Sharks and rays are key functional components of coral reef ecosystems, yet many populations of a few species exhibit signs of depletion and local extinctions. The question is whether these declines forewarn of a global extinction crisis. We use IUCN Red List to quantify the status, trajectory, and threats to all coral reef sharks and rays worldwide. Here, we show that nearly two-thirds (59%) of the 134 coral-reef associated shark and ray species are threatened with extinction. Alongside marine mammals, sharks and rays are among the most threatened groups found on coral reefs. Overfishing is the main cause of elevated extinction risk, compounded by climate change and habitat degradation. Risk is greatest for species that are larger-bodied (less resilient and higher trophic level), widely distributed across several national jurisdictions (subject to a patchwork of management), and in nations with greater fishing pressure and weaker governance. Population declines have occurred over more than half a century, with greatest declines prior to 2005. Immediate action through local protections, combined with broad-scale fisheries management and Marine Protected Areas, is required to avoid extinctions and the loss of critical ecosystem function condemning reefs to a loss of shark and ray biodiversity and ecosystem services, limiting livelihoods and food security. © 2023, The Author(s).

Background. Expanding fisheries in developing nations like Sri Lanka have a significant impact on threatened marine species such as elasmobranchs. Manta and devil (mobu-lid) rays have some of the most conservative life history strategies of any elasmobranch, and even low to moderate levels of bycatch from gillnet fisheries may lead to significant population declines. A lack of information on life history, demographics, population trends, and fisheries impacts hinders effective management measures for these species. Method. We report on mobulid fishery landings over nine years between 2011 and 2020 across 38 landing sites in Sri Lanka. We collected data on catch numbers, body sizes, sex, and maturity status for five mobulid species. We used a Bayesian state-space model to estimate monthly country-wide catch rates and total annual landings of mobulid rays. We used catch curve analyses to estimate total mortality for Mobula mobular, and evaluated trends in recorded body sizes across the study period for M. mobular, M. birostris, M. tarapacana and M. thurstoni. Results. We find that catch rates have declined an order of magnitude for all species across the study period, and that total annual captures of mobulid rays by the Sri Lankan artisanal fishing fleet exceed the estimated annual captures of mobulids in all global, industrial purse seine fisheries combined. Catch curve analyses suggest that M. mobular is being fished at rates far above the species' intrinsic population growth rate, and the average sizes of all mobulids in the fishery except for M. birostris are declining. Collectively, these findings suggest overfishing of mobulid ray populations in the northern Indian Ocean by Sri Lankan artisanal fisheries. We recommend strengthening the management of these species through improved implementation of CITES, CMS, and regional fisheries management actions. In addition, we report on the demographic characteristics of mobulids landed in Sri Lanka and provide the first record of M. eregoodoo in the country.

The scale and drivers of marine biodiversity loss are being revealed by the International Union for Conservation of Nature (IUCN) Red List assessment process. We present the first global reassessment of 1,199 species in Class Chondrichthyes-sharks, rays, and chimeras. The first global assessment (in 2014) concluded that one-quarter (24%) of species were threatened. Now, 391 (32.6%) species are threatened with extinction. When this percentage of threat is applied to Data Deficient species, more than one-third (37.5%) of chondrichthyans are estimated to be threatened, with much of this change resulting from new information. Three species are Critically Endangered (Possibly Extinct), representing possibly the first globalmarine fish extinctions due to overfishing. Consequently, the chondrichthyan extinction rate is potentially 25 extinctions per million species years, comparable to that of terrestrial vertebrates. Overfishing is the universal threat affecting all 391 threatened species and is the sole threat for 67.3% of species and interacts with three other threats for the remaining third: loss and degradation of habitat (31.2% of threatened species), climate change (10.2%), and pollution (6.9%). Species are disproportionately threatened in tropical and subtropical coastal waters. Science-based limits on fishing, effective marine protected areas, and approaches that reduce or eliminate fishing mortality are urgently needed to minimize mortality of threatened species and ensure sustainable catch and trade of others. Immediate action is essential to prevent further extinctions and protect the potential for food security and ecosystem functions provided by this iconic lineage of predators.

