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Surprisingly, little is known about basic life history of the largest moray eel species in the Caribbean region, the green moray eel (Gymnothorax funebris). Sixteen eels were captured from the mangrove fringe in multiple bays on St. Croix, USVI, implanted with coded acoustic transmitters, and their movements were tracked for up to 11 months using an array of 37 stationary acoustic receivers. They exhibited high site fidelity in the bays during their residence, using the same general parts of individual bays and did not switch bays except for one individual. There was no relationship between eel size (mean TL = 83 cm, range = 54–126 cm) and home range size (mean area of 95% KUD = 5.8 ha ± 0.7 SE). Most individuals were more frequently detected at night than during the day suggesting greater nocturnal activity. Several of the larger eels (mean TL = 93 cm ± 5.9 SE) showed clear and permanent emigration tracks out of the mangrove estuary to coral reef habitats offshore. For some individuals, these habitat shifts were preceded by exploratory movements away from the eel’s typical home range the night before emigration. All final emigration events took place nocturnally, happened during a single night, and occurred during months from December to May. Mean emigration speed was 3.4 km/h. This study is the first documentation of an ontogenetic habitat shift in moray eels, as well as the first determination of home range size for this species and their site fidelity in mangrove habitats.

A new species, Strophidon dawydoffi sp. n., from Nha Trang Bay (South China Sea, Vietnam) was described. The new species is well distinguished from the cooccurring S. sathete species by a thinner and elongated body, tail lobiform-extended at the end, external absence of vertical fins, a much smaller number of preanal vertebrae, elongated vertebral centra in the middle portion of the caudal region of the vertebral column, the structure of neural arches and parapophyses, variegated coloring of the body and oral cavity, a larger number of teeth in the inner rows on maxillare and dentale, and two or three rows of papillae on the lips. Differences in the number of infraorbital pores and in the shape of the snout between S. sathete specimens are associated with individual variability.

Since the initial discovery of Aqueoria victoria’s green fluorescence off the coast of Washington’s Puget Sound, biofluorescent marine organisms have been found across the globe. The variety of colors of biofluorescence as well as the variability in the organisms that exhibit this fluorescence is astounding. The mechanisms of biofluorescence in marine organisms are also variable. To fluoresce, some organisms use fluorescent proteins, while others use small molecules. In eels, green biofluorescence was first identified in Anguilla japonica. The green fluorescence in A. japonica was discovered to be caused by a fatty acid binding protein (UnaG) whose fluorescence is induced by the addition of bilirubin. Members of this class of proteins were later discovered in Kaupichthys eels (Chlopsid FP I and Chlopsid FP II). Here, we report the discovery and characterization of the first member of this class of green fluorescent fatty acid binding proteins from the moray eel Gymnothorax zonipectis. This protein, GymFP, is 15.6 kDa with a fluorescence excitation at 496 nm and an emission maximum at 532 nm upon addition of bilirubin. GymFP is 61% homologous to UnaG and 47% homologous to Chlopsid FP I. Here, we report de novo transcriptome assembly, protein expression, and fluorescence spectroscopic characterization of GymFP. These findings extend the fluorescent fatty acid binding proteins into a third family of true eels (Anguilliformes).

In this study, the first record of Gymnothorax reticularis for the Southwest coast of India was reported from the Mangalore Fishing Harbour (MFH). The morphometric, meristic characters and colour patterns of the recorded specimens confirmed that the identified specimen was G. reticularis and it has 18 dark bars with pale cream coloured background. The unique key characters of G. reticularis having 114 vertebrae, the teeth patterns of maxillary and vomerine was counted as each 10 and dentary teeth was 14, whilst there is no inter maxillary teeth. The maxillary and dentary teeth were canine, whereas molar shape of teeth was found in vomerine. The occurrence of G. reticularis in southwest coast of India revealed the range of extension of its known geographical distribution. Further, the present study is an addition to the ichthyofaunal biodiversity of southwest coast of India.

