Devil Ray Mobula Research Articles

‘Flash Mobula’: first observations of courtship behaviour of the shortfin devil ray Mobula kuhlii

First-time observations of courtship behaviour of the Endangered shortfin devil ray Mobula kuhlii are described from the Aliwal Shoal Marine Protected Area (MPA), KwaZulu-Natal, South Africa. Three events of M. kuhlii courtship, called ‘mating trains’, were recorded on video during the months of November 2020 and January 2021. These included a near-term pregnant female, and two lead females followed by up to four males. The common behaviours associated with courtship were documented: multiple males following a single female, rapid speed bursts, avoidance of the female, and swerving. This study confirms that M. kuhlii mating occurs in KwaZulu-Natal waters and that courtship is similar across mobulids. The findings demonstrate the importance of the habitat provided by the Aliwal Shoal MPA for this currently unprotected species.

First record of spinetail devil ray, Mobula japanica (Müller & Henle 1841) from the Gulf of Antalya

On 11 October 2019, one specimen of spinetail devilray Mobula japanica (Müller and Henle, 1841) was caught inadvertently by a commercial fisherman at a depth of approximately 25 m off the Gulf of Antalya. One specimen was examined in detail. M. japanica was recorded for the first time in the Gulf of Antalya.Keyword: by-catch; Gulf of Antalya; Mobula japonica; spinetail devil ray

First record of Spinetail Devil Ray, Mobula japanica (Müller & Henle 1841) from the Gulf of Antalya

On 11 October 2019, one specimen of spinetail devilray Mobula japanica (Müller and Henle, 1841) was caught inadvertently by a commercial fisherman at a depth of approximately 25 m off the Gulf of Antalya. One specimen was examined in detail. M. japanica was recorded for the first time in the Gulf of Antalya.Keywords: Mobula japanica, spinetail devil ray, by-catch, Gulf of Antalya

The occurrence of mobulid rays at St Helena Island, Cardno seamount and Bonaparte seamount in the South Atlantic and its significance for conservation

Data from 369 sightings of mobulid rays from St Helena Island, Cardno and Bonaparte seamounts in the South Atlantic are summarised. 50 % (183) of sightings were observed from a boat, 48 % (176) of sightings were encountered in water, of which 95 % (168) were whilst actively scuba diving. 2 % (10) of mobulid ray sightings were observed from land. Sightings data indicate that the Chilean devil ray Mobula tarapacana (Philippi, 1892) is a frequent visitor to St Helena and is present all year. We document the first photographic evidence of the presence of oceanic manta, Mobula birostris (Walbaum, 1792) at St Helena. Two solitary individuals were photographed off the north coast of St Helena in June 2018. These sightings confirm previous unverified reports on the species occurrence and extend the known distribution range of M. birostris in the open South Atlantic Ocean to 16°S.

Integrating Literature, Biodiversity Databases, and Citizen-Science to Reconstruct the Checklist of Chondrichthyans in Cyprus (Eastern Mediterranean Sea)

Chondrichthyans are apex predators influencing the trophic web through a top-down process thus their depletion will affect the remaining biota. Notwithstanding that, research on chondrichthyans is sparse or data-limited in several biogeographic areas worldwide, including the Levantine Sea. We revise and update the knowledge of chondrichthyans in Cyprus based on a bibliographic review that gains information retrieved from peer-reviewed and grey literature, Global Biodiversity Information Facility (135 records of at least 18 species) and the Ocean Biodiversity Information System (65 records of at least14 species), and the citizen science project Mediterranean Elasmobranchs Citizen Observations (117 records per 23 species). Our updated checklist reports 60 species that account for about 70% of the Mediterranean chondrichthyan biota. The list includes 15 more species than the previous checklist and our study reports three new species for Cyprus waters, namely the blackmouth catshark Dalatias licha, the round fantail stingray Taeniurops grabatus, and the sawback angelshark Squatina aculeata. Our research highlights the need for conservation measures and more studies regarding the highly threatened blackchin guitarfish Glaucostegus cemiculus and the devil ray Mobula mobular, and stresses the importance for training a new generation of observers to strengthen the knowledge and conservation of elasmobranchs in the region.

