bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Morphological and Biochemical Changes in Steelhead Trout During the Parr–Smolt Transformation
Authors: Fessler James L. , Wagner Harry H.
Published: April 2011

This study was initiated to determine changes in chemical composition, coefficient of condition, and body morphology for juvenile steelhead trout from premigratory through postmigratory periods, January through July. Winter-run steelhead trout, originating from Big Creek and the Sandy River, in Oregon, were used as experimental animals.A discriminant analysis indicated that coefficient of condition and fork length were nearly as powerful in separating smolts from parr as were 10 morphological measurements.The parr–smolt transformation in winter steelhead is size-dependent and characterized by a marked decrease in body depth and coefficient of condition. Changes in depth measurements and coefficient of condition provided the most meaningful measure of morphological change at the time of parr–smolt transformation.During the migratory period, lipid content was substantially lower than in the premigratory period for migrant-sized fish (≥ 160 mm) but remained relatively constant in nonmigrants (≤ 159 mm) throughout all periods. Seasonal changes in moisture and protein levels occurred in the larger fish, although moisture and protein content for the smaller fish remained relatively constant. The amount of ash did not change within a size group.The coefficient of condition of migrant-sized fish declined continuously from February through May but increased in June and July. The mean coefficient of condition for nonmigrants declined from December through February, but remained relatively stable from March through June, with an upward trend in July.
Chondracanthus narium sp.n. (Copepoda: Chondracanthidae), a Parasite of Nasal Cavities of Ophiodon elongatus (Pisces: Teleostei) in British Columbia
Authors: Kabata Z.
Published: April 2011

The male and the female of Chondracanthus narium sp.n. (Copepoda: Chondracanthidae), living in the nasal cavities of Ophiodon elongatus Girard, 1854, off the coast of British Columbia are described and illustrated. The parasite differs from all other species of Chondracanthus by the structure of its trunk, particularly by the absence of the posterior processes.
Grazing Rates and Food Selection in Diaptomus oregonensis (Copepoda) from Marion Lake, British Columbia
Authors: McQueen Donald J.
Published: April 2011

The filtration and ingestion rates of Diaptomus oregonensis females and stage V copepodids were examined in three experimental situations. When unialgal cultures of 20,000 cells per milliliter were offered to D. oregonensis the filtration rates remained constant for cells ranging from 120 to 10,000 µ3. When a mixture of diatoms was offered the animals did not filter cells ranging from 1 to 60 µ3 despite the fact that the cells in this size range were concentrated at about 20,000 per milliliter. When natural phytoplankton from Marion Lake was used as a food source, the filtration rates were low for cells smaller than 100 µ3, increased to a maximum of 12.9 ml per animal per day for cells ranging from 102 to 333 µ3, and remained constant with increased cell volume and decreased cell concentration. Several species of Cyclotella and Merismopedia were not removed from the Marion Lake plankton by D. oregonensis.
Chloride Regulation in the Burrowing Worm Eel Moringua linearis
Authors: Subramanian A.
Published: April 2011

The concentration of chloride in the blood of Moringua linearis (Gray) varied within a narrow range in association with wide fluctuations of salinity in both the natural environment and the laboratory.
Action Spectrum of the Photoperiod Mechanism Controlling Sexual Maturation in the Threespine Stickleback, Gasterosteus aculeatus
Authors: McInernev John E. , Evans David O.
Published: April 2011

Experiments in which groups of 80 threespine stickleback (Gasterosteus aculeatus) were exposed to four discrete segments of the visible spectrum (388–466, 455–518, 513–583, and 585–653 mμ) and compared with two control groups (experimental and wild) showed no major differences in seasonal rates of gonad maturation. This result contrasts with the narrower action spectra of the photoperiod mechanisms in some birds (600–750 mμ) and many insects (400–500 mμ). Light energy levels of < 0.37 × 103 erqs/cm2-sec (equivalent to approximately 5 lux at 420 mμ) induced normal seasonal changes indicating a level of sensitivity for the photoperiod mechanism in this species comparable to that of certain birds and insects (approximately 1 lux). Histological comparisons of ovary development with the brook stickleback (Culaea inconstans) showed closely similar development patterns except for the final stage of yolk deposition. A further stage of yolk differentiation described for the threespine stickleback probably accounts for the larger egg size in this species.
A Possible Optimization Experiment in Fishery Management
Authors: Knight William
Published: April 2011

A tag–recapture method for deciding whether a change in effort governing regulations will improve a fishery or the opposite is proposed. When the criterion is weight of catch, this reduces to seeing whether the total weight of fish recaptured in a certain tag–recapture experiment exceeds the total weight of fish released. Most of the many practical objections besetting this experiment are common to any method depending on tag–recapture methods to estimate rate of exploitation.
Habitat Characteristics of the Pacific Hagfish, Polistotrema stouti
Authors: McInerney J. E. , Evans D. O.
Published: April 2011

Environmental information from Mayne Bay on Barkley Sound, Vancouver Island, indicates that the Pacific hagfish, Polistotrema stouti (Lockington), occurs on substrates consisting mainly of silt and in water characterized by high near-bottom salinities (31–32‰) but low surface salinities (24‰) into which they occasionally swim. Near-bottom dissolved oxygen concentrations were low, an observation in harmony with the high oxygen affinity of hagfish hemoglobin.
In Vivo Assimilation by Cod Muscle and Liver Tissue of Elemental Phosphorus from Polluted Sea Water
Authors: Dyer W. J. , Hiltz D. F. , Ackman R. G. , Hingley J. , Fletcher G. L.
Published: April 2011

