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Two rarely caught species of the roughy fish genus Hoplostethus have been identified for the first time in the fish collections of Taiwan. The first, H. grandperrini Roberts & Gomon, 2012 was previously known only from two type specimens collected in the Southern Hemisphere off the coast of New Caledonia. Its distribution is now extended to the Northern Hemisphere off the coast of Pingtung, southern Taiwan. Our specimen represents the only record of this species since its initial description. The second, H. robustispinus Moore & Dodd, 2010 was originally described from a single specimen collected in the Philippines and was only known from the type locality and a single record off the Paracel Islands, South China Sea. This specimen represents the third record of the species since its original description. A single specimen of H. crassispinus Kotlyar, 1980, whose name has long appeared in the ichthyological literature of Taiwan and adjacent areas, was also identified as the first specimen-based record for Taiwan. Detailed descriptions of these species are provided and compared with available data of respective type specimens and related species, with intraspecific variations also discussed. Also included is a dichotomous key to all known species of the subgenus Hoplostethus in Taiwan.

Spatial stock assessment models are recognised as increasingly important for estimation of stock status and a sustainable exploitation rate. The inclusion of movement between spatial units within a model is difficult because the data requirements are high. However, for populations with low levels of spatial exchange it is possible to reduce the data requirements by distributing information on biological parameters between neighbouring units, or units with shared environmental conditions. This can allow spatial modelling to be applied even in data-limited situations. We develop this approach here through application to orange roughy (Hoplostethus atlanticus) subpopulations inhabiting neighbouring seamounts in the South Pacific. Despite limited data for each seamount, we were able to simultaneously fit multiple, localised, process-based models of the depletion dynamics. This was achieved by sharing information on the unexploited population size via known environmental covariates, with the relationship estimated in a hierarchical and integrated manner during the model fit. Cross-validation demonstrated that this approach can compensate for a lack of seamount-specific abundance data and improve ability of the model to estimate localised depletions.

Hoplostethus mediterraneus Cuvier 1829 ���Mediterranean slimehead Taxonomy. First record from Lebanon as Hoplostethus mediterraneus by Colloca & Lelli (2012: 13); as Hoplostethus mediterraneus by Aguillar et al. (2018: 81). Recent unpublished records from Batroun (5 March 2005 and 1 July 2013). Material in collection: AUBM (OS3965; OS3968). Distribution. Atlantic; western Mediterranean Sea; western Indian Ocean: South Africa to Madagascar Ridge; southeastern Indian Ocean and southwestern Pacific: southern Australia and New Zealand [including intermedius in Southern Hemisphere]. Conservation. IUCN: Global (LC: 22 May 2013); Med. (LC: 16 November 2007). Capture and threats: Unknown. Occurrence: Rare. Low priority for conservation action. Clupeiformes, Published as part of Bariche, Michel & Fricke, Ronald, 2020, The marine ichthyofauna of Lebanon: an annotated checklist, history, biogeography, and conservation status, pp. 1-157 in Zootaxa 4775 (1) on pages 43-44, DOI: 10.11646/zootaxa.4775.1.1, http://zenodo.org/record/3983887, {"references":["Colloca, F. & Lelli, S. (2012) Report of the FAO EastMed support to the fishing trials carried out off the South Lebanese Coast. EastMed technical documents 14. FAO, Rome, 38 pp."]}

Summary The objective of this study was to estimate a prey body size from the hard parts (e.g. otoliths) of a fish species frequently found in the guts of predators. Length–weight relationships between otolith size (length, height, weight and aspect ratio) and fish size (total length and weight) were determined for four fish species captured in the Arabian Sea by bottom trawl (2015 survey on-board FORV Sagar Sampada, 200–300 m depth), off the west coast of India: Psenopsis cyanea, Pterygotrigla hemisticta, Bembrops caudimacula and Hoplostethus rubellopterus. No significant differences were noted between the size of the left and right otoliths (t test) in any of the four species. The length–weight relationship of the otolith in all four species showed a negative allometric growth pattern (t test, p

