Grenadier Species Research Articles

Decay of parasite community similarity with host phylogenetic and geographic distances among deep-sea fish (grenadiers).

Although parasite community studies are growing in numbers, our understanding of which macro-ecological and evolutionary processes have shaped parasite communities is still based on a narrow range of host–parasite systems. The present study assessed the diversity and endoparasite species composition in New Zealand deep-sea fish (grenadiers, family Macrouridae), and tested the effects of host phylogeny and geography on the structure of endoparasite communities using a distance decay framework. We found that grenadiers from the Chatham Rise harboured a surprisingly high diversity of digeneans, cestodes and nematodes, with different species of grenadiers having different parasite assemblages. Our results demonstrate that community similarity based on the presence/absence of parasites was only affected by the phylogenetic relatedness among grenadier species. In contrast, both phylogenetic distance among grenadiers (measured as the number of base-pair differences of DNA sequences) and geographic distance between sample locations influenced the similarity of parasite communities based on the parasites' prevalence and mean abundance. Our key findings highlight the significant effect of deep-sea host phylogeny in shaping their parasite assemblages, a factor previously neglected in studies of parasite communities in deep-sea systems.

New grenadier Coelorinchus ganymedes sp. nova from the Waters of Polynesia (Macrouridae)

A new grenadier species, Coelorinchus ganymedes sp. nova, from the waters of the Marquesas Islands, belonging to the group of species “C. hubbsi”, has been described. The new species is most similar to C. gladius and C. spilonotus, but differs in color, fewer rows of spinules on body scales, and a number of proportions. A key has been compiled to determine the species of the group “C. hubbsi”.

Coelorinchus posteromaculatus (Actinopterygii, Gadiformes, Macrouridae), a new species of grenadier from the eastern Indian Ocean

A new species of grenadier, Coelorinchus posteromaculatus, is described from nine specimens collected from the tropical eastern Indian Ocean at depths of 100–323 m. This species belongs to the Coelorinchus argentatus group (defined here to include 13 species), but differs from other members of that group in its unique body markings consisting of a single, prominent, lateral, dark blotch on the anterior part of the tail, and a slightly diagonal, narrow, dark stripe extending from the upper margin of the gill opening to below the first dorsal-fin midbase or beyond. Coelorinchus posteromaculatus is most similar to C. gaesorhynchus Iwamoto and Williams 1999 and C. longissimus Matsubara 1943, but further differs from the former in its much shorter snout (74–91% of postrostral length vs. 93–100% in C. gaesorhynchus), and from the latter in its relatively small mouth (upper-jaw length 38–43% of postrostral length vs. 42–49%).

Diet of six deep-sea grenadiers (Macrouridae).

Feeding habits of six deep-sea demersal trawl-caught macrourids on Chatham Rise, New Zealand, were examined from stomach contents during the austral summer. Three species were predominantly benthic foragers: smallbanded rattail Coelorinchus parvifasciatus on small epifaunal crustaceans, twosaddle rattail Coelorinchus biclinozonalis on epifaunal decapods and humpback rattail Coryphaenoides dossenus on benthic fishes and epifaunal decapods. Three species were predominantly benthopelagic foragers: banded rattail Coelorinchus fasciatus on hyperiid and gammarid amphipods and calanoid copepods, blackspot rattail Lucigadus nigromaculatus on small epifaunal crustaceans and suprabenthic mysids and Mahia rattail Coelorinchus matamua on epifaunal decapods and calanoid copepods. The most important predictors of diet variability were identified using distance-based linear models and included areal predictors in C. parvifasciatus, L. nigromaculatus and C. dossenus, fish size in C. dossenus, C. biclinozonalis and C. matamua, sample year in C. biclinozonalis and C. fasciatus and depth in C. matamua. Results are compared with previously published data for four other macrourid species from the same study area. The 10 grenadier species comprise benthic, benthopelagic and mesopelagic foraging guilds. This study brings the number of grenadier species for which diet on Chatham Rise has been described in detail to 12.

