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We validated the daily formation of increments in otoliths of yellow goosefish Lophius litulon using reared individuals to examine the growth in the field. Single, round-shaped core structures were observed in 41% of sagittae and in 73% of the lapilli. Therefore, lapillar otoliths were used for further observations of daily increment analysis. The lapillus radius of newly hatched larvae was 15.0 ± 1.4 μm (mean ± standard deviation) forming the hatch check (first check). At 6 days after hatching (DAH), the second check was observed, which may correspond to the energy transition from endogenous to exogenous nutrition, located at 28.1 ± 0.7 μm from the core structures. Thereafter, clear daily increments formed outside the check. To estimate larval growth in the field, we examined the relationship between the notochord length (NL) and lapillus radius by an allometric equation. The mean growth rate was estimated as ca. 0.18 mm in NL/day during 10–40 DAH. The results of this study provide insights into the previously unknown early life history and will enable further understanding of the population dynamics of the genus Lophius.

New information is given on the morphology and distribution of two little-known species of ceratioid anglerfish—Linophryne pennibarbata and Himantolophus appelii. The species L. pennibarbata was first found in the Indian Ocean. The new specimen differs from the fishes of the type series in the details of the structure of the escal appendages and the posterior branch of the hyoid barbel. Ontogenetic variability in the structure of the esca of L. pennibarbata is discussed; it has been shown that the length of the distal appendage of the esca and its lateral branches, as well as the number of appendages of the posterior (unpaired) branch of the hyoid barbel in this species are subject to significant individual variability, not related to growth. It was revealed that the previously noted differences in the size and pigmentation of the distal appendages of esca in H. appelii cannot be associated with ontogenetic variability, as was assumed, but indicate the combined nature of this species. The reasons are given for assigning the name H. appelii to a form with short, intensely pigmented (except for the tips) distal appendages.

The almost complete skeleton of a fossil dreamer, identified as Oneirodes sp., is described from the middle–upper Miocene Kurasi Formation of southern Sakhalin Island, Russia. This is the second fossil skeletal record of oneirodid anglerfishes following those described from the Puente Formation of California, USA. The new specimen possesses morphological features very similar to those of the recent and fossil members of its genus, and cannot be separated from them at the species level. This finding confirms the idea of the high level of speciation of this fish family prior to the middle–late Miocene and demonstrates the wide geographic distribution of the genus Oneirodes already at this time.

Objective Analyze key features of the anglerfish Lophius piscatorius mitochondrial transcriptome based on high-throughput total RNA sequencing. Results We determined the complete mitochondrial DNA and corresponding transcriptome sequences of L. piscatorius. Key features include highly abundant mitochondrial ribosomal RNAs (10–100 times that of mRNAs), and that cytochrome oxidase mRNAs appeared > 5 times more abundant than both NADH dehydrogenase and ATPase mRNAs. Unusual for a vertebrate mitochondrial mRNA, the polyadenylated COI mRNA was found to harbor a 75 nucleotide 3′ untranslated region. The mitochondrial genome expressed several non-canonical genes, including the long noncoding RNAs lncCR-H, lncCR-L and lncCOI. Whereas lncCR-H and lncCR-L mapped to opposite strands in a non-overlapping organization within the control region, lncCOI appeared novel among vertebrates. We found lncCOI to be a highly abundant mitochondrial RNA in antisense to the COI mRNA. Finally, we present the coding potential of a humanin-like peptide within the large subunit ribosomal RNA.

WOS: 000510854900012, During the seasonal trawling studies between September 2017 and August 2018, one specimen of the Lophius budegassa (Spinola, 1807) was found as one-eyed. This is the first record of this type, morphological abnormality of this fish species from Aegean Sea. Abnormality could be caused by environmental or genetic factors. the other reason might be a one-eyed specimen could be attacked by other carnivores when specimens at early stages. However, based on morphological investigations there were no visible assault scar or wound lesion were found on orbital skin tissue., Ege UniversityEge University [18-SUF-009], This study supported by Ege University - Scientific Research Projects Coordination as 18-SUF-009 Scientific Research Project.

Understanding population connectivity within a species as well as potential interactions with its close relatives is crucial to define management units and to derive efficient management actions. However, although genetics can reveal mismatches between biological and management units and other relevant but hidden information such as species misidentification or hybridization, the uptake of genetic methods by the fisheries management process is far from having been consolidated. Here, we have assessed the power of genetics to better understand the population connectivity of white (Lophius piscatorius) and its interaction with its sister species, the black anglerfish (Lophius budegassa). Our analyses, based on thousands of genome-wide single nucleotide polymorphisms, show three findings that are crucial for white anglerfish management. We found (i) that white anglerfish is likely composed of a single panmictic population throughout the Northeast Atlantic, challenging the three-stock based management, (ii) that a fraction of specimens classified as white anglerfish using morphological characteristics are genetically identified as black anglerfish (L. budegassa), and iii) that the two Lophius species naturally hybridize leading to a population of hybrids of up to 20% in certain areas. Our results set the basics for a genetics-informed white anglerfish assessment framework that accounts for stock connectivity, revises and establishes new diagnostic characters for Lophius species identification, and evaluates the effect of hybrids in the current and future assessments of the white anglerfish. Furthermore, our study contributes to provide additional evidence of the potentially negative consequences of ignoring genetic data for assessing fisheries resources., SI