The diets of black oreo Allocyttus niger, smooth oreo Pseudocyttus maculatus, spiky oreo Neocyttus rhomboidalis and orange roughy Hoplostethus atlanticus were determined from examination of contents of 240, 311, 76 and 415 non-empty stomachs, from fishes sampled by bottom trawl on Chatham Rise to the east of South Island, New Zealand. Hoplostethus atlanticus had an opportunistic predatory strategy with a broad diet dominated by prawns and mesopelagic teleosts, but with substantial components of mysids and cephalopods. Pseudocyttus maculatus was strongly specialized on gelatinous zooplankton (jellyfish and salps). Allocyttus niger consumed mainly salps and hyperiid amphipods, and to a lesser extent fishes, prawns, mysids and copepods. Neocyttus rhomboidalis primarily consumed salps, along with mysids, euphausiids and fishes. Only P. maculatus did not exhibit significant ontogenetic variation in diet. The diets were also influenced by year and bottom depth. Differences in the distributions and diets of the four species probably reduce conflicts in resource use.

Two deep-sea roughies, Hoplostethus (Leiogaster) rubellopterus Kotlyar, 1980 and H. (L.) melanopus (Weber, 1913), are re-described based on several specimens collected from the Arabian Sea, Bay of Bengal and Andaman Sea. Some notes on the taxonomic status of these two species are also included, and their distributional ranges are updated. Hoplostethus (L.) rubellopterus is a commonly occurring species in the deep-sea catches from the upper continental slope (160–800 m) of this region, which is often misidentified and reported as H. mediterraneus Cuvier, 1829. Previous reports of H. mediterraneus from Indian waters were found to be misidentifications, and should be referred to H. (L.) rubellopterus. Hoplostethus (L.) melanopus is found to be distributed in much deeper waters at bathyal depths (>900 m) of the Arabian Sea and Andaman Sea.

Echo integration is a well-established method for estimating fish biomass, but is challenging for a low target strength (TS), deep-living fish species such as orange roughy (Hoplostethus atlanticus). A novel approach has been to utilize the infrastructure of the fishing vessel's trawlnet by attaching an acoustic-optical system (AOS) to the net's headline. Deep deployment of the AOS via the trawlnet reduces uncertainties associated with hull-mounted acoustics that include the influence of weather on data quality, low resolution due to the long range to target, large acoustic dead zone on sloping seabed, and inability to identify and differentiate other fish that co-occur with the target species. The AOS system simultaneously records acoustic data at multiple frequencies (38 and 120 kHz), species composition in video and stereo imagery, and environmental data as the net collects biological samples and/or commercial catch. All data streams were considered in a multiple-lines-of-evidence approach to give improved estimates of orange roughy biomass with low error due to species uncertainty. AOS-based biomass estimates, made over a 5-year period from 11 key spawning locations in Australia and New Zealand, showed a strong correlation (r2 = 0.97, n = 39) between frequencies (38 and 120 kHz); the 38 kHz estimates were, on average, 8% higher than 120 kHz, with a standard deviation of 20%. This similarity in estimates across frequencies improves confidence in results compared with single-frequency surveys that are potentially prone to large errors resulting from unknown (mixed) species composition and target strengths, calibration, and sound absorption uncertainties.

Although most otoliths of teleost fishes contain aragonite, a detailed survey of the otoliths of serveral species confirms that other crystalline forms of calcium carbonate occur. Otoliths of Hoplostethus atlanticus, Pagrus major, Macruronus novaezelandiae, Merluccius australis, Congiopodus coriaceus, Kathetostoma giganteum, Argentina elongata, Rhomobosolea tapirina, Neophrynichthys latus, Coelorinchus aspercephalus, Paranothothenia microlepidota, and Gonorhynchus gonorhynchus contained the aragonite, calcite, and vaterite morphs of calcium carbonate in varying proportions. Aragonitic otoliths of Allocyttus niger, Hoplostethus altlanticus, and Pagrus major contained sequences of calcite-like crystals. The surface of the vateritic otolith of Acipenser brevirostrum is shown in detail. Three classes of information are stored in the crystalline structure of the otolith: shape conservation, coexisting crystal morphs, and consecutive changes in crystal morph. Analysis of this crystalline information supports the hypothesis of control of growth of the otolith by proteins from the sensory epithelium or macula. Protein variation involved may be genetic in origin, or non-genetic arising from “stuttering” of the translation process. Proteins extracted from vateric and aragonitic morphs of the otolith of Macruronus novaezelandiae showed differences in infared absorption spectra that were consistent with two different amino acid sequences. © 1993 Wiley-Liss, Inc.