A new species of the grenadier genus Coryphaenoides (Actinopterygii: Gadiformes: Macrouridae) from Japan and a range extension of Coryphaenoides rudis Günther 1878 in the northwestern Pacific

A new species of grenadier, Coryphaenoides soyoae, is described from two specimens collected from the Shichito-Iojima Ridge (type locality) and off Fukushima, Honshu, Japan, at depths of 2740–2991 m. The new species belongs to the subgenus Coryphaenoides and is most similar to Coryphaenoides castaneus Shcherbachev and Iwamoto 1995 and Coryphaenoides longicirrhus (Gilbert 1905). It differs from all other congeners in having the following combination of features: pelvic-fin rays 11; snout short, scarcely protruding beyond upper jaw; terminal snout scute absent; scales on lateral angles of snout and head ridges only slightly enlarged and thickened; dorsal contour of head prominently humped over nape; posterior end of upper jaw extending to below hind 1/3 of orbit or beyond; posterior end of rictus not restricted by lip folds; outer gill slit greatly restricted, length 7–8 % of head length (HL); barbel length 11–15 % HL; head bones and body flesh firm; teeth in posteriorly tapering bands on both jaws, with outer premaxillary series enlarged; body scales not deciduous, covered with narrowly divergent rows of needle-like spinules, and the last spinule in each row greatly overlapping posterior scale margin; snout fully scaled dorsally, broadly naked ventrally; interdorsal space slightly less than first dorsal-fin base length; origins of second dorsal and anal fins on about same vertical; height of first dorsal fin 87 % HL; second spinous ray of first dorsal fin serrated along its leading edge; outer pelvic-fin ray greatly prolonged, its tip extending well beyond anal-fin origin; head and body uniformly blackish. In addition, Coryphaenoides rudis Gunther 1878 is recorded for the first time from Japan, based on six specimens collected from Hyuga-nada, Suruga Bay, and the west of Minami-torishima Island (=Marcus Island), at depths of 1100–1481 m. A previous record of this species from Japanese waters was based on a misidentified specimen of a different genus.

Technochemical characteristic and prospects of utilization for grenadier liver

Three species of grenadiers dwell in the North Pacific waters of Russia. Their liver weights 4-7 % of the body weight but is never used. Its utilization for BASF production is proposed. For this purpose, chemical composition and properties of liver from the grenadier Albatrossia pectoralis are investigated. Content of inorganic cations, including toxic ones, in the liver satisfies the allowed standards. Wet liver contains 30 % of proteins and 68 % of lipids, mainly triacyl-glycerides (90 %) and phospholipids (4.5 %). The oil extracted from the liver has the acid number 1.8 KOH/g and the peroxide number 6.4 mmol after three months of frozen storage. Microbiological parameters of the liver are satisfactory after three months of frozen storage, too. Chitosan-lipid complex is prepared by treatment of water extract from the liver tissue (extracted by 5 : 1 solvent of water and natrium hydroxide during 15 hours at the temperature 10-15 o C and centrifuged) with chitosan solution and 3-hour sedimentation from water-soluble fraction. It contains mostly lipids (> 80 %, 23 % of them are saturated fatty acids, 73 % - monounsaturated fatty acids, and 4 % - polyunsaturated fatty acids) and a big amount of essential amino acids, so it could be used as a raw material for restorative BASF production. On the contrary, the water-soluble fraction is poor by proteins and free amino acids; its antioxidant activity is low. The raw oil from grenadier liver could be used in technics or veterinary.

Length–weight relations for seven grenadier species (Actinopterygii: Gadiformes: Macrouridae) to the west of Ireland

Length–weight regressions for seven grenadier species: Coryphaenoides rupestris Gunnerus, 1765, Trachyrincus murrayi Günther, 1887, Coelorinchus caelorhincus (Risso, 1810), Nezumia aequalis (Günther, 1878), Coryphaenoides mediterraneus (Giglioli, 1893), Coelorinchus labiatus (Köhler, 1896), and Coryphaenoides guentheri (Vaillant, 1888) are calculated from data collected on a series of deepwater surveys conducted by the Irish Marine Institute from 2006 to 2009, on the continental slope to the west and northwest of Ireland and the northern slope of the Porcupine Bank. The regression calculated for roundnose grenadier, C. rupestris, is compared with other regressions calculated for the species from different areas of its north Atlantic range. The difficulties associated with measuring many grenadier species, due to the fragility of their tails, are discussed. A recommendation is made that pre-anal fin length should be accepted as the standard.

