bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Blood Pathway on the Blood-Pressure Drop in Fish Gills, With Special Reference to Tunas
Authors: Muir Barry S. , Brown Clinton E.
Published: April 2011

In tuna gills, blood flows obliquely to the long axis of the secondary lamellae rather than with it as in other teleosts. This pathway greatly shortens the length of the small diameter respiratory vessels; it shortens them by a factor of 4 in a 1.67-kg skipjack tuna (Euthynnus pelamis) and of 9 in a 272-kg bluefin tuna (Thunnus thynnus). Total blood-pressure drop across the entire gill varies as the square of the length of these vessels, so the drop is reduced by a factor of 16 in the skipjack and of about 80 in the bluefin tuna. Blood-pressure drop also varies as the inverse of the cube of the vessel diameter, and several teleosts we examined snowed a compensating increase in diameter as length increased with fish size. Because of the shorter vessel lengths, the diameters seen in tunas are relatively small.Vessel diameter determines, considerably, the thickness of the secondary lamellae. The specialized pathway of the tunas, in addition to reducing blood pressure drop, allows the secondary lamellae to remain relatively very thin. For a given lamellar spacing, this maximizes the interlamellar water channel thickness and minimizes resistance to water flow. The specialization is a major change in "design strategy" and its advantage appears to lie with the balance between the energy requirements of moving water and blood. Some such change may be essential to the attainment of high levels of activity in fish of large size.
Vulnerability of Some Fishes to Northern Pike (Esox lucius) Predation
Authors: Mauck Wilbur L. , Coble Daniel W.
Published: April 2011

To compare vulnerability to predation by northern pike (Esox lucius Linnaeus), several species of fish in various combinations were held with pike in plastic swimming pools with and without cover and in small ponds. The most vulnerable species in order were gizzard shad (Dorosoma cepedianum), carp (Cyprinus carpio), bigmouth buffalo (Ictiobus cyprinellus), fathead minnow (Pimephales promelas), and smallmouth bass (Micropterus dolomieui). White sucker (Catostomus commersoni), green sunfish (Lepomis cyanellus), largemouth bass (Micropterus salmoides), golden shiner (Notemigonus crysoleucas), and yellow perch (Perca flavescens) showed intermediate vulnerability. Channel catfish (Ictalurus punctatus), northern pike, bluegill (Lepomis macrochirus), and black bullhead (Ictalurus melas) were least vulnerable. In two experiments in which fish were put in cages in turbid water, relative vulnerability was the same as in clearer water. Pike could not be conditioned to eat golden shiner or bluegill. There was a tendency for certain sizes of pike to select the smaller carp, fathead minnow, and bluegill within the size ranges tested.
Life History, Ecological Production, and an Empirical Mathematical Model of the Population of Sagitta elegans in St. Margaret's Bay, Nova Scotia
Authors: Sameoto D. D.
Published: April 2011

The population of Sagitta elegans Verrill in St. Margaret's Bay, Nova Scotia, was polymodal throughout the year. The modes were distinct enough to be considered as representing subpopulations. Four subpopulations were present in the Bay during the early winter and a fifth subpopulation entered the Bay during the late winter. The growth of the subpopulations was followed through the year and related to the mean water temperature. A mathematical model describing the effect of temperature on development, length of the life cycle, and reproductive potential is presented. The model simulates the effects of temperature on the body length at maturation, ovary length, generation time, and numbers surviving at various body lengths. Predictions are made on the changes in population size due to temperature, and mortality and flushing rate changes. The calorific content of the animals at different stages of the life history are given along with the carbon content of the animals. A yearly ecological production figure is given based on the turnover rates derived from the Allen curve for one of the subpopulations. The significance of the findings is discussed in relation to the geographic distribution of the species.
An Interstitial Water-Sampling Receptacle for Intertidal Mud Flats
Authors: Creaser Jr. Edwin P.
Published: April 2011

In the apparatus described, a common receptacle may be used in conjunction with a pressure-compensating chamber or a vacuum service unit. The pressure-compensating unit is operable at any stage of the tide and requires from 12 to 24 hr to obtain a sample. The vacuum extract unit is operable on the exposed flat at low tide only and usually requires from 20 to 30 min to obtain a sample.
Genic Polymorphism of Tetrazolium Oxidase in Bluefin Tuna, Thunnus thynnus, from the Western North Atlantic
Authors: Edmunds Philip H. , Sammons James I.
Published: April 2011

Blood and tissues from bluefin tuna (Thunnus thynnus) contain several electrophoretically distinct forms of the enzyme tetrazolium oxidase. Every fish exhibits one of three oxidase phenotypes: a single band at either of two positions on the gel or both bands with a third midway between them. The pattern comprising three bands occurs in both males and females. Frequency distributions of phenotypes conform to Hardy-Weinberg distributions and apparently are not related to fish size. We conclude from these facts that bluefin tetrazolium oxidase contains two protein subunits and that phenotypic differences among individuals reflect segregation of two codominant autosomal alleles. Frequency distributions of phenotypes in three areas of the western North Atlantic do not differ significantly.
A Practical Method for Drying Freshwater Fish
Authors: Lantz A. W. , Iredale D. G.
Published: April 2011

A method and equipment suitable for drying fish in remote areas are described. Fish cut transversely into thin steaks dried faster and more completely than whole fillets, dressed fish, or minced fish. Fish were dried satisfactorily in about 7 hr on screen trays in a dryer constructed of plywood and accommodating an oil-fired space heater. The method is satisfactory for large and small quantities of fish, and may be applied to species with a limited sales potential that are frequently caught incidentally with more valuable commercial species.
Amphipacific Distribution of Polychaetes
Authors: Uschakov P. V.
Published: April 2011