Compared to an 18 year New Zealand study ( Clark et al., 2000 ) we found multiple signs of recovery for orange roughy in Australian waters. Orange roughy were listed as conservation dependent in Australian waters in 2006, with most stocks reported to be well below 20% of estimated pre-fishing equilibrium biomass and closed to targeted fishing. The largest known spawning aggregations occur on the east coast of Tasmania. This area has been fished and monitored since 1987. A specific monitoring programme was established in 2006 to determine whether and at what rate the spawning sites would rebuild. Acoustic biomass estimates were on average 1.5 times higher than that expected from a recent stock assessment and between 2006 and 2013 have shown an increasing then decreasing trend. Positive signs of a population recovery include an increased biomass at the spawning sites since fishing ceased, large change in the age structure of the population and a 74% increase in the reproductive potential of females since 1987. Given the late maturation of orange roughy entering the spawning biomass (∼30 years) and the short duration of fishing (∼26 years), these changes represent pre-fishing recruitment still entering the fishery. Biomass, age and length frequency data were variable between and within spawning sites; this complicates the use of a single or multiple spawning sites to monitor the exploitation and recovery of the fishery.

Genus Hoplostethus Cuvier, 1829 Description A large, adult otolith (Fig. 10F) of Hoplostethus lawleyi Koken, 1891 is easily distinguished from the Miocene Hoplostethus praemediterraneus Schubert, 1905 (Fig. 10 A���E) by its very depressed anterodorsal area. This feature also characterises large-sized otoliths of the extant Hoplostethus mediterraneus Cuvier, 1829, but otoliths of H. lawleyi are different from those of H. mediterraneus in having a wider sulcus, a strongly developed ostial colliculum and a narrower ventral area. The distinction between H. mediterraneus and H. praemediterraneus can be made with the help of the growth series of H. praemediterraneus from the Badenian of the Carpathian Foredeep (Brzobohat�� 1978: pl. 1, figs 1���16, as Hoplostethus levis biexcissus and H. l. levis) and of our material (Fig. 10 A���E), which clearly demonstrate that the otoliths of H. praemediterraneus are, at each stage, higher and more compact in shape than those of H. mediterraneus (see Nolf 2013: pl. 165)., Published as part of Lin, Chien-Hsiang, Brzobohat��, Rostislav, Nolf, Dirk & Girone, Angela, 2017, Tortonian teleost otoliths from northern Italy: taxonomic synthesis and stratigraphic significance, pp. 1-44 in European Journal of Taxonomy 322 on page 26, DOI: 10.5852/ejt.2017.322, http://zenodo.org/record/3829305, {"references":["Nolf D. 2013. The Diversity of Fish Otoliths, Past and Present. Royal Belgian Institute of Natural Sciences, Brussels."]}

Status of fish stocks in relation to fishing may differ from one area to another, but there is a general consensus that several fish stocks need effective management measures by taking into consideration different indicators of stock status. Through a review of literature, this paper shows the importance of integrating the reproductive characteristics into the plan for management and conservation of marine fisheries as well as ecosystems. Overexploited fishes display symptoms of (i) advancements in age and/or size at sexual maturity and (ii) reduction in fecundity in gonochoristic (bisexual) fishes. Protogynic hermaphroditic fishes show symptoms of advancement in sex/age at sex change and decrease in Reproductive Life Span (RLS). Consequent to these changes in reproductive characteristics, the Spawning Stock Biomass (SSB) will decrease leading to depletion and collapse of a stock or species of fishes. In response to advancement in Age at Sexual Maturity (ASM) and/or Size at Sexual Maturity (SSM), the depleted stock/species may display one of the following symptoms: (a) decrease in fecundity, as in European hake Meruluccius meruluccius, or (b) decrease in egg size, as in Gadus morhua or (c) both decrease in fecundity and egg size, as in roughy Hoplostethus atlanticus. The protogynics economize male and sperm availability by behavioral acts like spawning aggregation; however, the longer residency of such spawning aggregation in a particular site increases the vulnerability of reproductively active parents. Analyses of limited publications show that (i) overexploitation reduces not only male biomass but also female biomass and (ii) reduction in RLS to 50% in Available online at: www.mbai.org.in doi: 10.6024/jmbai.2014.56.1.01750s-08 female e.g. Epinephelus niveatus and 33% in male e.g. Pagrus pagrus through precocious sexual maturity and sex change.