Ciguatera fish poisoning (CFP) is one of the most frequently reported seafood poisoning diseases. It is endemic to the tropical region and occurs most commonly in the regions around the Pacific Ocean, Indian Ocean, and Caribbean Sea. The principal toxins causing CFP are ciguatoxins (CTXs). In the Pacific region, more than 20 analogs of CTXs have been identified to date. Based on their skeletal structures, they are classified into CTX1B-type and CTX3C-type toxins. We have previously reported species-specific and regional-specific toxin profiles. In this study, the levels and profiles of CTXs in fish present in the tropical western Pacific regions were analyzed using the liquid chromatography–tandem mass spectrometry (LC–MS/MS) technique. Forty-two fish specimens, belonging to the categories of snappers, groupers, Spanish mackerel, and moray eel, were purchased from various places such as Fiji, the Philippines, Thailand, and Taiwan. Only the fish captured from Fijian coastal waters contained detectable amounts of CTXs. The toxin levels in the fish species found along the coastal regions of the Viti Levu Island, the main island in Fiji, and the toxin profiles were significantly different from those of the fish species present in other coastal regions. The toxin levels and profiles varied among the different fish samples collected from different coastal areas. Based on the toxin levels and toxin profiles, the coast was demarcated into three zones. In Zone-1, which covers the northern coast of the main island and the regions of the Malake Island and Korovau, CTXs in fish were below the detection level. In Zone-2, CTX3C-type toxins were present in low levels in the fish. CTX1B-type and CTX3C-type toxins co-occurred in the fish present in Zone-3. The toxin profiles may have reflected the variation in Gambierdiscus spp.

Some species of durophagous moray eels (Muraenidae) have been documented emerging from the marine environment to capture intertidal crabs but how they consume prey out of water is unknown. Here, we trained snowflake morays, Echidna nebulosa, to undulate out of the aquatic environment to feed on land. On land, snowflake morays remove prey from the substrate by biting and swallow prey using pharyngeal jaw enabled transport. Although snowflake morays exhibit smaller jaw rotation angles on land when apprehending their prey, transport kinematics involving dorsoventral flexion of the head to protract the pharyngeal jaws and overall feeding times did not differ between terrestrial and aquatic treatments. We suggest that their elongate body plan, ability to rotate their heads in the dorsoventral and lateral directions, and extreme pharyngeal movements all contribute to the ability of durophagous morays to feed in the terrestrial environment., Summary: Body elongation and pharyngeal transport facilitates prey capture and swallowing on land for the snowflake moray, Echidna nebulosa.

Attempts were made to identify the species of food poisoning moray eel. Besides the causative processed moray eel meat, eight other raw commercial moray eel meats including Gymnothorax favagineus, G. fimbriatus, G. flavimarginatus, G. meleagris, G. pseudothyrsoideus, G. undulates, G. albimarginatus and G. javanicus were heated at 100℃ for 30 min and then assayed using the electrophoresis method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The SDS-PAGE patterns for eight processed commercial moray eel meats showed species-specific protein bands ＜30 kD. The species of causative processed moray eel implicated in food poisoning case was identified as G. javanicus in comparison to the 2% SDS and 8 M urea extracted protein revealed by SDS-PAGE patterns.

The taxonomic status of the widely distributed Indo-Pacific undulated moray eel, Gymnothorax undulatus, is revised using morphological and genetics features. Ninety-seven specimens previously identified as G. undulatus were examined and their mitochondrial COI and 16S rRNA genes were analysed. The multivariate analysis of eight morphometric characters resulted in separation with little to no overlap among some geographic regions. These groupings explained more than 90% of the total variation, with 86.6% overall classification. Two color morphs were identified, and the South African population was described as new species, Gymnothorax elaineheemstrae n. sp., distinct from G. undulatus in having mottled and faintly reticulated color pattern, 134–136 total vertebrae and further confirmed by the genetic analysis of COI and 16S rRNA with > 0.1 genetic distance. The morphological and genetics results indicate that G. undulatus, previously treated as a single species, consists of more than one species.