Cod rapidly assimilated elemental phosphorus from a seawater environment into their tissues. In a 16-hr exposure to a concentration of 20–80 ppb (parts per billion), phosphorus was concentrated a thousandfold in the liver (even more at lower exposure levels), from 10 to 25 times in white muscle, and about 50–100 times in red muscle. This distribution is roughly in proportion to lipid content. Distribution of the absorbed phosphorus is uniform throughout the white muscle of the fillet, thus facilitating sampling.
Oxygenating Device for Live-Bait Wells
Authors: Baldwin Wayne J.
Published: April 2011

Details are given for the construction of a device for oxygenating live-bait wells and holding tanks. The unit is made from a 6-inch grinding wheel mounted in a stainless steel clamp. A 240-ft3 cylinder of industrial oxygen is used as the source of supply. The oxygen, released as small bubbles, is controlled by a pressure regulator on the oxygen cylinder. The oxygen flow rate at 5–35 psi was determined and the size of bubbles measured.
Meristic and Lactate Dehydrogenase Genotype Differences in Stream Populations of Rainbow Trout Below and Above a Waterfall
Authors: Northcote T. G. , Williscroft S. N. , Tsuyuki H.
Published: April 2011

Rainbow trout (Salmo gairdneri) from above a waterfall on Kokanee Creek had significantly higher average number of parr marks and scale rows but lower number of vertebrae compared with those living below the falls. Three phenotypic forms of liver lactate dehydrogenase (LDH) were recognized in Kokanee Creek rainbow trout (two single-banded homozygous forms CC and C′C′ and a five-banded heterozygous form CC′), apparently under the control of a two allele system. Homozygote CC was predominant in trout from the above falls population and homozygote C′C′ was predominant in those from below the falls. Possible origins of meristic and LDH differences between above- and below-falls populations are discussed and their significance to differences in behaviour, particularly migratory, are considered.
Reproduction and Associated Behaviour in the Shorthorn Sculpin, Myoxocephalus scorpius in Newfoundland Waters
Authors: Ennis G. P.
Published: April 2011

In Newfoundland waters, maturing ovaries of the shorthorn sculpin contain three generations of ova. Only the largest or ripe ova of the first generation are deposited at spawning time, which starts in late November or early December and lasts for about 1 month. It appears that only one male and one female participate in the spawning act and the eggs are laid in V-shaped crevices on rocky bottom at depths between 20 and 35 ft (6 and 11 m). The eggs adhere firmly to each other and the egg mass so formed adheres firmly to the bottom. After spawning, the spent females move from the spawning area to deeper water, but the males remain guarding the eggs until they hatch. At temperatures near 0 C embryonic development takes over 3 months to complete. Hatching starts around mid-March and lasts for 3–4 weeks. Newly hatched larvae occupy all layers of the water column over the spawning grounds but tend to concentrate near the bottom. Fecundity of mature females ranging in length from 20.1 to 50.5 cm ranges from 4205 to 60,976 eggs.
Temperature Tolerance of Bloater (Coregonus hoyi)
Authors: Edsall Thomas A. , Rottiers Donald V. , Brown Edward H.
Published: April 2011

Juvenile and young adult bloaters (Coregonus hoyi) were tested for tolerance to high temperatures. The ultimate upper lethal temperature of juvenile bloaters (26.75 C) appeared to be slightly higher than that of young adult bloaters, but was similar to that of juvenile ciscoes, Coregonus artedii (26.0 C), the only other North American coregonine for which a detailed description of temperature tolerance has been published.Regression equations are given that permit estimation of the thermal tolerance when the lethal temperatures are incompletely known. The estimated thermal tolerance of juvenile bloaters (617 units) was slightly less than that of the brook trout (Salvelinus fontinalis; 625 units), but was higher than that of other Salmonidae.
The Banded Gunnel, Pholis fasciatus, in Newfoundland
Authors: Green John M.
Published: April 2011

Pholis fasciatus was collected at two Newfoundland sites. These are the most southerly records, as well as the first Newfoundland records, of P. fasciatus in the North Atlantic. The meristic counts of the Newfoundland specimens are near or below the low end of the range ordinarily given for the species.
Histological and Hematological Responses of an Estuarine Teleost to Cadmium
Authors: Gardner George R. , Yevich Paul P.
Published: April 2011

Pathological changes attributable to cadmium poisoning were observed in the intestinal tract, the kidney, and the gills of Fundulus heteroclitus after exposure to 50 ppm of the metal. Microscopic examination revealed pathological changes of the intestinal tract as early as 1 hr after exposure, in the kidney after 12 hr, and in the gill filaments and respiratory lamellae after 20 hr. These manifestations of cadmium poisoning bear resemblance to the pathological changes that have been demonstrated clinically and experimentally in mammals.The examination of circulating blood elements revealed rapid and striking changes among cells of the eosinophil lineage. The abundance of eosinophils increased steadily to a level approximately 45% above the usual amount. Indications of the cellular increase occurred as an early rise 4 hr after exposure.A reduction in the relative numbers of mature eosinophils was evident in imprints of head kidney tissue. Nuclear anomalies were associated with the thrombocytes of specimens after 8 hr exposure; however, these changes were not noticeable at either earlier or later time periods.
Comparison of Size, Structure, and Distributional Patterns of Two Salamander Populations in Marion Lake, British Columbia
Authors: Neish I. C.
Published: April 2011