Critical amino acid replacements in opsin proteins shift the maximal absorbance of visual pigments to perceive different photic environments (spectral tuning). Here we studied the molecular basis for spectral tuning of the rhodopsin (RH1) pigment in 19 species of marine teleosts inhabiting different light environments, from shallow waters to the deep-sea. We identified replacements at the critical sites 194, 195, 292 and 299, which have been defined relative to the bovine RH1 gene and are known to be involved in shifting the λmax value of RH1 pigments towards the blue light. All the species had the substitutions P194R and H195A. However, we detected a relationship between the combination of amino acids at the critical sites 292 and 299 and the maximum depth of the species under study. The combination 292S/299A was only found in the deep-sea congeners Hoplostethus atlanticus and H. mediterraneus. This may reflects an adaptation of these species to the bathypelagic light environment. All the epipelagic species studied and the epi-mesopelgic species Parapercis colias, had the combination 292A/299S, except Chelidonichthys kumu (292A/299A) and Notolabrus celidotus (292S/299S). It is possible that the combination 292A/299S is an adaptation to longer wavelengths of light in comparison with the deeper species. This is the first study in the rhodopsin gene sequence in all the species under study, except for Macruronus novaezelandiae and H. mediterraneus.

Scavengers perform an important role in deep-sea ecosystems, recycling carrion. However, scavenged material can be difficult to discern from predation. The synaphobranchid eel Diastobranchus capensis Barnard, 1923, is common bycatch in deep-water fisheries for orange roughy ( Hoplostethus atlanticus Collett, 1889) in New Zealand waters. Despite anecdotal reports of scavenging in D. capensis , their ecology and feeding are little known. Scavenged material was estimated to be approximately 39 per cent (by weight) of the diet of D. capensis from northeastern Chatham Rise, New Zealand, from water depths of 1062–1196 m. Scavenged material was defined as fragmentary food items from animals and plants either not normally available to the eel, or from animals larger than the eel consuming them (e.g., fish heads and tails, spent squid spermatophores, beaks and tentacle crowns, and seaweed). D. capensis were primarily piscivorous, with the diet supplemented by squid, natant decapods and mysids. The weight or number of food items did not increase with the size of the eel, nor was there any major ontogenetic shift in the composition of the diet. D. capensis probably plays an important role in mid-slope communities, recycling carrion.

A time-resolved record of inhabited water depth, metabolic rate and trophic behaviour of the orange roughy Hoplostethus atlanticus was recovered from combined stable-isotope analyses of otolith and muscle tissue. The results demonstrate that H. atlanticus from the north-east Atlantic Ocean have a complex life history with three distinct depth-stratified life stages. Early juvenile H. atlanticus occupy relatively shallow habitats, juvenile H. atlanticus show a deep-demersal phase, rising at sexual maturity, and adult H. atlanticus exploit increasingly deep habitats with increasing age. At all sampled sizes, H. atlanticus muscle tissues have an isotopic composition suggesting a benthic rather than benthopelagic or pelagic diet. Isotopic measures of relative metabolic rate provide an insight into energy partitioning throughout ontogeny. Hoplostethus atlanticus have relatively low metabolic rates compared to coexisting deep-water benthic fishes, consistent with their unusually high longevity. Surprisingly, lifetime fastest growth rates are achieved during juvenile stages when otolith isotopes imply deep-water residency and relatively low metabolic rates. Fast growth may be sustained during a period of high efficiency associated with reduced metabolic costs of prey capture or predator evasion. The stable-isotope approach can be applied to any teleost and provides a rapid, cost-effective technique for studying deep-water fish communities.

To assess the impact of exploitation on the fecundity and reproductive potential of orange roughy, historic biological data from when exploitation began (1987–1992) is compared with a current day assessment (2010) of the eastern Tasmanian stock. Findings highlight that fecundity was negatively related to stock size (r2 = 0.95, F = 80.11, P < 0.05), with length standardised fecundity increasing from 41,145 ± 1363 in 1992 to 59,236 ± 1047 eggs in 2010. This density dependent increase suggests that from the onset of the fishery (1987) length standardised fecundity has increased by 73%. Modelling this increase based on the 2006 stock assessment showed that the female spawning stock biomass was at 19% of virgin levels, whereas the total reproductive potential was markedly higher and estimated to be at 32% of virgin levels. The biological mechanisms of this compensatory effect were also investigated and showed fecundity was not related to ovarian atresia levels but was positively related to body condition, liver condition and ovarian lipid levels. The implications of these findings for stock recovery and management are discussed and suggest that the stock is in a better position to recover from overexploitation than would be expected if only spawning stock biomass were considered