Anglerfishes Lophius spp. are gaining high economic value day by day and becoming demand species worldwide. The black-bellied anglerfish, Lophius budegassa (Spinola, 1807) has prominently economic importance to the commercial fishing fleets and fish markets all over the European countries. However, in spite of their economic value, their biology, ecology and especially the feeding habits are poorly understood. In this study, to determine the feeding ecology of L. budegassa, a total of 558 specimens were collected by the commercial trawl fishing vessels in the Central Aegean Sea between September 2017 and August 2018. 284 stomachs of 558 individuals were found as empty and the full stomachs were examined as N%, W%, O% and IRI% values. As a result, it has been determined that this predatory fish feed on many preys in their natural habitat and overall diet of L. budegassa includes fishes, cephalopods, and crustaceans. Fishes were the most important group (IRI = 59.33%). European hake Merluccius merluccius and the deep-water rose shrimp Parapenaeus longirostris are the main prey species of L. budegassa in the area. The diet in the Central Aegean Sea varied among various size groups for juveniles (TL, Ege University (Turkey)-Scientific Research Projects Coordination [18-SUF-009], This study was supported by Ege University (Turkey)-Scientific Research Projects Coordination as 18-SUF-009 Scientific Research Project. Besides, we would like to thanks the reviewers of the journal for their valuable comments and suggestions.

Fishes are the most numerous group of vertebrates, with many different reproductive patterns. Some fish are parthenogenetic, while most fishes reproduce sexually. Many fishes leave the offspring alone, although, in some species, mothers and fathers care for the brood. Perhaps the best fathers in the animal world are sea horses, where males are the ones who get pregnant and deliver babies. Mechanisms of sex determination are also very varied in fishes, with different species using different approaches. In some fish, sex determination is chromosomal, like in mammals and birds. In others, the sex of the offspring is determined by the hatching environment, similar to reptiles. Interestingly, sex determination is not a conclusive process in many fish species like in birds and mammals. Rather, some fishes can switch sexes throughout life and thus adapt to their social environment.

Anglerfishes are a highly diverse group of species with unique characteristics. Here, we report the first chromosome-level genome of a species in the order Lophiiformes, the yellow goosefish (Lophius litulon), obtained by whole genome shotgun sequencing and high-throughput chromatin conformation capture. Approximately 97.20% of the assembly spanning 709.23 Mb could be anchored to 23 chromosomes with a contig N50 of 164.91 kb. The BUSCO value was 95.4%, suggesting that the quality of the assembly was high. A comparative gene family analysis identified expanded and contracted gene families, and these may be associated with adaptation to the benthic environment and the lack of scales in the species. A majority of positively selected genes were related to metabolic processes, suggesting that digestive and metabolic system evolution expanded the diversity of yellow goosefish prey. Our study provides a valuable genetic resource for understanding the mechanisms underlying the unique features of the yellow goosefish and for investigating anglerfish evolution.

Trypanorhynch cestodes are common parasites of marine fish with complicated life cycles which have been suggested as model taxa to study the evolution of marine helminth parasites and their life cycles. Among the Trypanorhyncha, the genus Grillotia includes 18 valid species, of which only four have been found in Mediterranean fish hosts. Morphological, histopathological, and molecular data are presented on a massive Grillotia plerocercus infection in an anglerfish (Lophius piscatorius) from the Tyrrhenian Sea. BLAST analysis of the 28S rDNA sequences revealed 99% similarity between specimens here found and a G. (Bathygrillotia) rowei sequence available in GenBank with a total of six nucleotide site differences. A morphological study suggested that the Grillotia sp. here reported did not match important characters to those previously reported from the Mediterranean Sea. Taking in account these differences, we prefer to place these specimens within Grillotia sensu lato until more material is available for study including sequences from adult specimens of Grillotia spp. from the Mediterranean Sea.

The European Union banned fishing operations with trammel, entangling and gillnets in Portuguese continental waters at depths >200 m in consideration of the potential impact of fisheries on deep-sea sharks. Derogation could be considered if Member States demonstrate that by-catch mortality does not adversely affect this group of species. This regulation has had an impact on the trammel net fishery for anglerfish (Lophius piscatorius and Lophius budegassa), one of the most important Portuguese multi-species fisheries. This study evaluates the impact of this fishery on deep-water shark populations by looking at onboard observations of by-catch in the commercial fishery and by analysing survey catch composition. Results suggest that this fishery has a very low impact on deep-water shark populations: by-catch was

The fin-to-limb transition is heralded as one of the most important events in vertebrate evolution. Over the last few decades our understanding of how limbs evolved has significantly increased; but, hypotheses forwhylimbs evolved are still rather open. Fishes that engage their fins to ‘walk' along substrate may provide some perspective. The charismatic frogfishes are often considered to have the most limb-like fins, yet we still know little about their underlying structure. Here we reconstruct the pectoral fin musculoskeletal anatomy of the scarlet frogfish to identify adaptations that support fin-assisted walking behaviours. The data are compared to three additional anglerfish species: the oval batfish, which represents an independent acquisition of fin-assisted walking; and two pelagic deep-sea swimmers, the triplewart seadevil and ghostly seadevil. Our results clearly show broad musculoskeletal differences between the pectoral fins of swimming and walking anglerfish species. The frogfish and batfish have longer and more robust fins; larger, differentiated muscles; and better developed joints, including a reverse ball-and-socket glenoid joint and mobile ‘wrist'. Further, the frogfish and batfish show finer-scale musculoskeletal differences that align with their specific locomotor ecologies. Within, we discuss the functional significance of these anatomical features in relation to walking, the recurring evolution of similar adaptations in other substrate locomoting fishes, as well as the selective pressures that may underlie the evolution of limbs.