Spatio-temporal distribution of spinetail devil ray Mobula mobular in the eastern tropical Atlantic Ocean

The distribution of the spinetail devil ray Mobula mobular in the eastern tropical Atlantic remains poorly known compared to the Pacific and Indian Oceans. We used fishery-dependent data and generalized additive models to examine the environmental characteristics associated with the presence of M. mobular in the eastern Atlantic Ocean. Results revealed that the distribution of M. mobular is significantly associated with seasonal upwelling systems in coastal and pelagic areas. Our model predicted the presence of the species in areas where there is evidence of its occurrence, such as the Angolan upwelling system and the coast of Ghana. In addition, our model predicted new hotspot areas, including locations around the Mauritanian upwelling system, the Guinea coast, offshore Ghana and the south coast of Angola and Brazil, where sample sizes are limited. Those areas, as well as the environmental preferences depicted by the model, provide valuable information about the habitat and ecology of the spinetail devil ray. Future research lines derived from this study, as well as its limitations, are discussed. Furthermore, in light of our results we discuss the improvements that are needed to contribute to the conservation and management of this vulnerable species.

The giant devil ray Mobula mobular (Bonnaterre, 1788) is not giant, but it is the only spinetail devil ray

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”.

Taxonomic status, biological notes, and conservation of the longhorned pygmy devil ray Mobula eregoodoo (Cantor, 1849)

Abstract 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 (Müller & 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.

NEW RECORD OF GIANT DEVIL RAY (CHONDRICHTHYES: MYLIOBATIDAE) FROM ORAN BAY (WESTERN MEDITERRANEAN SEA)

The present paper reports a new record of Giant devil ray Mobula mobular (Bonnaterre, 1788) from western Algerian waters that is encountered for the first time in that coast since its first description in 1901 and last observation in late 80’s. This elasmobranch is categorized as endangered on the IUCN Red List (Endangered A2d ver 3.1) and is likely to be the rarest of the nine species of Mobula genus. Occasionally it is captured in Mediterranean Sea by purse seines, bottom and pelagic trawls, pelagic nets, bottom longlines, drifters and harpoons. The specimen stranded in “la Madrague Beach” in Western Algerian coasts. Its disc length was measuring 108.96 cm and disc width was 226.02 cm. This Myliobatidae is rarely seen with daily landed fish at Oran fishery. Up to date no explicit reason can be given for the strand of M. mobular but ghost fishing and important maritime traffic stay the most plausible cause of this incident.

Seasonal aggregation and diel activity by the sicklefin devil ray Mobula tarapacana off a small, equatorial outcrop of the Mid-Atlantic Ridge.

The present study aimed to analyse occurrence patterns, relative abundance and habitat use by the sicklefin devil ray Mobula tarapacana in the Saint Peter and Saint Paul Archipelago (SPSPA), Brazil, located in the Mid-Atlantic Ridge. Sampling was conducted between December 2008 and December 2012 by surface surveys and tagging with conventional tags and acoustic transmitters. Mobula tarapacana were sighted in the SPSPA year round but the highest frequency of occurrence was observed from January to June, probably due to greater food availability during this season. However, M. tarapacana might also use the area for reproductive purposes based on evidence of mating behaviour. The residency period of tagged rays measured by three autonomous acoustic receivers deployed around SPSPA spanned from 1 to 74 days with most of the detections occurring during daytime. These results suggest that the SPSPA could be an ecologically-important aggregation area for M. tarapacana, possibly providing the species with a feeding or resting habitat while transiting in the equatorial Atlantic Ocean.

First observation of the courtship behaviour of the giant devil ray Mobula mobular (Myliobatiformes: Mobulidae)

ABSTRACTCourtship behaviour of the giant devil ray Mobula mobular is described from northern New Zealand, temperate southwest Pacific Ocean, for the first time. A mating train consisting of a full-term pregnant female and up to four males was observed over a period of 147 minutes. Their behaviour was similar to courtship behaviour observed in other large mobulids. Biting of the female was not observed, possibly due to the female’s use of the surface to prevent males positioning themselves above her. However, the lead male pressed the female’s abdomen and underside each time the female reached or stopped at the surface. The occurrence of pregnant females and mating behaviour off northern North Island confirms breeding occurs in New Zealand waters.

<b>A first record of the Bentfin Devil Ray <I>Mobula thurstoni</I> (Lloyd, 1908) (Myliobatiformes: Mobulidae) from the Indian EEZ of the Andaman Sea</b>

This manuscript deals with the Bent-fin Devil Ray Mobula thurstoni for its first time occurrence in the Andaman & Nicobar waters around the Indian EEZ which is a new locality record confirming the range extension of the species to the southeast of Bay of Bengal (the Andaman Sea). A female specimen of 318mm disc length and weighing 2.47Kg was caught by a multiday bottom trawler operated off North Bay and was landed at Junglighat fishing harbour, South Andaman. A detailed diagnostic description and morphometric measurements of M. thurstoni is provided. For the first time this species has been described from Indian waters and compared with the other related species, and so documenting its first occurrence in the Andaman & Nicobar waters.