It is often assumed that in situ target strength (TS) measurements from dispersed fish are representative of the surveyed schooling fish. For in situ TS measurements of orange roughy in deep water, it has been difficult to validate the target species, individual lengths, and tilt angles and how representative these are of schooling fish. These problems have been addressed by attaching an acoustic optical system (AOS) to a trawl net. The AOS enables in situ measurements of TS and volume backscattering strength (Sv) at 38 and 120 kHz with optical verification of species and stereo camera measurements of fish length and tilt angle. TS estimates believed representative of the schooling population were derived by (1) weighting the frequency-dependent TS values by the Sv frequency difference distribution of orange roughy schools and (2) weighting the in situ TS measurements with an assumed tilt angle distribution. The 120-kHz TS estimates were less sensitive to variations in frequency difference and tilt angle, suggesting that this frequency may be better for biomass estimates than 38 kHz, the traditional survey frequency. Computations performed with an anatomically detailed scattering model agree with measurements of TS at both frequencies over a range of tilt angles.

The widely distributed teleost orange roughy, Hoplostethus atlanticus , has been one of the main species targeted in deep-sea fisheries. While morphometric, parasite and otolith analyses have generally found differentiation among populations within ocean basins, genetic techniques have shown contradictory results at different geographical scales. Here, we used nine microsatellite DNA loci to study genetic diversity and differentiation in orange roughy at a global scale using samples from New Zealand, Australia, Namibia, Chile, and the Northeast Atlantic Ocean. Additionally, temporal genetic variation was assessed for eight sites in Northern New Zealand sampled in two different years. The expected heterozygosity was high in all the sites, suggesting high levels of genetic diversity in orange roughy. Overall, we detected low but significant differentiation at the global scale: across the Southern hemisphere and between the Southern hemisphere regions and the Northeast Atlantic Ocean. However, genetic homogeneity was found between New Zealand and Australia. The present data does not showed temporal variation in orange roughy from Northern New Zealand. A pattern of isolation by distance at the global scale suggests stepping-stone migration, which is likely the result of active adult dispersal. This study revealed levels of genetic differentiation at the global scale that were undetected with mitochondrial DNA sequences analyses.

Research trawling surveys and visual observations aboard manned underwater vehicles carried out at Whale Ridge revealed 116 species of bottom, near-bottom, over-bottom, and over-bottom-pelagic fish of 46 families. The data on the distribution, number, and behavior, along with some data on biology of the mass fish species, are given in the present paper. The following species prevail by number and biomass: splendid alfonsino Beryx splendens; boarfish Pseudopentaceros richardsoni; redbait Emmelichthys nitidus; flintperch Hoplostethus atlanticus; Helicolenus mouchezi; and fish of families Gempylidae, Oreosomatidae, Macrouridae, Moridae, Alepocephalidae, etc. All these species are subject to fisheries but the boarfish and alfonsino are most commercially important.

Macaulay, G. J., Kloser, R. J., and Ryan, T. E. 2013. In situ target strength estimates of visually verified orange roughy. – ICES Journal of Marine Science, 70:215–222. The first estimates of orange roughy (Hoplostethus atlanticus) target strength at 38 and 120 kHz with visual verification were obtained from a self-contained echosounder and video camera system affixed to a demersal trawl towed through dense aggregations of spawning orange roughy. Mean target strength estimates were obtained from 24 tracks of orange roughy containing 83 echoes. The mean target strength at 38 kHz was –52.0 dB with a 95% confidence interval of –53.3 to –50.9 dB for fish with a mean length of 33.9 cm. At 120 kHz the mean target strength was –47.9 dB (confidence interval of –48.8 to –46.4 dB). This work makes two significant advances: in situ TS measurements have been made that can be confidently attributed to orange roughy, and using a trawl to herd orange roughy past the system resolved the previously intractable problem of fish avoidance.

