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Aim: Greenland is one of the places on Earth where the effects of climate change are most evident. The retreat of sea ice has made East Greenland more accessible for longer periods during the year. East Greenland fjords have been notoriously difficult to study due to their remoteness, dense sea ice conditions and lack of infrastructure. As a result, biological monitoring across latitudinal gradients is scarce in East Greenland and relies on sporadic research cruises and trawl data from commercial vessels. We here aim to investigate the transition in fish and marine mammal communities from South to Northeast Greenland using environmental DNA (eDNA). Location: South to Northeast Greenland. Methods: We investigated the transition in fish and marine mammal communities from South to Northeast Greenland using eDNA metabarcoding of seawater samples. We included both surface and mesopelagic samples, collected over approximately 2400 km waterway distance, by sampling from Cape Farewell to Ella Island in August 2021. Results: We demonstrate a clear transition in biological communities from south to northeast, with detected fish and mammal species matching known distributions. Samples from the southern areas were dominated by capelin (Mallotus villosus) and redfish (Sebastes), whereas northeastern samples were dominated by polar cod (Boreogadus saida), sculpins (Myoxocephalus) and ringed seal (Pusa hispida). We provide newly generated 12S rRNA barcodes from 87 fish species, bringing the public DNA database closer to full taxonomic coverage for Greenlandic fish species for this locus. Main Conclusions: Our results demonstrate that eDNA sampling can detect latitudinal shifts in marine biological communities of the Arctic region, which can supplement traditional fish surveys in understanding species distributions and community compositions of marine vertebrates. Importantly, sampling of eDNA can be a feasible approach for detecting northward range expansions in remote areas as climate change progresses.

Several Arctic marine mammal species are predicted to be negatively impacted by rapid sea ice loss associated with ongoing ocean warming. However, consequences for Arctic whales remain uncertain. To investigate how Arctic whales responded to past climatic fluctuations, we analysed 206 mitochondrial genomes from beluga whales (Delphinapterus leucas) sampled across their circumpolar range, and four nuclear genomes, covering both the Atlantic and the Pacific Arctic region. We found four well-differentiated mitochondrial lineages, which were established before the onset of the last glacial expansion ~110 thousand years ago. Our findings suggested these lineages diverged in allopatry, reflecting isolation of populations during glacial periods when the Arctic sea-shelf was covered by multiyear sea ice. Subsequent population expansion and secondary contact between the Atlantic and Pacific Oceans shaped the current geographic distribution of lineages, and may have facilitated mitochondrial introgression. Our demographic reconstructions based on both mitochondrial and nuclear genomes showed markedly lower population sizes during the Last Glacial Maximum (LGM) compared to the preceding Eemian and current Holocene interglacial periods. Habitat modelling similarly revealed less suitable habitat during the LGM (glacial) than at present (interglacial). Together, our findings suggested the association between climate, population size, and available habitat in belugas. Forecasts for year 2100 showed that beluga habitat will decrease and shift northwards as oceans continue to warm, putatively leading to population declines in some beluga populations. Finally, we identified vulnerable populations which, if extirpated as a consequence of ocean warming, will lead to a substantial decline of species-wide haplotype diversity.

Fisheries enforcement relies on visual catch identification and quantification at sea or when landed. Silage (fish dissolved in acid) and fish blocks (block frozen fish) are promising methods for on-board processing and storage of low-value catches. We examined the use of non-destructive sampling and two DNA-based methods, quantitative PCR (qPCR) and metabarcoding, to assess species composition and relative abundance in industrial grade experimental silage and fish blocks. We demonstrate the ability to identify and quantify DNA from fish species in both products. qPCR analysis of small silage samples collected over 21 days detected all target control species. DNA from one species (Atlantic wolffish) was consistently overrepresented while, for three species of gadoids (Atlantic cod, haddock and whiting), the DNA content matched input tissue proportions with high accuracy. qPCR and metabarcoding of fish blocks, sampled as run-off water and exterior swabs, provided consistent species detection, with the highest variance observed in quantification from swab samples. Our analysis shows that DNA-based methods have significant potential as a tool for species identification and quantification of complex on-board-processed seafood products and are readily applicable to taxonomically and morphologically similar fish. There is, however, a need for establishing DNA/weight calibration factors for primary fisheries species.