Some 25 polychaete species common to Asiatic and American coasts are recorded in south-boreal and subtropical waters of the Pacific; they are absent in both northern cold regions (Bering and Okhotsk seas) and in tropical zones. Examples are also given of analogous, closely related twin species, and subspecies. Such disjunct amphipacific ranges of these species are probably caused by ancient changes in climatic conditions. The possibility of modern oceanic currents having some influence on this is also not excluded. The author suggests a study of life cycles of amphipacific species in the extremes of their habitats.
Eualus berkeleyorum n.sp., and Records of Other Caridean Shrimps (Order Decapoda) from British Columbia
Authors: Butler T. H.
Published: April 2011

A new shrimp species Eualus berkeleyorum (family Hippolytidae) is described. The first known occurrence off British Columbia of four pelagic species are recorded: Parapasiphaë sulcatifrons Smith (family Pasiphaeidae); Acanthephyra curtirostris Wood-Mason, A. quadrispinosa Kemp, and Systellaspis braueri (Balss) (family Oplophoridae).
Taxonomy, Distribution, and Biology of the Northern Rockflsh, Sebastes polyspinis
Authors: Westrheim S. J. , Tsuyuki H.
Published: April 2011

Available information is summarized on the taxonomy, distribution, abundance, and biology of the northern rockfish, Sebastes polyspinis (Taranetz and Moiseev 1933). Morphological and biochemical descriptions of the taxon are provided. Geographic range is east Kamchatka (USSR) to Yakutat, Alaska (USA). Maximum depth of capture in the Gulf of Alaska is 196 fath (358 m). Absolute abundance appears to be low, and centered in shallow water with juvenile Pacific ocean perch (Sebastes alutus). Von Bertalanffy growth constants, for combined sexes, are: K = 0.18, and L∞ = 31.4 cm. All females larger (older) than 21 cm (7 years) were mature, and all smaller (younger) than 18 cm (5 years) were immature.
Eutrophication of Lake 227, Experimental Lakes Area, Northwestern Ontario, by Addition of Phosphate and Nitrate
Authors: Schindler D. W. , Armstrong F. A. J. , Holmgren S. K. , Brunskill G. J.
Published: April 2011

Addition of 0.34 g P as Na2HPO4 and 5.04 g N as NaNO3 per square meter to a small unproductive Canadian Shield lake over a period of 17 weeks caused a severalfold increase in phytoplankton standing crop, and a change in dominant species from Chrysophyceae to Chlorophyta. Reactive phosphate concentrations remained at undetectable levels in the epilimnion after fertilization, and inorganic nitrogen concentrations remained low. Most of the added phosphorus and nitrogen was rapidly taken up by phytoplankton and sedimented with the seston.Although concentrations of total CO2 decreased to less than 20 μmoles/liter and pH values increased to greater than 9 in late summer, a high standing crop of phytoplankton was maintained. No marked increase in the rate of phytoplankton production was noticed Experiments in polyethylene containers suspended in the lake during this period of low total CO2 indicated that carbon was not limiting to algal production, except possibly at algal standing crops in excess of 100 μg/liter chlorophyll a, and that phosphorus was the primary limiting nutrient.Sodium added with the nutrients remained in the epilimnion until fall overturn, indicating that very little of it was utilized by phytoplankton.
Effects of Adaptive and Nonadaptive Feeding of Hydrogenated and Raw Herring Oil on Hearts and Livers of Weanling Rats
Authors: Odense P. H. , Brockerhoff H.
Published: April 2011

It has been reported that the feeding of high levels of rapeseed oil to weanling rats leads to the eventual appearance of cardiac lesions. Marine oils have come under suspicion since most of them contain lesser amounts of the long-chain (C20 and C22) monounsaturated acids found in rapeseed oil. Weanling rats, male and female, were given diets containing 18% hydrogenated or raw herring oil for 24 days. Two other groups were adapted gradually to these diets during an initial period of 12 days. Control groups were kept on diets containing corn oil and lard. Histological investigations of the hearts failed to produce any evidence of unusual fat deposition or cardiac damage in any of the rats, either control or experimental. The possibility that a more prolonged feeding of the oil could lead to lesions cannot be excluded. Liver weights, when expressed as fractions of the body weights, were slightly, though significantly, higher (13–27%) in all groups fed with raw or hydrogenated herring oil, but histological examination failed to disclose any difference between these livers and those of the control groups. The experiments indicate that herring oil, raw or hydrogenated, when fed to weanling rats for 24 days, produced no untoward histological changes in the heart or liver tissues.
Fertilization of Steelhead Trout (Salmo gairdneri) Eggs With Cryo-preserved Sperm
Authors: Ott A. G. , Horton H. F.
Published: April 2011

The average percent fertilization of fresh steelhead trout (Salmo gairdneri) ova inseminated with cryo-preserved sperm was 59 in 90 tests. Sodium bicarbonate, lecithin, and mannitol at 750, 750, and 250 mg/100 ml, respectively, were included in the extender. The most effective concentration of dimethyl sulfoxide in the extender was 12% (v/v). Significant differences in percent of fresh ova fertilized with cryo-preserved sperm were attributed to both parents.
Orientation of Goldfish (Carassius auratus) in Response to a Shallow Gradient of a Sublethal Concentration of Copper in an Open Field
Authors: Kleerekoper H. , Westlake G. F. , Matis J. H. , Gensler P. J.
Published: April 2011