During 1968 and 1969, populations of Taricha granulosa and neotenous Ambystoma gracile were trapped and observed in Marion Lake, B.C. The adult T. granulosa and A. gracile populations were estimated respectively at 2450 and 14,500. It was estimated that there were about 45,000 A. gracile young of the 2nd year in the lake. These populations represent total lake biomasses of about 18 kg for Taricha and 408 kg for Ambystoma. The numbers of young larvae were not determined for either species. The A. gracile population was widely dispersed throughout the spring and summer. Density and size composition varied between areas with different vegetation and substratum. The T. granulosa distribution within the lake was highly contagious and changed through time. Although displaced animals returned to the areas where they were caught, the positions of their home ranges changed through time. Taricha granulosa entered the lake in April and May, showed evidence of wandering in midsummer, and left the lake in September and October. Fifty percent of adult A. gracile seen during the breeding season were metamorphosed and were found in the lake only during April and May. Neotenous adults remained in the lake all year, as did larvae of the 1st and 2nd years. Those larvae that metamorphosed did so in late August and early September. Ambystoma gracile grew rapidly in the lake, but no growth was seen in T. granulosa. No source of T. granulosa mortality was found in the lake, but A. gracile were preyed on by fish and diving bugs, and dead specimens were found on the lake bottom.
Plotting of Bathythermograph Transect Data on a Printer
Authors: Reynolds James B. , McLain Douglas R.
Published: April 2011

A program for plotting bathythermograph transect data on a computer (IBM 1130) printer is available from the Great Lakes Fishery Laboratory. Temperature values are printed in positions proportional to their depths and distances from shore. Contour lines are drawn manually through the plotted points.
Chemical Factors Involved in the Control of Phytoplankton Production in the Experimental Lakes Area, Northwestern Ontario
Authors: Sakamoto Mitsuru
Published: April 2011

In short-term experiments (6 hr–3 days) the general order of decreasing importance of nutrients added individually to samples of lake water and contained phytoplankton was inorganic carbon, Fe, P, and N. The comparable order for long-term experiments (8–20 days) was P, Fe, N; or P, N, Fe. No relation was found between concentrations of chlorophyll and inorganic carbon in the lakes. The addition of iron and trace elements in chelated form and chelators (HEDTA, NTA) alone, increased photosynthetic carbon uptake. The deficiency of iron was mostly due to a lack of iron in a readily assimilable form.
A Hypothesis to Explain Differences and Similarities Among Lakes in the Experimental Lakes Area, Northwestern Ontario
Authors: Schindler D. W.
Published: April 2011

A preliminary hypothesis is proposed to explain biological differences between Experimental Lakes Area (ELA) lakes in terms of simple morphometric and meteorological parameters, via their effect on nutrient supplies to the lakes.
X-Ray Spectrometric and Multivariate Analysis of Sockeye Salmon (Oncorhynchus nerka) from Different Geographic Regions
Authors: Calaprice J. R.
Published: April 2011

The chemical composition of samples of fry and adult sockeye salmon (Oncorhynchus nerka) collected in different areas was characterized by X-ray fluorescence spectrometry. Multivariate analysis of the spectra indicate that fish taken from an area possess recognizably distinct chemical compositions. Discriminant functions computed using spectral data were used to classify unknowns successfully. The relative similarity of groups characterized by fluorescence spectrometry is shown by canonical analysis and the nature of the chemical differences is discussed. The results indicate that these aquatic organisms possess a chemoprint, a form of natural tag.
A Range Extension for the Squid Abraliopsis (Watasenia) felis
Authors: MacAskie I. B.
Published: April 2011

Four complete specimens of Abraliopsis (Watasenia) felis McGowan and Okutani, 1968, were collected by net in July 1968 at 48°06′N, 126°10′W. Dorsal mantle lengths of three of these, measured after preservation in 10% formalin, were 19, 23, and 30 mm. Previously reported as found near 43°00′ (McGowan and Okutani 1968), the range of this species is therefore extended 300 miles northwards.
Octopine in Postmortem Adductor Muscle of the Sea Scallop (Placopecten magellanicus)
Authors: Hiltz Doris Fraser , Dyer W. J.
Published: April 2011

Study of the rate and extent of octopine formation in ice-stored sea scallop meat (Placopecten magellanicus) confirms that it, rather than lactate, is a principal end product of carbohydrate metabolism in this species. Little or no octopine is detectable in fresh muscle dissected from live scallops, but on subsequent iced storage octopine accumulates, with reciprocal decrease in arginine, to maximum levels of about 1% in 6–10 days. An active octopine dehydrogenase, catalyzing the reductive condensation of arginine and pyruvate, was present, and lactic dehydrogenase activity was absent. Octopine accumulation occurs concomitantly with nucleotide degradation (dephosphorylation of adenosine 5′-triphosphate (ATP)). Its formation is linearly related to decline in muscle pH.Octopine production had usually attained its maximum considerably before the point of inedibility was reached; hence, the use of octopine content as an index of quality in scallop meats seems limited to the early postmortem storage period, as confirmation of freshness.
Effects of Temperature on Movements of Prespawning Brook Sticklebacks, Culaea inconstans, in the Roseau River, Manitoba
Authors: MacLean J. A. , Gee John H.
Published: April 2011