Temporal variation in eDNA signals is increasingly explored for understanding community ecology in aquatic habitats. Seasonal changes have been addressed using eDNA sampling, but very little is known regarding short-term temporal variation that spans hours to days. To address this, we filtered marine water samples from a single coastal site in Denmark every hour for 32 h. We used metabarcoding to target both fish and broader eukaryote diversity and evaluated temporal changes in this marine community. Results revealed variation in fish species richness (15–27) and eukaryote class richness (35–64) across the 32 h of sampling, and we further evaluated sampling efforts needed to reach different levels of diversity saturation. Relative read frequency data for both fish and eukaryotes indicated a clear diel change in community composition, with different communities detected during daylight versus dark hours. The abundance signals in our data reflected biological variation rather than stochastic variation, since replicates taken at the same hour were more similar to each other than those taken at different hours. Our compositional results indicated a dynamic community, rather than a static pool of eDNA—even across a few hours. The fish data showed a daily pattern of relative species abundances, and the uncoupling of fish and broader eukaryote data suggest that variation in eDNA profiles across a single day can provide valuable information reflecting diel changes, at least for highly mobile organism groups. However, our results also point to several pitfalls in current eDNA experimental design, in which samples are taken over large areas without relative time-consistency or short-term replication. Our findings shed new light on short-term variation in coastal eDNA and have wide implications for experimental study design and for incorporating temporality into project conceptualization for future aquatic biodiversity monitoring.

A new endemic species of triplefin Ruanoho scurra is described from deep water (108–216 m) on the shelf region around coastal New Zealand (Northland to Stewart Island). It is differentiated from its congeners by the combination of fresh colour (bright yellow spots on the head and anterior body, oblique lines on the dorsal and anal fins, and sub-vertical lines on the caudal) as well as some proportional measurements. Comments are made on the relationship with its congeners, and evolutionary history of the family in New Zealand waters, along with observations on the habitat in which this new species is found. This paper formally describes the species first mentioned in Stewart & Clements 2015:1523 as the polkadot triplefin.

Aim: Herbivorous reef fishes are considered to have difficulty digesting plant material at extratropical temperatures and are thus largely restricted to tropical waters where they are thought to have evolved. However, the herbivorous Kyphosidae, with both temperate and tropical species, provides an ideal opportunity to test this view. Previous studies have resolved the taxonomy and distribution patterns of all species. Here, we use a calibrated phylogeny to analyse the age, geographical origin and pattern of diversification of kyphosids to determine their origins in space and time, and thus refine hypotheses on the evolutionary origins of herbivory in reef fishes. Location: Pacific Ocean, Atlantic Ocean, Indian Ocean, Western Australia. Methods: The age and geographic origin of Kyphosidae were determined by incorporating fossil calibrations and species distributions onto a phylogeny of all extant species based on fragments from mitochondrial markers and three nuclear markers, and using Bayesian modelling to reconstruct ancestral distributions. Evolution of both diet and tooth shape was also examined using ancestral reconstruction. Results: Ancestral reconstruction suggested a subtropical, Southern Hemisphere Indo-Pacific origin for the family. The chronogram indicates that Kyphosus originated in the early Miocene and that tropical diversity reflects very recent diversification. Main conclusions: Contrary to the general perception that herbivorous reef fishes invaded high latitudes from the tropics, herbivorous kyphosids evolved at intermediate latitudes in the Southern Hemisphere and subsequently diversified into low latitudes where several species dispersed recently to achieve circumglobal distributions. The southern temperate/subtropical reef environment appears to have generated episodes of diversification in several, well-established, widespread reef fish taxa. Some of these reef fish taxa have remained restricted to southern temperate reef environments despite a long tenure in the Cenozoic (e.g. odacines and aplodactylids), and some such as the kyphosids which diversified very recently in both hemispheres resulting in both regional endemics and species with worldwide distributions.

