 1908)
syn. Dicerobatis thurstoni, Mobula lucasana
1.9 m54 kg1-110 mCITES ICritically Endangered
939

The bentfin devil ray (Mobula thurstoni), also known as the lesser devil ray, smoothtail devil ray, smoothtail mobula, or Thurston's devil ray, is a species of ray belonging to the family Mobulidae. It can be found in tropical, subtropical, and warm temperate oceans across the globe, with numerous sightings in locations such as 🇦🇺 Australia, 🇧🇷 Brazil, 🇨🇱 Chile, 🇨🇷 Costa Rica, 🇪🇨 Ecuador, 🇪🇬 Egypt, 🇸🇻 El Salvador, 🇪🇷 Eritrea, 🇬🇹 Guatemala, 🇭🇳 Honduras, 🇮🇳 India, 🇮🇩 Indonesia, 🇨🇮 Ivory Coast, 🇯🇵 Japan, 🇲🇾 Malaysia, 🇲🇻 Maldives, 🇲🇽 Mexico, 🇲🇲 Myanmar, 🇳🇮 Nicaragua, 🇴🇲 Oman, 🇵🇰 Pakistan, 🇵🇪 Peru, the 🇵🇭 Philippines, 🇸🇦 Saudi Arabia, 🇸🇳 Senegal, 🇿🇦 South Africa, 🇱🇰 Sri Lanka, 🇹🇭 Thailand, 🇦🇪 United Arab Emirates, 🇺🇸 United States (specifically 🇺🇸 California), 🇺🇾 Uruguay, 🇻🇺 Vanuatu, as well as throughout the central and western Pacific. It is probable that this species also occurs in many other areas within tropical, subtropical, and warm temperate oceans, both offshore and near the coast.

The adult bentfin devil ray can reach a noteworthy disc width of 189 cm (6.2 ft) and weigh approximately 54 kg (120 lb). The length of the disc is around 1.95 times its width. The front edge of the disc is nearly straight near the snout, but gracefully curves as it extends towards the broad, triangular pectoral fins. The back edge is concave, which gradually straightens as it approaches the tail. The ray possesses cephalic flaps on either side of its snout, with the mouth located on the underside of its head. The dorsal fin is about 80% as tall as it is long. The tail length ranges between half of the disc width and the entirety of the disc width, with the tail not bearing a spine. The upper surface of this ray typically exhibits colors ranging from dark grey to olive-gray, while the under surface is white. The rear of the tip of the pectoral fins is black, contrasting with the white front edge of these fins. The tip of the dorsal fin is also white.

Mobula thurstoni demonstrates global distribution, encompassing tropical and subtropical waters throughout the Atlantic Ocean, 🌊 Indian Ocean, and 🌊 Pacific Ocean. While it is primarily pelagic in inshore waters, it is uncommon for it to venture beyond depths of 100 m (330 ft).

Similar to other closely related species, the bentfin devil ray sustains itself on a diet consisting primarily of plankton. As it swims, it funnels water into its mouth, subsequently filtering plankton from the water using its gill rakers. In the Gulf of 🇺🇸 California, the most prevalent item in its diet is Nyctiphanes simplex, a species of krill. However, this ray also feeds seasonally on opossum shrimps.

Mobula thurstoni is a large fish that matures relatively late and has a low reproductive rate, producing only one offspring at a time. Although it has a widespread distribution, it is subject to fishing activities in certain regions and falls victim to incidental capture in gill nets and trawling practices in others. Reports indicate that it is frequently landed in 🇮🇩 Indonesia, the 🇵🇭 Philippines, 🇲🇽 Mexico, and 🇧🇷 Brazil, with the likelihood that landings occur in other areas such as West Africa. In eastern Asia, the gill rakers of this species are also highly valued in addition to its flesh. The population trend of the bentfin devil ray remains unknown, although it is considered uncommon. Consequently, the International Union for Conservation of Nature has designated its conservation status as "endangered".

Why it's threatened

Biological resource use
Intentional use: (subsistence/small scale) [harvest] · Intentional use: (large scale) [harvest] · Unintentional effects: (subsistence/small scale) [harvest] · Unintentional effects: (large scale) [harvest]
Human intrusions & disturbance
Recreational activities
Climate change & severe weather
Habitat shifting & alteration