During spring, brook sticklebacks (Culaea inconstans (Kirtland)) in the Roseau River, Man., moved upstream from deep, cool, overwintering areas to shallow warmer waters in meltwater ponds and ditches, where they reproduced. Movement upstream occurred during daylight, in water velocities less than 90 cm/sec, when a temperature gradient was present, but ceased at night or when water temperatures exceeded 19–20 C. In a horizontal laboratory gradient, prespawning sticklebacks from the field selected a range of temperatures from 14.9 to 20.2 C, considerably narrower than after spawning. More prespawning sticklebacks moved upstream in an artificial stream tank at water temperatures of 15.6 and 21.1 C than at 7.2, 10.0, or 23.9 C, and more moved upstream in light than in darkness.
Trouts of the Upper Kern River Basin, California, with Reference to Systematics and Evolution of Western North American Salmo
Authors: Schreck Carl B. , Behnke Robert J.
Published: April 2011

The five endemic species and subspecies of trout named from the upper Kern River drainage of the southern Sierras are revised to two subspecies of Salmo aguabonita: S. a. aguabonita and S. a. gilberti. Analysis of various characters led us to conclude that S. a. aguabonita did not differentiate from a coastal rainbow trout as surmised by other workers. This conclusion was based on: (1) morphological similarities with the inland cutthroat trout; (2) apparent relationships with the Gila, Apache, and Mexican golden trouts of New Mexico, Arizona, and northern Mexico, respectively; (3) a chromosomal complement identical to that of the Apache trout and more readily derived from that of S. clarki than from that of S. gairdneri; and (4) geomorphogeny and zoogeography of the southern Sierras. This evidence suggests the golden trout represents an ancient form whose origin was associated with a widely distributed group of goldenlike trouts.The trout originally from the Kern River has a chromosome count and a chromosome arm number identical to those of S. a. aguabonita and therefore is classified as S. aguabonita gilberti. The Little Kern golden trout, S. whitei, is considered a synonym of S. a. gilberti. Similarities with an undescribed form of the McCloud-Pit drainage of northern California suggests a common ancestry. Today, S. a. gilberti is best represented by populations in the upper Little Kern watershed. Salmo roosevelti is considered a synonym of S. a. aguabonita, and S. rosei most likely had a hybrid origin derived from introductions of S. a. gilberti and S. a. aguabonita.
Locomotory Mechanisms in Caligidae (Crustacea: Copepoda)
Authors: Kabata Z. , Hewitt G. C.
Published: April 2011

Structure of locomotory appendages of Caligidae (Copepoda: Caligoida) is briefly reviewed from the point of view of functional morphology. Locomotory mechanisms are studied on examples of Lepeophtheirus salmonis and Caligus clemensi. Rapid propulsion is attributed to antagonistic movements of the first two pairs of legs, the second pair being a more important contributor. Beating towards each other, the legs produce a jet of water, which propels the parasite. In a subsequent recovery stroke, the second leg, made watertight by a dorsal membrane, gives further impetus to the jet, pushing it out through the sinus opening of the cephalothorax. Water is replenished under the cephalothorax by intake via space under the frontal plates. Settling movements help to improve the grip of the parasite on the host's surface and involve rapid side-to-side motion, involving the second maxillae. Steering is carried out by lateral and vertical movements of the posterior part of the body. Functions of other appendages are discussed.
Supernumerary Copulatory Organs in Dugesia tigrina (Girard 1850) (Platyhelminthes: Turbellaria)
Authors: Boddington M. J. , Mettrick D. F.
Published: April 2011

One complete and two incomplete sets of copulatory organs were found in a specimen of Dugesia tigrina that had been maintained in the laboratory for 6 months. This is the first record of supernumerary copulatory organs occurring in this species. Their development at a high temperature (23 C) does not support the hypothesis that supernumerary copulatory organs are related to zooid formation.
Estimation of the Pacific Hake (Merluccius productus) Population in Port Susan, Washington, Using an Echo Integrator
Authors: Thorne Richard E. , Reeves Jerry E. , Millikan Alan E.
Published: April 2011

Echo integrators developed at the University of Washington were utilized for estimation of the size of a commercially exploited spawning stock of Pacific hake (Merluccius productus) in Port Susan, Washington, in 1969 and 1970. A simple voltage integrator was used in 1969, and a voltage-squared integrator was used in 1970. This change increased the objectivity of the technique, and enabled estimation of confidence intervals. Both population estimates were based on the results of echo integration over a number of transects distributed over the survey area. The integrators were calibrated against net hauls on the assumption of 100% net efficiency. An apparent decrease in the spawning stock size between 1969 and 1970 was indicated by the acoustical census and was supported by a decline in the commercial fishing catch rates between years. Annual catch and age data indicate that this difference apparently is not due to overfishing. The difference probably resulted from variation in the proportion of the total stock that was present in Port Susan at the time of maximum concentration. The major source of variability in the estimates for both years was associated with the net haul calibration. Alternate methods of calibration and improvements in the technique are discussed.
A Quantitative Sampler for Aquatic Phytomacrofauna
Authors: Mackie G. L. , Qadri S. U.
Published: April 2011