Deep-sea fishes are the target of directed fisheries and are considered a conservation concern. Yet, we still know little about the factors that affect deep-sea fish distributions and assemblage patterns on relatively small spatial scales. We used results from remotely operated vehicle surveys that observed 105 km (∼346 960 m 2 ) of seafloor over a depth range of 351–2245 m in three canyons off Newfoundland to examine the occurrence, behavior, habitat specificity, and regional assemblage patterns of deep-sea fishes in this region. We found distinct assemblages based on both depth and habitat classifications. The most obvious unique assemblage was that associated with outcrops, which served as habitat for relatively rare species such as Neocyttus helgae , Hoplostethus atlanticus , and Lepidion eques . Several coral habitats hosted distinct assemblages when compared to other habitats with low or medium structural complexity. Our results illustrate that any program targeted at protecting deep-sea ecosystems must protect a wide-range of habitats and depths to conserve a variety of fish species and assemblages.

O'Driscoll, R. L., de Joux, P., Nelson, R., Macaulay, G. J., Dunford, A. J., Marriott, P. M., Stewart, C., and Miller, B. S. 2012. Species identification in seamount fish aggregations using moored underwater video. – ICES Journal of Marine Science, 69: 648–659. Acoustic surveys of New Zealand deep-water seamounts often show fish aggregations up to 150 m high on the summit. Although bottom trawls on the seamount slopes catch predominantly orange roughy (Hoplostethus atlanticus), species composition in the midwater plumes is extremely uncertain. In June 2010, moored underwater video cameras were deployed on the summit of the Morgue seamount (summit depth 890 m), a feature that has been closed to fishing since 2001. Cameras and lights were timed to come on for 2 min every 2 h. Fish response to the mooring was monitored using vessel-mounted echosounders. Moored cameras confirmed that orange roughy were present up to 70 m above the seamount summit. Orange roughy made up 97% of the fish identified from the video. Other species observed included smooth oreo (Pseudocyttus maculatus), spiky oreo (Neocyttus rhomboidalis), deep-water dogfish, cardinalfish (Epigonus spp.), and squid. Total along-track backscatter from the plume varied by a factor of 25 over a period of hours. Peak acoustic densities in the plume (equivalent to 20 orange roughy m−3) were an order of magnitude higher than peak visual estimates (0.64 orange roughy m−3), but relative densities between paired video and acoustic observations were generally consistent.

The orange roughy Hoplostethus atlanticus is a well-known commercial species with a global distribution. There is no consensus about levels of connectivity among populations despite a range of techniques having been applied. We used cytochrome c oxidase subunit I (COI) and cytochrome b sequences to study genetic connectivity at a global scale. Pairwise ΦST analyses revealed a lack of significant differentiation among samples from New Zealand, Australia, Namibia, and Chile. However, low but significant differentiation (ΦST = 0.02–0.13, P < 0.05) was found between two Northeast Atlantic sites and all the other sites with COI. AMOVA and the haplotype genealogy confirmed these results. The prevalent lack of genetic differentiation is probably due to active adult dispersal under the stepping-stone model. Demographic analyses suggested the occurrence of two expansion events during the Pleistocene period.

Ro berts, C.D. & Gomon, M.F. 2012. A review of giant roughies of the genus Hoplostethus (Beryciformes, Trachichthyidae), with descriptions of two new Australasian species. Memoirs of Museum Victoria 69: 341–354. Hoplostethus gigas McCulloch, 1914 and two previously unnamed species of the genus that reach a similarly ‘giant’ size are described. The redescription of H. gigas, which is confined in distribution to the southern coast of Australia, is based on specimens identified as comprising at least part of McCulloch’s type series (one herein designated lectotype), together with subsequently collected material. The very similar H. melanopeza sp. nov., occurring in northern New Zealand and southeastern Australian waters, as well as seamounts in the intervening Tasman Sea, is distinguished by the distinctly black outer margins of fins in large adults and count of predorsal scales. The New Caledonian H. grandperrini sp. nov., known only from the two types, differs from previously described species in having the combination of 17 or 18 pectoral–fin rays, 13 or 14 abdominal scutes, 19 or 20 total gill rakers and a buccal cavity that is mostly pale, the only black pigmentation occurring posterior to the gill arches.