In slowly flowing water, seven naive goldfish 30-cm long changed their locomotor behavior upon entering a mass of water containing shallow gradients of copper chloride. The concentration was 11–17 μg/liter Cu++ in most of this mass, with small isolated pockets containing maximally 50 μg/liter. The amount of time spent by the fish, the average size of turn, and the variance of the size of turn increased in the "polluted" region. The orientation of the fish in this region deviated consistently in the upstream direction resulting in the increase in time spent in the area of highest concentration. Comparison of the locomotor behavior of the fish in sodium chloride of the same concentration and in laboratory water established that the changes mentioned were in response to the copper rather than the chloride ion.
Distinguishing Cunner and Tautog Eggs by Immunodiffusion
Authors: Orlowski Stanley J. , Herman Sidney S. , Malsberger Richard G. , Pritchard Hayden N.
Published: April 2011

This note describes a simple and rapid immunodiffusion method used to distinguish Tautoga onitis (tautog) eggs from those of Tautogolabrus adspersus (cunner). These closely related species have eggs so similar in their early stages that positive identification was considered virtually impossible using previously established techniques.
Recovery of Planted Brook Trout, Splake, and Rainbow Trout from Selected Ontario Lakes
Authors: Fraser J. M.
Published: April 2011

Recoveries of hatchery-reared brook trout (Salvelinus fontinalis), splake (Salvelinus namaycush × S. fontinalis), and rainbow trout (Salmo gairdneri), planted in lakes having different resident fishes, were highest (9–30%) in a lake in which minnows and the brook stickleback were the only other fishes. Recoveries, by angling and gillnetting, were considerably lower (2–15%) in two lakes containing the white sucker and minnows, and still lower (0.5–5%,) in two lakes containing spiny-rayed species as well. Recoveries were lowest (< 0.5%) in a lake having a complex fish community that included native brook and lake trout. Planted splake and rainbow trout generally yielded higher returns, in weight, than brook trout in comparable situations.The low survival of planted fish was apparently due to the low fertility of the waters and to competition with, or predation by, resident fish species. Predation by fish-eating birds and mammals may also have had an effect.The weight of the catch of salmonids exceeded the weight planted in only one lake. Here, the mean yield of planted salmonids was 8.4 kg/ha per year in comparison with 2.6 to < 0.5 kg/ha per year in the five other study lakes.
Effects of Volcanic Ashfalls on Chemical and Sediment Characteristics of Two Alaskan Lakes
Authors: Barsdate Robert J. , Dugdale Richard C.
Published: April 2011

Cores from two lakes on Afognak Island, 150 km southeast of the Aleutian volcanic arc, indicated that several ashfalls have formed continuous layers over the lake basins, at least partially returning the lakes to a juvenile state with respect to their sediments. Abundant diatom remains were found in the sediments above each ash layer. During several hundred years after each ashfall, the transition to mature conditions followed a pattern characterized by decreasing diatom abundance and gradual increases in organic matter and clay-size inorganic particulates. High silica concentrations occurred in lakes within the area covered by the ashfall of the 1912 Mount Katmai eruption.
Effects of Acclimation and Acute Temperature Experience on the Swimming Speed of Juvenile Coho Salmon
Authors: Griffiths J. S. , Alderdice D. F.
Published: April 2011

Swimming performance of juvenile coho salmon (Oncorhynchus kisutch), 7.5–9.5 cm in total length, was investigated in a stamina tunnel, generally at 3 C intervals of temperature over the range of thermal tolerance.Optimum (ultimate maximum) performance (5.8 lengths/sec) occurred at a combination of acclimation and test temperatures near 20 C. A declining ridge of sub-optimum performance (test temperature ridge) was found at acclimation temperatures below 20 C; maximum performance at each acclimation temperature level was found on the ridge at test temperatures higher than those of acclimation. Conversely, maximum performance at given test temperatures occurred on a second ridge (acclimation temperature ridge) at acclimation temperatures near those of testing. There was an apparent shift in location of the acclimation temperature ridge, indicative of seasonal performance compensation and improved capacity to perform at low acclimation temperatures during the winter period. At test temperatures below 5 C, maximum performance occurred at acclimation temperatures of about 6–8 C. Lowest performance within the zone of thermal tolerance was associated with acclimation and test temperatures of 2 C.
Parasites of Fish from Lake of the Woods, Ontario
Authors: Dechtiar Alex O.
Published: April 2011

Results of a survey of the parasite fauna of fish from Lake of the Woods and adjacent lakes are presented. Over 600 fish representing 41 species were examined, and 170 species of parasites, mostly helminths, are recorded. Every species of fish and 97% of all fish examined carried at least one parasite. No parasites considered hazardous to human health were found. A number of parasites, reported elsewhere as contributors to fish mortalities, are recorded.
Effects of Four Insecticides on the Ability of Atlantic Salmon Parr (Salmo salar) to Learn and Retain a Simple Conditioned Response
Authors: Hatfield C. T. , Johansen P. H.
Published: April 2011