Complete mitochondrial genome of the Devil Ray, Mobula thurstoni (Lloyd, 1908) (Myliobatiformes: Myliobatidae)

The Devil Ray (Mobula thurstoni) is a species with global distribution and is an important species in conservation terms, here we present its complete mitochondrial genome assembled with Illumina sequencing data. The circular genome was 17,610 bp in length, and consists of 13 protein-coding, two ribosomal RNAs (rRNAs), and 22 transfer RNA (tRNA) genes. Base composition is 30.7% A, 29.1% T, 26.5% C, and 13.7% G, and 40.2% GC content. Protein-coding genes present two start codon (ATG and GUG) and seven stop codon (UAA, AUA, UUU, UUA, AAU, CCU, and UAG). The control region possesses the highest A + T (66.6%) content among all mitochondrial regions. These data would contribute to the evolutionary studies of this genus, where there has been recent reclassification.

First record of the sicklefin devilray Mobula tarapacana (Myliobatiformes: Mobulidae) from Australian waters.

The sicklefin devilray Mobula tarapacana (Philippi, 1892) is one of the largest and least known mobulids (Compagno & Last 1999; Couturier et al. 2012). Collections, fisheries bycatch data and visual records suggest it is primarily oceanic, with a circumglobal tropical and warm temperate distribution (Notarbartolo-di-Sciara 1987; Compagno & Last 1999; Gadig & Sampaio 2002; White et al. 2006a, b; Weir et al. 2012; Sobral 2013; Tomita et al. 2013). In the Pacific Ocean it has been recorded from Chile, Gulf of California, Japan, Taiwan, South China Sea and Indonesia (Compagno & Last 1999; White et al. 2006b; Couturier et al. 2012; Tomita et al. 2013).

Movement, depth distribution and survival of spinetail devilrays (Mobula japanica) tagged and released from purse‐seine catches in New Zealand

Abstract Mobulid rays are protected in New Zealand, but the spinetail devilray Mobula japanica is caught as bycatch in skipjack tuna purse seine fisheries. Between 2005 and 2014, rays were recorded in 8.2% of observed purse seine sets. Rays were caught during summer, with a ‘hotspot’ (24.3% of sets) near the shelf edge off North Island over seabed depths of 150–350 m. Rays were usually brailed aboard with the tuna catch from successful sets, but were often entangled in the bunt of the net during unsuccessful sets. Observers tagged nine rays with popup archival tags to obtain preliminary information on their post‐release survival, and spatial and vertical movements. Seven of the nine tags reported data, and four of those rays died within 2–4 days of release. All four rays that died had been brought aboard entangled in the bunt. The three surviving rays were all brailed aboard with the tuna catch. One surviving ray remained near New Zealand for 2.7 months during summer, and the other two migrated 1400–1800 km northward to tropical waters near Vanuatu and Fiji at minimum speeds of 47 and 63 km day−1 at the end of summer. Archive data from one ray showed that it made regular vertical movements of 25–100 m amplitude, but spent most of its time shallower than 50 m, more so during the night (89.6%) than the day (76.6%), and mainly experienced temperatures of 18−22 °C. Dives deeper than 200 m were usually made during the day or twilight. All three surviving rays typically moved between the surface and 200–300 m daily, and reached greatest depths of 649 m, 1000 m and 1112 m, respectively, substantially exceeding the previous depth record for this species of 445 m. Recommendations are made for reducing purse seine mortality of mobulid rays by avoiding areas of high ray abundance, avoiding setting on ray‐associated tuna schools, and adopting best‐practice methods of returning rays to the sea from the net or vessel. Copyright © 2016 John Wiley & Sons, Ltd.

The Devil We Don't Know: Investigating Habitat and Abundance of Endangered Giant Devil Rays in the North-Western Mediterranean Sea.