12 pages, 9 figures, 2 tables, The presence of emergent visible parasites at commercial valuable fish species is increasingly causing problems at fisheries and seafood industries. Microsporidians have been previously reported to appear forming apparent xenomas complexes in anglerfish species, but no effort has been carried out to simultaneously integrate epidemiological data, phenotypic, genotypic and fine structural characterizations in the same parasite sample. In this work, specimens of Lophius budegassa and Lophius piscatorius from NE Atlantic waters were sampled and examined to provide information about specific site of infection and demographic data of two groups of different sizes of xenomas present at both fish species. Histological descriptions and scanning and transmission electron microscopy were carried out on fresh spores of Lophius budegassa for ultrastructural studies. In both types of xenomas, it was observed simultaneously the microsporidian genus Spraguea in the form of two different types of spores. Molecular analyses of both xenomas from the two fish species, based on the small subunit ribosomal DNA gene, were also performed to genetically support the morphological diagnostic provided., Xunta de Galicia has funded this work under Projects INCITE-07MMA015CT, IN841C, 10TAL 001CT and 10TAL033E. M. Llarena-Reino thanks Fundação para a Ciência e a Tecnologia for its financial support (Grant SFRH/BD/45398/2008).

Maturation, reproduction and early life history of Lophius piscatorius was investigated in Faroese waters. Length at first maturity (L50) was 58 cm for males and 84 cm for females, corresponding to an age of about four years for males and seven years for females. The proportions of females and males were similar in fish less than 55 cm long, and were skewed towards more males in medium sized fish (55–75 cm). Females were predominant in the larger fish (> 85 cm). Observations of spawning males and females, egg ribbons and pelagic anglerfish larvae, suggest that the main spawning season is from February to April and the spawning area seems to be southwest of the Faroe Plateau and in the Faroe Bank area. The Faroe Plateau probably serves as a nursery ground for juvenile anglerfish. Morphological transformation from larvae to juveniles occurred when the fish were about 7–9 cm long and they settled to the bottom when they were about 11 cm long. Thus, all life stages, as well as nursery areas, spawning areas and feeding areas of anglerfish are found in Faroese waters, indicating a separate stock in the area.

Deep-sea anglerfishes are relatively abundant and diverse, but their luminescent bacterial symbionts remain enigmatic. The genomes of two symbiont species have qualities common to vertically transmitted, host-dependent bacteria. However, a number of traits suggest that these symbionts may be environmentally acquired. To determine how anglerfish symbionts are transmitted, we analyzed bacteria-host codivergence across six diverse anglerfish genera. Most of the anglerfish species surveyed shared a common species of symbiont. Only one other symbiont species was found, which had a specific relationship with one anglerfish species, Cryptopsaras couesii. Host and symbiont phylogenies lacked congruence, and there was no statistical support for codivergence broadly. We also recovered symbiont-specific gene sequences from water collected near hosts, suggesting environmental persistence of symbionts. Based on these results we conclude that diverse anglerfishes share symbionts that are acquired from the environment, and that these bacteria have undergone extreme genome reduction although they are not vertically transmitted., eLife digest The deep sea is home to many different species of anglerfish, a group of animals in which females often display a dangling lure on the top of their heads. This organ shelters bacteria that make light, a partnership (known as symbiosis) that benefits both parties. The bacteria get a safe environment in which to grow, while the animal may use the light to confuse predators as well as attract prey and mates. The genetic information of these bacteria has changed since they became associated with their host. Their genomes have become smaller and more specialized, limiting their ability to survive outside of the fish. This phenomenon is also observed in other symbiotic bacteria, but mostly in microorganisms that are directly transmitted from parent to offspring, never having to live on their own. Yet, some evidence suggests that the bacteria in the lure of anglerfish may be spending time in the water until they find a new host, crossing thousands of meters of ocean in the process. To explore this paradox, Baker et al. looked into the type of bacteria carried by different groups of anglerfish. If each type of fish has its own kind of bacteria, this would suggest that the microorganisms are passed from one generation to the next, and are evolving with their hosts. On the other hand, if the same sort of bacteria can be found in different anglerfish species, this would imply that the bacteria pass from host to host and evolve independently from the fish. Genetic data analysis showed that amongst six groups of anglerfishes, one species of bacteria is shared across five groups while another is specific to one type of fish. The analyses also revealed that anglerfish and their bacteria are most likely not evolving together. This means that the bacteria must make the difficult journey from host to host by persisting in the deep sea, which was confirmed by finding the genetic information of these bacteria in the water near the fish. Anglerfish and the bacteria that light up their lure are hard to study, as they live so deep in the ocean. In fact, many symbiotic relationships are equally difficult to investigate. Examining genetic information can help to give an insight into how hosts and bacteria interact across the tree of life.

The interdependence of diverse organisms through symbiosis reaches even the deepest parts of the oceans. As part of the DEEPEND project (deependconsortium.org) research on deep Gulf of Mexico biodiversity, we profiled the bacterial communities (‘microbiomes’) and luminous symbionts of 36 specimens of adult and larval deep-sea anglerfishes of the suborder Ceratioidei using 16S rDNA. Transmission electron microscopy was used to characterize the location of symbionts in adult light organs (esca). Whole larval microbiomes, and adult skin and gut microbiomes, were dominated by bacteria in the genera Moritella and Pseudoalteromonas. 16S rDNA sequencing results from adult fishes corroborate the previously published identity of ceratioid bioluminescent symbionts and support the findings that these symbionts do not consistently exhibit host specificity at the host family level. Bioluminescent symbiont amplicon sequence variants were absent from larval ceratioid samples, but were found at all depths in the seawater, with a highest abundance found at mesopelagic depths. As adults spend the majority of their lives in the meso- and bathypelagic zones, the trend in symbiont abundance is consistent with their life history. These findings support the hypothesis that bioluminescent symbionts are not present throughout host development, and that ceratioids acquire their bioluminescent symbionts from the environment., Molecular characterization of bioluminescent bacterial symbionts and comparison with bacteria at other body parts in six families of anglerfish of the Gulf of Mexico.

