Ocean Perch Research Articles

Swimming Endurance of Some Northwest Atlantic Fishes

Endurance was determined in relation to swimming speed and temperature for Atlantic cod, Gadus morhua Linnaeus, redfish, Sebastes marinus (Linnaeus), winter flounder, Pseudopleuronectes americanus (Walbaum), and to swimming speed at 8 C for longhorn sculpin, Myoxocephalus octodecimspinosus (Mitchill), sea raven, Hemitripterus americanus (Gmelin), and ocean pout, Macrozoarces americanus (Block and Schneider).In an activity chamber at a swimming speed of 4 body lengths per second (BL/sec) Atlantic cod swam for about equally long periods at 5 and 8 C, and redfish and winter flounder each about equally long at 5, 8, and 11 C. The pattern was similar for higher speeds. At 14 C winter flounder swam longer at 6 BL/sec than at the lower temperatures. For swimming speeds less than 4 BL/sec all species swam longer at the higher temperatures. At 8 C, the only temperature at which all species were tested, endurance at comparable swimming speeds was greatest for winter flounder, followed by cod, redfish, longhorn sculpin, ocean pout, and sea raven.

Redfish, Sebastes marinus var. mentella, from the Kennebecasis River, N.B.

Redfish, Sebastes marinus var. mentella, from the Kennebecasis River, N.B.

Identity of Larval Redfish Populations in the North Atlantic

THE large redfish or ocean perch was of little importance to commercial fishing fleets in the North Atlantic until 1930, the total landings from all areas being below 20,000 metric tons per annum. Since then, however, American and Canadian fishermen have directed more attention to redfish, and after 1945 German, Icelandic and Russian fishing fleets deployed a large effort. The annual catch increased to 385,000 metric tons by 1955, since when it has been maintained at about this level. Redfish are caught off the coasts of North America between Cape Cod and Labrador, off Greenland and Iceland, and from areas in the north Norwegian and Barents Seas. There is a serious lack of information about the identity of the populations, the fecundity, and the growth-rate, all of which are essential for a proper understanding of the biology of the species.

Distribution pattern of groundfishes hooked along a row of setline in the shallower part of the continental slope in the Bering Sea 2 bathymetric difference in relative abundance in relation to distribution pattern

Summary and Conclusion This report demonstrates the well‐defined bathymetric distribution of relative abundance of groundfishes in relation to the distribution pattern conjectured from the records of catch along a row of setline with remarkably large variation in the settled depth (from shallower than 350 m to deeper than 700 m) observed around 580 18′ N and 1750 28′ W on Aug. 24, 1962. The results of the analyses are depicted in Fig. 1. It is found that halibut, true cod and Sebastodes sp. (or Menuke in Japanese) show sharp or abrupt decrease in the relative abundance in accordance with depth whereas sablefish and rattail increase sharply. Arrow toothed halibut and ray do not show any clear bathymetric change in relative abundance and Pacific ocean perch shows decrease in the density in accordance with the disparity in the depth from the 500 m isobath. The patterns conjectured from this example are compared with either those shown in other reports, the results of the observations on other examples or general view of our fishermen. And many proofs to the high reliability and wide universality of the conjectured pattern of the first four species are found out. But, for the last three species, the present results differ more or less from the general view of our fishermen and the observations on other examples. For the distribution pattern, most of groundfishes incline to show chance distribution in the shallower part of the continental slope (350 m to 700 m deep) and only the species showing sharp decrease in density with increase in the depth are distributed contagiously on the shallower bottom (not deeper than 450 m).

The infestation of the redfish Sebastes marinus (L.) and S. mentella Travin (Scleroparei: Scorpaenidae) by the copepods Peniculus clavatus (Müller), Sphyrion lumpi (Krøyer) and Chondracanthopsis nodosus (Müller) in the eastern North Atlantic

1. An account is given of the intensity and incidence of infestation of the scorpaenid redfish, Sebastes marinus and S. mentella, by the parasitic copepods Peniculus clavatus, Sphyrion lumpi and Chondracanthopsis nodosus on three fishing grounds in the eastern North Atlantic, namely Iceland, Bear Island and the Barents Sea.2. Peniculus clavatus was found to be a rare parasite on both species of redfish in the eastern North Atlantic. Adult female parasites were found during the months from September to February only; they were usually attached to the pelvic or dorsal fins of the host causing little damage.3. Sphyrion lumpi was found to be a comparatively rare parasite on the deep-water Sebastes mentella throughout the eastern North Atlantic but it was found on S. marinus in the vicinity of Bear Island only. It seems justifiable to regard the Bear Island grounds as a centre of abundance of Sphyrion lumpi in the eastern North Atlantic. Adult female S. lumpi tended to infest medium-sized redfish more often than smaller or larger fish.4. The infestation of Sebastes marinus and S. mentella by Chondracanthopsis nodosus has been examined in some detail and attention directed to the influence on infestation of the host species, geographical distribution, body length, age and sex of the host, and seasonal variations. The distribution of female C. nodosus within the gill chamber of the two species of redfish is described; it appears to be related to the need of the parasite to secure a protected and spatially limited habitat out of the mainstream of the ventilation current through the gill chamber.5. The ecological relationships between Sebastes marinus and S. mentella and the three species of parasitic copepod are described together with the possibility of using these and other parasites as indicators of the host's mode of life. It is concluded that Chondracanthopsis nodosus and Sphyrion lumpi merit more detailed and extensive study as possible parasitological indicators of different stocks of redfish.I wish to express my thanks to Messrs Jackson Mills Ltd., Fish Merchants and Curers, Hull, and to the Officer-in-Charge, D.S.I.R., Humber Laboratory, Hull, for their generous assistance in making redfish available for examination. I am also most grateful to Miss E. C. Howard, Librarian, Ministry of Agriculture, Fisheries and Food, Fisheries Laboratory, Lowestoft, for her invaluable assistance in providing certain otherwise unobtainable references in the literature.