Analysis of variations of basic morphometric characters in the species of grenadier (Macrouridae, Gadiformes) from the waters of the northern part of the Mid-Atlantic ridge

We investigate variations of the basic morphometric characters (length of head, length of snout, diameter of orbit, interorbital distance, etc.) of ten of the most common species of grenadiers (Macrouridae) in the waters of the northern part of the Mid-Atlantic ridge: Coelorinchus labiatus, Coryphaenoides armatus, C. brevibarbis, C. carapinus, C. guentheri, C. leptolepis, C. mediterraneus, C. rupestris, Macrourus berglax, and Paracetonurus flagellicauda. It is shown that most morphometric characters of the investigated species vary within the wider limits as compared with the published data. The representatives of genera Coelorinchus, Macrourus, and Paracetonurus well differ by a number of characters from the species of genus Coryphaenoides and from each other. In spite of a significant likeness in many characters of the species of genus Coryphaenoides, there are individual characters that differ well from one species to another.

Distribution and relative abundance of main species of grenadiers (Macrouridae, Gadiformes) from the African Atlantic Coast

This study describes the geographic and bathymetric distribution patterns of abundance of the main macrourid species found in Atlantic African waters. A series of demersal trawl surveys, carried out in waters off Morocco, Western Sahara, Mauritania, Guinea Bissau, Gabon, Angola, and Namibia provided the catch data analysed. The survey area was between latitudes 35°56′N and 29°39.50′S and the sampled depths from 20 to 2000 m on the continental shelf and the slope. We collected 50 macrourid species belonging to 15 genera. The most abundant species was Nezumia micronychodon, with 91980 specimens caught, followed by Nezumia duodecim, Trachyrincus scabrus, and Hymenocephalus italicus with 31461, 28411, and 25349 specimens, respectively. The bathymetrical distribution ranges are extended for 21 species of grenadiers.

Evaluation of potential sustainability of deep-sea fisheries for grenadiers (Macrouridae)

The ability of six grenadier species from the North Atlantic, North Pacific, and Southern Ocean to sustain deep-sea fisheries is assessed. These species are captured in high amounts as bycatch and a few are taken in targeted fisheries, yet population status for most is poorly known or known for only a small portion of their range. A productivity and susceptibility analysis showed that none of the species was highly productive, which was not unexpected given their life history characteristics. While grenadiers were ranked more vulnerable than species in the northeastern Pacific groundfish fisheries, none of the investigated species was ranked as highly susceptible or heavily exploited. This result exposed several weaknesses in the PSA technique and attribute scoring. Management actions and regulations are discussed, which, if employed, might make grenadier fisheries sustainable.

Notes on the diet of seven grenadier fishes (Macrouridae) from the lower continental slope of Chatham Rise, New Zealand

Diets of 8 rarely sampled species of grenadiers were examined from the lower continental slope (1178 to 1837 m) on Chatham Rise, New Zealand and includes the first known records of the diet of Bathygadus cottoides, Coryphaenoides mcmillani, C. murrayi, and Idiolophorhynchus andriashevi. Most species fed benthopelagically on small crustaceans, e.g., calanoid copepods, amphipods and mysids and others.

Specific features of feeding and trophic status of mass species of the family Macrouridae in the northwestern part of the Pacific Ocean

Based on materials of expeditions of TINRO-Center into the northwestern part of the Pacific Ocean, we analyze data on feeding of mass species of Macrouridae. Grenadiers Albatrossia pectoralis and Caryphaenoides longifilis are consumers (in order of importance) of cephalopods, fish, and crustaceans and C. acrolepis and C. cinereus are consumers of crustaceans, cephalopods, and fish. All grenadiers demonstrate age-related variability of food composition from polychaetes and small crustaceans to fish, squids, and large crustaceans. The change in dominant prey of A. pectoralis occurs upon its reaching a length of 50–60 cm, and that in C. cinereus occurs upon its reaching a length of approximately 50 cm. Changes in the feeding spectra from prey of in- and epifauna to macroplanktonic and nektonic organisms indicate the widening of trophic niches of grenadiers in ontogenesis. The spatial position of each species of grenadiers correlates with its size: the smaller the species, the less it is separated from the ground trophically. According to the type of feeding, C. cinereus is a bentho-planktonic feeder, A. pectoralis is a nekto-benthonic feeder, and C. acrolepis occupies an intermediate position between them. According to the calculated values of trophic levels, the studied species are (in order of decrease) A. pectoralis, C. acrolepis, and C. cinereus; the trophic level of C. longfilis can be preliminarily assessed as close to that of A. pectoralis.