The rare ceratioid anglerfish Gigantactis microdontis was formerly known from 12 specimens collected in the Eastern Pacific from 158° W eastward: off Hawaiian Islands, Oregon, California and Peru. Thirteenth specimen reported herein extends the known distribution of this species some 7630 km westward into the western tropical Pacific (off Caroline Islands). The newly reported specimen shows no principal differences in morphology from the previously known individuals.

The early life history of the angler Lophius piscatorius in the Bay of Biscay was investigated by growth increments in the lapillar otoliths, this being the first time this type of analysis was conducted for this species among specimens of the Iberian stock (ICES Divisions 8.c, 9.a). Lapilli of 34 juvenile fish collected during autumn bottom trawl surveys, were successfully aged between 113 and 198 days (116–213 mm fish length). Morphology and ultrastructure analyses of the otolith’s check marks enabled us to determine the period of endogenous feeding (which according to these estimations would last between 9 and 19 days after hatching), as well as the settlement check, which indicated a relatively long pelagic phase (ca. 91 days). Hatch date was back-calculated from the date of capture indicating a spawning period from April to June, in agreement with that estimated for this population. The age–length relationship was described by the linear function LT = 7.30 + 0.98 age (days) and showed an average growth rate of 0.98 mm day−1 . Our results present a faster growth pattern of 0+ juveniles L. piscatorius in the Bay of Biscay than previously estimated by annual growth studies, showing that juveniles of up to 213 mm length collected in October were hatched in the same year and belonged to age class 0. These results are relevant to the knowledge of the early life history of this species and are in agreement with those obtained in the only previous microstructural study of L. piscatorius in Atlantic waters. The implications of these findings on the annual age estimation protocol based on illicia are discussed., Sí

Genome studies in fish provide evidence for the adaptability of the vertebrate immune system, revealing alternative immune strategies. The reported absence of the major compatibility complex (MHC) class II pathway components in certain species of pipefish (genus Syngnathus ) and cod-like fishes (order Gadiformes) is of particular interest. The MHC II pathway is responsible for immunization and defence against extracellular threats through the presentation of exogenous peptides to T helper cells. Here, we demonstrate the absence of all genes encoding MHC II components (CD4, CD74 A/B, and both classical and non-classical MHC II α / β ) in the genome of an anglerfish, Lophius piscatorius , indicating loss of the MHC II pathway. By contrast, it has previously been reported that another anglerfish, Antennarius striatus , retains all MHC II genes, placing the loss of MHC II in the Lophius clade to their most recent common ancestor . In the three taxa where MHC II loss has occurred, the gene loss has been restricted to four or five core MHC II components, suggesting that, in teleosts, only these genes have functions that are restricted to the MHC II pathway.

Effective species management requires good knowledge on vessel dynamics, either at a stock basis or through the establishment of multiannual management plans as advisable under the new European Common Fisheries Policy (CFP). Achieving such knowledge on Portuguese multi-gear fisheries is challenging given the large number of species caught and the different management measures applied to potential target species. The latter ranges from no input or output controls to output controls based on individual vessel quotas (IVQ). To provide accurate regional knowledge to the CFP, the dynamics of vessels involved in the trammel net fishery targeting anglerfish ( Lophius spp.) was characterised based on onboard sampling data and logbook reports. The selected vessels were very dynamic, and were found to target other species such as hake ( Merluccius merluccius ), John Dory ( Zeus faber ) and octopus ( Octopus vulgaris ). Anglerfish landing trends can be explained by changes in abundance, quota availability and shifts/changes in fishing effort. Overall, the dynamics of these vessels varied with area of exploitation, IVQ value and anglerfish total allowable catch (TAC). These results show the influence of different management systems in the dynamics of vessels and the advantage of an IVQ management system, where fishers can spatially and temporally allocate effort. Results also highlight a fishing effort shift towards unregulated species in face of IVQ or TAC restrictions.

The goosefish, Lophius americanus, is a dorso-ventrally compressed marine fish that spends most of its life sitting on the substrate waiting to ambush prey. Species in the genus Lophius have some of the slowest ventilatory cycles recorded in fishes, with a typical cycle lasting more than 90s. They have a large gill chamber, supported by long branchiostegal rays and ending in a siphon-like gill opening positioned underneath and behind the base of the pectoral fin. Our goals were to characterize the kinematics of gill ventilation in L. americanus relative to those of more typical ray-finned fishes, address previous assertions about ventilation in this genus, and describe the anatomy of the gill opening. We found that phase 1 of ventilation (during which both the buccal and gill chamber are expanding) is greatly increased in duration relative to that of typical ray-finned fishes (ranging from 62 to 127s), and during this phase, the branchiostegal rays are slowly expanding. This slow expansion is almost visually imperceptible, especially from a dorsal view. Despite this unusually long phase 1, the pattern of skeletal movements follows that of a typical actinopterygian, refuting previous assertions that Lophius does not use its jaws, suspensorium, and operculum during ventilation. When individuals were disturbed from the sediment, they tended to breathe more rapidly by decreasing the duration of phase 1 (to 18-30s). Dissections of the gill opening revealed a previously undocumented dorsal extension of the adductor hyohyoideus muscle, which passes from between the branchiostegal rays, through the ventro-medial wall of the gill opening, and to the dorsal midline of the body. This morphology of the adductor hyohyoideus shares similarities with that of many Tetraodontiformes, and we suggest that it may be a synapomorphy for Lophiiformes+Tetraodontiformes. The specialized anatomy and function of the gill chamber of Lophius represents extreme modifications that provide insight into the potential limits of the actinopterygian gill ventilatory system.