Mobulid rays, including the Bentfin Devil Ray, are both targeted and caught incidentally in industrial and artisanal fisheries (Couturier et al. 2012, Croll et al. 2016). These rays are captured in a wide range of gear types, including harpoons, drift nets, purse seine nets, gillnets, traps, trawls, and longlines. Their coastal and offshore distribution, and tendency to aggregate, makes mobulid rays susceptible to incidental catch in purse seine fisheries and longline fisheries, and susceptible to targeted capture in artisanal fisheries and incidental entanglement (Croll et al. 2016, Duffy and Griffiths 2017). However, there are an increasing number of studies that indicate that gillnet fisheries are responsible for a significantly higher proportion of mobulid interactions (>99%) compared to purse seine fisheries (Martin 2020, Bucair et al. 2024, Rojas-Perea et al. 2025). Incidental catch in these fisheries is believed to be an important source of mortality (Martin 2020). Like many mobulid rays, the Bentfin Devil Ray is easy to target because of its relatively large size, slow swimming speed, tendency to aggregate or predictably use specific habitats, and its general lack of human avoidance (Couturier et al. 2012). The Bentfin Devil Ray’s epipelagic tropical distribution in regions of high productivity, which overlaps with that of tuna and other highly valued target teleost (bony fish) species, means it is exposed to multiple targeted and incidental catch fisheries (White et al. 2006b, Couturier et al. 2012, Croll et al. 2012, Croll et al. 2016). Furthermore, this species’ preference for coastal waters places it within the range of inshore fisheries, which are known to be intensive in many parts of its range, including Pakistan, India, and Sri Lanka (de Young 2006, Flewelling and Hosch 2006, Jabado et al. 2018).

Mobulid rays are caught in at least 85 countries worldwide, with at least 85% of catches originating from fisheries operating small vessels (or ‘small-scale’ fisheries) (B. Laglbauer unpubl. data 2025). When comparing estimates of annual catch/landings, Indonesia, India, Sri Lanka, Myanmar, and Peru are the major mobulid fisheries globally, each catching >10,000 mobulids per year (Fernando and Stewart 2021, Rojas-Perea et al. 2025, T. Ko Gyi unpubl. data 15/02/2025, B. Laglbauer unpubl. data 2025). At least 35 countries catch the Bentfin Devil Ray. Comparing estimates of annual mobulid catch, Indonesia, Sri Lanka, Peru, the Philippines, emerge as the leading fisheries for the Bentfin Devil Ray globally, and large-scale fisheries off West and Central Africa, the Mozambique Channel, and the Eastern Tropical Pacific (Couturier et al. 2012, Ward-Paige et al. 2013, Croll et al. 2016, Moazzam 2018, Rambahiniarison et al. 2018, Lezama-Ochoa et al. 2019, Haque et al. 2021, Clavareau et al. 2020, Fernando and Stewart 2021, M. Chopra unpubl. data 2025, B. Laglbauer unpubl. data 2025). In some directed artisanal fisheries, hundreds of Bentfin Devil Rays have been observed or estimated to be landed each year (Alava et al. 2002, Dewar 2002, White et al. 2006b, Fernando and Stevens 2011, Lewis et al. 2015, Acebes and Tull 2016, Fernando and Stewart 2021, B. Laglbauer unpubl. data 2025). While many artisanal fisheries have grown into trade fisheries, some still target these rays mainly for food and local products (White et al. 2006b, Fernando and Stevens 2011, Palacios et al. 2024). Prices per kilogram vary widely across countries catching mobulid rays, including those known to land the Bentfin Devil Ray. Mobulids are typically retained because of (1) their relatively high value (due to demand for meat and/or gills), or (2) the relatively large volume of animals (for use as a cheap protein source, or as bait and fish feed) (Palacios et al. 2024). Even when discarded alive, for example from tuna purse seine fisheries, they are often injured and have high post-release mortality (Tremblay-Boyer and Brouwer 2016, Francis and Jones 2017, Stewart et al. 2024). However, under optimal handling conditions, survival rates can be as high 74.2–95.3% in purse seine fisheries (Stewart et al. 2024).

Even after listing on Appendix I and II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), Appendix II of the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES), non-retention measures at four tuna-Regional Fisheries Management Organizations, and increasing national fishing bans, most fisheries interacting with these species remain open and active. Robust, quantitative assessments are challenging because multiple mobulid species are caught and landed simultaneously, and species identification continues to be a source of error in this group (Croll et al. 2016).