Hoplostethus mediterraneus Cuvier, 1829 Hoplostethus mediterraneus Cuvier in Cuvier & Valenciennes, 1829: 469, Pl. 97. Type locality: Nice, Mediterranean coast of France. Hoplostethus mediterraneus, Goren & Galil, 1997: 201, 2002: 151; Galil & Zibrowius, 1998: 115. Material examined. TAU P- 10514, 1 spec., off Haifa, 1500 m, coll: B. Galil, 10 May, 1994; TAU P. 12980, 3 spec. off Akko, 032�� 54 'N, 034�� 50 'E, 800 m. coll: B. Galil, 22 August, 2004; TAU P. 12981, 3 spec. off Akko, 032�� 54 'N, 034�� 50 'E, 800 m. coll: B. Galil, 24 August, 2004; TAU P. 13534, 2 spec. Eratosthenes seamount, 033�� 47.750 N, 034�� 46.996 E, 927m. coll: B. Galil, 21 June, 2006; TAU P. 13892, 1 spec. Eratosthenes seamount, 033�� 47.750 N, 034�� 46.996 E, 946 m. coll: B. Galil, 21 June, 2006. Distribution. Atlantic, Indian Ocean and the Mediterranean; depth range 100���1175 m. The present record constitutes a depth record for the species., Published as part of Goren, Menachem & Galil, Bella S., 2015, A checklist of the deep sea fishes of the Levant Sea, Mediterranean Sea, pp. 507-530 in Zootaxa 3994 (4) on page 521, DOI: 10.11646/zootaxa.3994.4.2, http://zenodo.org/record/244394, {"references":["Goren, M. & Galil, B. S. (1997) New records of deep-sea fishes from the Levant Basin and a note on the deep-sea fishes of the Mediterranean. Israel Journal of Zoology, 43, 197 - 203."]}

Risk to children of women who choose a favorite fish without regard to its methylmercury or omega-3 content was estimated under three consumption scenarios: (1) current fish consumption rate by U.S. women if limited to orange roughy (Hoplostethus atlanticus), (2) 12 oz of roughy per week, and (3) roughy consumption to meet docosahexaenoic acid (DHA) requirements. Risks were similarly assessed if king mackerel (Scomberomorus cavalla) were eaten. Based on mercury concentrations in fillets purchased from 2004–2007 (0.73 ± 0.29 mg Hg/kg; n = 45), women would have an 85% probability of exceeding USEPA's reference dose (RfD) if they ate only roughy. Based on literature-derived concentrations, they would have a 91% probability of exceeding the RfD if they ate only mackerel. Increasing consumption of either fish to 12 oz per week would increase their probability of exceeding the RfD to 100%. Attempting to meet DHA requirements through eating these fish also results in a 100% probability of exceeding the ...

Microsatellite and otolith chemistry variability were analysed to assess fine scale genetic structure in the deep-sea teleost orange roughy (Hoplostethus atlanticus). The Porcupine Bank located on the continental shelf west of Ireland, comprises a complex system of mounds and flat areas that are broken up by canyons. Orange roughy form spawning aggregations on mounds and flat areas, and were heavily fished until the resource was depleted. By analysing adults in spawning condition and juvenile orange roughy from six mounds and one flat area, shallow but significant genetic population structure was evident (FST=0.0031, Dest across loci=0.0306 and G-test). Most of the structure was accounted for by inclusion of a sample from the flats (six of ten significant pairwise FST estimates and G-tests, and five of the highest Dest estimates included the flat sample). While the flat sample contributed most to the genetic structure, there was still significant (albeit weaker) structure among mound samples. The observed structure was supported by otolith analyses. Fish caught as late juveniles in either the flat or mound areas showed consistent differences in chemistry at the otolith core throughout the initial 10 years of growth, which could indicate site fidelity. We hypothesise that seafloor topographic structures (mounds and flats) may provide discrete spawning areas for orange roughy and that the limited gene flow between these spawning areas is insufficient to counteract genetic drift.