Several studies in the last 20 years have revealed that morphological asymmetry in fish can be characterized as ‘antisymmetry’. Antisymmetry is a lateral dimorphism in which each population consists of individuals with well-developed left sides (lefties) and well-developed right sides (righties). This dimorphism influences predator–prey interactions. In some piscivorous fishes, it has been found that predators can catch more prey of the opposite morphological type to themselves (cross-predation) than of the same morphological type (parallel-predation). Our previous work clarified that the predominance of cross-predation is caused by lateralized behaviors of predators and prey that correspond to their morphological antisymmetry. Moreover, based on the results of our behavioral observations, we hypothesized that parallel-predation can predominate when predators encounter the potential prey frontally. To test this hypothesis, in the present study we investigated the relationship between lateral morphological types of anglerfish (Lophiomus setigerus) and those of the prey fishes found in their stomachs. Anglerfish attract potential prey using their first dorsal fin (illicium) as a lure, and their frontal encounters with potential prey fishes were photographed in situ and observed in an aquarium. The results of a stomach contents analysis indicated that parallel-predation predominated in five benthopelagic prey fish species (perches and eels). By contrast, five benthic prey fishes (gobies and weevers) exhibited the predominance of cross-predation. These results not only demonstrate the predominance of parallel-predation in a natural fish community, but also suggest that the relationship between morphological types of predator and prey species can be reversed depending on the lifestyle of prey.

Summary A survey-based assessment of an eastern Mediterranean data-limited black anglerfish (Lophius budegassa; Spinola, 1807) stock was carried out to elucidate its population and exploitation trends. A catch-based method was also applied to estimate its maximum sustainable yield (MSY). The effect on the long-term spawning stock biomass and yield of a wide range of exploitation regimes (combinations of F and selectivity) was investigated using an age-structured population model parameterised for Mediterranean anglerfish stocks. The analysis indicated an increasing trend of anglerfish fishing mortality (F) in the eastern Mediterranean from the mid-1990s onwards, and that recent catches were 41% higher than the median MSY estimate. Catching Mediterranean anglerfish at least three years after they mature at an F = 0.4–1 year−1 would ensure high yields at sustainable levels of stock depletion. Examination of the empirical exploitation regimes in five anglerfish stocks across the Mediterranean Sea illustrates their unfulfilled potential for higher sustainable yields, mainly due to overexploitation of juveniles.

A new species of the deep-sea ceratioid anglerfish genus Oneirodes Lutken (Lophiiformes: Oneirodidae) is described on the basis of a single female specimen collected from the Western Indian Ocean. The new form is distinguished from its congeners by a combination of features that includes a relatively short illicium, a unique escal morphology, and shape of the subopercle bone.

The Mediterranean distributions of two species of anglerfish, the blackbellied anglerfish (Lophius budegassa) and the white anglerfish (Lophius piscatorius), were analysed from trawl survey data (MEDITS project – Spain, France, Italy and Greece) from 2006 to 2015 implementing a Delta model approach with residuals autocovariate boosted regression trees. Sea bottom temperature (SBT), sea bottom salinity (SBS), bathymetry, slope of the seabed and distance to the coast were considered possible predictors. The results show that the locations with a higher presence, abundance and biomass of L. budegassa are those with a depth range between 150 to 300 m, with an SBT range between 17.5 and 18.5°C, and SBS of 37- 38 PSU. Similarly, L. piscatorius shows a higher probability of presence, abundance and biomass in location with a bathymetry range of 200-400 m, an SBT of 17.5°C to 18.5°C and an SBS of 36.5 to 37.5. Our results identify preference habitats for the anglerfishes in the Mediterranean Sea such as the Aegean Sea, the Gulf of Lions, south and southeast Spain and the northwestern Ionian Sea. In general terms, these findings enhance our understanding of the differences in the spatio-temporal distribution of these two species, providing useful information that can help their fisheries management and conservation., Sí

The present article is the first to describe the diet of the black anglerfish Lophius budegassa, an opportunistic, non-selective, ambush predator, on the upper slope of the south eastern Mediterranean Sea. The deep-water rose prawn, Parapenaeus longirostris, and the short nose green eye, Chlorophthalmus agassizi, are identified as its main prey items. We used stomach contents as a proxy of prey availability, thus reflecting the local species abundance in the warm, oligotrophic environment of the south eastern Levant. Current models predict increasing temperatures and oligotrophy in the Mediterranean Sea. The results of this study depicting the diet of the Levantine population of L. budegassa, which varies from other Mediterranean populations, could indicate possible Mediterranean-wide shifts in prey distribution and abundance driven by climate change and anthropogenic disturbance. In addition, we augment the knowledge regarding the species’ feeding ecology, especially regarding possible sex and size dissimilarity. We propose the use of diet analyses from non-selective predators like L. budegassa as a mean to identify changes in community compositions and differences among communities.

10 pages, 1 figure, 3 tables, This study investigates the occurrence of anisakids and raphidascarids in commercial fish from Balearic Sea (Western Mediterranean). A total of 335 fish including 19 black anglerfish (Lophius budegassa), 33 white anglerfish (L. piscatorius), 129 European hake (Merluccius merluccius), 30 red mullet (Mullus barbatus), and 124 striped mullet (M. surmuletus) were examined using enzymatic digestion. A total of 948 nematode larvae were isolated (prevalence 52.53%) being the highest prevalence observed in striped mullet. Forty-six larvae were identified using molecular analyses which included PCR and sequencing of the 629-bp fragment of mitochondrial cox2 gene region. Anisakis pegreffii (80.43%), A. physeteris (8.69%), Hysterothylacium fabri (6.52%), and A. simplex (4.35%) were detected based on molecular analyses of larvae. Total nematode prevalence was positively correlated with weight, length, condition factor, and maturity stage of the host and also with fishing ground depth. Statistical differences between total nematode prevalence and geographical sector of capture were observed when fishing hauls were grouped according to the abundance of sperm whales or common bottlenose dolphins. The results also corroborate that fishing water depth may play an important role in anisakid and raphidascarid parasitization.

