The Red Sea Torpedo (Torpedo suessii) is considered a valid species. It is known from only three specimens captured off Mocha, Yemen, in 1897 (Steindachner 1898) which are housed at Naturhistorisches Museum, Vienna, Austria.

Steindachner (1898) did not assign the holotype and paratypes but de Carvalho et al. (2002) nominated the lectotype (NMW 88240) and the paralectotype (NMW 78016) from Steindachner’s original specimens. Steindachner’s third specimen (NMW 87406) was recently rediscovered and assigned as a paralectotype (Palandačić et al. 2023). The Red Sea Torpedo can be differentiated from other torpedo rays in the Western Indian Ocean, the Red Sea, and nearby gulfs by its distinctive patterning consisting of eight, large brown spots (de Carvalho et al. 2002).

The Red Sea Torpedo was previously considered a junior synonym of T. sinuspersici (de Carvalho et al. 2002). Garman (1913) considered T. suessii to be a valid species but postulated that it may be synonymous with T. panthera. It is however unlikely that the ornate colour pattern of T. suessii could morph into the small, irregular whitish spots typical of both juvenile and adult T. panthera (de Carvalho et al. 2002).

This species has been referred to as Torpedo suessi, however this is a misspelling.

The Red Sea Torpedo (Torpedo suessii) is only known from a very small area (estimated to be <100 km²) off Mocha, Yemen, in the southern Red Sea. It has not been recorded since the original collection of three specimens in 1897. Further records of the species have not been identified in landing site surveys in Yemen and adjacent countries such as Saudi Arabia and Sudan, or in underwater surveys in Saudi Arabia. Artisanal and industrial fisheries are intense in Yemeni waters, and illegal fishing is an ongoing issue. Conflict in the region is driving more people to sustain livelihoods and many fish stocks are overfished. Government policy has aimed to develop small-scale fisheries, with artisanal catches peaking in 2004. Industrial fishing occurred in the Yemeni Red Sea from 1993–2007, with industrial catches rapidly declining immediately from a peak in 1993. Unlicensed industrial fishing fleets still occur in the Yemeni Red Sea. Overfishing in the region is likely to have depleted the Red Sea Torpedo population through incidental capture as bycatch. While electric rays are generally not utilized and are usually discarded at sea, survival of bycatch is predicted to be low. Life history is generally not well studied among torpedo rays, and nothing is known about the biology of the Red Sea Torpedo.

The Framework for using the Threats Model and the Records and Surveys Model to list a species as EX or CR(PE) was applied to the Red Sea Torpedo. This is the first application of the Framework to this species. The probability that the combination of threats affecting the species occurred for a sufficient duration and were sufficiently severe that they caused local extinction, and the probability that the threats occurred over the entire range of the species were both high. Sustainability of fisheries in the region are a concern, as communities in Yemen are highly dependent on small-scale fisheries, and the number of fishers and fishing boats has increased, causing a decline in stocks and catch since the early 2000s. The probability that the Red Sea Torpedo is extinct from the Threats Model is therefore 0.68 (minimum = 0.56; maximum = 0.81). The only species-appropriate surveys which may have documented further specimens in Yemen occurred at landing sites in 2000 and 2001, and although extensive surveys have occurred in Saudi Arabia since 2010 and Sudan since 2013, these surveys fall outside the predicted geographic range of the Red Sea Torpedo. The probability that the species is extinct from the Records and Surveys Model is therefore 0.9 (minimum = 0.36; maximum = 1.0), as there have been no records since 1897 and few surveys aside from potential passive surveys. The weighted average probability of extinction is 0.74 and 0.75 for the two weighting methods, and the overall average probability of extinction is 0.79, or 79%. The probability that the Red Sea Torpedo is extinct is >0.5 and <0.9, therefore the species falls within the threshold for Critically Endangered (Possibly Extinct). Given the lack of contemporary records, the very restricted extent of occurrence, presence in only one location, and a continuing decline in the number of mature individuals inferred from intensive and ongoing fishing, the species is assessed as Critically Endangered (Possibly Extinct) under criterion B1ab(v).