Hallett, C. S., and Daley, R. K. 2011. Feeding ecology of the southern lanternshark (Etmopterus baxteri) and the brown lanternshark (E. unicolor) off southeastern Australia. – ICES Journal of Marine Science, 68: 157–165. Little is known about the ecological interactions between bycatch species and orange roughy (Hoplostethus atlanticus) within exploited slope and seamount communities off Tasmania. The diet of Etmopterus baxteri and E. unicolor, two important bycatch species of these fisheries, is described using four indices [percentage frequency of occurrence, percentage by number, percentage by weight, and percentage by the index of relative importance (%IRI)] calculated for broad prey categories, individual prey taxa, and functional prey groups. The identifiable diet of E. unicolor was dominated by benthic cephalopods (96%IRI), whereas benthic teleost prey, notably orange roughy (43%IRI), dominated the diet of E. baxteri. Similar trophic mechanisms appear to support aggregations of orange roughy and Etmopterus spp. off Tasmania; they feed on demersal species and mesopelagic or vertically migrating nekton advected laterally onto the mid-slope. The importance of teleost prey in the diet of E. baxteri apparently increases with shark length, whereas crustaceans become less important, which is a similar diet shift to that of orange roughy. Etmopterus baxteri is both a potential competitor and predator of orange roughy in these ecosystems. Fishery managers need to understand and consider the complex trophic interactions between orange roughy, sharks, and other exploited species in managing recently reopened deep-water fisheries off southeastern Australia.

Priede, I. G., Godbold, J. A., Niedzielski, T., Collins, M. A., Bailey, D. M., Gordon, J. D. M., and Zuur, A. F. 2011. A review of the spatial extent of fishery effects and species vulnerability of the deep-sea demersal fish assemblage of the Porcupine Seabight, Northeast Atlantic Ocean (ICES Subarea VII). – ICES Journal of Marine Science, 68: 281–289. We review information from scientific trawl surveys carried out between 1977 and 2002 in the Porcupine Seabight and Abyssal Plain area of the Northeast Atlantic (240–4865 m water depth). Since the late 1980s, commercial bottom-trawl fisheries targeting mainly roundnose grenadier (Coryphaenoides rupestris), black scabbardfish (Aphanopus carbo), and orange roughy (Hoplostethus atlanticus) have been operating at depths of 500–1500 m, intersecting the depth ranges of 77 demersal fish species that would therefore be vulnerable to fishery effects. Comparisons of trawls pre-1989 and post-1997 indicate a significant decrease in total abundance of demersal fish down to 2500 m. Detailed analyses of the 15 most-abundant species showed that nine species with depth ranges within the commercial fishing depth have decreased in abundance. Other species were either not affected (Bathypterois dubius) or only affected at the shallow end of their range (Coryphaenoides guentheri). Species with a minimum depth of occurrence >1500 m (Coryphaenoides armatus and Coryphaenoides leptolepis) increased in abundance over part of their depth range. Decreases in abundance are probably caused by commercial fishing activities, an effect that is transmitted downslope by removal of fish at the shallow end of their depth range, resulting in declines at the deeper end of the depth range. The estimated fishery area is ca. 52 000 km2, but the potential impact probably extends to ca. 142 000 km2 and to many non-target species.

A new species of roughy in the genus Hoplostethus is described from a single specimen collected at depths of 648 to 660 m just east of the Calagua Islands off the east coast of Luzon Island, Philippines. It is characterized by extremely thick fin spines (greatest width of dorsal fin spines 17.4% to 23.1% of spine length; width of spines on pelvic fin 12.9% to 14.2% of spine length; width of anal fin spines 24.4% to 34.2% of spine length), lack of black pigment in the spinous portion of the dorsal fin, and a unique combination of counts and morphometric characters (56 digitiform pyloric caeca, 13 enlarged ventral scutes, ventral fin origin to anal fin origin 38.7% of standard length).

Orange roughy Hoplostethus atlanticus juveniles

Life-span estimates for orange roughy ( Hoplostethus atlanticus ) range from ~20 years to well over 100 years. In this study, an improved lead–radium dating technique provided independent age estimates from sagittal otoliths. This technique used the known properties of radioactivity for lead-210 and radium-226 to determine the validity of fish age estimates. An improvement to lead–radium dating using mass spectrometry allowed the use of smaller samples than previously possible; therefore, an application was made to otolith cores, the first few years of otolith growth. This approach circumvented the use of whole otoliths and alleviated many of the assumptions that were necessary in previous lead–radium dating applications. Hence, it was possible to critically evaluate lead–radium dating as a tool in fish age validation. The measurement of lead–radium ratios for a series of age groups that consisted of otolith cores, grouped based on growth-zone counts from thin sections, showed a high degree of correlation to the expected lead–radium ingrowth curve. This finding provided support for age estimation procedures using thin otolith sectioning. As independent estimates of age, the results indicated that fish in the oldest age group were at least 93 years old, providing robust support for a centenarian life span.