A sampler was designed to quantitatively sample the invertebrates associated with submerged aquatic macrophytes. The advantage of this design over the previous ones is that it excludes benthic macrofauna.
Postmortem Changes in the Glycogen Phosphorylase Activity of the Muscle of White Sucker (Catostomus commersoni) and Northern Pike (Esox lucius)
Authors: Manohar S. V. , Boese Helen
Published: April 2011

Glycogen phosphorylase "a" activity in the muscle of northern pike (Esox lucius) decreased during 7 days of storage at 0 C. Under similar conditions, activity of this enzyme increased in the muscle of white sucker (Catostomus commersoni). The total amount of phosphorylase "a" + phosphorylase "b" remained constant during storage for 7 days in both species. The reduced phosphorylase "a" activity in pike muscle may explain the slow degradation of glycogen in the muscle of this fish during storage as compared to that in white sucker.
The Zoogeographic Problem Involved in the Presence of the Glacial Relict Pontoporeia affinis (Crustacea Amphipoda) in Lake Washington, USA
Authors: Segerstråle Sven G.
Published: April 2011

The discovery in 1939 of the glacial relict amphipod Pontoporeia affinis Lindström in Lake Washington raised the question of the provenience of this population of the species, quite isolated as it is from the main area of relict localities of continental North America, situated east of the Continental Divide. Recent geological work and studies on the dispersal routes of freshwater fish in glacial times suggest that the P. affinis of Lake Washington has been able to cross the divide from proglacial waters east of it.
Concentration of Bunker C Fuel Oil in the Waters of Chedabucto Bay, April 1971
Authors: Gordon Jr. Donald C. , Michalik Paula A.
Published: April 2011

The concentrations of Bunker C fuel oil in the waters of Chedabucto Bay in April 1971, 14 months after the Arrow disaster, were uniformly low, averaging 1.5 ppb. Comparison with other data indicates that concentrations in the bay have dropped more than an order of magnitude in the last year and now are at a level that is typical for the concentration of petroleum residues in the marine waters off Atlantic Canada. Although practically all of the Bunker C originating from the Arrow appears to be gone from the water column, oil coverage is still extensive in some inshore areas and considerable quantities of sedimented oil are probably present in the sediments of the bay.
A Sculpin (Icelus spiniger) New to the Coastal Waters of British Columbia
Authors: Barraclough W. E.
Published: April 2011

Icelus spiniger Gilbert was collected at two locations off the coast of British Columbia. These are the most southerly records, as well as the first records of I. spiniger in British Columbia.
Occurrence of the Bering Poacher (Occella dodacaedron) and the Pacific Staghorn Sculpin (Leptocottus armatus) near Chignik, Alaska
Authors: Phinney Duane E.
Published: April 2011

In August 1967, a specimen of the Bering poacher, Occella dodacaedron (Tilesius), was taken by a commercial fisherman in Chignik Bay, Alaska; this catch indicates that it ranges farther south than Bristol Bay, the previously reported limit of its distribution. Sampling by beach seine by personnel of the Fisheries Research Institute in Chignik Lagoon, Alaska, in 1963–65 and in 1967, showed that the staghorn sculpin (Leptocottus armatus Girard) was a common resident; the northwestern range of the species is clarified.
Bioenergetics of a Sand Goby (Gobius minutus) Population
Authors: Healey M. C.
Published: April 2011

This paper describes utilization of ingested energy by a population of sand gobies (Gobius minutus) in the Ythan estuary, Scotland, from November 1966 to March 1969. After metamorphosis (July) the gobies survived about 22 months, and their life could be divided into five stages: somatic growth (July–November); gonad growth (November–February); reproduction (February–June); more somatic growth (June–October); and further gonad growth (October–December). I calculated energy budgets for each stage from the relation:[Formula: see text]where: I = ingested calories; M = calories of metabolism; G = calories of growth.Since I had measures of ingestion, growth, and routine oxygen consumption, I hoped to predict active metabolism by the energy ingested not accounted for in growth and routine metabolism. In fact, 0.8I either equalled the sum of growth and routine metabolism or was much too little to explain predicted expenditures for these parameters. Analysis of published feeding and growth studies in fish indicated that energy imbalances of this sort at low rations are general and that fish seem able to shunt more energy into growth when on a restricted ration than one would predict from studies of standard oxygen consumption. This result together with earlier analyses of Paloheimo and Dickie (1966) indicate that energy budgets for natural populations not based on accurate natural ingestion rates are at best only crude approximations.
Some Athecate Hydroids From the Shelf Waters of Northern Canada
Authors: Calder Dale R.
Published: April 2011

Sixteen species of athecate hydroids were identified in collections from the shelf waters of northern Canada between the Strait of Belle Isle and the Alaska–Yukon border. This brings the number of athecate species reported from Canada's north coast to 21, and the total number of hydroid species known from the region to 92. One species, Eudendrium caricum Jäderholm 1908 is placed in synonymy with Eudendrium arbusculum Wright 1859. No high-arctic forms were represented, and only eight of the species are panarctic or low-arctic in distribution. Of the remaining species, six occur in boreal as well as subarctic waters, and two have a wide latitudinal range. Five species, Corymorpha groenlandica, Tubularia regalis, Monocoryne gigantea, Rhizogeton nudus, and Hydractinia monocarpa, are recorded in North American waters for the first time. These five, plus Myriothela phrygia, Eudendrium capillare, and the hydroid of Euphysa, are new records for northern Canada.
Identification of Major British Columbia and Alaska Runs of Even-Year and Odd-Year Pink Salmon from Scale Characters
Authors: Bilton H. T.
Published: April 2011