Fish allergy risk derived from ambiguous vernacular fish names: Forensic DNA-based detection in Greek markets

Some fish species, like hakes, are amongst the most allergenic seafood species and represent a high proportion of food allergies, particularly in children. Seafood mislabelling or incomplete labelling may enhance inadvertent consumption of allergenic species. The problem can be accentuated in countries where vernacular names do not distinguish fish species, like in Greece, where hake, cod and other Gadoids are generically named with the same Greek word Bakaliaros. The purpose of the study was to detect and quantify allergenic fish species contained in commercial seafood labelled with generic and unspecific names. Commercial samples were obtained at random from Greek fish markets and fish species were identified based on PCR fragments of the 5S rDNA. Almost 85% of the analysed products contained highly allergenic hake or grenadier species and only 15% contained less allergenic species like cod and haddock. We conclude that commercial fish markets are potential hotspots of allergy risk, and suggest labelling containing species names and consumer education for reading labels as preventive measures.

Geographic and bathymetric trends in abundance, biomass and body size of four grenadier fishes along the Iberian coast in the western Mediterranean

The present study is a mesoscale analysis of latitude and depth related trends in abundance, biomass and body size of the four grenadier species Caelorinchus caelorhincus, Hymenocephalus italicus, Nezumia aequalis and Trachyrinchus scabrus inhabiting the deep western Mediterranean. We have analysed data from seven annual bottom trawl surveys, carried out down to 800 m depth along the Iberian Mediterranean coast covering a distance of approximately 1200 km. The objectives were to establish general patterns in the mesoscale distribution of abundance, biomass and body size of deep-water grenadier fishes and also analyse the consistency of the bathymetric distribution of these parameters along a large latitudinal gradient. Five complementary series of analyses have been completed. The first focussed on describing the general patterns of abundance and size by correspondence canonical analysis, CCA, in the area. The second and third series focussed on the existence of temporal, geographical and bathymetric trends of abundance, weight and mean size by analysis of covariance, ANCOVA and multiple regression analysis. The fourth series compared the frequency distributions of body length. Finally, the last series focussed on the patterns of abundance versus size. The total number of individuals of all four grenadier species captured in 260 bottom trawls amounted to 27,435 and their weight was 1404 kg. No general trends for the four species have been observed between years. All four species showed a general pattern of increasing size with depth, which, except in the case of C. caelorhincus, was consistent along a large latitudinal gradient. Nezumia aequalis was unique in showing the same noticeable trend of increasing abundance with depth along the entire latitudinal range, but with clear differences in the intercepts. The abundance of N. aequalis and C. caelorhincus decreased significantly northwards. Hymenocephalus italicus was the least abundant species and had a homogeneous distribution without any specific trend along the entire latitudinal range analysed. The distribution of T. scabrus in the Mediterranean seemed to be more localised. Higher abundances were found to the north and south of the latitudinal gradient with lower values between. The grenadiers studied also showed a general trend of decreasing mean size northwards, except in the case of the smallest species, H. italicus. The relation between abundance and body size differed between sectors for the whole grenadier population and species-specific variations were also observed. The relationship between individual body mass and population density fit well to a second-order polynomial function rather than to a linear regression, showing a significant trend for density to increase with increasing size until some mid-point, then to decline with increasing size thereafter. The observed latitudinal gradient in the distribution patterns of grenadiers along the upper slope of the western Mediterranean can be discussed in relation to direct and indirect factors of biogeographic, environmental and anthropogenic origin.