Biomass assesment of fish stocks is a difficult task that often involves costly fisheries trawl surveys. Trawl surveys rarely return replicate samples, as trawling attempts are expensive and difficult to reproduce. Furthermore, traditional benthic trawling is often detrimental to habitats and the organisms associated with the sea bottom. The rapidly developing field of environmental DNA (eDNA) analysis offers a new approach to non-invasive monitoring of fish. In the present study, we develop and test species-specific primers and probes for qPCR detection of eDNA from Atlantic herring (Clupea harengus ), Atlantic cod ( Gadus morhua ), European flounder ( Platichthys flesus ), European plaice ( Pleuronectes platessa), and Atlantic mackerel ( Scomber scombrus ) in the Baltic Sea. A recently published qPCR system was applied for European eel (Anguilla anguilla ). Filtered water samples were collected during a stratified benthic trawl survey, enabling parallel comparisons of eDNA concentrations with biomass caught by trawling. No significant correlation was found between eDNA concentrations and the biomass of fish caught by the trawl, although an association was observed between the measured concentrations of eDNA and the known distributions and main abundances of cod, herring, plaice and flounder. This indicates that while eDNA concentrations may not be directly comparable to results from existing methods – likely because aquatic eDNA concentrations are not controlled by the same combinations of factors as e.g. trawl biomass catch – eDNA analysis could prove a useful supplement for monitoring fish stocks in the future.

Summary Aqueous environmental DNA (eDNA) is an emerging efficient non-invasive tool for species inventory studies. To maximize performance of downstream quantitative PCR (qPCR) and next-generation sequencing (NGS) applications, quality and quantity of the starting material is crucial, calling for optimized capture, storage and extraction techniques of eDNA. Previous comparative studies for eDNA capture/storage have tested precipitation and ‘open’ filters. However, practical ‘enclosed’ filters which reduce unnecessary handling have not been included. Here, we fill this gap by comparing a filter capsule (Sterivex-GP polyethersulfone, pore size 0·22 μm, hereafter called SX) with commonly used methods. Our experimental set-up, covering altogether 41 treatments combining capture by precipitation or filtration with different preservation techniques and storage times, sampled one single lake (and a fish-free control pond). We selected documented capture methods that have successfully targeted a wide range of fauna. The eDNA was extracted using an optimized protocol modified from the DNeasy® Blood & Tissue kit (Qiagen). We measured total eDNA concentrations and Cq-values (cycles used for DNA quantification by qPCR) to target specific mtDNA cytochrome b (cyt b) sequences in two local keystone fish species. SX yielded higher amounts of total eDNA along with lower Cq-values than polycarbonate track-etched filters (PCTE), glass fibre filters (GF) or ethanol precipitation (EP). SX also generated lower Cq-values than cellulose nitrate filters (CN) for one of the target species. DNA integrity of SX samples did not decrease significantly after 2 weeks of storage in contrast to GF and PCTE. Adding preservative before storage improved SX results. In conclusion, we recommend SX filters (originally designed for filtering micro-organisms) as an efficient capture method for sampling macrobial eDNA. Ethanol or Longmire's buffer preservation of SX immediately after filtration is recommended. Preserved SX capsules may be stored at room temperature for at least 2 weeks without significant degradation. Reduced handling and less exposure to outside stress compared with other filters may contribute to better eDNA results. SX capsules are easily transported and enable eDNA sampling in remote and harsh field conditions as samples can be filtered/preserved on site.