Practical biodiversity conservation relies on delineation of biologically meaningful units. Manta and devil rays (Mobulidae) are threatened worldwide, yet morphological similarities and a succession of recent taxonomic changes impede the development of an effective conservation strategy. Here, we generate genome-wide single nucleotide polymorphism (SNP) data from a geographically and taxonomically representative set of manta and devil ray samples to reconstruct phylogenetic relationships and evaluate species boundaries under the general lineage concept. We show that nominal species units supported by alternative data sources constitute independently evolving lineages, and find robust evidence for a putative new species of manta ray in the Gulf of Mexico. Additionally, we uncover substantial incomplete lineage sorting indicating that rapid speciation together with standing variation in ancestral populations has driven phylogenetic uncertainty within Mobulidae. Finally, we detect cryptic diversity in geographically distinct populations, demonstrating that management below the species level may be warranted in certain species. Overall, our study provides a framework for molecular genetic species delimitation that is relevant to wide-ranging taxa of conservation concern, and highlights the potential for genomic data to support effective management, conservation and law enforcement strategies.

The longhorned pygmy devil ray Mobula eregoodoo (Cantor, 1849), formerly known as Mobula eregoodootenkee (Bleeker, 1859), is a small mobulid with a disc reaching a maximum width of 1.3 m, widely ranging in tropical and subtropical latitudes across the Indian Ocean, the Indo-Pacific region, and the western Pacific Ocean. A recently emerged opportunity to examine several (n = 47) M. eregoodoo specimens bycaught in bather protection gillnets off New South Wales, Australia, together with new information assembled from other areas of its range, now allows for a redescription of the species, which was incompletely described in the past because of a paucity of specimens. Based on the morphometric, morphological, ecological, and behavioural elements presented here, corroborated by recent genetic investigations, we argue that M. eregoodoo (Cantor, 1849) is a valid species, distinct from shorthorned pygmy devil ray Mobula kuhlii (Muller & Henle, 1841). These findings are contrary to a recent revision of Mobula, where it was assessed as a synonym of M. kuhlii. The accuracy of taxonomic assessments underpins the effectiveness of species conservation, particularly when direct exploitation or bycatch in various fisheries needs to be managed for sustainability. Failing to recognize that two similar-looking species are distinct, such as M. eregoodoo and M. kuhlii, creates uncertainties that could result in mismanagement and underestimating local and global threats of extinction.

Mobula mobular, a mobulid species once considered a Mediterranean Sea endemic, has received its common name "giant devil ray" based on repeated misidentifications of oceanic manta rays, Mobula birostris, that had strayed into the Mediterranean, where they had never been reported from before. Based on the maximum known size (350 cm disc width) of M. mobular, when compared to some of its congenerics, the giant devil ray is not giant at all. A recent revision of the phylogeny and taxonomy of genus Mobula, which included, amongst other things, the decision to consider the circumtropical spinetail devil ray M. japanica a junior synonym of M. mobular, has caused the latter species to become circumglobal, and the only known mobulid with a tail spine. As a consequence, it is here recommended that the common name of M. mobular be "spinetail devil ray".

Manta and devil rays are filter-feeding elasmobranchs that are found circumglobally in tropical and subtropical waters. Although relatively understudied for most of the Twentieth century, public awareness and scientific research on these species has increased dramatically in recent years. Much of this attention has been in response to targeted fisheries, international trade in mobulid products, and a growing concern over the fate of exploited populations. Despite progress in mobulid research, major knowledge gaps still exist, hindering the development of effective management and conservation strategies. We assembled 30 leaders and emerging experts in the fields of mobulid biology, ecology, and conservation to identify pressing knowledge gaps that must be filled to facilitate improved science-based management of these vulnerable species. We highlight focal research topics in the subject areas of taxonomy and diversity, life history, reproduction and nursery areas, population trends, bycatch and fisheries, spatial dynamics and movements, foraging and diving, pollution and contaminants, and sub-lethal impacts. Mobulid rays remain a poorly studied group, and therefore our list of important knowledge gaps is extensive. However, we hope that this identification of high priority knowledge gaps will stimulate and focus future mobulid research.