A COMPARATIVE STUDY OF RETINAL STRUCTURE IN SOME FISHES FROM MODERATELY DEEP WATERS OF THE WESTERN NORTH ATLANTIC

Examination of the retinae of 13 species from waters off Labrador shows that the retinal layers are closely related with one another in their development and that the general retinal features vary with habitat depth. The retinae of Aspidophoroides monopterygius, Triglops ommatistius, and Gadus callarias with as yet well-developed pigment epithelium, many cones, and conducting elements appear to be capable of functioning fairly normally even in a brighter environment. The retinae of Lycodes lavalaei, L. vahlii maculatus, Sebastes marinus marinus, and S. m. mentella with degenerating pigment epithelium, numerous rods, and poor conducting elements are presumably not any longer suitable for bright light vision. The pure rod retinae of Notoscopelus kröyeri, Ceratoscopelus maderensis, and Argentina situs are different from those of Macrourus bairdii, Coryphaenoides rupestris, and Antimora rostrata in having much better developed layers of conducting elements. This may mean that, in the former three species, form perception plays a significant role, while it is of little importance in the latter three species which are adapted completely to a habitat with only very meager light. In the cone-bearing species, with the exception of A. monopterygius and G. callarias, the cones are mostly of the twin type. This contradicts the generally held opinion that twin cones seem to be associated with vision in bright light.

The lipid depressant activities of whole fish and their component oils

AbstractHypercholesteremic rats were used to investigate the lipid depressant activities of lyophilized whole fish prepared from menhaden, silver salmon, mullet, and ocean perch. Ingestion of the whole fish supplements promoted a significant reduction in the circulating levels of cholesterol and phospholipids, and in the TC/TP ratios of blood lipids from the rat. The effects of whole fish were duplicated by feeding rats proportionate amounts of the oils found in these fish supplements. These supplements had similar, but less dramatic, effects on the liver lipids of the rats. The nonlipid components, isolated from the fish, had no apparent influence on the distribution of lipids in the blood and liver tissues. The preparations of lipid and nonlipid components of the fish are described, and the GLC analyses of marine oils are discussed.

Proximate Composition and Sodium and Potassium Contents of Four Species of Commercial Bottom Fish

SUMMARYThe proximate composition and sodium and potassium contents of four species of bottom fish from Pacific Coast waters were investigated. Pacific Ocean perch, Pacific cod, and lingcod were quite uniform in composition regardless of species, size, season and area of capture, and method of preservation on board the fishing vessel. The averages were 79‐81% moisture, 18‐19% protein, 0.5‐1.5% oil, 1.1‐1.3% ash, 60‐70 mg% sodium, and 390‐440 mg% potassium. Sablefish varied greatly in oil content, with a range of 3‐23% and an average of 15%. Variations in the other constituents were rather large; averages were 71% moisture, 13% protein, 1% ash, 56 mg% sodium, and 348 mg% potassium.

Presence of Blood Antigens in Fish Mucus and its Possible Parasitological Significance

WE have recently shown in this laboratory that each species of fish appears to secrete its own specific mucus1. The differences between mucus from various species can be detected by chromatographic methods. With closely related species, like Sebastes marinus L. and S. mentella Travin, several types of chromatographic technique may be required in order to detect any difference between the two forms of mucus2. At present we know very little about the nature of this species specificity of the mucus. Some of the chromatographically separable components fluoresce on exposure to ultra-violet radiation and some are ninhydrin-positive.

Chemical Indices of Decomposition in Ocean Perch

Chemical Indices of Decomposition in Ocean Perch

Records of Uncommon and Unusual Fishes from Eastern Canadian Waters, 1950–1958

Records of fishes rare in Canada, and unusual occurrences of commoner ones, are presented for 65 species. First Canadian records are given for the short-nosed sturgeon (Acipenser brevirostrum), halfbeak (Hyporhamphus unifasciatus), four spot flounder (Paralichthys oblongus), weakflsh (Cynoscion regalis) and striped sea robin (Prionotus evolvans). Specimens of unusually large size include a cunner (Tautogolabrus adspersus) of 171/4 inches and 31/4 lb, and a redfish (Sebastes marinus) of 311/2 inches and 231/2 lb.