The order Ophidiiformes is a large but not very well known group of fishes, unique among teleosts for showing high diversity in both deep sea and shallow reef habitats. The current classification includes more than 500 species, 115 genera and four families, based primarily on mode of reproduction: viviparous Aphyonidae and Bythitidae vs oviparous Carapidae and Ophidiidae. Since 2004 we revised the bythitid tribe Dinematichthyini, described more than 100 new species and noticed that this group has unique morphological characters, perhaps supporting a higher level of classification than the current status. Here we study the viviparous families phylogenetically with partial mitochondrial (nd4, 16s) and nuclear (Rag1) DNA sequences (2194bp). We use a fossil calibration of otolith-based taxa to calibrate the age of the clade comprising bythitid and dinematicththyid representatives, together with fossil calibrations adopted from previous phylogenetic studies. The separation of the order into two major lineages, the viviparous Bythitoidei and the oviparous Ophidioidei is confirmed. At the familial level, however, a new classification is presented for the viviparous clades, placing Aphyonidae as a derived, pedomorphic member of Bythitidae (new diagnosis provided, 33 genera and 118 species). The current subfamily Brosmophycinae is considered polyphyletic and we propose family status for Dinematichthyidae (25 genera, 114 species), supported by unique, morphological synapomorphic characters in the male copulatory apparatus. Previous use of the caudal fin separation or fusion with vertical fins is ambiguous. Age estimates based on calibrated molecular phylogeny agrees with fossil data, giving an origin within the Cretaceous (between 84 and 104mya) for a common ancestor to Ophidiiformes.

Although the Greenland fish fauna has been studied for more than 200 years, new species continue to be discovered. We here take the opportunity of the International Polar Year 2007–08 (IPY) to present an updated check-list of the fishes of Greenland and discuss whether the growing diversity can be explained by global warming. A total of 269 species from 80 families are known from the Greenland Exclusive Economic Zone (EEZ), based on published literature and specimens in museum collections. Since the latest publication covering all known Greenland fishes [Nielsen & Bertelsen 1992], 57 species have been added. Nineteen of these (Harriotta raleighana, Centroscymnus coelolepis, Bathytroctes microlepis, Einara edentula, Ceratoscopelus maderensis, Argyropelecus gigas, Maurolicus muelleri, Polyipnus asteroides, Nansenia oblita, Melanostomias bartonbeani, Polymetme corythaeola, Coryphaenoides mediterraneus, Merlangius merlangus, Guttigadus latifrons, Entelurus aequoreus, Helicolenus dactylopterus, Epigonus telescopus, Lophius piscatorius, Linophryne bicornis) are reported here for the first time. Twenty-nine of the species were added on the basis of taxonomic revisions and/ or identification of specimens caught before 1992, whereas 28 species have been caught in Greenland waters for the first time since 1992. Ten species were new to science described since 1992. Only five of the added species are Arctic – i.e. mainly caught north of the Davis and Denmark Straits. Of the 28 species caught after 1992, five species (Maurolicus muelleri, Merlangius merlangus, Helicolenus dactylopterus, Lophius piscatorius, Entelurus aequoreus) from the southern regions (Atlantic) are mainly from shallow waters (< 400 m) and their arrival is likely to be a result of increasing temperatures. The explanation of the many new records of deep-water fishes is most likely increasing fishing efforts down to depths of 1500 m. The deep waters off Greenland (> 1500 m), however, remain almost unstudied.

Trophic interactions in complex mesopelagic ecosystems are generally poorly understood, but tracing diet remains of predators provides key insights into these. In many cases, however, the prey remains obtained from predator stomachs are unidentifiable by visual inspection and identification depends on new molecular techniques. Here, we search for predators on larvae of the critically endangered European eel (Anguilla anguilla), a species which has shown a dramatic decline in recruitment to the stock. We sampled for predators among mesopelagic fishes using pelagic trawling in the known area of spawning and larval distribution of A. anguilla in the Sargasso Sea. We aimed at developing a species-specific quantitative PCR (qPCR) system, targeting the nd4-region of mitochondrial DNA (mtDNA), to search for eel remains in the stomachs of 17 mesopelagic fish taxa (62 specimens). Remains of A. anguilla were confirmed in 9.7% of all fish stomachs investigated, representing six species (Lampanyctus cuprarius, L. photonotus, Myctophum selenops, Notoscopelus caudispinosus, Melamphaes typhlops, and Chauliodus danae). Thus, our study documents that mesopelagic fishes in the Sargasso Sea to some extent predate the A. anguilla larvae, motivating further studies on upper-level trophic interactions in this oceanic ecosystem.