The learning ability of untreated, acetone-treated, and insecticide-treated Atlantic salmon parr was determined in a shuttlebox conditioning apparatus. Learning improvement on second conditioning was also tested.The results were that: (1), acetone did not affect learning; (2), with treatment for 24 hr at the 96-hr LC50 Sumithion® completely inhibited learning, Abate® retarded learning, DDT mildly enhanced learning, and methoxychlor was without a detectable effect; (3), when Abate and methoxychlor-treated salmon in item (2) above were retrained 1 or 7 days later their learning ability improved; but DDT-treated fish showed no improvement; (4), four days of recovery from a 24-hr exposure to the 96-hr LC50 of Abate or Sumithion still resulted in slow learning ability, although after 7 days of recovery learning rate was the same as that of controls; (5), insecticide treatment at the 96-hr LC50 level for 24 hr interposed between first and second conditioning had little or no effect on learning ability; (6), insecticide concentrations at one-tenth the 96-hr LC50 or lower had no effect on learning ability.
Pathological Effects in Formalin-Treated Rainbow Trout (Salmo gairdneri)
Authors: Smith Charlie E. , Piper Robert G.
Published: April 2011

When rainbow trout (Salmo gairdneri) were exposed to 167 and 250 ppm formalin for 1 hr, moribund fish showed severe histopathological changes in gill epithelium. Hematocrit values and numbers of immature red blood cells were increased, suggesting a physiological response to hypoxia. The results are discussed in relation to the probable cause of death.
Review of Studies on Feeding of Aquatic Invertebrates Conducted at the Institute of Biology of Inland Waters, Academy of Science, USSR
Authors: Monakov A. V.
Published: April 2011

The main results obtained at the Borok Institute during the last decade are reviewed. Food and methods of feeding by various aquatic invertebrates (Rotatoria, Oligochaeta, Mollusca, Cladocera, Copepoda, Chironomidae larvae), daily food consumption, and assimilation of food have been investigated. Most invertebrates are omnivores although some species live on only one type of food. Daily food consumption changes with food concentration, temperature, and size of consumer. At 15–22 C and a concentration of food close to optimum, mean daily rations of most invertebrates studied usually range from 25 to 100% of body weight. Only in pulmonary Gastropoda and silt-eating Tubificidae does it greatly exceed body weight. In rare cases, at very high concentration of food unusual in nature, the so-called "extra feeding" may take place under experimental conditions. For most invertebrates feeding on natural food at optimum concentrations, index of assimilation varies widely, but rarely exceeds 50%. The assimilability of plant food was 45–55% in the majority of investigated species and appears to be considerably higher when animal food is used.
Distribution of Iron, Magnesium, Copper, Zinc, and Silver in Oysters Along the Georgia Coast
Authors: Windom Herbert L. , Smith Ralph G.
Published: April 2011

The shells and soft tissues of approximately 50 oysters (Crassostrea virginica Gmelin) collected along the Georgia coast were analyzed for iron, magnesium, copper, zinc, and silver. Magnesium was the only metal found to be more concentrated in the shells. Correlations between the metals in the soft tissues suggest that iron and magnesium, and copper, zinc, and silver form two separate groups of metals which are concentrated similarly by the oyster. Geochemical characteristics of a given metal are an important control in their uptake by the oyster.
Failure of Bluegill Sunfish, Lepomis macrochirus, to Habituate to Handling
Authors: Chiszar David , Moody Mark , Windell J. T.
Published: April 2011

Two experiments measured changes in breathing rate in bluegill sunfish (Lepomis macrochirus) after several forms of routine daily handling. Both experiments revealed large increases in this measure after handling. However, the magnitude of this response did not diminish during 10 days of handling. Thus, the bluegill's respiratory response does not readily habituate to these treatments.
Introduction to the Proceedings of the 1971 Symposium on Salmonid Communities in Oligotrophic Lakes
Authors: Loftus Kenneth H. , Regier Henry A.
Published: April 2011

not available
Cayuga Lake: Effects of Exploitation and Introductions on the Salmonid Community
Authors: Youngs William D. , Oglesby Ray T.
Published: April 2011

Cayuga Lake, a glacially formed, warm monomictic lake in New York State, has an area of 172.1 km2 and a mean depth of 54.5 m. It now exhibits qualitative signs of eutrophication in phytoplankton composition and aquatic vegetation. However, hypolimnetic oxygen depletion has not changed to any great extent over the last fifty years.Early commercial fisheries were for nonsalmonid species. Whitefish have apparently never been common in the lake, though cisco have at times been abundant. In recent times the lake and rainbow trouts have provided an appreciable sport fishery. The lake trout population is maintained by annual stocking at a level that provides good sport fishing. Natural reproduction is not successful for lake trout, presumably due to siltation of spawning areas.Introduced species appear to have caused some changes in the native fish community. The alewife appears to have replaced the cisco and now is the major forage species in the lake. Other important introductions include the smelt and the sea lamprey. The salmonine populations were built up despite the presence of sea lamprey. Life history information on other species common in the lake is presented.
Evidence for a Home Site and Homing of Adult Yellowtail Rockfish, Sebastes flavidus
Authors: Carlson H. Richard , Haight R. E.
Published: April 2011

Existence of a home site and homing ability was established for adult yellowtail rockfish, Sebastes flavidus (Ayres). Fish returned to the home site from as far as 22.5 km, some after displacement to other schools of the species and some after 3 months in captivity. Stretches of deep open water appeared to pose a hindrance to homing. Intensive fishing of a localized adult stock could cause a long-term decline in its abundance.
The Structure of the Attachment Organ of Lernaeopodidae (Crustacea: Copepoda)
Authors: Kabata Z. , Cousens B.
Published: April 2011

