Neobrachiella rostrata (Copepoda: Lernaeopodidae) on the gills of the Greenland halibut, Reinhardtius hippoglossoides from the Gulf of St. Lawrence

1988 ◽  
Vol 66 (2) ◽  
pp. 504-507 ◽  
Author(s):  
L. A. Rubec
Keyword(s):  
Body Size ◽  
Short Form ◽  
Atlantic Halibut ◽  
Greenland Halibut ◽  
Hippoglossus Hippoglossus ◽  
Size And Shape ◽  
Intraspecific Variations ◽  
Structural Details ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides

A short form of Neobrachiella rostrata is found on the gills of Greenland halibut, Reinhardtius hippoglossoides, in the Gulf of St. Lawrence. Female copepods from Greenland halibut differ from females occurring on Atlantic halibut, Hippoglossus hippoglossus, in body size and shape of trunk; males differ in the specific structural details of the second antenna and maxilliped and in the presence of armed uropods and a tympanum between the second maxillae. Intraspecific variations are commonly found in females of the genus Neobrachiella but have never been reported in males.

Helminth parasites of the alimentary tract of Atlantic halibut (Hippoglossus hippoglossus L.) and Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) on the Scotian Shelf

1989 ◽  
Vol 67 (6) ◽  
pp. 1476-1481 ◽  
Author(s):  
James S. Scott ◽  
Shelley A. Bray
Keyword(s):  
Parasite Prevalence ◽  
Fish Length ◽  
Atlantic Halibut ◽  
Helminth Parasites ◽  
Intermediate Hosts ◽  
Scotian Shelf ◽  
Greenland Halibut ◽  
Hippoglossus Hippoglossus ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides

Examination of the alimentary tracts of 272 Atlantic halibut (Hippoglossus hippoglossus (L.)) and 71 Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) from the Scotian Shelf yielded a total of 25 helminth parasite species, 23 from H. hippoglossus (16 Digenea, 3 Cestoda, 2 Acanthocephala, 2 Nematoda) and 16 from R. hippoglossoides (11 Digenea, 3 Cestoda, 1 Acanthocephala, 1 Nematoda). Parasite prevalence and intensity were low (< 50% and < 10%, respectively) in both hosts, except for Derogenes varicus and Steganoderma formosum in H. hippoglossus and anisakid nematodes in R. hippoglossoides. Consideration of change in parasite prevalence and mean intensity in relation to fish length and diet suggests fish prey as transport hosts for D. varicus in larger halibuts, and crustaceans as the intermediate hosts for S. formosum before transmission to its principal host, H. hippoglossus. Geographical change in parasite prevalence and intensity was in the form of southwest to northeast clines along the Shelf, probably related to environmental factors. There was no evidence for stock differentiation in either of the hosts based on parasite fauna.

A new species of Entobdella Blainville in Lamarck, 1818 (Monogenea: Capsalidae: Entobdellinae) from the Greenland halibut, Reinhardtius hippoglossoides

2015 ◽  
Vol 60 (3) ◽  
Author(s):  
Graham Kearn ◽  
Egil Karlsbakk ◽  
Richard Evans-Gowing ◽  
Pavel Gerasev
Keyword(s):  
Ventral Surface ◽  
Molecular Techniques ◽  
Atlantic Halibut ◽  
Greenland Halibut ◽  
Gill Parasite ◽  
Pacific Halibut ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides ◽  
The Relationship ◽  
Reproductive Apparatus

AbstractA previously undescribed species of Entobdella is reported from the skin of the Greenland halibut, Reinhardtius hippoglossoides (Pleuronectiformes, Pleuronectidae). Entobdella whittingtoni sp. nov. differs from other species of Entobdella, including skin parasites of the related pleuronectids Hippoglossus hippoglossus (Atlantic halibut) and H. stenolepis (Pacific halibut), in lacking papillae on the ventral surface of the haptor. Other characteristics of E. whittingtoni are as follows: the absence of vitelline follicles lateral to the pharynx thereby exposing gut caeca in this region of whole mounts; the presence of a circular feature of unknown function, resembling a rosette in sections, attached to the wall of the internal male accessory reservoir; the lack of eyes. Papillae are also absent from the ventral surface of the haptor of the gill-parasitic entobdelline Branchobdella pugetensis, a gill parasite of the pleuronectid Atheresthes stomias. This raises the question as to whether this gill parasite has evolved from a skin-parasitic ancestor similar to E. whittingtoni. An answer to this question requires a more detailed study of the male reproductive apparatus of B. pugetensis and the use of molecular techniques to explore the relationship between B. pugetensis and E. whittingtoni

scholarly journals Reproductive strategy, egg characteristics and embryonic development of Greenland halibut (Reinhardtius hippoglossoides)

2012 ◽  
Vol 70 (2) ◽  
pp. 342-351 ◽  
Author(s):  
Rosario Domínguez-Petit ◽  
Patrick Ouellet ◽  
Yvan Lambert
Keyword(s):  
Embryonic Development ◽  
Reproductive Strategy ◽  
Biochemical Composition ◽  
Incubation Temperature ◽  
Life Stage ◽  
Early Life Stage ◽  
Greenland Halibut ◽  
Hatching Time ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides

Abstract Domínguez-Petit, R., Ouellet, P., and Lambert, Y. 2013. Reproductive strategy, egg characteristics and embryonic development of Greenland halibut (Reinhardtius hippoglossoides). – ICES Journal of Marine Science, 70: 342–351. Despite the commercial importance of Greenland halibut (GH), important gaps exist in our knowledge of the reproductive and early life stage biology for this species. The present study examined through laboratory experiments the spawning strategy, realized fecundity, egg characteristics, biochemical composition, and embryonic development of GH. The results confirmed the hypothesis that GH is a single-batch spawner producing large eggs, resulting in low realized fecundity. Embryonic development and hatching time are highly dependent on incubation temperature; 50% hatching occurred after 46, 30, and 24 days at 2, 4, and 6°C, respectively. Few changes in the biochemical composition of the eggs are observed during embryonic development. Newly hatched larvae are not well developed, having a large yolk sac, no pigmentation and incomplete development of the jaws. Egg specific density confirmed the mesopelagic distribution of the eggs at sea. However, important buoyancy changes occurring in the last 3–4 days before hatching indicate that larvae hatch higher in the water column. These results are important for understanding advection and dispersion processes of GH eggs and larvae and the connectivity between spawning grounds and nursery areas.