Identification of commercial hake and grenadier species by proteomic analysis of the parvalbumin fraction

Analysis of parvalbumin fractions through proteomic methodologies allowed the differential classification of ten commercial, closely related species of the family Merlucciidae. Muscle extracts from nine hake species of the genus Merluccius including two subspecies of Merluccius australis (australis and polylepsis) and one grenadier species Macruronus novaezelandiae with two populations (novaezelandiae and magellanicus) were evaluated by 2-DE and MALDI-TOF MS. 2-DE demonstrated that the species tested displayed a low intra-specific degree of polymorphism and the isoform patterns were noticeably species-specific. MALDI-TOF mass fingerprints showed clear differences in the pattern of peptides produced by tryptic digestion between the Merluccius and the Macruronus, making the genus differentiation possible. In addition, a selective peptide mass present in the spectra from certain hakes allowed its classification in two groups: Euro-African and American hakes. Besides, some specific masses allowed a clearly individual identification for M. bilinearis, M. australis polylepsis, M. australis australis, M. productus, M. paradoxus and M. polli, while the rest of the hake species can be grouped in two clusters, comprising M. hubbsi and M. gayi in one and M. merluccius and M. capensis in the other.

A trophic ecology of two grenadier species (Macrouridae, Pisces) in deep waters of the Southwest Atlantic

The feeding habits of slope-dwelling macrourid fishes from the southern Southwest Atlantic is unknown. In this study the feeding ecology of the two most abundant species, Macrourus carinatus and M. holotrachys, was investigated. Both these grenadiers fed on a variety of prey, including gelatinous plankton, crustaceans, mesopelagic and benthic fish and cephalopods, echinoderms, as well as fishery discards. M. carinatus forage mostly in depths shallower than 900 m and its feeding spectrum and hunting strategy display important seasonal variability. It consumes more pelagic fish, squid and crustaceans than M. holotrachys, which probably indicates occasional feeding in the water column and higher availability of pelagic prey. M. holotrachys forages mostly in depths deeper than 1100 m and is a specialised bottom feeder. Macrourids are able to switch their feeding strategy from browsing on abundant food sources in summer and autumn (a narrow niche breadth and high number of prey per stomach) to hunting occasional prey in winter and spring (a wide niche breadth, low number of prey per stomach). Both species are of similar size and hard to distinguish morphologically, but in deep water M. holotrachys males are smaller than, and females larger than, those of M. carinatus. A probable reason for such energy re-distribution within a population in M. holotrachys is to achieve a higher reproductive output in a food-poor and harsh deep-sea environment.

New Species of Caelorinchus (Macrouridae, Gadiformes, Teleostei) from the Indian Ocean

Caelorinchus melanosagmatus n. sp. is newly described from upper continental slope waters of the Indian Ocean off Tanzania, Kenya, and in the Andaman Sea. The distinctive banding pattern on the body in combination with a high second dorsal fin, slender snout with terminal scute elongated and sharp, and naked underside of head, among other features, distinguish the new species from all others of the genus. It is most similar to two Pacific species C. cingulatus and C. spilonotus, but the three species differ in details of the banding pattern, and C. spilonotus differs also in pyloric caeca count. The disjunct distribution of the new species, with its apparent absence in the Arabian Sea and Bay of Bengal, is perplexing. The number of currently recognized grenadier species from the Indian Ocean is 114, but many more are known and yet to be described.

Temporal change in foraging behaviour of the fish Coryphaenoides (Nematonurus) yaquinae in the central North Pacific