The morphology and the anatomy of the bulla, a unique attachment organ of the parasitic copepods belonging to Lernaeopodidae (Caligoida) is described. By their anatomy the bullae can be divided into three types, associated with three groups of fishes: freshwater teleosts, marine teleosts, and elasmobranchs. The evolution of Lernaeopodidae is briefly outlined. The authors point out that the type of the bulla appears independent of the phylogenetic position of the parasite but is related only to the type of the host. It is concluded that the bulla is more than an attachment organ and that it enters into physiological association with the tissues of the fish.
Dimethyl Sulfide as an Odor Component in Nova Scotia Fall Mackerel
Authors: Ackman R. G. , Hingley J. , MacKay K. T.
Published: April 2011

A strong petroleum refinery odor in mackerel taken in late November 1971, near Halifax and on the outer edge of the Emerald Bank, has been identified as harmless dimethyl sulfide. It has been shown to originate from stomach contents and is specifically associated with the pteropod Spiratella retroversa. The dimethyl sulfide was not accompanied by any very large deposition in the fish of the known precursor of algal origin, dimethyl-β-propiothetin. Petroleum product pollution was not involved.
A Survey of the Total Cadmium Content of 406 Fish from 49 New York State Fresh Waters
Authors: Lovett Raymond J. , Gutenmann Walter H. , Pakkala Irene S. , Youngs William D. , Lisk Donald J. , Burdick George E. , Harris Earl J.
Published: April 2011

Fish from New York State fresh waters were surveyed for total cadmium. The majority of samples contained 20 ppb or below. The remainder showed concentrations up to 100 ppb with only few above this concentration. Fishes from central New York waters rarely contained cadmium greater than 20 ppb. Fish from Adirondack waters contained cadmium above 20 ppb most consistently. These higher concentrations may be related to generally higher background cadmium levels in this Adirondack area where many metallic ore deposits are located with which cadmium is typically associated. Cadmium accumulation only occasionally appeared species-dependent. No relation was obvious between total residues of the metal and size or sex of fish or age of lake trout. The cadmium concentrations observed are comparable to those commonly present in many other foods.
Change in Thermal Regime as a Cause of Reduction of Benthic Fauna Downstream of a Reservoir
Authors: Lehmkuhl D. M.
Published: April 2011

The kinds and numbers of Ephemeroptera and other insects in the Saskatchewan River are greatly reduced downstream of a dam. This is attributed to changes in river temperatures caused by the reservoir. The river is warmed in winter and cooled in summer. Consequently, mayflies and other insects with strict thermal requirements cannot hatch and grow successfully. The effect is evident 70 miles downstream.
Biology of Bothrimonus (= Diplocotyle) (Pseudophyllidea: Cestoda): Ecology, Life Cycle, and Evolution; a Review and Synthesis
Authors: Sandeman I. M. , Burt M. D. B.
Published: April 2011

An integrated account of the ecology and life cycle of Bothrimonus is synthesized from the literature, experiment, and observation of larval and adult stages of the parasite. Bothrimonus has a circumpolar distribution in boreal or subarctic conditions. As an adult it is found in a wide variety of fish hosts which feed in littoral or estuarine waters. Adult worms have a short life-span in the fish host and occur only seasonally. A single intermediate host appears to be involved in the life cycle and this is most commonly a brackish-water gammarid. The operculate eggs, which contain unciliated larvae, possess characteristic polar filaments which have an adhesive function. Entry is almost certainly by ingestion of eggs by the gammarid host; the larval forms often attain sexual maturity within the gammarid host with accompanying production of apparently normal eggs. Although it has been possible to infect fish hosts experimentally with larval stages, it has not yet been possible to infect gammarids with eggs obtained either from neotenic individuals in gammarids or from adults in the fish host.The life cycle of Bothrimonus indicates closer affinities of the Cyathocephalidae with caryophyllaeid than with other pseudophyllidean tapeworms. Distribution is discussed in terms of its evolution and a freshwater origin in the Ponto–Aralo–Caspian province is proposed.
Inadequacy of Aquarium Antibacterial Formulations for the Inhibition of Potential Pathogens of Freshwater Fish
Authors: Trust T. J.
Published: April 2011

The antibacterial activity of fourteen products marketed for the therapy and prophylaxis of bacterial infections of aquarium fishes was tested. When used at the dilution recommended by the manufacturers, the products failed to inhibit the growth of bacterial species known to be potential pathogens of freshwater fishes and failed to reduce significantly the bacterial numbers in water containing fish. Concentrations of the products that were bacteriostatic, bactericidal, or sporicidal were markedly higher than the recommended concentrations. Use of the products at higher concentrations in aquaria showed two of the products to be inimical to fish.
Oxidation of Lactate to Carbon Dioxide by Rainbow Trout (Salmo gairdneri) Tissues
Authors: Bilinski E. , Jonas R. E. E.
Published: April 2011

A comparative study on the ability of various fish tissues to carry out different stages of lactate oxidation was conducted with rainbow trout (Salmo gairdneri). Rate of oxidation of Na-L-lactate-1-14C (5 mM) and Na-L-lactate-3-14C (5 mM) by tissue slices from white muscle, red lateral line muscle, heart, liver, kidney, and gills was determined at 15 C by measuring the formation of 14CO2. In all tissues the liberation of 14CO2 was considerably higher with lactate-1-14C than with lactate-3-14C. Liver was the most active tissue for oxidation of lactate-1-14C (2805 mμmoles/g wet tissue/hr at 15 C) and gills for oxidation of lactate-3-14C (556 mμmoles/g wet tissue/hr at 15 C). With both substrates activity in the white muscle was very limited, whereas other tissues had an intermediate level of activity. The results suggest that, in trout, the catabolism of lactate may take place through oxidative decarboxylation of pyruvate and that liver plays an important role in such a process. It appears also that complete oxidation of lactate may be of significance in supplying energy for the exchange reactions in gills.
Differences in Littoral Fauna Due to Fluctuating Water Levels Below a Hydroelectric Dam
Authors: Fisher Stuart G. , Lavoy Alison
Published: April 2011