Use of Parasites for Separating Stocks of Greenland Halibut (Reinhardtius hippoglossoides) in the Canadian Northwest Atlantic

1993 ◽  
Vol 50 (10) ◽  
pp. 2175-2181 ◽  
Author(s):  
J. R. Arthur ◽  
E. Albert
Keyword(s):  
Atlantic Coast ◽  
Large Fish ◽  
Adult Fish ◽  
Greenland Halibut ◽  
Pseudoterranova Decipiens ◽  
Saguenay Fjord ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides ◽  
Biological Tags ◽  
Discriminant Function Analyses

The usefulness of parasites as biological tags for stocks of Greenland halibut (Reinharditius hippoglossoides) occurring off the Atlantic coast of Canada and in the Gulf of St. Lawrence was investigated. Nonparametric discriminant function analyses of eight collections comprising a total of 231 large fish (>39 cm) using counts for selected parasite taxa (Corynosoma strumosum juvenile, Otodistomum sp. metacercaria, Contracaecinea spp. larva, Anisakis simplex larva, and Pseudoterranova decipiens larva) gave accurate results (almost 100% correct classification) for the separation of fish from the Gulf of St. Lawrence from those collected from adjacent areas of the Saguenay Fjord and the Atlantic Ocean off Labrador. Little, if any, mixing of subadult or adult fish apparently occurs among these areas.

scholarly journals Chromosome-level assembly reveals a putative Y-autosomal fusion in the sex determination system of the Greenland Halibut (Reinhardtius hippoglossoides)

2021 ◽  
Author(s):  
Anne-Laure Ferchaud ◽  
Claire Mérot ◽  
Eric Normandeau ◽  
Jiannis Ragoussis ◽  
Charles Babin ◽  
...  
Keyword(s):  
Sex Determination ◽  
Single Molecule ◽  
Sex Chromosome ◽  
Whole Genome Sequence ◽  
Greenland Halibut ◽  
Syntenic Relationship ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides ◽  
Sex Determination System ◽  
Chromosome Level

Abstract Despite the commercial importance of Greenland Halibut (Reinhardtius hippoglossoides), important gaps still persist in our knowledge of this species, including its reproductive biology and sex determination mechanism. Here, we combined single-molecule sequencing of long reads (Pacific Sciences) with chromatin conformation capture sequencing (Hi-C) data to assemble the first chromosome-level reference genome for this species. The high-quality assembly encompassed more than 598 Megabases (Mb) assigned to 1 594 scaffolds (scaffold N50 = 25 Mb) with 96% of its total length distributed among 24 chromosomes. Investigation of the syntenic relationship with other economically important flatfish species revealed a high conservation of synteny blocks among members of this phylogenetic clade. Sex determination analysis revealed that, similar to other teleost fishes, flatfishes also exhibit a high level of plasticity and turnover in sex-determination mechanisms. A low-coverage whole-genome sequence analysis of 198 individuals revealed that Greenland Halibut possesses a male heterogametic XY system and several putative candidate genes implied in the sex determination of this species. Our study also suggests for the first time in flatfishes that a putative Y-autosomal fusion could be associated with a reduction of recombination typical of the early steps of sex chromosome evolution.

Evidence supporting panmixia in Greenland halibut (Reinhardtius hippoglossoides) in the Northwest Atlantic

2014 ◽  
Vol 71 (5) ◽  
pp. 763-774 ◽  
Author(s):  
Denis Roy ◽  
David C. Hardie ◽  
Margaret A. Treble ◽  
James D. Reist ◽  
Daniel E. Ruzzante
Keyword(s):  
Population Structure ◽  
Population Genetic ◽  
Conservation Strategies ◽  
Greenland Halibut ◽  
Northwest Atlantic ◽  
Population Genetic Differentiation ◽  
Conservation Implications ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Reinhardtius Hippoglossoides ◽  
Species Specific

Assessment of population structure is critical to the design and implementation of sound management and conservation strategies. However, population structure must be assessed using markers attuned to population genetic processes such as genetic drift and gene flow, which reflect actual levels of reproductive isolation among putative genetic clusters. This is critical for highly exploited, commercial species that form the backbone of regional and local economies. Here, we show extremely low levels of population genetic differentiation among Greenland halibut (Reinhardtius hippoglossoides) collected from throughout the Northwest Atlantic, which cannot be statistically differentiated from panmixia using 12 species-specific polymorphic microsatellite markers. In contrast, some previous studies have demonstrated significant differences among individuals collected from various parts of the species’ range using a variety of both genetic and nongenetic techniques. In accordance with other reports and consistent with the species’ life history, we demonstrate that the most parsimonious explanation reconciling observed patterns is a repeated high degree of local differentiation of new recruits and colonizers originating from a common gene pool. Such a scenario has important conservation implications in terms of devising more appropriate strategies balancing species persistence and replenishment with sustainable resource use.

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