The present study indicates to what extent the various even- and odd-year pink salmon runs originating in British Columbia and Alaska may be identified from two scale characteristics. Discriminant function analysis indicates that for both the even- and odd-year runs in most instances only small proportions of each of the runs could be correctly identified to their specific place of origin. The only exceptions were the Fraser River and Aleutians runs where more than half were correctly classified to their place of origin. However, quite large proportions of most of the major even- and odd-year runs from the British Columbia and Alaska regions could be correctly classified to their region of origin.An analysis, using a simple regression line method, of fish grouped into two regions rather than by run indicates that quite large proportions of fish from both even- and odd-year runs from the British Columbia and Alaska regions could be correctly classified to their region of origin. It would appear that the simpler analysis was equally as good as the discriminant function analysis of the individual runs for classifying fish to their region of origin on the basis of only two scale characters.
Aerobic Microflora of the Bluefish (Pomatomus saltatrix) Intestine
Authors: Newman Jr. Joseph T. , Cosenza Benjamin J. , Buck John D.
Published: April 2011

From 65 bluefish caught in Long Island Sound, 433 isolates of bacteria from the intestinal contents were assigned to various groups, the most abundant being Vibrio, Pseudomonas, Enterobacteriaceae, and Achromobacter. Unidentified fermenters, yeasts, and strains of Flavobacterium, Micrococcus, and Bacillus were found also. In each group, two or three biotypes predominated. Flagellar arrangements and biochemical characteristics are presented for the major groups of Gram-negative bacteria isolated. The majority of cultures required sea water for growth, and grew preferentially at 20 C. Relationships between these data and studies of the intestinal microflora of other marine fish are discussed. Generic and physiological similarities and differences as well as taxonomic difficulties encountered are considered.
The Deepwater Sculpin, Myoxocephalus quadricornis thompsoni, New to Alberta, Canada
Authors: McAllister D. E. , Ward J. C.
Published: April 2011

Specimens of the deepwater sculpin from Upper Waterton Lake provide the first record for Alberta and extend the known range over 450 miles to the southwest.
Tissue Culture Bioassay Method for Water Pollution with Special Reference to Mercuric Chloride
Authors: Li M. F. , Traxler G. S.
Published: April 2011

The effect of HgCl2 on multiplication and respiration of L-cells cultivated in suspension was studied. The nutritional history, growth phase, initial density of the cells, as well as the concentration of the serum supplement used in the test medium had significant effects on the sensitivity of the bioassay system. We concluded that the cells used for the test should be in the stationary phase at an initial cell density of approximately 2 × 105 per milliliter, and the test medium should be free of fetal calf serum.Under our experimental conditions mercuric chloride at a concentration of 10 ⁁g/liter or less inhibited the cellular multiplication significantly; the results indicated that this assay procedure could be adequate for monitoring water quality. The cellular respiration method, however, was less sensitive, but simple and rapid with results being made available within a few hours, and therefore useful for screening or preliminary testing of heavily polluted samples.
The Eutrophication Problem
Authors: Beeton A. M. , Edmondson W. T.
Published: April 2011

The trophic state of a lake is maintained by continued inputs of nutrients. In very large lakes the inshore environments are affected first by increased nutrient loading and, depending upon the morphology and morphometry, gradually the offshore waters are altered. The near-shore waters of Lake Michigan have greater concentrations of nitrogen and phosphorus and a lower silica content than open lake waters. Diatoms are more abundant inshore than offshore, the doubling times for diatom populations are shorter inshore, and species favored by nutrient-rich conditions are more abundant inshore. Data on plankton, nitrogen concentrations, and fish, from early studies on Lake Erie, show progressive changes from the shore lakeward and from the western basin eastward.
Lake Superior: Effects of Exploitation and Introductions on the Salmonid Community
Authors: Lawrie A. H. , Rahrer J. F.
Published: April 2011

Lake Superior is highly oligotrophic and not very productive. It has not, however, been much affected by man's activities. Substantial quantities of woody allochthonous materials entered the lower reaches of tributaries and their estuaries from the pioneer lumbering industry. These undoubtedly depreciated the shallow-water benthic environment and may have adversely affected fish stocks in the immediate areas concerned, especially those of lake sturgeon (Acipenser fulvescens) and lake whitefish (Coregonus clupeaformis). At present, local areas of urban or industrial pollution can be identified but, in general, appear to have had little adverse effect on fish stocks, although the collapse of one walleye stock has been attributed to pollution from a paper mill. Every commercial species has, however, been severely depleted. Recent declines can be correlated with predation by sea lamprey (Petromyzon marinus) but, without exception, all species give evidence of extensive overfishing long before sea lamprey entered the lake. That this has not been more obvious is due to the stratification of catch statistics by arbitrary geographic areas (statistical districts) which are too large to relate meaningfully to either fish distributions or patterns of fishery operations. Because fish are generally distributed as local, often small, quasi-discrete stocks, they were exploited sequentially by the young, developing fishery. In this way stock after stock was depleted while conventional yield statistics gave an impression of relative stability. The lag before these statistics indicated the decline appears to be related to the degree of dispersal characteristic of each species. Thus the decline of the sturgeon was first evident, that of the lake trout (Salvelinus namaycush) last. Recovery has been slight but modern hatchery technology clearly provides a prospect for rejuvenating existing stocks or developing new ones. In either case, such synthetic populations will offer favorable opportunities for detailed investigation of the nature of fish distribution and its bearing on the interpretation of catch statistics.
Lake Opeongo: Effects of Exploitation and Introductions on the Salmonid Community
Authors: Martin N. V. , Fry F. E. J.
Published: April 2011