Water level fluctuations below a hydroelectric dam on the Connecticut River produce a freshwater "intertidal" zone. Along a transect in this zone from high to low water mark benthic invertebrates increased markedly in density and taxonomic diversity. Community composition shifted from chironomid–oligochaete predominance on the most exposed sites to mollusc predominance on the least exposed sites.
Fatty Acids in Surface Particulate Matter From the North Atlantic
Authors: Schultz David M. , Quinn James G.
Published: April 2011

The fatty acid composition of particulate matter from surface waters in the North Atlantic has been investigated. A high proportion is long-chain polyunsaturated acids, typical of a marine origin. The low relative abundance of iso and anteiso 15-carbon acids indicates little bacterial contribution to the particulate matter. This fatty acid distribution is in contrast to that found in estuarine particulate matter, which contains only trace amounts of the long-chain polyunsaturated acids and substantial quantities of branched chain acids.
Mercury Content of Spiny Dogfish (Squalus acanthias) in the Strait of Georgia, British Columbia
Authors: Forrester C. R. , Ketchen K. S. , Wong C. C.
Published: April 2011

Total mercury content of Squalus acanthias sampled in the Strait of Georgia reached levels of 0.5 ppm at fish lengths of 72 and 77 cm for male and female fish, respectively. For any given length above 65 cm the mercury content was higher among males than females and higher in samples taken off the Fraser River Estuary than in other areas of the Strait. Levels of mercury reached 1.7 ppm in males (to 95 cm in total length) and almost 2.0 ppm in females (to 120 cm in total length).
The Arctic Dredge, a Benthic Biological Sampler for Mixed Boulder and Mud Substrates
Authors: Clarke A. H.
Published: April 2011

Benthic biological dredges of a new design have been used successfully on ice-rafted archibenthal and abyssal sediments of boulders and mud. The dredge is kite-shaped, of massive construction, and features a single point for cable attachment and a removable cannister for specimen retrieval. Experience in Baffin Bay, the Labrador Sea, and the Icelandic Shelf indicates that the arctic dredge is a reliable tool for arctic and subarctic research.
Food Specialization By Individual Trout
Authors: Bryan James E. , Larkin P. A.
Published: April 2011

Analyses of stomach contents showed that the kinds of prey eaten by brook trout (Salvelinus fontinalis), cutthroat trout (Salmo clarki), and rainbow trout (Salmo gairdneri) were seldom distributed at random among the individuals. Repeated observation of food eaten by individuals in a stream and ponds showed that prey types were eaten in proportions which were characteristic for an individual.Specialization occurred on several different kinds of prey. Although the degree of specialization was higher during shorter intervals, the data suggested that some specialization persisted for half a year. There were no striking correlations between degree of specialization and other individual properties such as size, growth rate, weight of food, number of food items, previous specialization, or area of recapture.In addition to the observations on trout in relatively undisturbed habitats, a field experiment was conducted using laboratory-reared rainbow trout held in small ponds. The food of each trout in the experiment was sampled repeatedly. In analysis of variance, interaction among the individuals and kinds of prey eaten showed that food specialization occurred. Both the absolute and relative abundance of potential prey were constant during the experiment.
New Complexities in Zoogeography and Taxonomy of the Pygmy Whitefish (Prosopium coulteri)
Authors: Lindsey C. C. , Franzin W. G.
Published: April 2011

Pygmy whitefish (Prosopium coulteri) are recorded for the first time from the Peel–Mackenzie river drainage (Elliott Lake, Yukon Territory) and from the Hudson Bay drainage (Waterton Lakes, Alberta, in the South Saskatchewan–Nelson river system). The morphology of specimens from both localities contradicts the previously known pattern of a southeastern "low-rakered" and a northwestern "high-rakered" form (with the two forms occurring sympatrically in some lakes of the Bristol Bay area). Specimens from Elliott Lake, the most northerly known locality, resemble the southeastern form and those from Waterton Lakes the northwestern form. Both Waterton and Elliott lakes lie close to unglaciated refugia, suggesting that the species may have survived Wisconsin glaciation and diverged in several different watersheds.
Arsenic, Cadmium, Copper, Mercury, and Zinc in Some Species of North Atlantic Finfish
Authors: Windom H. , Stickney R. , Smith R. , White D. , Taylor F.
Published: April 2011

Arsenic, cadmium, copper, mercury, and zinc analyses of 91 individuals representing 35 species of North Atlantic finfish (Chondrichthys and Osteichthys) indicate that these metals occur at similar levels in both inshore and offshore species. Chondrichthys and Osteichthys have similar concentrations of all the metals, excepting arsenic which is higher in Chondrichthys. Analyses of various tissues in Chondrichthys reveal higher metal concentrations in the liver except for mercury which was higher in muscles.
Extension of Shelf-Life of Indian Mackerel (Rastrelliger kanagurta) by Irradiation
Authors: Venugopal V. , Savagaon K. A. , Kumta U. S. , Sreenivasan A.
Published: April 2011