Local population frequently consumes moray eels and dusky groupers from the Canary Islands. These species are top predators and the interactions between them include predation but also, in some cases, collaborative hunting. These fish are well known to cause ciguatera (CFP) outbreaks in several marine areas such as Japan, Hawaii, French Polynesia and Caribe. Groupers have been involved in CFP events in the Canary Islands, however, moray eels have not yet been well studied in this regard. The present research seeks to describe the finding of a black moray in the stomach of a positive dusky grouper during its necropsy, and to clarify the implication of groupers and moray eels in the food webs, accumulating CTXs in the Canarian environment. The study also updates statistics on the presence of toxic groupers in this archipelago. For these purposes, 248 grouper samples from the CFP official control in the Canary Islands (2018–2019) were analysed and 36 moray eels (5 species) were collected under the EuroCigua project and one was obtained during a dusky grouper necropsy. All samples were analysed with the Neuro-2a cell-based assay (CBA) to evidence CTX-like toxicity. Regarding the necropsied grouper and the moray eel found in its stomach content, the LCMS/MS method allowed the identification and quantification of CCTX1 in both fish at similar levels while none of the P-CTXs for which standards were available were detected. Among groupers, 25.4 % displayed CTX-like toxicity with differences between islands. For moray eels 38.9 % showed toxicity, involving 4 species. Black moray exhibited a high proportion of positives (9/12) and a positive correlation was found between CTX-like toxicity quantification and the black moray weight. Regarding the grouper, and the moray eel found in its stomach, the LCMS/MS method allowed the identification and quantification of C-CTX1 in both fish at similar levels. This found suggests a trophic interaction between these species and their role in maintaining CTXs in the Canary waters where local population commonly demand those species for consumption. The island of El Hierro stands out above all the other Canary Islands with the concerning percentage of positive grouper samples and the high CTX toxicity levels obtained in moray eel specimens analysed in this marine area. This is the first report of CTX-like toxicity in flesh of moray eels fished in the Canary archipelago and the confirmation of the presence of C-CTX1 by LCMS/MS in a black moray from this marine area. info:eu-repo/semantics/acceptedVersion

Gymnothorax minor is a moray eel of the family Muraenidae found in the Western Pacific Ocean. We report here its complete mitogenome as determined by Illumina next-generation sequencing and the phylogenetic relationship with its congeners and other taxa of the family Muraenidae. The whole mitogenome of G. minor had a total length of 16,574 bp, comprising 37 genes - 13 protein-coding genes (PCGs), two ribosomal ribonucleic acid (rRNA) and 22 transfer ribonucleic acid (tRNA) genes - and a control region. Excepting cox1 with GTG, the other 12 PCGs had ATG start codon. Seven of its PCGs had incomplete stop codon - five (nad2; cox1; cox2; nad3 and nad4) with T and two (atp6 and cox3) with TA. Molecular phylogeny based on 13 PCGs was concordant with 15 mitochondrial genes (13 PCGs and 2 rRNA genes). The subfamily Muraeninae as well as the subfamily Uropterygiinae were monophyletic. However, the genus Gymnothorax was paraphyletic, with G. minor forming a sister group with Rhinomuraena quaesita in the lineage containing also G. kidako and G. formosus forming a sister group with Enchelynassa canina. The phylogenetic relationship of the genus Gymnothorax and related taxa of the family Muraenidae, based on the mitochondrial cob gene, was in general similar to that based on 15 mt-genes. The mitogenome is useful for future studies on phylogenetics and systematics of eels of the family Muraenidae and other taxa of the order Anguilliformes.

Although common in the Mediterranean, the morphological and biological characteristics of the moray eel Muraena helena are largely unknown. This study, based on 310 specimens caught using a longline at a depth of 50–100 m, addresses this knowledge gap for northern Tunisia, which is a stronghold of the species. There were significantly more males than females, with a sex ratio of 1:1.5. The number of vertebrae between individuals were variable, especially abdominal and caudal vertebrae (range 56–72; 70–84, respectively). Overall, the total number of vertebrae was less variable (138–146 ± 3.6 SE) and similar between males and females. The length-length relationship recorded for M. helena is provided for the first time, with the pre-anal length (paL), pre-dorsal length (pdL) and the head length (hL) growing faster than the total length (TL). According to the weight-length relationship (WLR), positive allometric growth was established for males (b = 3.6), females (b = 3.46) and combined sexes (b = 3.54). The relative condition factor (CF) did not show significant differences between seasons. The gonadosomatic index (GSI) indicated a significant difference between the seasons for females, whilst the hepatosomatic index (HSI) highlighted a significant difference between seasons for both males and females.