For further information about this species, see Supplementary Information.

The Red Sea Torpedo is endemic to the southern Red Sea, where three individuals were fished off Mocha, Yemen, and then transported to Port of Perim in 1897 (Steindachner 1898). Steindachner (1898) did not provide any additional information about the collection of these individuals (e.g., habitat, fishing gear, etc.). A photograph of an electric ray taken in ~1993 off Port Sudan in the Sudanese Red Sea was proposed as a potential Red Sea Torpedo specimen (de Carvalho et al. 2002), however the photo evidence is not convincing, and the species is considered to only occur off Yemen for this assessment.

The Framework (Akçakaya et al. 2017) for using the Threats Model (Keith et al. 2017) and the Records and Surveys Model (Thompson et al. 2017) to list species as EX or CR(PE) was applied to the Red Sea Torpedo. The Threats Model considered the severity, duration, and scope of threats and their interaction with the species’ life history characteristics to determine the probability that a species is extinct (Keith et al. 2017). Fishing is important for the livelihoods of coastal communities in Yemen, with the number of fishers increasing rapidly from the mid-1970s to 2010 (MoFW 2012, Tesfamichael et al. 2016). Although there is an overall lack of both reliable statistics and detailed, recent stock assessments, many stocks are considered overexploited due to declining catches, including demersal species (Morgan 2006). In Yemen, rays have been included in catch statistics for elasmobranchs since 1995, with ‘shark and ray’ landings increasing annually since a trough in the early 1990s (Jabado and Spaet 2017). Illegal fishing is an ongoing issue in Yemen and throughout the Red Sea (Jabado and Spaet 2017), with foreign fishers often using bottom trawls or destructive practices such as explosives (Al-Fareh 2018). Fisheries in Yemen have few regulations (Morgan 2006), and there is little capacity to implement or enforce regulations particularly due to political conflict in the region (Al-Fareh 2018). The species is considered susceptible to population decline as a result of threats, particularly fishing. The probability that the combination of threats affecting the Red Sea Torpedo occurred for a sufficient duration and were sufficiently severe that they caused local extinction P(local) and the probability that the threats occurred over the entire range of the species P(spatial) were both high (P(local) minimum = 0.7, best = 0.8, maximum = 0.9; P(spatial) minimum = 0.8, best = 0.85, maximum = 0.9). As a result, the probability that the Red Sea Torpedo is extinct from the Threats Model is 0.68, or 68% (minimum = 0.56, maximum = 0.81).

The Records and Surveys Model estimates the probability that a species is extinct based on a time series of known records of the species, and the timing, extent, and species-specific adequacy of surveys (Thompson et al. 2017). The species is known from three records from the Yemeni Red Sea in 1897, which were retained and later designated the lectotype and paralectotypes (Steindachner 1898, de Carvalho et al. 2002, Palandacic et al. 2023). The probability that the species was correctly identified as extant (p(ci)) best was therefore set at 0.97 (lower = 0.95, upper = 0.99) as per guidelines in the Instructions for multiple specimens (Instructions for Using Models to List Species as EX or CR(PE)). No further specimens have been recorded in Yemen or in the adjacent nations of Sudan, Eritrea, Djibouti, Somalia, or Saudi Arabia. A photograph taken of an electric ray in the Sudanese Red Sea which was proposed to be the Red Sea Torpedo (de Carvalho et al. 2002) is not convincing and is not considered as a valid record for this assessment. If this record was included in the Models and given a low probability of being correctly identified (p(ci) best = 0.25), P(E) would be lower, but the CR(PE) outcome would not change (Constance 2021).