A dose of 150 krad was optimum for extending refrigerated (0–2 C) shelf-life of fresh Indian mackerel (Rastrelliger kanagurta). This dose extended the shelf-life to 25–30 days from 10–12 days without inducing undesirable changes in the organoleptic qualities. Vacuum-packaging affected the appearance of the irradiated product by drawing out muscle fluids during storage. Samples irradiated aerobically did not become rancid and were acceptable to a taste panel. Storage of fish in ice beyond 5 days before irradiation reduced its post-irradiation shelf-life.
Clostridium botulinum Control in Cold-Smoked Salmon: a Review
Authors: Southcott B. A. , Razzell W. E.
Published: April 2011

This review considers questions concerning the growth and toxin production of Clostridium botulinum in cold-smoked salmon. In order to produce a product which would be safe as well as acceptable from the consumers’ point of view, consideration must be given to the worst abuses to which the product might be exposed. Present knowledge regarding the effects of salt, smoke, and other factors on the preservation of cold-smoked salmon is inconclusive. Strict control of the storage temperature is the only method of positively preventing toxin production or outgrowth of spores of C. botulinum. In comparison with fish processed through a hot-smoke procedure, cold-smoked salmon appears to present a lesser hazard, but for unknown reasons.
Sensitivity of American Eels (Anguilla rostrata) and Atlantic Salmon (Salmo salar) to Weak Electric and Magnetic Fields
Authors: Rommel Jr. S. A. , McCleave J. D.
Published: April 2011

Two long distance migrating fishes, the American eel (Anguilla rostrata) and the Atlantic salmon (Salmo salar), consistently showed conditioned cardiac responses to weak electric fields applied perpendicular but not parallel to their bodies. In fields with a power density of 0.11 × 10−3 pW/cm3, 63% of the eels tested were successfully conditioned, as were 56% of the salmon tested at 0.9 × 10−4 pW/cm3. At greater field intensities greater percentages of salmon and eels were successfully conditioned. However, at two lower intensities fewer salmon and no eels responded. These fields are of the magnitude that occur naturally in ocean currents. As geoelectric fields are perpendicular to the water motion that generates them, this sensitivity might allow a migrating fish to align itself upstream or downstream in an ocean current in the absence of fixed references. Results of magnetic conditioning experiments in eels were equivocal. Attempts to condition salmon to weak magnetic fields were unsuccessful.
Effect of Sodium Tripolyphosphate on Thaw Drip and Taste of Fillets of Some Freshwater Fish
Authors: Manohar S. V. , Rigby D. L. , Dugal L. C.
Published: April 2011

The effect of polyphosphate treatment on thaw drip was determined on six freshwater fish species. No relation could be found between state of rigor and thaw drip in control and treated fillets or increase in weight due to dipping. Thaw drip was reduced by an average of 60% as a result of treatment. The difference in weight between control and treated fillets after thawing averaged 5% or more of the initial weight in favor of the treated products. A difference in taste could be detected in yellow walleye (Stizostedion vitreum) and in whitefish (Coregonus clupeaformis) samples, but preferences were equally divided between treated and untreated samples.
Macrophthalmia in the American Eel (Anguilla rostrata)
Authors: Vladykov Vadim D.
Published: April 2011

Three American eels (Anguilla rostrata) with unusually large eyes, obtained from the collections of the Museum of Zoology, University of Michigan (UMMZ 80616), are described. Two are males, 495 and 521 mm in total length, and the third, probably of the same sex, had an estimated length of 752 mm. The horizontal diameter of the eye was equal to the inter-orbital width in the smallest specimen, while in the two others it was greater. These fish, captured in 1926, came from a sample of elvers liberated into Sherman Lake, Michigan, about 35–40 years earlier.
Interaction of Temperature and Copper Ions as Orienting Stimuli in the Locomotor Behavior of the Goldfish (Carassius auratus)
Authors: Kleerekoper H. , Waxman J. B. , Matis J.
Published: April 2011

Movements of single goldfish (Carassius auratus) were monitored in a free choice situation comprising zones of laboratory water or copper-containing water (0.010 ppm as CuCl2) each at two temperatures, 21.1 ±.1 and 21.5 ±.1 C.Fish entered the copper zone at 21.1 C significantly less frequently and spent less time there per entry as compared to the noncopper zone ("avoidance" behavior). The copper zone at 21.5 C became significantly "attractive" to the fish in terms of both frequency of entry and time spent.In the same terms, laboratory water at 21.5 C was "attractive" to the fish but became significantly more so in the presence of copper ions at the concentration of 0.010 ppm.
Preliminary Comparisons of Day and Night Habits of Freshwater Fish in Ontario Lakes
Authors: Emery Alan R.
Published: April 2011

Observations by SCUBA in Georgian Bay and Algonquin Park, Ont., indicate fish have specific habits of diurnal, crepuscular, and nocturnal activity in freshwater lakes. Of 21 species investigated, 17 either schooled or aggregated in the daytime, but only one (Osmerus mordax) schooled at night. The number of fish apparent at night in shallow water was greater than in the daytime primarily because of the influx of offshore species and lack of cover for resting diurnal species. Color changes parallel those reported in tropical oceans; at night a barred or mottled pattern was assumed by some fish resting on the bottom and bold daytime horizontal patterns faded. The parallel evolution of these color patterns in fresh and salt water suggests a strong evolutionary pressure for prey animals to disguise body shape when at rest at night, and that bold color patterns are disadvantageous when swimming at night.
Direct Estimates of Gillnet Selectivity to Walleye (Stizostedion vitreum vitreum)
Authors: Hamley John M. , Regier Henry A.
Published: April 2011