Spotted handfish are a critically endangered anglerfish. Monitoring of the species has, in the past, been undertaken via underwater visual census (UVC) parameterised with fixed length 100 m × 3 m strip transects measured with reel lines. However, the sparse distribution and cryptic nature of handfish resulted in low statistical power to track populations through time. To achieve reasonable confidence of detecting change ~ 40 transects are required for density estimates, making the logistical constraints of monitoring onerous. We trialled a new survey method for UVC at one study site with a known local population of fish, replacing reel transects with variable length strip transects parameterised with a diver towed Global Positioning System (GPS) float. From 18 transects we determined a density of 24 (± 3.5) handfish per hectare, but bootstrapping suggested little improvement in precision occurred after 8 transects. Modelling these results to previous estimates at the site indicated that our GPS float approach required many fewer transects and dives to determine 50% increases or decreases in fish densities. This improvement was partly due to the better sampling efficiency; with 3 times the average search area per transect but was also a result of longer transects being a better solution for monitoring a sparse population. Our results returned a normal sample distribution of fish counts with few zeros and many multiple observations, which differed to the original approach which was heavily skewed towards zero observations per transect. However, at very low population densities even this more robust solution will require many samples to detect change. Our GPS parameterized surveys also improved the functionality of observing fish behaviour as we could accurately plot fish allowing for detailed investigation of distributions. When fish were observed they were also bi-laterally digitally photographed to record their unique natural markings. By synchronising the photographs timestamp with the GPS clock, we were able to geo-locate individual recaptures and our preliminary results suggests net movements were limited. This new approach increases the logistical feasibility for monitoring spotted handfish and may have applications for other sparsely distributed benthic species.

A new species of the deep-sea ceratioid anglerfish genus Lasiognathus Regan (family Oneirodidae) is described on the basis of three female specimens collected in the northern Gulf of Mexico. Not especially similar to any of the five previously described members of the genus, the new species is unique in having a cylindrical, internally pigmented, anterior escal appendage and a pair of elongate distal escal appendages. The new species is diagnosed and described, and a revised key to the species of the genus is provided.

The chorion surface ultrastructure of unfertilized eggs of black anglerfish Lophius budegassa and white anglerfish Lophius piscatorius was examined by scanning electron microscopy. Species-specific differences were observed.

Due to global declines, skates and sharks have become a focus of marine conservation in recent years. Despite protective measures, they remain vulnerable to bycatch by fisheries, especially bottom-trawls and pose a problem for fisheries management measures that aim to eliminate discards in the future. In the mixed-species bottom-trawl fisheries of the North Atlantic catches can be increased by fitting a length of chain known as a “tickler” in front of the groundgear of the trawl. It was hypothesized that the tickler is especially effective at catching skates and rays that may otherwise escape beneath the net. A trial was undertaken with paired tows with and without the tickler chain. The trial demonstrated that the catch rate of skates and sharks can be significantly lowered by removing the tickler. A set of secondary nets (groundgear bags) attached behind the groundgear of the main net allowed the number of fish escaping under the net to be estimated and showed that the reduction of skates and sharks in the main net was accompanied by an increase in number in the groundgear bags. This suggests that prohibition of the use of tickler chains in areas that are known to be especially important to skates and sharks could have conservation benefits. The removal of the tickler chain had little effect on catch rates of haddock, whiting, and flatfish, but caused a marked decrease in the catch rate of commercially valuable anglerfish.

Batfishes (Ogcocephalidae) are an understudied, group of marine anglerfishes that are dorsoventrally flattened and have an illicium and esca (terminal lure) used to attract prey. The family contains 10 genera and 75 recognized species from nearly all tropical and subtropical seas. Relationships among these taxa, as well as the position of Ogcocephalidae within Lophiiformes, remain poorly understood with previous studies showing conflicting, and poorly resolved results. The timing of divergence and depth of origination in the water column have also not been explored in any detail. In this study a concatenated nuclear (three genes) and mitochondrial (two genes) dataset was constructed across several anglerfish families to elucidate phylogenetic relationships among all ten batfish genera, to clarify the placement of Ogcocephaloidei within Lophiiformes, and to estimate divergence times using fossil calibrations. An ancestral state reconstruction was also conducted to examine the history of shifts in preferred habitat depths within batfishes. Phylogenetic analyses supported monophyly of each sub-order within Lophiiformes and placed Ogcocephaloidei as the sister group to Antennarioidei. Batfish genera were divided into an Eastern Pacific/Western Atlantic clade and an Indo-Pacific clade; Halieutaea was recovered as the sister group to all other batfishes. Based on divergence time estimations and ancestral state reconstructions of preferred depth, Ogcocephalidae is Eocene in age and originated on the lower continental shelf/upper continental slope (disphotic zone).

A new deep-sea anglerfish of the genus Chaunacops is described based on three specimens collected from eastern Australia and New Caledonia. It differs from its congeners in having fine dermal spinules, mixed with simple and bifurcate ones, densely covering the body, four neuromasts on the pectoral series of the lateral line and a combination of other characteristics. Data for Chaunacops melanostomus based on 31 specimens newly collected from Western Australia are provided. An underwater observation of C. melanostomus made by a remotely operated vehicle is also provided.