Deep-sea grenadier fish Coryphaenoides (Nematonurus) yaquinae were attracted to a baited free-fall video camera and tracklng vehicle dunng deployments in the central North Pacific (31°N, 159 W) at a depth of 5800 m. The mean time of arrival of the first fish was 31.0 min after landing on the sea floor. The mean number of fish within camera view increased to a peak of 5.25 at 90 min after landing and decreased thereafter The mitial arrival rate was 0.06 fish mm-' , and mean fish staying time was 122 min The staying time was much shorter than in previous work at this site, suggesting a change in food supply with time of year Grenadiers were tracked using ingestible acoustic transmitters. The mean time until transmitter ingestion after the bait landed was 85.1 min. Fish that swallowed transmitters dispersed at radial rates of l to 20 cm S ' , and all had departed to a range of > 1000 m by 13 h after landlng. Movements to an altitude of > 15 m were recorded for 60 % of fish tracked and occupied 12.9 10 of total tracking time. Bottom current speeds were between < 1 and 9 cm S-' with a tidal rhythmicity Deep-sea macrourid fish, Coryphaenoides (Nematonurus) armatus and C. (N.) yaquinae, are attracted to baits deployed at abyssal depths (Wilson & Smith 1984). Movements of these fish can then be tracked since they will swallow (Priede & Smith 1986) and retain (Armstrong & Baldwin 1990) acoustic transmitters. Earlier work has compared arrival rates and staying time of grenadiers at a standard bait in contrasting areas of the Pacific Ocean (Priede et al. 1990). The areas studied were a relatively eutrophic region at 4400 m under the California current (Stn F, 32 50' N, 124 W) and an oligotrophic station a t 5800 m under the central North Pacific gyre (CNP, 31°N, 159 W). Priede et al. (1990) were able to record the range and the degree of vertical movement of acoustically tagged fish at Stn F but not at CNP. Present address SOAFD, Freshwater Fishenes Laboratory, Pitlochry, Perthshire PHI6 5LB, UK O Inter-Research/Pnnted in Germany The present study collected acoustic tracking data from CNP to supplement the previous work. The study was conducted at a different time of the year to earlier work at CNP and therefore allows a n assessment of temporal variation in foraging behaviour of Coryphaenoides yaquinae, the only grenadier species recorded from this area (Wilson & Waples 1983). Methods. First fish arrival times and the change in fish numbers around a standard mackerel bait were recorded using the free-fall vehicle (FVV) described by Priede et al. (1990). Photographic data were collected during deployments of the FVV between 30 March and 23 April 1989. Either 2 or 3 baited acoustic transmitters were included on each of 8 of these deployments; range and altitude of fish that swallowed these transmitters were also recorded on the FVV. The acoustic recording system utilised in this study had a maximum range of over 1000 m, substantially greater than that in the earlier study. Current speed was measured on a separate mooring using a current meter (S10 Model 6 with Savonius rotor and directional vane) suspended at 2 to 3 m above the seabed. Results. The delay between FVV landing and arrival of the first fish seen swimming against the current ranged from 9 to 54 min with a mean of 31.0 min (n = 10, SD = 11.28). On 2 occasions fish that apparently did not detect the food were seen swimming across and down-current; these were excluded from the analysis since they were apparently not responding to the odour plume from the bait (Wilson & Smith 1984). Mean maximum numbers of fish within camera view increased steadily to a peak of 5 fish at ca 90 rnin after landing (Fig. l ) . Thereafter the numbers gradually declined to a mean of less than 1 fish at 12 h from landing. The equation of Priede et al. (1990) was fitted to the data to give estimates of the initial arrival rate of fish (%, min-l), mean fish staying time (p , min) and a 196 Mar. Ecol. Prog. Ser. 76: 195-199, 1991 Fig. l . Coryphaenoides (Nematonurus) yaquinae. Video observations of mean (+ SE) number of grenadier fish within camera view, an area of ca 2 m2 of seafloor, in relation to time after landing from deployments at Stn CNP. Means are given for the maximum number of fish observed in each Yz or l h period, depending on sampling frequency Rangc (m) 0 0 0 0 8 8 8 o c u + a m ~

Food habits of some deep-sea fish off South Africa's west coast and Agulhas Bank. 1. The grenadiers (Teleostei: Macrouridae)

The food habits of 10 species of grenadier collected from the upper continental slope off South Africa's west coast and Agulhas Bank are described. Three feeding strategies were identified. Members of the demersal micro- or mesocarnivore feeding guild and grazer feeding method include Caelorinchus braueri, C. simorhynchus, juvenile Coryphaenoides striaturus, Lucigadus ori, Malacocephalus laevis, Nezumia brevibarbata, N. micronychodon and N. umbracincta. A second strategy, that of Caelorinchus matamua and adult Coryphaenoides striaturus, involved switching approximately equally from demersal grazing to midwater picking or stalking. The deep-pelagic Mesobius antipodum displayed a third strategy, that of a midwater mesocarnivore picking or stalking. Ontogenetic dietary shifts were noted for the primarily demersal grazers Caelorinchus braueri, C. simorhynchus, Coryphaenoides striaturus and Malacocephalus laevis. Mesopelagic fish, shrimps and squid formed part of the diet of all species. These prey, taken at the bathyal/deep-pelagic interface, are an important source of energy transport from productive surface waters to the deep benthos.