A single muraenid specimen (genus Uropterygius), recovered from the stomach of a live Yellow-lipped Sea Krait, Laticauda colubrina (Schneider, 1799), captured at Iriomote Island, Japan, was found to possess intermediate traits between 2 rare species, Uropterygius xenodontus McCosker & Smith, 1997 and Uropterygius golanii McCosker & Smith, 1997. The specimen is provisionally identified as U. xenodontus and is described below with its morphs, as an important addition to material of rare specimens of the genus in the western North Pacific.

Moray eels comprise a large radiation of elongate marine predators that are thought to swallow large prey whole but also circumvent gape constraints by manipulating prey into more manageable pieces. Prey manipulation behaviors include shaking, rotation, knotting, and ramming prey against another object to assist in swallowing. Most morays feed on a wide variety of prey that vary in mechanical properties such as stiffness and toughness, which could potentially affect feeding behaviors. There is little diet data informing us of the maximum prey size morays can swallow whole and whether maximum prey size differs between prey types. Our study examines feeding behaviors for the California moray (Gymnothorax mordax) in the laboratory. We recorded morays feeding on freshly thawed fish and cephalopods of varying size. We found that prey size had a strong effect on total feeding time and manipulation duration for both fish and cephalopods. While morays were observed using a diversity of prey manipulation behaviors and the durations for each of these behaviors increased with prey size, prey type had no effect on manipulation behaviors employed. Total manipulation duration, however, comprised a greater proportion of total feeding time for fish compared to cephalopods. As relative prey mass (RPM) increased for cephalopods, morays spent a greater proportion of their total feeding time transporting prey. Transport rate was higher for cephalopod prey but the relationship between RPM and transport rate was negative for both prey types. Despite this decrease in transport rate, we attribute the lower total feeding times for larger cephalopod prey compared to fish to behavioral tactics of morays. Morays used the corners of the aquaria to aid in the transport of larger cephalopod prey. We hypothesize that the deformable tissues of cephalopods and the presumably low coefficient of friction of their thawed mantles and tentacles may be difficult for the recurved teeth on the pharyngeal jaws to pierce and grip during transport.

Lionfish (Pterois miles) were observed avoiding coral pinnacles inhabited by the moray eels Gymnothorax flavimarginatus and G. javanicus in the northern Red Sea, Egypt. Release of lionfish (Standard Length 93–104 mm) in such coral pinnacles in November 2016 resulted in almost immediate predation by large moray eels (Total Length > 1 m). Predation by moray eels may be the key control mechanism of population growth in the native biogeographical range of Pterois spp. and may indirectly explain the success of the invasive populations. This is the first video-documented record of moray eels feeding on the lionfish P. miles.

A new species of moray eel, Diaphenchelys dalmatian is described based on five specimens [289.8–503.0 mm total length (TL)] collected from the western coast of peninsular Thailand and the Gulf of Thailand. It can be easily distinguished from Diaphenchelys pelonates McCosker and Randall 2007, another species of the genus Diaphenchelys McCosker and Randall 2007, by its coloration (ground color white with brown dalmatian-like spots vs. brown with pale vermiculate pattern). The present new species also differs from D. pelonates in its longer tail (62.0–64.6% TL vs. 59.6–61.5%), fewer infraorbital pores along upper lip (three vs. four), fewer mandibular pores (five vs. six or seven), and fewer vertebral counts (preanal vertebrae 43–46 vs. 55–58; total 126–131 vs. 153–155). Diaphenchelys is closely similar to the genus Strophidon McClelland 1844 in the shape of neurocranium, the elongate body, low vertical fins, eye location, jaw shape, and presence of inner mandibular teeth. However, both differ in the vertebral counts (126–155 in Diaphenchelys vs. 164–208 in Strophidon) and coloration (prominent pattern vs. uniform).