Lake Opeongo, a 58.6 km2 lake in the highlands of Algonquin Park, Ontario, has been under study since 1936. Due to little human development of the area, environmental conditions have been stable but because of its geological setting and location the lake waters are relatively unproductive.The smallmouth bass introduced in 1928 has had no apparent major impact on the salmonid community but has served to buffer fishing pressure on the lake trout. The cisco introduction in 1948 resulted in faster growing, better conditioned, and more fecund lake trout but has also contributed to their later maturity. Weight production of trout increased and in recent years stronger classes have apparently resulted from the improvement in fecundity. Declines in the perch and benthic insects and a decrease in growth rate of certain fishes since the mid-1950s are apparently related to the cisco introduction.Harvest of lake trout by the sport fishery has varied from 630 to 2700 fish/year representing a long term yield of 0.33 kilos/ha. Mean total mortality rate is 50%/year and exploitation has served to double the mortality rate after the trout have entered the fishery. Year-class production is correlated with spawning escapement and exploitation has limited recruitment to the trout population.
Lac Léman: Effects of Exploitation, Eutrophication, and Introductions on the Salmonid Community
Authors: Laurent P. J.
Published: April 2011

Review of 14 years of data concerning the geographic and hydrographic characteristics of Léman show that this lake is in the process of eutrophication: nutrient levels are increasing, oxygen levels are decreasing in the deep waters, and the algal flora has changed. The effect of the current warming of the climate on its evolution is taken into consideration.Since 1900 the fishing regulations of the Swiss and French have been dissimilar. Excessively small size limits and at certain times the abusive use of nets have repeatedly led to a reduction of the most valued species.French catch data, covering more than 70 years, reveal fluctuations which reflect biological disturbances due primarily to overexploitation and also to eutrophication. Landings have increased but value has decreased.Numerous introductions have been made purposely or accidentally. Certain of these species have had deleterious effects (sticklebacks) and some beneficial (introductions of a new population of coregonines after the extinction of the indigenous species).Some aspects of the biology of the most valued salmonids (Salmo trutta, Salmo gairdneri, Salvelinus alpinus) have been shown as well as the results of attempts to repopulate them using pisciculture and marking. Plantings of rainbow trout along the shoreline during summer gave best results (percentage return and growth being most important), although their reproduction seems to be doubtful.Overexploitation of coregonines followed by that of perch (Perca fluviatilis) has left roach (Rutilus rutilus) to inhabit all the central zone of the lake. This valueless species is favored by eutrophication and is thus able to utilize plankton without undergoing competition from coregonines and young perch, or predation by larger perch. No fishing profits are derived from the invasion of the lake by roach.
The Future of Salmonid Communities in the European Subalpine Lakes
Authors: Grimaldi E. , Nümann W.
Published: April 2011

Eutrophication is the main danger threatening European subalpine lakes, particularly the small ones. Among salmonids, char seems already to have suffered severely from organic pollution, and may fare even less well in future, though forecasts are less pessimistic for trout and coregonines. Building of industries and power plants, tampering with shores, shipping, and hydrologic and hydrographic changes must be opposed if these bodies of water are to be preserved in ecologically healthy states. The future of fisheries largely depends on commercial and socio-economic factors.
Length–Weight Relationship for Pomfret
Authors: Manzer J. I.
Published: April 2011

The length–weight relationship for 298 pomfret (Brama japonica) ranging in fork length from 30 to 49 cm, and caught in 1956 and 1957 in the Gulf of Alaska by gillnets varying in mesh size from [Formula: see text] (63 mm) to [Formula: see text] inches (133 mm) was examined. Covariance analysis of the data indicated that within years the length–weight relationship did not differ between males and females; and, on the average, both males and females of a particular length were significantly heavier in 1956 than in 1957. Allometric equations for each year based on data for sexes combined are considered more appropriate than a single equation based on pooled data. The equations relating weight in kilograms to length in centimeters, for 1956 and 1957, respectively, are[Formula: see text]and apply to the lower third of the known size range for pomfret in the Gulf of Alaska.
First Records of Bathysaurus mollis (Pisces: Bathysauridae) From the Northeast Pacific Ocean
Authors: Stein David , Butler John
Published: April 2011

Three male Bathysaurus mollis, standard lengths 678, 458, and 440 mm, were captured 560 km off the coast of Oregon in 3358–3780 m. These are the first records of this species in the northeast Pacific. The 678-mm specimen, the largest reported individual of the species, has irregular rather than oval orbits. Variation exists between individuals in the position of the gill tooth plates.
Crustacean Plankton and the Eutrophication of St. Lawrence Great Lakes
Authors: Patalas K.
Published: April 2011