Global landings of mobulid species, including the Bentfin Devil Ray, increased steadily between 1990–2015 due in large part to the rise in demand for gill plates (O’Malley et al. 2017). Many former fisheries incidentally capturing these species expanded into directed commercial export fisheries (Dewar 2002, White et al. 2006b, Fernando and Stevens 2011, Heinrichs et al. 2011, Acebes and Tull 2016). Between 2000–2016, combined total landings of ‘Manta, devil rays nei’ ('nei' refers to 'not elsewhere included'), ‘Mantas, devil rays, etc. nei’, and ‘Giant manta’ increased from 931 tonnes to 8,083 tonnes (FAO FishStat Capture Production database 2025). These landings then declined by 87% to 2023 (1,028 t) despite an increase in the number of countries reporting from 2016 onwards. While this equates to an average of 2,423 t per annum (2000–2023), reported landings are likely to represent only a fraction of total fishing-related mortality (e.g., Ward-Paige et al. 2013). Only 12 countries reported catches to the FAO (Colombia, Ecuador, Indonesia, Kenya, Liberia, Mauritania, Mexico, Pakistan, Peru, Puerto Rico, and Sri Lanka), with reporting periods ranging from one (Puerto Rico, Kenya, Colombia) to 19 years (Indonesia). Compared with recent estimates of global mobulid catch per year (~264,000 individuals), this represents less than 1% of catches reported to the FAO (B. Laglbauer unpubl. data 2025).

Mobulid rays are also taken as incidental catch in pelagic gillnet and longline fisheries in the Indian Ocean targeting swordfish (Coelho et al. 2011), and the tuna purse seine fishery (Lezama-Ochoa et al. 2015), but effort trends for these fisheries are unknown. In India, intensive gillnet fisheries take mobulid species like the Bentfin Devil Ray, along the western coast (Rajapackiam et al. 2007, Kizhakudan et al. 2015, Nair et al. 2015). In Sri Lanka, it is estimated that the Bentfin Devil Ray comprises only 1.4% of the total number of devil rays landed, with an estimated median of 559 individuals landed annually as of 2019 (Fernando and Stewart 2021). In Tanzania, 319 Bentfin Devil Rays were recorded in landing surveys in Zanzibar (47% of these catches) and along the mainland coast (53%) between 2019–2023, with 83% of records reported as incidental catch from gillnet fisheries (Wildlife Conservation Society pers. comm. 18/02/2025). Landings of Bentfin Devil Ray were recorded during opportunistic sampling at the Kilifi in Kenya between June 2021 and October 2022 (n=28 animals; Barrowclift et al. 2025). In the Bohol Sea, Philippines, gillnet fisheries for tunas used to incidentally catch up to 300 individuals per year (LAMAVE pers. comm. 16/03/2025).

In the Indian Ocean, specifically India, intensive gillnet fisheries take mobulid species, including the Bentfin Devil Ray, along the western coast (Rajapackiam et al. 2007, Nair et al. 2013, Kizhakudan et al. 2015). In Sri Lanka, an estimated 449 Bentfin Devil Ray were landed annually, based on market surveys in 2011 (Fernando and Stevens 2011, Heinrichs et al. 2011). Devil rays are also taken as bycatch in pelagic gillnet and longline fisheries in the Indian Ocean targeting swordfish (Coelho et al. 2011), and the tuna purse seine fishery (Lezama-Ochoa et al. 2015) but effort trends for these fisheries are unknown. In Pakistan, Bentfin Devil Ray represented 7% of the mobulids landed by number in tuna gillnet fisheries (Nawaz and Khan 2015). In Oman and the Saudi Red Sea, only a few specimens of this species were recorded during extensive landing site surveys (Henderson et al. 2007, Spaet and Berumen 2015).

Data from French purse seiners operating in the western Indian Ocean between 2005 and 2023 (observer coverage varying between 1–12% until 2012 and 14–47% after 2012) indicate that 311 individuals were captured (Sabarros et al. 2024). Bentfin Devil Ray (n=1) represented 0.32% of catches, noting that 32% of animals were not identified to the species level. This suggests a total estimated catch of up to 0.025 t per year. All animals were discarded and by 2023, up to 89% of animals were released alive, although post release survivorship has not been assessed (Sabarros et al. 2024).

In the Atlantic Ocean, mobulid rays are taken as incidental catch in the Southwest Atlantic Uruguayan and Japanese Longline Fisheries, which operate within the Uruguayan Exclusive Economic Zone and adjacent international waters (Mas et al. 2015). Mas et al. (2015) estimated that 201 animals were incidentally caught during 1998–2013, equaling a catch-per-unit-effort (CPUE) of 0.028 individuals per 1,000 hooks, which represents only 0.05% of total catch combined of both fleets. Catches of mobulid rays, whichincluded the Bentfin Devil Ray peaked at ~50 individuals in 2009, and remained consistent at this level until 2013 when catches fell to <5 (Mas et al. 2015).