Murina (Muraena helena L.) mediteranska je vrsta ribe poznata iz antičkih vremena, zanimljiva sa biološkog, i komercijalnog stajališta. Zbog bentičkog i višegodišnjeg načina života, sedentarnog stila života, ograničene stope migracije zajedno s brzinom rasta i konzumiranjem širokog raspona vrsta na različitim trofičkim pozicijama, ova vrsta mogla bi biti zanimljiv potencijalni bioindikatorski organizam za proučavanje bentičkog zagađenja teškim metalima u Jadranu/Mediteranu. Ovim se radom nastoji pokazati kako se glavni rezidualni metali akumuliraju unutar različitih organa ove vrste. Murine su prikupljene u nezagađenom području Jadranskog mora, Elafiti-Dubrovnik u ljetnom i zimskom periodu. Cilj rada je pokazati bioakumulacijski potencijal različitih organa za metale Hg, As, Cd, Pb i odrediti koji organi bi bili najbolji za bioindikatorski potencijal nakupljanja metala iz morskog okoliša. U većini organa, osim srca, najveća je bioakumulacija tijekom ljetnog perioda. Iznimno u zimskom periodu, živa i arsen akumuliraju se najviše samo u mišićnom tkivu. Od svih istraživanih metala, promatramo li sve prikupljene uzorke riba bez obzira na sezonu, živa je najzastupljeniji akumulirani metal u svim organima osim srca i kože. Koža najviše nakuplja olovo. Arsen je drugi po zastupljenosti metal prisutan u većini organa osim jetre i škrga (u škrgama je olovo jednako zastupljeno po postotnom udjelu). Iako je olovo treće po zastupljenosti u svim organima (osim škrga), postotni udio koncentracije u odnosu na druge metale nije zanemariv i relativno je visok. Najveće dosegnute prosječne koncentracije za živu su oko 0,5 mg/kg u jetri i oko 0,25 mg/kg u kostima, za arsen oko 0,2 mg/kg u škrgama, za olovo oko 0,175 mg/kg u kostima a za kadmij 0,25 mg/kg u koži. Moray eel (Muraena helena L.) is a Mediterranean species of fish known from ancient times, interesting from a biological and commercial point of view, and due to its benthic and perennial lifestyle, sedentary lifestyle, limited migration rate along with growth rate and consumption of a wide range of species in different trophic positions, this species could be an interesting potential bioindicator for studying benthic heavy metal pollution in the Adriatic / Mediterranean. This paper shows how the major residual metals accumulate within different organs of this species. Moray eels were collected in the unpolluted area of the Adriatic Sea, Elafiti-Dubrovnik in summer and winter period. The aim of the work is to show the bioaccumulation potential of different organs for metals Hg, As, Cd, Pb and to determine which would be best for the bioindicative potential for the accumulation of metals from the marine environment. In most organs, except the heart, the highest bioaccumulation occurs during the summer. Exceptionally, in winter, mercury and arsenic accumulate most only in muscle tissue. Of all the metals studied, if we look at all collected samples regardless of season, mercury is the most represented accumulated metal in all organs except heart and skin. The skin mostly accumulates lead. Arsenic is the second most abundant metal present in most organs except liver and gills (in gills lead is equally abundant by percentage). Although lead is the third largest in all organs (except gills), the percentage concentration relative to other metals is not negligible and is relatively high. The highest average concentrations reached for mercury are about 0.5 mg/kg in the liver and about 0.25 mg/kg in the bones, for arsenic about 0.2 mg/kg in the gills, for lead about 0.175 mg/kg in the bones and for cadmium 0.25 mg/kg in the skin.

Gymnothorax andamanensis sp. nov., a new short brown moray eel, is described here on the basis of two specimens collected from Port Mout, Port Blair, South Andaman (11.659327°N; 92.696148°E), caught using baited hand-lines in a sandy habitat at a depth of less than 2 m. The species is characterized in having the dorsal-fin origin before the gill opening, pre-anal length 2.1–2.2, jaw pores with black rim, two branchial pores, predorsal vertebrae 3, preanal vertebrae 57 and total vertebrae 135–136, teeth smooth, three large fang-like median intermaxillary teeth, biserial maxillary and uniserial vomerine teeth, and dentary teeth biserial with two teeth in each side in the second row of the dentary. The new species is compared with all 10 short brown unpatterned moray eels known from the world and two from Indian waters.