There has been very limited research on elasmobranchs conducted in the Red Sea (Spaet et al. 2012), and there have been no dedicated surveys in Yemen specifically for this species. Bonfil (2003) conducted surveys of landing sites in Yemen in 2000 and 2001 and this represents the only dedicated surveys in the Yemeni Red Sea which would have recorded the Red Sea Torpedo if it were present. For these years, the proportion of geographic range surveyed (epsilon) was low (best = 0.15 [2000], 0.25 [2001]), as the majority of landing site surveys occurred in the Gulf of Aden (Bonfil 2003). The probability that the species would have been recorded (p(r)) was set as per the guidelines for rare species (Instructions, Table 3) at best = 0.2 (lower = 0.1, upper = 0.3), and the probability that the species would have been reliably identified (p(i)) was set at best = 0.7 (lower = 0.6, upper = 0.8; Instructions, Table 4). For passive surveys, epsilon was set based on the restricted range of the species and relatively wide coverage by fishers who fish daily and land catches locally (lower = 0.35; best = 0.45; upper = 0.55). p(r) and p(i) for passive surveys were low (p(r): lower = 0.1; best = 0.2; upper = 0.3; p(i): lower = 0.1; best = 0.2; upper = 0.3) due to the rarity, small-size, and low economic value of the Red Sea Torpedo. The probability that the species is extinct from the Records and Surveys Model is 0.9, or 90% (minimum = 0.36, maximum = 1.0).

The overall probability that the Red Sea Torpedo is Extinct in 2023 is the average of the results for both models, which is 0.79, or 79%. The weighted average probability of extinction is 0.74 for the weight = 1/range method, and 0.75 for the weight = 1-range method. The Models also separately calculate the probability that the species is extant (P(Xt)) each year over the observation period (1897–2023). The probability that the Red Sea Torpedo is extant in 2023 is 0.1, or 10%. Although there is some uncertainty in the Models, both Model results and both weighted averages are >0.5 and <0.9, and therefore the species falls within the thresholds for Critically Endangered (Possibly Extinct). Given the lack of contemporary records, very restricted extent of occurrence, presence in only one location, and a continuing decline in the number of mature individuals inferred from intensive and ongoing fishing, the species is assessed as Critically Endangered (Possibly Extinct) B1ab(v).

The Threats Model and Records and Surveys Model were also run to include surveys throughout the Red Sea which would have identified further Red Sea Torpedo records if the species were present within a wider geographic range (Constance 2021). All parameters remained the same as above, however dedicated surveys in Yemen, Saudi Arabia, Djibouti, Egypt, and Sudan in 2000 and 2001 (Bonfil 2003) and in Saudi Arabia and Sudan since 2010 were added into the Model. In this scenario, epsilon best was on average 0.51, p(r) best was 0.2 (lower = 0.1, upper = 0.3), and p(i) best was 0.7 (lower = 0.6, upper = 0.8). According to the Records and Surveys Model, if the Red Sea Torpedo was predicted to have a geographic range throughout the Red Sea (rather than the Yemeni Red Sea only), the overall probability of the species being extinct would be 0.82, or 82%, and as such the Red Sea Torpedo would still be assessed as Critically Endangered (Possibly Extinct) B1ab(v).

For further information, see the Supplementary Information.

The Red Sea Torpedo is known only from three specimens captured off Mocha, Yemen, in 1897: the lectotype, a female (29.1 cm total length [TL]; 18.6 cm disc width [DW]) and two male paralectotypes (23.2 cm TL; 13.0 cm TL) (Steindachner 1898, de Carvalho et al. 2002, Palandacic et al. 2023). Its habitat is unknown, however electric rays of the genus Torpedo generally occur primarily in shallow inshore waters, while Tetronarce electric rays occur in deeper waters to around 600 m on the continental slope (de Carvalho et al. 2002). Torpedo rays are benthic and often occur on soft sand and mud (Ratão et al. 2022). Reproduction is lecithotrophic viviparous in torpedo rays (e.g., Capapé et al. 2000), however the life history of the Red Sea Torpedo is unknown, and there are few studies on torpedinid life history and reproductive biology. Generally, fecundity among Torpedo rays is variable, increasing with body size, and species are relatively long-lived (e.g., Tiralongo et al. 2019, Bellodi et al. 2021).