The effects of precooling with slurry ice on the quality and microstructure of anglerfish liver were determined during further storage at −1.5C. The results showed that compared with the samples directly frozen at −1.5C (group B), precooling with slurry ice (group A) can significantly reduce the cooking loss (P

Weight–lengthrelationships,weightconversionfactorsandsomaticindicesarepresentedfromadecade (2006 to 2015) for two stocks of Lophius budegassa and L.piscatorius in northern Iberian Atlantic waters (ICES Div. VIIIc–IXa2) and in Celtic Sea, south-western Ireland and Porcupine Bank (Div. VIIb,c,h,j,k). A total of 3298 L.budegassa and 7219 L.piscatorius were sampled from commercial landings and research surveys. Total length (Lt), total weight (Wt), ‘‘commercial’’ weight (Wgl) and ‘‘scientific’’ weight (Wg) were obtained. The parameters (a, b) in the power relationships weight–length for combined sexes in L.budegassa were: 0.020, 2.916; 0.017, 2.929; 0.017, 2.922 for Wt, Wgl and Wg respectively in Div. VIIIc–IXa2;0.025,2.841;0.013,2.984;0.013,2.971inDiv.VIIb,c,h,j,k.ForL.piscatorius:0.025,2.853;0.020, 2.868;0.024,2.861inDiv.VIIIc–IXa2;0.027,2.826;0.023,2.825;0.023,2.816inDiv.VIIb,c,h,j,k.Significant differences between stocks were found in both species. The conversion factors between total and gutted weight in L.budegassa were: 1.186, 1.236 for Wgl and Wg respectively in Div. VIIIc–IXa2; 1.187, 1.233 in Div. VIIb,c,h,j,k. For L.piscatorius: 1.181, 1.241 in Div. VIIIc–IXa2; 1.210, 1.262 in Div. VIIb,c,h,j,k. The parameters can be used in the process of annual assessment of the state of each stock. Gonadosomatic index (GSI), hepatosomatic index (HSI) and Le Cren’s condition factor, indicators of reproductive and nutritional status, were seasonally analyzed and compared between sexes and stocks. Significant better condition and higher GSI and HSI were found in females. In Div. VIIb,c,h,j,k better condition was found for both species and higher GSI for L.piscatorius. The analysis throughout the year of GSI and HSI for L.budegassashowedseasonalityinlivergrowthprevioustospawnandcorroboratedthespawningseason from January to June in VIIIc–IXa2. The parameters obtained were compared with previous ones from these and others Lophiiformes, showing common patterns., SI

Blackbellied angler ( Lophius budegassa ) and angler ( L. piscatorius ) are two important commercial species in the Bay of Biscay and the European fisheries infected by the microsporidian parasite Spraguea lophii . Samplings of both anglerfish were performed from a nine year time-series (2006–2014) from commercial fleet and bottom research surveys operating in southern Bay of Biscay and Galician waters (ICES Div. VIIIc and IXa2), Celtic Sea (Div. VIIh), south-western Ireland (Div. VIIj and VIIk), western Ireland and Porcupine Bank (Div. VIIb and VIIc). Length and sex of fish and presence or absence of the parasite were recorded. The prevalence by Spraguea was used to analyse the infection level. The role of each variable (fish length, fish sex, geographical area and year) and the interactions among them on the Spraguea prevalence were analyzed by using a binomial GLM. Area and fish length had a more relevant effect on the infestation of both anglerfish, while the impact of the year and fish sex was less evident. The Spraguea prevalence by area ranged between 11% and 52% in L. budegassa and between 39% and 66% in L. piscatorius . This is the first study in which the prevalence of this parasite in L. budegassa is analyzed in several areas and inter-annually compared. A non-linear relationship with a sharp increment of the prevalence with fish length was obtained in both anglerfish. The results were compared with those from the scarce previous studies and discussed.

14 pages, 7 figures, 2 tables, Reproductive parameters of the white anglerfish (Lophius piscatorius) in the northwestern Mediterranean Sea were studied in 556 specimens collected monthly aboard commercial fishing vessels that were trawling at depths of 12-836 m. The main spawning season occurred from February through June. The size at maturity was estimated to be 48.8 cm in total length (TL) for males, 59.9 cm TL for females, and 51.3 cm TL for both sexes combined. The white anglerfish has group-synchronous oocyte development and determinate fecundity. It is a total spawner (spawns all its eggs once during a spawning season) and has a batch fecundity ranging from 661,647 to 885,214 oocytes, a relative batch fecundity of 66-128 oocytes per gram of female gutted weight, and a potential fecundity with values from 54,717 to 104,506 oocytes per kilogram of female total weight. This study is the first to provide the reproductive biology of white anglerfish in the northwestern Mediterranean Sea and provide valuable information that can be used to improve the stock assessment and ensure proper management of this species

The reproduction of black anglerfish (Lophius budegassa) was studied from samples collected during 5 years, from January 2006 to December 2010, in Celtic Sea, West and South of Ireland (ICES Div. VIIb-k) and Northern Spanish Atlantic waters (ICES Div. VIIIc-IXa). A total of 1167 specimens (4-99 cm) were sampled. The sex ratio, the spawning period and the maturity ogives by length were studied. The sex ratio in both areas studied varied with length, and it was close to 1:1 (male:female), 1:1.22 (54.90% of females) in Div. VIIb-k, and 1:1.01 (50.30% of females) in Div. VIIIc-IXa. A seasonal variation in sex ratio by length was observed at first time in Div VIIIc-IXa, with a very low proportion of intermediate sized females (40-60 cm) in the second semester. A seasonal reproductive migratory behaviour is discussed. The spawning period was between December and July in Div. VIIIc-IXa. Spawning males were found throughout the year, but fewer spawning females, as in previous studies. The L50 values were estimated in Div. VIIIc-IXa: 38.2 cm for combined sexes, 36.0 cm for males and 53.0 cm for females. These values of sex ratio and L50 are similar to those obtained in closed areas studied. Versión del editor

As an important part of renewable energy, the development and utilization of biomass hydrothermal liquefaction and oil production technology has become one of the important topics in the field of sustainable energy research in the new century. Based on China is rich in resources, low comprehensive utilization of seafood waste as raw materials, with low energy consumption, reaction conditions are relatively mild hydrothermal liquefaction process of the production of oil, to study the efficiency of oil in the process of hydrothermal liquefaction of biomass, and by comparing the experimental conditions (temperature, raw material and the water ratio, reaction time, catalyst and its concentration) the influence of the reaction. Through the analysis of the infrared spectrum, density and viscosity of the bio-oil, the bio-oil contains alcohols, phenols, acids, esters, ketones and amines. The product oil is heavy oil and can be used after certain processing.