A new species of white-spotted moray eel Gymnothorax smithi sp. nov. is described based on three specimens collected from the southeastern Arabian Sea, India. This is the first deep water report of a moray eel from Indian waters from 200 m depth. This new species is distinguishable from its congeners by the following combination of characters: greyish brown body overlain with white spots of irregular shape, dorsal-fin origin anterior to gill opening, anus positioned slightly behind the mid-point of the body, serrated teeth and a unique vertebral count 3–5 /57/130–132. [Zoobank URL: urn:lsid:zoobank.org:act:9554CE07-E9E7-4B4F-95CD-54F2BB26FF28]

Gymnothorax mucifer Snyder, 1904 has been synonymized with G. kidako (Temminck & Schlegel, 1846) since 2000. Examination of material from Hawaii (type locality) and Taiwan reveal that G. mucifer is a valid species based on morphological and molecular data. It can be distinguished from G. kidako by a plainly colored lower jaw (vs. mottled), white margin of the anal fin replaced by serial pale blotches posteriorly on the tail (vs. white margin continuous to tip of tail), more dentary teeth (17–27 vs. 16–20), and fewer total vertebrae (130–141 vs. 140–143). In the present study, a redescription of G. mucifer is provided, and the distribution of G. mucifer and G. kidako is reevaluated.

International audience; This study used otolith microchemistry to evaluate whether the moray eel Gymnothorax chilospilus uses different habitats throughout its life (mainly juvenile and adult phases). Of the most informative trace elements within otoliths (the twelve isotopes 23Na, 25Mg, 43Ca, 55Mn, 59Co, 60Ni, 63Cu, 66Zn, 86Sr, 111Cd, 138Ba and 208Pb) only three ratios of Ca (Na:Ca, Sr:Ca and Ba:Ca) were informative and therefore used in a multivariate regression-tree analysis. Using a multivariate partitioning, three main phases were described from profiles, including the larval life phase (leptocephali), the intermediate phase (longest section between the larval life phase and the terminal phase) and the terminal phase (final section i.e., the most recent months preceding the death of fish). According to concentrations of the three ratios to Ca, G. chilospilus can be separated into three groups during their larval life stage (very different in Sr and Na), four groups during the intermediate phase (few differences in Sr and Na) and three groups during the terminal phase (differences in Sr), illustrating that G. chilospilus inhabit different habitats during these three phases. Our results showed that the leptocephali encountered different oceanic water masses with fluctuating Sr:Ca ratios during the early larval phase. During the intermediate phase (main part of their life-span), they lived in lagoonal waters such as fringing reefs or reef flats of lagoonal islets, characterized by a lower Sr:Ca ratio. During the latter part of their life, approximately one third of G. chilospilus encountered more oceanic waters close to or at barrier reefs, suggesting possible movements of these fish along a coast-to-ocean gradient.

On the basis of traditional morphological classification, Gymnothorax minor has been misidentified as Gymnothorax reticularis in China. Because of the special ecological habits and aggressiveness of this species, little research has been performed on its population genetics. Given the general decline in offshore fishery resources, it is necessary to study the genetic characteristics of G. minor in order to protect this resource. In the present study, six different geographical populations of G. minor were collected from their distribution areas in China, and their genetic signatures were investigated for the first time based on the control region fragments. The results showed that G. minor had a very high degree of genetic diversity, and there was no genetic differentiation between these populations. However, the genetic analysis failed to reject panmixia among geographic populations of this species. The life-history characteristics of G. minor and the heterogeneity of its habitat promote the rapid growth of its populations, resulting in gene mutation accumulation and rich genetic diversity. G. minor experienced a population expansion event during the late Pleistocene, which shaped its various genetic signatures. The prolonged pelagic larval duration (PLD) of this species ensures that its leptocephali effectively avoid various physical obstacles and have the opportunity to follow ocean currents to various coastal areas of China. Finally, this moray eel exchanges genetic material with recruitment populations from other locations. All the current genetic signature results for G. minor will serve as a reference for genetic research on moray eels with similar life-history characteristics.