The giant devil ray Mobula mobular, the only Mediterranean mobulid, is subject to mortality caused by directed and accidental captures in fisheries throughout the region. Whilst the combination of human impacts, limited range and a low reproductive potential is not inconsistent with its endangered listing, there are insufficient data to enable a quantitative assessment of trends. Without this, it is difficult to assess and prioritise threats and develop effective conservation actions. Using results from aerial surveys conducted between 2009 and 2014 over the Ligurian, Corsican, Sardinian, northern and central Tyrrhenian seas (626,228 km2), this study provides the first quantitative information on giant devil ray abundance and habitat choice in the western Mediterranean. Devil rays were observed in all seasons except winter, with their estimated abundance in the study area peaking in summer. The overall uncorrected mean density in the study area during summer was estimated at 0.0257 individuals km-2 (range: 0.017–0.044), resulting in a total abundance estimate of 6,092 (12.7%CV) individuals at the surface; once corrected for availability bias, this estimate indicates a summer presence of >12,700 devil rays in the study area. Rays were mostly observed alone even if occasionally, larger aggregations up to a maximum of 18 individuals were observed. Although observed throughout the study area, spatial modelling identified their preferred habitat to be over a broad strip connecting the Tuscan Archipelago to Eastern Sardinia, over a wide range of water depths ranging from 10 to 2000m. The observed seasonal changes in giant devil ray distribution in this study, combined with similar evidence from other areas in the Mediterranean, support the hypothesis that the species undertakes latitudinal migrations across the region, taking advantage of highly productive waters in the north during summer, and warmer southern waters during winter.

New records of whale shark (Rhincodon typus), giant manta ray (Manta birostris) and Chilean devil ray (Mobula tarapacana) for Suriname

Little is known about elasmobranchs along the northern coast of South America. During five boat surveys in Suriname offshore waters we visually documented the presence and behaviour of the free-ranging whale shark Rhincodon typus and two mobulid rays: the giant manta ray Manta birostris and the Chilean devil ray Mobula tarapacana. Three sightings were made of R. typus at the surface in shallow coastal waters where the water depth measured 46–67 m. One of these sightings was confirmed by photographs. Manta birostris was positively identified on five occasions while at the surface, all in shallow waters of less than 57 m deep. Four additional sightings, not accompanied by photographs, were identified as Manta spp. One devil ray, photographed and identified as Mobula tarapacana, was recorded at the surface in deep waters (2491 m) in July 2012. These records of R. typus, Manta birostris and Mobula tarapacana are the first for Suriname and therefore add to the documented information of these species within the Wider Caribbean Region and contribute to the knowledge of the pelagic distribution of these species. Little is known about elasmobranchs along the northern coast of South America. During five boat surveys in Suriname offshore waters we visually documented the presence and behaviour of the free-ranging whale shark Rhincodon typus and two mobulid rays: the giant manta ray Manta birostris and the Chilean devil ray Mobula tarapacana. Three sightings were made of R. typus at the surface in shallow coastal waters where the water depth measured 46-67 m. One of these sightings was confirmed by photographs. Manta birostris was positively identified on five occasions while at the surface, all in shallow waters of less than 57 m deep. Four additional sightings, not accompanied by photographs, were identified as Manta spp. One devil ray, photographed and identified as Mobula tarapacana, was recorded at the surface in deep waters (2491 m) in July 2012. These records of R. typus, Manta birostris and Mobula tarapacana are the first for Suriname and therefore add to the documented information of these species within the Wider Caribbean Region and contribute to the knowledge of the pelagic distribution of these species.

Occurrence of mobulids in the Azores, central North Atlantic

An updated checklist of manta and devil rays (family Mobulidae) occurring in waters of the Azores archipelago is given based on new data from underwater images and on the re-evaluation of previous citations for the region. There are, at least, three species of mobulids occurring in the region, possibly four: giant mantaManta birostris; Chilean devil rayMobula tarapacana; and one or both of the giant devil rayMobula mobular/spinetail devil rayMobula japanicaspecies complex. These findings have direct implications for the known ranges of all these species and for the conservation of their North Atlantic populations.

Occurrence of the Chilean devil ray Mobula tarapacana (Elasmobranchii: Batoidea: Myliobatiformes) in the Sea of Okhotsk: first record from cold temperate waters

The northernmost record for Chilean devil ray Mobula tarapacana, a circumglobal species that occurs in tropical, subtropical and limited warm temperate waters, is described. An adult female was caught incidentally in the Sea of Okhotsk on 17 September 2011. This specimen is the first confirmed occurrence of devil rays Mobula spp. in cold temperate waters.

On the occurrence of the giant devil ray Mobula mobular (Bonnaterre, 1788) from the Mediterranean coast of Turkey - a by-catch documentation

On the occurrence of the giant devil ray Mobula mobular (Bonnaterre, 1788) from the Mediterranean coast of Turkey – a by-catch documentation By D. Yaglioglu, C. Turan and M. Gurlek Biodiversity Implementation and Research Center (DU–BIYOM), Duzce University, Duzce, Turkey; Faculty of Fisheries, Molecular Ecology and Fisheries Genetics Laboratory, Mustafa Kemal University, Iskenderun, Hatay, Turkey