Europe has a long tradition of exploiting marine fishes and is promoting marine economic activity through its Blue Growth strategy. This increase in anthropogenic pressure, along with climate change, threatens the biodiversity of fishes and food security. Here, we examine the conservation status of 1,020 species of European marine fishes and identify factors that contribute to their extinction risk. Large fish species (greater than 1.5 m total length) are most at risk; half of these are threatened with extinction, predominantly sharks, rays and sturgeons. This analysis was based on the latest International Union for Conservation of Nature (IUCN) European regional Red List of marine fishes, which was coherent with assessments of the status of fish stocks carried out independently by fisheries management agencies: no species classified by IUCN as threatened were considered sustainable by these agencies. A remarkable geographic divergence in stock status was also evident: in northern Europe, most stocks were not overfished, whereas in the Mediterranean Sea, almost all stocks were overfished. As Europe proceeds with its sustainable Blue Growth agenda, two main issues stand out as needing priority actions in relation to its marine fishes: the conservation of marine fish megafauna and the sustainability of Mediterranean fish stocks. Marine fishes exhibit high biodiversity 1,2 and have been culturally and nutritionally important throughout human history 3 . Europe, in particular, has a well-documented history of exploiting marine fish populations, written records of which commence in the classical works of ancient Greece. Although this historical exploitation has undoubtedly altered populations 4,5 and changed many seascapes 6 , marine defaunation in the region has not been as great as in terrestrial systems 7 . However, the use of ocean space and resources is increasing due to Europe’s Blue Growth strategy 8 , the nutritional requirements of an expanding human population are growing 9,10 and marine ecosystems will experience unusually rapid changes in future due to climate change 11,12 . Consequently there are imminent threats both to European marine biodiversity and fish resources 13 . It is important, therefore, to assess the threats of extinction to fish species and to ensure consistency in the management approach by the various agencies involved. We analysed data on the conservation status of 1,020 species of Europe’s marine fishes from the recent International Union for Conservation of Nature (IUCN) Red List assessments 14 to identify characteristics that make Europe’s fishes most susceptible to extinction risk. We then compared the Red List with 115 fish stock assessments (of 31 species) made by intergovernmental agencies charged with providing advice on the exploitation of commercial fishes. Previous comparisons of this sort applied criteria under various modelling assumptions 15,16, 17 or limited the comparison to biomass reference points 18 .

Nature Ecology & Evolution 1, 0170 (2017); published 26 May 2017; corrected 12 June 2017. In the original version of this Article, the European Commission was mistakenly included as an affiliation for Christos D. Maravelias. His contribution to this work was exclusively completed while at the Hellenic Centre for Marine Research.

Coastal marine fish populations are in decline due to overfishing, habitat destruction, climate change and invasive species. Seasonal monitoring is important for detecting temporal changes in the composition of fish communities, but current monitoring is often non-existent or limited to annual or semi-annual surveys. In the present study, we investigate the potential of using environmental DNA (eDNA) metabarcoding of seawater samples to detect the seasonal changes in a coastal marine fish community. Water sampling and snorkelling visual census were performed over 1 year (from 23rd of August 2013 to 11th of August 2014) at a temperate coastal habitat in Denmark (55°45′39″N, 12°35′59″E) and compared to long-term data collected over a 7-year period. We used Illumina sequencing of PCR products to demonstrate that seawater eDNA showed compositional changes in accordance with seasonal changes in the fish community. The vast majority of fish diversity observed in the study area by snorkelling was recovered from sequencing, although the overlap between methods varied widely among sampling events. In total, 24 taxa were detected by both methods, while five taxa were only detected using eDNA and three taxa were only detected by snorkelling. A limitation of the applied primers was the lack of resolution to species level in a few diverse families, and varying sequencing depth between samples represents a potential bias. However, our study demonstrates the utility of eDNA for recovering seasonal variation in marine fish communities, knowledge of which is essential for standardised long-term monitoring of marine biodiversity.