Being able to tie their body into a knot is beneficial to some moray eels and other cylindrical vertebrates for various reasons, although not all morays’ tie knots. Knot tying can generate leverage for feeding activity by moving the knot up the body, and this leverage may be affected by knot type. Three types of knots are known to have been used by morays’ and this study further elucidates this behaviour and ability. Baited Remote Underwater Videos (BRUVs) were used to compare knot tying between the moray eels Gymnothorax prasinus and Gymnothorax prionodon in the Solitary Islands region, eastern Australia. Gymnothorax prasinus tied more knots overall and more types of knot than G. prionodon (five types vs one type, respectively). Both tied the overhand knot and this was the most common knot used by G. prasinus. The figure of eight knot was used two times more than the double overhand knot, being relatively wider and likely easier to move up the body. Gymnothorax prasinus also tied two undescribed knots, now called the ‘moray knot’ and the ‘morays banana knot’, which have more crossings and are bulkier, increasing potential for generating leverage. However, their uncommon use indicates costs may outweigh benefits of these more complex knots. Lower habitat complexity in deeper waters may influence differences in knot tying as G. prasinus were only recorded shallower than 40 m and G. prionodon mainly deeper. These findings further reveal the utility and complexity of knot tying in moray species and cylindrical vertebrates generally.

Gymnothorax odishi sp. nov., a new short brown moray eel, is described here on the basis of eleven specimens collected from Gopalpur, Odisha, along the east coast of India, Bay of Bengal. The species is characterized with dorsal-fin origin before gill opening, jaw pores with dark rim, small black patch just behind the eye of about eye size or more, gill opening with dark rim, two branchial pores, predorsal vertebrae 4, preanal vertebrae 55–58 and total vertebrae 133–138, three large fang like median intermaxillary teeth, uniserial maxillary and vomerine teeth. The new species is compared with all short brown unpatterned moray eels known from the world.

In this paper, we develop a gripper by mimicking the pharyngeal jaw of a moray eel to perform assembly tasks. A moray eel has two sets of jaws called the oral jaw (the main jaw) and the pharyngeal jaw (the smaller jaw). The pharyngeal jaw is mobile, which means it is able to go forward or backward relative to the oral jaw. By likening each jaw as a two-finger parallel gripper, we develop a bio-inspired robotic hand with similar structure, which we call a double jaw hand. The two parallel grippers in the double jaw hand are connected by a prismatic joint on a common approaching vector. Similar to moray eels, the double jaw hand is able to hold objects using the outer gripper and hand over them to the inner gripper (inspired by how a moray eel captures and swallows objects). Also, it is able to assemble and disassemble industrial parts (inspired by how a moray eel cuts its prey). Several experiments are performed to demonstrate the design and the abilities.

Fish consumption in antiquity, particularly of fresh fish, varied greatly according to geographic locations, epochs, and social strata, but certain kinds of fish certainly appeared regularly in the diet of ordinary people. In wanting to assess the role fish and seafood had in the diet of ordinary people in antiquity, the literary record, written by the educated upper class for their peers, is of limited use. Iconographic evidence – the mosaics and wall paintings that decorated fine villas and urban houses – also give an idea of the types of seafood that were appreciated. The species that are depicted most often, either as still life or in marine scenes, are bass, red mullet, moray eel, lobster, and octopus. As the Roman Empire encompassed a vast geographic area, not only were there differences in diet among the social classes, but there were also regional differences based on culinary traditions and what fish and other seafood were naturally available in the area.

International audience; Moray eels form a speciose lineage that belongs to Elopomorpha, a super-order with a worldwide distribution.As is the case for many anguilliform fish, moray eels are characterized by distinctive life history traits, notably aprolonged larval dispersal phase that determines settlement to distant reef habitats, thus influencing the spatialstructuring of their populations. They can be very abundant in coral reef ecosystems and represent major mesopredators,playing a crucial role in food webs. Yet, due to their elusive nature (i.e. cryptic behaviour, nocturnalactivity), these organisms are generally difficult to study and collect. To our knowledge, only a few studies performedover large geographical and phylogenetic scales have been conducted. We used a unique and cost-efficientsampling approach, involving forced regurgitation from sea snake predators, to collect large numbers of a widespreadmoray eel species (Gymnothorax chilospilus). When combined with the development of 11 new microsatellitemarkers, this efficient sampling technique allowed us to examine the genetic structure of Gymnothoraxpopulations occurring in the South Lagoon of New Caledonia. Analyses revealed a lack of genetic differentiationamong populations. This result echoes the strong genetic homogeneity of populations of their main predator, thesea snake. This convergence might result from a distinctive trait involved in population functioning of both morayeels and sea snakes, where immature individuals emerge from common breeding grounds and disperse over longdistances before settlement.