Storage of Frozen Rosefish Fillets

Taste panel assessments of taste, texture, and grade of cooked samples, examination prior to cooking, and analyses of soluble actomyosin and of fat spoilage on frozen rosefish (Sebastes marinus) fillets, with and without treatment with ascorbic acid, stored at −10°F. (−23 °C.) and +10°F. (−12 °C.), are reported.Rosefish fillets stored at +10°F. remained in good condition for 17 to 22 weeks, but became unpalatable in 7 months; stored at −10°F. these conditions applied after 30 weeks and 80 weeks.Ascorbic acid prevented fading of the red pigment and delayed discoloration, but had no effect on the taste panel assessment. Almost no loss in actomyosin extractability occurred at −10°F. up to 85 weeks.

A Study of the Proteolytic Enzyme Activity of the Pyloric Caeca of Redfish

The proteolytic activity of an enzyme preparation from the pyloric caeca of redfish (Sebastes marinus) was studied and measured colorimetrically by the biuret reaction. The optimum temperature of this preparation was found to be 51–52 °C. A statistical study of the data showed the optimum pH to be 8.75, or slightly higher than the optimum pH of trypsin. A comparison of the actions of a commercial leather bate, hog intestinal mucosa, papain, pancreatin, trypsin and the caecal enzyme of redfish on casein led to the conclusion that the pyloric caeca of redfish would furnish a suitable material from which to prepare a leather bate.

The internal anatomy of sphyrion lumpi (Krøyer, 1845) Bassett‐Smith 1899, A copepod parasitic on ocean perch

The internal anatomy of sphyrion lumpi (Krøyer, 1845) Bassett‐Smith 1899, A copepod parasitic on ocean perch

Contribution to the Study of the Fishes of Ungava Bay

The aquatic environment of the Ungava Bay area and watershed is described. Forty-four species of fishes are recorded, belonging to twenty-one families. Twenty-nine are marine forms, two are anadromous, and thirteen are predominantly or entirely freshwater forms. Seventeen are new records for Ungava Bay, and a few are new for the whole of the Canadian Eastern Arctic. The marine piscine fauna is shown to be in the main subarctic, containing such arctic-subarctic forms as Salvelinus alpinus, Reinhardtius hippoglossoidès, Gymnocanthus tricuspis, Icelus bicornis, Aspidophoroides olriki, Lumpenus fabricii, etc., and subarctic-boreal species such as Salmo solar, Gadus callarias, Sebastes marinus, Liparis atlanticus and Mallotus villosus. More strictly arctic species in the fauna are Boreogadus saida, Triglops nybelini and Oncocottus quadricornis; there are two Atlantic boreal species recorded, Faralepis rissoi kröyeri and Lampanyctus crocodilus, and the remainder are fishes of wide north-south range, found in all three zones (arctic, subarctic, boreal), such as Somniosus microcephalus, Myctophum glaciale, Ammodytes dubius, Triglops pingeli, Eumicrotremus spinosus, Liparis tunicatus, Lumpenus maculatus, Lycodes reticulatus.

The Positional Pattern of the Copepod Parasite Sphyrion lumpi on the Rosefish, Sebastes marinus, and Its Relationship to the Behavior of the Fish

The Positional Pattern of the Copepod Parasite Sphyrion lumpi on the Rosefish, Sebastes marinus, and Its Relationship to the Behavior of the Fish

NOTES ON THE FAUNA ABOVE MUD BOTTOMS IN DEEP WATER IN THE GULF OF MAINE

Findings from 22 trawl-hauls, at 20 stations on mud bottoms in the western and northern parts of the Gulf of Maine, in depths between 120 and 228 meters, August, 1936, are:1. The faunal community of the water just above these deep mud bottoms is so monotonous that the catch consisted, in every case, almost wholly of five species of fish (Sebastes marinus, Merluccius bilinearis, Urophycis tenuis, Hippoglossoides platessoides, Glyptocephalus cynoglossus) and of the shrimp, Pandalus borealis, in varying combinations of relative abundance. The only exception was at one station where a larger catch was made of crabs (Geryon) than of shrimp.2. The only other fishes taken were odd examples of the 19 species listed on page 309. The total number of species to be expected in such situations (except as accidental strays) is probably not more than 35.3. As the nets were arranged to fish off bottom, benthonic invertebrates were not sampled.4. The most significant faunal contrast, from the regional standpoint, is that ...

On Sphyrion lumpi (Krøyer), a copepod parasite on the redfish, Sebastes marinus (Linnaeus), with special reference to the host-parasite relationships

On Sphyrion lumpi (Krøyer), a copepod parasite on the redfish, Sebastes marinus (Linnaeus), with special reference to the host-parasite relationships

The liver oil of Norway Haddock (Sebastes marinus)

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