Two morphologically distinct forms of the nominal species Kyphosus sydneyanus (Günther, 1886) (Kyphosidae) were discerned while collecting off Western Australia near Perth in 2009. A morphological comparison with recognized species of Kyphosus and an analysis of mtDNA (Cytochrome b, control region, 12S and 16S) and three nDNA markers (RAG1, RAG2 and Tmo-4C4) demonstrated that the more elongate of these forms was an undescribed species of Kyphosus. It differs from congeners in the Pacific and Indian Oceans in the combination of the following characters: green bar on the operculum, 11–12 dorsal soft fin rays, depth of caudal peduncle 9.9–11.8 % SL, body depth 33.3–41.6 % SL, 55–63 scales in lateral line, 12–16 interorbital scales, 44–55 pored scales in the lateral line, 3–5 gill rakers on upper limb of first gill arch internally, 11–15 gill rakers on lower limb of first gill arch internally, 15–19 total gill rakers on first gill arch, and by having 10 precaudal vertebrae and 16 caudal vertebrae. Examination of museum specimens and available underwater photographs suggests that the new species is restricted to Western Australia, and to date it has been recorded between the Houtman Abrolhos Islands and Albany. Discrepancies between the type specimen and original description of Segutilum klunzingeri Whitley made it impossible to determine the relationship between this taxon and the new species from Western Australia, and thus we consider S. klunzingeri a nomen dubium.

Population genetics is essential for understanding and managing marine ecosystems, but sampling remains challenging. We demonstrate that high-throughput sequencing of seawater environmental DNA can provide useful estimates of genetic diversity in a whale shark (Rhincodon typus) aggregation. We recover similar mitochondrial haplotype frequencies in seawater compared to tissue samples, reliably placing the studied aggregation in a global genetic context and expanding the applications of environmental DNA to encompass population genetics of aquatic organisms.

Sea chubs of the family Kyphosidae are major consumers of macroalgae on both temperate and tropical reefs, where they can comprise a significant proportion of fish biomass. However, the relationships and taxonomic status of sea chubs (including the junior synonyms Hermosilla, Kyphosus, Neoscorpis and Sectator) worldwide have long been problematical due to perceived lack of character differentiation, complicating ecological assessment. More recently, the situation has been further complicated by publication of conflicting taxonomic treatments. Here, we resolve the relationships, taxonomy and distribution of all known species of sea chubs through a combined analysis of partial fragments from mitochondrial markers (12s, 16s, cytb, tRNA -Pro, -Phe, -Thr and -Val) and three nuclear markers (rag1, rag2, tmo4c4). These new results provide independent evidence for the presence of several junior synonyms among Atlantic and Indo-Pacific taxa, demonstrating that several sea chub species are more widespread than previously thought. In particular, our results can reject the hypothesis of endemic species in the Atlantic Ocean. At a higher taxonomic level, our results shed light on the relationships between Girellidae, Kuhliidae, Kyphosidae, Microcanthidae, Oplegnathidae and Scorpididae, with Scorpididae resolved as the sister group to Kyphosidae.