There are artisanal fisheries in multiple West African countries that target mobulid rays for human consumption both locally and for export to other markets (Doumbouya 2011, Couturier et al. 2012, Ender and Fernando 2014, Palacios et al. 2024). While commonly targeted or caught incidentally, little is known of the extent of these fisheries at present. In West Africa, Mobula species, particularly, the Bentfin Devil Ray, have been reported in landings in the Republic of Guinea since 2001, where they are dried and distributed from Kassa (Doumbouya 2011). Fishing areas have extended beyond Guinean territorial waters since 2005, following strong pressure on the resource in the northern part of the coast. Breeding areas have been identified off Alcatraz Island and Kamsar Buoy and this species is targeted from January to March, which corresponds to the pupping season and breeding season, leading to additional negative impacts on these species (Doumbouya 2011). Industrial trawlers operating off the northwest African coast also capture mobulid rays, which likely include the Bentfin Devil Ray (Zeeberg et al. 2006).

In the Western and Central Pacific from 2010 to 2015, observed incidental catch of mobulids (excluding Oceanic Manta Ray) in purse seine fisheries was 4,324 individuals, and in longline fisheries was 410 individuals. Some of these were identified as the Bentfin Devil Ray, although the numbers of individuals reported were low (from 1995 to 2015, 16 in purse seines) and the numbers reported as Mobula spp. were much higher, hence many were not identified to species level (Tremblay-Boyer and Brouwer 2016).

Eastern Pacific Ocean (EPO) fisheries data indicate a substantial increase in the incidental catch of mobulid rays. Between 1993–2013, an average of 2,800 individuals were caught per year, with a range of 1,100–6,500 (Croll et al. 2016). Purse seine fisheries in this region capture the greatest volume of mobulid incidental catch when compared to other gears and regions (Mas et al. 2015, Croll et al. 2016, Alfaro-Cordova et al. 2017). Around 4,700 individuals per year were taken in purse seiners in the EPO between 1993 and 2009 (Alfaro-Cordova et al. 2017). Much of the mobulid ray catch in this area occurred in the Costa Rica Dome region off Central America (Croll et al. 2016). A longstanding targeted mobulid fishery existed off Baja California Sur, Mexico with the Bentfin Devil Ray the most commonly landed species (58% of total numbers of catch) (Notarbartolo-di-Sciara 1988). By the early 1980, concern existed over the sustainability of Bentfin Devil Ray landings with 72% of individuals reported as immature (Notarbartolo-di-Sciara 1988). By the late 1990s, the primary target of this fishery had shifted to the Pygmy Devil Ray (M. munkiana) and Bentfin Devil Rays were a minor component of landings (Bizzarro et al. 2009a). During the same time period, Bentfin Devil Rays were rarely encountered among shark and ray landings from the more temperate northern Gulf of California (Bizzarro et al. 2009b, Smith et al. 2009). Still, mobulid catch in Mexico remains especially prominent along the Eastern Pacific coastline, where an estimated ~2,459 individuals are caught annually (Laglbauer et al. unpubl. data 2025). In Peru, mobulid rays account for 28% of total ray catch, with the majority being captured in gillnets (Rojas-Perea et al. 2025). The Inter-American Tropical Tuna Commission purse seine vessels with observers operating during 2015 in the EPO reported 71 t of mobulid landings, and this likely included the Bentfin Devil Ray (Miller and Klimovich 2017). Recent landings data from IATTC fisheries are unavailable due to the ban on capture of mobulid species, however, fisheries for these species continue to operate.

An assessment of extinction risk of sharks and rays in Australia indicates that most mobulid rays are not likely to interact with Australian fisheries due to habitat, behaviour, and limited catchability which suggests that there is limited impact from these fisheries on the Spinetail Devil Ray across this range (Kyne et al. 2021).

In the markets of Guangzhou, China, where 99% of mobulid products are routed, mobulid products are sourced from over 20 countries and regions (O’Malley et al. 2017). The source locations for the largest quantities of product are Indonesia, Sri Lanka, India, China, and Viet Nam (O’Malley et al. 2017). Demand for products has driven up the price and traded volume of these products since the 2000s. Between 2011 and 2013, there was an increase from 60 to 120 t of mobulid product moved through shops in Guangzhou (O’Malley et al. 2017).

Indirect and sublethal sources of mortality include habitat destruction and degradation, climate change, ocean acidification, oil spills, and other pollution and contaminants (e.g., heavy metals) (Essumang 2010, Ooi et al. 2015, Poortvliet et al. 2015, Stewart et al. 2018). Tourism industries may also to a certain extent negatively impact individual behaviour, and if unmanaged, may affect localized use of and visitation rates to critical habitats, and may disrupt important social behaviour (Stewart et al. 2018).

Threat classification from the IUCN Red List.

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Last Update: June 28, 2026