The selectivity of gillnets is usually estimated "indirectly" from comparisons of catches by two or more mesh sizes, assuming that the selectivity curves for all meshes have the same shape and amplitude. We estimated selectivity "directly" by fishing marked walleye (Stizostedion vitreum vitreum) with gillnets of [Formula: see text] (3.81–11.43-cm) mesh. The selectivity curves were bimodal but each could be resolved into two unimodal components representing fish caught by wedging and tangling, respectively. We fitted the selectivity of each mesh to a pair of Pearson’s Type I curves. As the mesh size increased, amplitude of the selectivity curves increased rapidly and tangling occurred over a progressively narrower range of (fish girth)/(mesh perimeter) ratio. Our estimates agreed with data from four out of seven other gillnetting studies, indicating a wider applicability but also a need to consider additional variables or to standardize fishing methods. Because the assumption of equal amplitudes is not realistic, the indirect methods overestimate selectivity curves on the left and underestimate them on the right.
Life History of Two Isolated Populations of Arctic Char (Salvelinus alpinus) in Spring-Fed Tributaries of the Canning River, Alaska
Authors: McCart P. , Craig P.
Published: April 2011

Two isolated populations of Arctic char (Salvelinus alpinus) in spring-fed tributaries of the Canning River, Alaska, had meristic characters that corresponded to those of the Western Arctic–Bering Sea form of Arctic char. The two populations demonstrated slight differences in growth rates, age at maturity, longevity, and food habits. The fish were characterized by small size (maximum 235 mm), low growth rates, low fecundities (maximum 199 eggs), and annual spawning after maturity. Mature fish were darkly pigmented and parr marks were retained throughout life. The spawning season appeared to be sometime in November, when the eggs of mature females averaged 3.8 mm in diameter.
Claw Loss and Other Wounds in Commercially Caught Lobsters (Homarus americanus)
Authors: Scakratt D. J.
Published: April 2011

Incidence of claw loss in commercially caught lobsters (Homarus americanus) ranged between 5 and 19% but could not be attributed to any single cause, although factors such as rough handling by fishermen, moving fishing gear, and ice in shallow waters may contribute. The incidence of other wounds ranged between 1 and 11% and there was evidence that serious wounding was related to the local practice of harvesting Irish moss by rakes.
First Record of Bacterial Kidney Disease in an Apparently Wild Salmonid in British Columbia
Authors: Evelyn T. P. T. , Hoskins G. E. , Bell G. R.
Published: April 2011

A confirmed case of bacterial kidney disease in a sports-caught rainbow trout (Salmo gairdneri) from Loon Lake, British Columbia, is reported. The case represents the first record of this disease in an apparently wild fish in this province. Descriptions of the affected trout and of the causative bacterium are provided.
Fatty Acid Content of Coho Salmon, Oncorhynchus kisutch — A Statistical Approach to Changes Produced by Diet
Authors: Tinsley Ian J. , Krueger Hugo M. , Saddler James B.
Published: April 2011

Stepwise multiple regression procedures have been used to develop equations expressing the fatty acid content of fingerling coho salmon, Oncorhynchus kisutch, as a function of fish length and the time the salmon had been maintained in the laboratory on a specific diet. High correlation coefficients from the multiple regressions were obtained for most of the fatty acids studied and from the derived equations the fatty acid content of individual fish could be predicted with a fair degree of precision.Under the specified experimental conditions changes in wet weight, the total mass of fatty acids per salmon, and the mass of most individual fatty acids per salmon were dependent on the time in the laboratory and on the product (interaction) of time in laboratory with length of the salmon. At 8-cm length body weight was increasing 30 mg daily and the fatty acid content 7.3 mg daily.A detailed analysis is presented for several fatty acids whose predicting equations are representative of the different relationships observed. A case is presented for the unique role of fatty acid 22:6 in fish.
Karyotypes and Erythrocyte Sizes of some Diploid and Triploid Fishes of the Genus Poeciliopsis
Authors: Cimino Michael C.
Published: April 2011

Karyotypes of diploid (2n = 48) and triploid (3n = 72) members of a unisexual–bisexual complex of fish of the viviparous genus Poeciliopsis consist of morphologically uniform acrocentrics, graded in size from large to small, and thus unsuitable for tracing evolutionary pathways within the complex. A comparison of blood samples from diploid and triploid forms showed that the mean diameters of erythrocytes of the triploids are one and one-half times those of diploids. This relationship provides an important tool for easily distinguishing the two types in samples taken from field populations.
Occurrence of American Eels, Anguilla rostrata, in Waters Overlying the Eastern North American Continental Shelf
Authors: Wenner Charles A.
Published: April 2011

Eleven reproductively maturing specimens of the American eel, Anguilla rostrata, were collected during three independent off-shore trawling operations. Three females were taken on December 5, 1967 southeast of the mouth of Chesapeake Bay in 10–13 fathoms, one male and one female on November 5, 1969 southeast of Cape Cod in 35–45 fathoms, and six females east of Assateague Island on December 22, 1971 in 5 fathoms. Morphometrical analysis showed that the specimens were within the range of "silver" phase of Anguilla rostrata. Gonadal observations were made on all specimens.