Fishes of the order Alepocephaliformes, slickheads and tubeshoulders, constitute a group of deep-sea fishes poorly known in respect to most areas of their biology and systematics. Morphological studies have found alepocephaliform fishes to display a mosaic of synapomorphic and symplesiomorphic characters, resulting in great difficulties when attempting to resolve intra- and interrelationships. Molecular data recently added to the confusion by removing Alepocephaliformes from the Euteleostei and placed them as incertae sedis within the Otocephala. In the present study we attempt to further clarify relationships of Alepocephaliformes by adding newly determined whole mitogenome sequences from 19 alepocephaliforms in order to address 1) phylogenetic position of Alepocephaliformes within the Otocephala; and 2) intrarelationships of Alepocephaliformes. The present study includes 96 taxa of which 30 are alepocephaliforms and unambiguously aligned sequences were subjected to partitioned maximum likelihood and Bayesian analyses. Results from the present study support Alepocephaliformes as a genetically distinct otocephalan order as sister clade to Ostariophysi (mostly freshwater fishes comprising Gonorynchiformes, Cypriniformes, Characiformes, Siluriformes and Gymnotiformes). The disputed family Bathylaconidae was found to be an artificial assemblage of the two genera Bathylaco and Herwigia, with the former as the sister group of the family Alepocephalidae and the latter nested within Alepocephalidae. Platytroctidae was found to be monophyletic as sister clade to the rest of Alepocephaliformes. Previously unrecognized clades within the family Alepocephalidae are presented and a clade comprising Alepocephalus, Conocara and Leptoderma was recovered as the most derived. As long as the current classification is being followed, the genera Alepocephalus, Bathytroctes, Conocara and Narcetes were all found non-monophyletic. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98, 923–936.

Careproctus kidoi sp. nov. is described from the Baffin Bay between Greenland and Canada, in the northern most part of the western North Atlantic. During a series of bottom trawl surveys conducted in 1988–2004, 22 specimens of an undescribed species of Careproctus were caught at depths between 952 and 1,487 m. It differs from Arctic and North Atlantic congeners in the combination of the characters: pectoral fin rays 21–26, dorsal fin rays 54–60, anal fin rays 50–54, vertebrae 61–64; sucking disc oval, 4.2–6.6% SL; teeth simple; pyloric coeca 3–12; head pore formula (2-6-7-1); color light to dark brown, stomach dusky to dark brown, peritoneum black. It is generally found in deeper waters than the sympatric C. reinhardti.

Liparidae (snailfishes) is one of the most diverse and abundant fish families in polar and deep-sea habitats. However, the evolution of this family is poorly known because of the rarity of many species and difficulties in scoring morphological characters. We perform phylogenetic analyses of Liparidae using sequences from two mtDNA genes, 16S (585 bp) and cytochrome b (426 bp), and 84 morphological characters from 24 species of Liparidae and 4 species of Cyclopteridae (outgroup). The present study confirms earlier hypotheses that the shallow-water genera, such as Liparis and Crystallichthys, occupy basal positions and that deep-water genera, such as Careproctus, Elassodiscus, Rhinoliparis, Paraliparis, Rhodichthys and Psednos, are increasingly derived. The later two genera form a terminal clade which does not include Paraliparis. The topology shows that the family has undergone a reductive type of evolution, with a gradual loss of characters (e.g. sucking disc/pelvic fins, pseudobranchial filaments, skin spinules). Nectoliparis, which had previously been placed either as the basal most genus or among the most derived genera, are found to occupy the most basal position among the taxa analyzed. This result indicates that the sucking disc has been lost at least twice during the evolution of the Liparidae. The basal position of Nectoliparis is supported by its plesiomorphic otolith morphology, whereas an advanced overgrown otolith ostium, unique among teleosts, is found to be apomorphic for a clade containing the derived genera: Paraliparis, Psednos, Rhinoliparis and Rhodichthys. We also identify the presence of probable nuclear inserts of mitochondrial DNA (Numts) in three species of Careproctus and in Elassodiscus caudatus.