Little is known about the giant devil ray (Mobula mobular), an endangered species endemic to the Mediterranean. Gaza is the only region where this species is targeted, hence, this fishery was studied to address the knowledge gap on fishery interactions, species behavior, and life-history traits. Devil rays have been frequenting this maritime area for at least the past 50 years for a short window from February to April. Landings are reported from 2005 to 2016, along with disc-width (DW) measurements for recent years. A total of 304 M. mobular (over 90% males) were landed in Gaza from 2014 to 2016, most which were mature and appeared to be mating (over 90% of males had sperm-filled claspers), providing critical insight that this area may serve as a mating ground. Yearly landings are shown here to closely match the allowed fishing distance from shore, which changes regularly, indicating that the rays are normally caught between 6 and 12 n.m. offshore. Width-weight conversion parameters are calculated for the first time for this species: a = 2.68 x 10(-6) and b = 4.39. Fresh protein drives this local fishery, as food security is a major issue. An export market for gill plates was reported intermittently, and is no longer possible due to strict trade restrictions. We highlight the lack of awareness of fishers regarding the IUCN's Red List 'Endangered' status of devil rays, and stress the urgent need for national protection of this species, particularly due to the species' very slow life-history traits and probable usage of this area as a mating ground.

The extinction risk of sharks, rays and chimaeras is higher than that for most other vertebrates due to low intrinsic population growth rates of many species and the fishing intensity they face. The Arabian Sea and adjacent waters border some of the most important chondrichthyan fishing and trading nations globally, yet there has been no previous attempt to assess the conservation status of species occurring here. Using IUCN Red List of Threatened Species Categories and Criteria and their guidelines for application at the regional level, we present the first assessment of extinction risk for 153 species of sharks, rays and chimaeras. Results indicate that this region, home to 15% of described chondrichthyans including 30 endemic species, has some of the most threatened chondrichthyan populations in the world. Seventy-eight species (50.9%) were assessed as threatened (Critically Endangered, Endangered or Vulnerable), and 27 species (17.6%) as Near Threatened. Twenty-nine species (19%) were Data Deficient with insufficient information to assess their status. Chondrichthyan populations have significantly declined due to largely uncontrolled and unregulated fisheries combined with habitat degradation. Further, there is limited political will and national and regional capacities to assess, manage, conserve or rebuild stocks. Outside the few deepsea locations that are lightly exploited, the prognosis for the recovery of most species is poor in the near-absence of management. Concerted national and regional management measures are urgently needed to ensure extinctions are avoided, the sustainability of more productive species is secured, and to avoid the continued thinning of the regional food security portfolio.

Devil rays (genus Mobula) are pelagic elasmobranchs widely distributed throughout tropical, subtropical and warm-temperate waters. Their occurrence and distribution remains poorly documented in the Arabian Seas region. A review is provided of species occurrence in these water bodies along with a synthesis of regional information on their biology and ecology. Based on the available evidence, five Mobula species occur in the region (M. eregoodootenkee, M. japanica, M. kuhlii, M. tarapacana, and M. thurstoni). Of these, three (M. eregoodootenkee, M. tarapacana and M. thurstoni) were found to occur in the Red Sea, and three (M. eregoodootenkee, M. japanica, and M. kuhlii) were found to occur in the Arabian/Persian Gulf. Mobula japanica and M. kuhlii are reported here for the first time in Gulf waters. All five species were found in the Indian Ocean waters between the Gulf of Aden and Pakistan. To address the still uncertain taxonomy of M. kuhlii, a redescription of this species is provided based on a sample of fresh specimen material. Mobula diabolus is a nomen ambiguum, never used to unambiguously designate any newly described species, and its use should be avoided. Considering the life-history traits that make these species particularly vulnerable to fishing pressure, current levels of exploitation in by-catch fisheries are unlikely to be sustainable, despite the fact that the trade in gill plates does not seem to be prevalent in this region. Critical knowledge gaps unfortunately still exist, crippling effective management and conservation actions. Copyright (c) 2016 John Wiley & Sons, Ltd.