Fourteen copepod and 13 cladoceran species were found in the summer plankton of lakes Superior, Huron, Erie, and Ontario. Cyclops bicuspidatus thomasi was the most abundant species in lakes Huron, Ontario, and Erie, and Diaptomus sicilis in Lake Superior. A general trend was seen from oligotrophic Lake Superior to eutrophic Lake Erie: the diminishing significance of calanoids (Diaptomus sicilis and Diaptomus ashlandi) accompanied by the increasing predominance of cyclopoids and cladocerans (Cyclops bicuspidatus thomasi, Mesocyclops edax, Daphnia retrocurva, Daphnia galeata mendotae, Bosmina longirostris, and Bosmina coregoni coregoni). The average crustacean abundance varied from 43 individuals/cm2 in Lake Superior to 400/cm2 in Lake Erie, and was related to both the heat and chlorophyll content of the water.Total phosphorus loadings for the five Great Lakes were calculated using Vollenweider's criteria based on phosphorus exports from soils and human population densities in the drainage basins. They amounted to 0.03 g total P/m2∙year for Lake Superior, 0.15 for Lake Huron, 0.29 for Lake Michigan, 0.86 for Lake Ontario, and 0.98 for Lake Erie. The lake-average summer chlorophyll-a concentrations as well as Secchi disc visibilities were closely related to the phosphorus loading rates. Crustacean abundance was then indirectly related to the phosphorus loading rates. Based on the correlations found, predictions were made about changes in Secchi disc visibility and chlorophyll concentration with increasing human population densities in the drainage basin.
Prediction of Copper Toxicity in Receiving Waters
Authors: Wilson R. C. H.
Published: April 2011

The 96-hr LC50 of copper to Atlantic salmon parr in water taken from the Exploits River, Newfoundland, is about 125 μg/liter at a total hardness of 8–10 mg/liter CaCO3 and a total alkalinity of 4 mg/liter. However, the addition of spent sulphite liquor from a pulp mill allowed fish to survive more than 180 μg/liter Cu. Considering the variety of organic compounds which have now been shown to chelate dissolved copper, it is likely that a simple model for the prediction of copper toxicity in waters receiving mine effluent will prove impossible.
The Effects of Sublethal Concentrations of Whole Bleached Kraftmill Effluent on the Growth and Food Conversion Efficiency of Underyearling Sockeye Salmon (Oncorhynchus nerka)
Authors: Webb P. W. , Brett J. R.
Published: April 2011

Changes in growth rate and gross conversion efficiency were measured for underyearling sockeye salmon during and after exposure to full bleached kraftmill effluent (BKME). Five groups of fish were exposed for 56 days to 0, 1.0, 2.5, 10, and 25% BKME (v/v). Fresh 24-hr composite effluent at pH 6.8 was used daily after filtering. Growth was followed for a further 56 days after BKME exposure. Temperature was held at 15 C and dissolved oxygen between 90 and 100% air saturation. Growth rate and conversion efficiency were unaffected at 1.0 and 2.5% BKME. Reduced mean growth rate and conversion efficiency at 10% BKME were not statistically significant from controls but were considered to be biologically important in estimating threshold response levels. Significant reductions were found at 25% BKME. No recovery in retarded growth was found after exposure to BKME. Condition factor and percentage dry weight were not affected. It was concluded from computed response curves that the EC50 of the effluent was approximately 3.7% (v/v).
Developmental Stages of Caligus clemensi (Copepoda: Caligidae)
Authors: Kabata Z.
Published: April 2011

Morphology of developmental stages of Caligus clemensi (Copepoda: Caligoida), a parasite of important commercial fish species, is described. The development cycle consists of two nauplius stages, one copepodid, four chalimus stages, and one preadult. This cycle is compared with ontogeny of five other species of Caligidae. The author concludes that one preadult stage has been missed in the cycle of C. clemensi and that evidence so far available points to existence of a ten-stage cycle of development, including two preadult stages and the adult.
Use of the DeLury Method to Estimate Gillnet Selectivity
Authors: Hamley John M.
Published: April 2011

Catch–effort methods of population estimation can also be applied to estimate the selectivity of fishing gear. Extensions of DeLury's formulae are considered, and the method is demonstrated on published data of gillnetting whitefish.
Evidence for Expatriate Populations of the Lanternfish Myctophum punctatum in the Northwest Atlantic
Authors: Zurbrigg R. E. , Scott W. B.
Published: April 2011

Myctophum punctatum populations in the Northwest Atlantic are probably expatriate, being composed almost exclusively of very large individuals and lacking postlarvae. Females do not possess maturing or gravid ovaries. The apparent physiological stress on these fish is reflected by irregular and sometimes regressive growth evidenced in their scales, otoliths and subopercles.
Mercury Removal from Fish Protein Concentrate
Authors: Regier L. W.
Published: April 2011

The potential reclamation of mercury contaminated proteinaceous food by an extraction procedure such as employed in making fish protein concentrate was investigated. The addition of hydrochloric acid to the isopropanol extractant was found to give removals as high as 93% from dry swordfish protein concentrate. The normal Halifax isopropanol extraction process did not effect any significant removal of the mercury.Preliminary studies of the variables indicated acid concentration, kind of alcohol (ethanol and isopropanol), alcohol concentration, extractant volume, and number of extractions were important in the extraction.