A molecular phylogenetic analysis with complete species sampling of the family Kyphosidae revealed several discrepancies with the current taxonomy. We thus undertook a complete taxonomic revision of all kyphosid genera, i.e. Kyphosus Lacepede, 1801, and the monotypic Hermosilla Jenkins and Evermann, 1889, Sectator Jordan and Evermann, 1903 and Neoscorpis Smith, 1931. Species delimitation was determined on the basis of congruence between (a) monophyletic groupings in the molecular phylogeny, and (b) clusters of morphological variation in type material. Twelve species are supported and redescribed. Both Hermosilla and Sectator are considered junior synonyms of Kyphosus. Kyphosus azureus (Jenkins & Evermann, 1889) and K. ocyurus (Jordan & Gilbert, 1882) are redescribed accordingly. We designate a neotype for Kyphosus cornelii (Whitley, 1944), as the original material is lost, and new material was collected at the type locality for this study to facilitate comparison with other species of Kyphosus. Kyphosus sandwicensis (sensu Sauvage, 1880) was found to be a junior synonym of K. elegans (Peters, 1869). Kyphosus incisor (Cuvier in Cuvier & Valenciennes, 1831) and K. analogus (Gill, 1862) are considered junior synonyms of K. vaigiensis (Quoy & Gaimard, 1825). Kyphosus gallveii (Cunningham, 1910), K. pacificus Sakai and Nakabo, 2004 and K. lutescens (Jordan & Gilbert, 1882) are all considered junior synonyms of K. sectatrix (Linnaeus, 1758). One of the two syntype specimens of K. sectatrix was identified as the holotype of Pimelepterus bosquii (Lacepede, 1802), and proved to be a specimen of K. bigibbus Lacepede, 1801. This specimen is re-assigned as a non-type of K. bigibbus. Full re-descriptions of the following valid species are presented: K. bigibbus, K. cinerascens (Forsskal, 1775), K. cornelii, K. elegans, K. hawaiiensis Sakai and Nakabo, 2004, K. gladius Knudsen and Clements, 2013, K. sydneyanus (Gunther, 1886) and K. vaigiensis, together with a key to the family. The distribution of Kyphosus species is reconsidered based on our taxonomic revision, indicating that four species (K. bigibbus, K. cinerascens, K. sectatrix and K. vaigiensis) occur in both the Atlantic and Indo-Pacific regions.

Environmental changes are prominent in Arctic ecosystems, where the distribution, abundance, life history, and health of marine organisms such as the bowhead whale (Balaena mysticetus) are tightly connected to sea ice and sea temperature. However, due to logistical and other challenges of data collection in the Arctic, appropriate assessments of past, present and future effects of climate change and human activities are lacking for many Arctic species. Environmental DNA (eDNA) is emerging as a noninvasive and cost‐effective way of obtaining genetic material from the environment and has the potential to complement traditional methods for biodiversity and genetic monitoring. In this study, we investigate whether eDNA isolated from seawater samples has the capacity to capture the genetic diversity of bowhead whales in Disko Bay, West Greenland, for the implementation of long‐term genetic monitoring programs of key Arctic marine species. A total of 41 eDNA “footprint” samples were obtained from the water surface after a whale had dived and an additional 54 eDNA samples were collected along transect lines. Samples were screened for bowhead DNA using a species‐specific qPCR primer and probe assay, and a subset of 30 samples were successfully Sanger‐sequenced to generate individual mitochondrial control region haplotypes. Moreover, by shotgun sequencing ten footprint samples on an Illumina NovaSeq platform we show that footprints generally contain less than 1% endogenous DNA, resulting in partial mitochondrial genomes in four samples out of ten samples. Our findings suggest that sampling in the footprint or wake of traveling animals is a promising method for capturing the genetic diversity of bowhead whales and other marine megafauna. With optimization of sampling and target DNA sequencing for higher endogenous DNA yield, seawater eDNA samples have a large potential for implementation in the long‐term population genetic monitoring of marine megafauna in the Arctic and elsewhere.