Yemen is one of the largest shark fishing nations in the world by reported catch (Dent and Clarke 2015), however the total biomass and number of species landed in Yemen from the Red Sea is unknown due to a lack of species-specific reporting (Spaet et al. 2012, Jabado and Spaet 2017). There is a high level of community dependence on artisanal fisheries in Yemen, which account for over 90% of the nation’s total fisheries production (Alabsi and Komatsu 2014). Fisheries in the Red Sea are primarily small-scale and artisanal vessels fish primarily in nearshore coastal waters using a range of fishing gears including traps, gillnets, hook-and-line, and longlines (Tesfamichael et al. 2012, Jabado et al. 2018). Industrial fisheries operating in the Yemeni Red Sea utilize trawls, longlines, and purse seines (Morgan 2006, Jabado et al. 2018). Industrial fishing commenced in the Yemeni Red Sea in 1993 after the unification of the nation in 1990, with a peak in catches in the late 1990s, and a decline by the end of the 2000s (Tesfamichael et al. 2016). Although no new licenses for industrial vessels have been granted since 2004, illegal industrial fleets still operate in the Yemeni Red Sea (Alabsi and Komatsu 2014). Foreign fleets conducting illegal, unreported, and unregulated (IUU) fishing is a major issue in Yemen (Alabsi and Komatsu 2014). Illegal, destructive fishing practices such as bottom trawling, and the use of sound, light, dynamite, and guns to catch fish also operate in Yemen, damaging habitats (Al-Fareh 2018). Species occurring in shallow, coastal waters are particularly threatened by habitat loss and degradation (Notarbartolo di Sciara and Jabado 2021), and this species is likely to have been affected by habitat destruction.

Heavy fishing pressure resulting in bycatch of electric rays is the primary concern for the Red Sea Torpedo, with fishing effort rapidly increasing and many fisheries resources considered depleted (Morgan 2006, Al-Fareh 2018, Jabado et al. 2018). Catch is not reported at the species-level in Yemen, with ray landings lumped with sharks as elasmobranchs (Jabado and Spaet 2017). An increasing human population is driving increased reliance on already overexploited fisheries resources and increasing damage to coastal habitats (Alabsi and Komatsu 2014). The Red Sea Torpedo has not been recorded in landings or Baited Remote Underwater Video (BRUV) surveys in adjacent areas such as the Saudi Arabian or Sudanese Red Sea (Spaet and Berumen 2015, Spaet et al. 2016, McIvor et al. 2022). The sluggish, benthic nature of electric rays make them susceptible to trawl capture and although there has been little published research to determine the survivorship of discarded electric rays at sea (Ellis et al. 2017), post-release mortality is considered to be high (R. Jabado pers. obs.). Two studies have reported electric ray survival after trawling based on very small sample sizes, and survivorship ranges from 40–100% between the two (n=5, Fennessy 1994; n=1, Tsagarakis et al. 2018). Electric rays are thought to use their electric charge when in nets and are expected to be at least physiologically impaired upon release (Ellis et al. 2017). The species is also potentially caught as bycatch in gillnet fisheries in Yemen, with other electric ray species recorded as bycatch in bottom-set gillnets in other regions (e.g., Capapé et al. 2006, Ruiz-Escobar et al. 2023).

No utilization or commercial trade of the Red Sea Torpedo is known to exist, although information is limited. Electric rays are usually discarded at sea due to their low economic value (e.g., Tiralongo et al. 2018, Mar Gil et al. 2018, Moore et al. 2019), although can be retained in some regions, for example, the Mediterranean Sea (e.g., Baeta et al. 2010).

There are no species-specific measures in place for the conservation or management of this species. Although the Ministry of Fish Wealth and Marine Science and Biological Research Authority of Yemen aim to monitor landings and implement seasonal closures of fisheries, these actions are limited due to a lack of resources and closures are not enforced (Al-Fareh 2018). There is little legislation throughout the Red Sea region concerning the conservation of rays, aside from wedgefishes, guitarfishes, and sawfishes (Notarbatolo di Sciara and Jabado 2021). An urgent assessment of the status of the species is required, particularly through underwater and landings surveys in Yemen.