A sexually parasitized female of the deep-sea ceratioid anglerfish Centrophryne spinulosa is described for the first time, bringing the number of ceratioid species known to exhibit sexual parasitism to 24 and the number of ceratioid families to six. The attached pair represents the largest known individuals of both sexes. The extreme and puzzling rarity of parasitized females in some of the best known ceratioid species is discussed. While it has been hypothesized that some ceratioid taxa reproduce solely by temporary male–female attachment, it now seems reasonable to expect the eventual discovery of parasitized females in any of the remaining ceratioid taxa.

A visual survey technique was employed to estimate the abundance and distribution of anglerfish Lophius spp. in areas where destructive sampling methods, such as trawling, are unacceptable. To enable visual surveying at depths of over 300 m, a deep towed vehicle was developed equipped with video, lights and other sensors and was towed at speeds of up to 1·5 m s−1 and altitudes of up to 10 m (from the seabed) to survey large areas of the seabed around the Rockall Bank in the north-west Atlantic Ocean. The system allowed for areas up to 125 000 m2 to be surveyed, a substantial area comparable to that surveyed by demersal-trawl sampling. Lophius spp. densities ranged from 15 to 736 fish km−2; these are comparable to estimated Lophius spp. densities determined by trawl surveys in adjacent areas. Estimates of Lophius spp. abundance in the closed areas ranged between 99 855 and 176 887 for the time series considered (2007–2011).

Species of the anglerfish genus Chaunax Lowe, 1846 from the New Zealand region are taxonomically reviewed with six species recognized and described: Chaunax penicillatus McCulloch; C. nudiventer Ho & Shao, a new record for New Zealand; and four species new to science. Chaunax flavomaculatus sp. nov. distinguished by having its skin covered with a mix of numerous bifurcated and simple spinules, large yellow spots on dorsal surface of fresh specimens, and brownish coloured escal cirri; Chaunax mulleus sp. nov. by having a uniformly pink body with a deep red colour on ventral surfaces of the outer pectoral-fin and pelvic-fin, and lower part of caudal fin; Chaunax reticulatus sp. nov. by having cirri on the dorsal surface of head, and a pale reticulate colour pattern on a greyish background dorsally; and Chaunax russatus sp. nov. by its very wide illicial trough that is usually as wide or wider than the diameter of the pupil, and uniformly deep red body colour with creamy white to fuzzy greyish spots or patches on its dorsal surface. A key to species recognized from the study area is given.

To investigate the reliability of age–length growth estimates of anglerfish Lophius piscatorius in Faroese waters, results from illicia age determination, length frequency and mark-recapture analyses were compared. Features of the illicium, such as the time of deposition and sizes of the benthic and first annual zones, width and the marginal increment progression of the edge were studied in detail. Results showed that the average horizontal diameters of the benthic and first annual zones were 0.18 mm (age 0) and 0.32 mm (age 1), respectively, and these zones could be identified in anglerfish of any length. There was a strong positive correlation between illicium width and fish length. In transmitted light the edge was usually dark in the winter and light in the summer, and the transition between them took place in May/June. Results from illicia age-readings and length-frequency analysis show that anglerfish in these waters have a very high growth rate during their first years of life (age 0–1, 18.5 cm year−1), after which smaller individuals grow faster than larger fish. Growth rates of fish larger than 35 cm in length are comparable to the fastest growth rates in other areas of the North Atlantic. Since the illicia age determinations resulted in growth rates that were consistent with length frequency and mark-recapture analyses, we believe that illicia derived age length keys could be used in age-based assessment of anglerfish in Faroese waters.

Anglerfish (Lophius piscatorius) collected from several locations in the southwestern European waters (from southwest of Ireland to northwest of Spain) were examined for the parasitic copepod Chondracanthus lophii in 2007, 2008 and 2009. The influence of host size, time (season, year) and spatial variables (geographical area, depth, latitude and longitude) on the infestation variability was studied. Zero-altered models (ZAMs) and generalized additive models (GAMs) were used to assess the prevalence and intensity of infection related to the variables studied. The variables which proved to have the greatest effects on the infestation were host size and geographical area, while the impact of variables such as year and season turned out to be less evident. Abundance, prevalence and intensity of C. lophii increased with host size. The highest infestation levels were recorded in the West of Ireland and on the Porcupine Bank, and within these areas the parasite load increased with latitude. Prevalence o...

Summary Stomach contents of 283 anglerfish (Lophius budegassa), collected in the Adriatic Sea (north-eastern Mediterranean) from experimental trawl surveys in 2005 and 2006, were examined to assess their diet as influenced by fish size, sex and water depth. Changes in food quantities in the stomach were observed, the percentage of empty stomachs decreasing with increasing body size and depth. No differences were found between male and female diets. The anglerfish is essentially an ‘opportunistic feeder’ that consumes mainly fishes, crustaceans and molluscs. Fishes were the primary food consumed by all size classes; the favourite prey was Merluccius merluccius (TL >150 mm for medium and large anglerfish) and Gaidropsarus biscayensis (TL