bluuebunny/crossref_metadata_2025 huggingface dataset:
Sternal Spines as a Characteristic for Differentiating between Females of some Pandalidae
Authors: McCrary Jerry A.
Published: April 2011

A life-history study of four commercially important species of pandalid shrimps in Alaska shows that with the exception of one species, a morphological characteristic is possessed that is useful in estimating age and survival of certain females. Pandalus borealis, P. goniurus, P. hypsinotus, and Pandalopsis dispar possess a series of small spines located on the median ventral surface of the abdomen or sternites. With the exception of P. dispar, the sternal spines are present throughout the postlarval life of the shrimp until the first molt into breeding dress as a female. Only females that are sexually mature and are very near egg extrusion undergo this molt. At this time, the spines are either completely lost or reduced to minute protuberances. Between spawning seasons, females that extruded eggs during a prior spawning season can be easily identified as those that do not possess abdominal spines or possess only minute protuberances. Therefore, females that possess spines during any time of year are those that have not previously spawned. This characteristic is especially useful during the period between successive spawning seasons when it can be an effective tool in determining the number of females surviving one or more spawnings. Age and survival of pandalids is usually estimated through analysis of length-frequency ranges. This is often difficult with respect to females because of overlapping length ranges between age classes. Sternal spines may be useful in studies of other pandalids and families of shrimp.
An Undifferentiated Hematopoietic Neoplasm with Histologic Manifestations of Leukemia in a Cutthroat Trout (Salmo clarki)
Authors: Smith Charlie E.
Published: April 2011

An undifferentiated hematopoietic neoplasm was diagnosed in a 2-year-old cutthroat trout (Salmo clarki). Malignant tumor cells had invaded spleen, kidney, and liver tissue. These same cells were found circulating freely in peripheral blood, suggesting leukemia.
Sampling of Fish Muscle for M.S. 222 and Quinaldine Residues
Authors: Luhning Charles W. , Harman Paul D.
Published: April 2011

Large variations in concentrations of M.S. 222 (tricaine methanesulfonate) and quinaldine (2-methylquinoline) residues occurred in various areas of fish fillets. Residue analyses of replicate samples from homogenized fillets yielded more representative results than samples cut from various areas of fillets.
Rationale, Background, and Development of Experimental Lake Studies in Northwestern Ontario
Authors: Johnson W. E. , Vallentyne J. R.
Published: April 2011

Reasons why experimental lake studies form a useful addition to more conventional laboratory experiments and observational field studies of eutrophication are discussed. The developmental history of the Experimental Lakes Area is given, including reasons for the location and a general description of the area set aside for experimental manipulation.
Preliminary Chemical Characterization of Waters in the Experimental Lakes Area, Northwestern Ontario
Authors: Armstrong F. A. J. , Schindler D. W.
Published: April 2011

Water analyses in 1968 and 1969 from 40 small lakes within a small area of the Canadian Shield in northwestern Ontario gave mean values for Ca, Na, Mg, and K of 1.6, 0.9, 0.9, and 0.4 mg/liter with Ca > Na > Mg > K on a molar basis. HCO3, SO4, and Cl (on a smaller number of samples) were 4.1, 3.0, and 1.4 mg/liter. Total CO2 was variable in the range 0.3–12.0 mg/liter. Specific conductance was in the range 10–35 μmho/cm at 25 C and pH 5.4–7.5. Color was < 5–150 Hazen units, and plant pigments (as chlorophyll a) < 1–21 μg/liter. Total dissolved nitrogen was in the range 110–300 mg N/liter and total dissolved phosphorus 3–20 μg P/liter. NO3-N and PO4-P were often undetectable in summer, and reached winter maxima around 100 and 10 μg/liter.Total dissolved nitrogen and phosphorus contents of five lakes were computed at the beginning and end of periods of several weeks during summer stagnation. Changes were negligibly small in three of the deeper lakes, but the two shallowest showed increases of 0.22 and 0.62 g N/m2 and 0.03 and 0.13 g P/m2. Analyses of precipitation and stream waters were used, with stream flow rates, to calculate input and output of nutrients from four of these lakes during the same periods. Retention of nutrients had occurred in all, and it was concluded that in the two deeper lakes nutrients had been lost to the sediments, whereas in the two shallower ones the increases in dissolved nutrients found were derived from the sediments.Analyses of 33 other Canadian Shield lake areas and of 13 other dilute lakes in other regions are tabulated. Comparison with the Experimental Lakes Area (ELA) lakes shows that the latter are more dilute than any in the Shield area except for some in the Northwest Territories, and much more dilute than any others in the world except for some alpine lakes in California.
Periphyton of the Experimental Lakes Area, Northwestern Ontario
Authors: Stockner John G. , Armstrong F. A. J.
Published: April 2011

The periphyton of four Experimental Lakes Area (ELA) lakes was examined in 1969. The littoral zone of all lakes was composed chiefly of large boulders and rock shelfs and the epilithic algal assemblage was accordingly dominant. Depending directly on light penetration and substrate availability benthic algal growth in most lakes was negligible at depths greater than 10 m. Throughout the growing season diatoms were the dominant algal group within the epilithic assemblage, comprising more than 60–70% of the total algal volume. Filamentous green and blue-green algae increased in importance in July and August but never constituted more than 40% of the volume of the total algal biomass. A well-defined diatom succession was observed both on the natural lithic substrate and on glass slides. Achnangthes minutissima was the most abundant diatom encountered in the littoral zone of all lakes. Periphyton growth on glass slides in lake 240 was 27 mg organic matter/m2∙day during initial colonization and 250 mg organic matter/m2∙day during the period of maximum growth. The vertical distribution of littoral diatoms in lake 240 was examined and differences among species are discussed in light of possible regulating mechanisms. Achnanthes flexella and Eunotia pectinalis were found only in the psammonal habitat of lake 240.Statistical treatment of chemical analyses of N, P, and chlorophyll a content of periphyton showed no significant difference in amounts of total N among periphyton from lakes, but the distribution of both total P and chlorophyll a was significantly different among lakes examined. Highest concentrations of both P and chlorophyll a were found in lakes 239 and 227. In lake 227, a lake receiving weekly additions of N and P, concentrations of P were significantly greater than in the other lakes. Concentrations of N and P/unit organic weight of periphyton taken at a depth of 1 m in each of the study lakes were greatest in lake 227. Comparisons among lakes are made and, based on the results of these comparisons, the role of N and P as regulators of periphyton growth in the ELA lakes is discussed.
Crustacean Plankton Communities in Forty-Five Lakes in the Experimental Lakes Area, Northwestern Ontario
Authors: Patalas Kazimierz
Published: April 2011

Zooplankton communities were characterized on the basis of samples taken in summer as vertical net hauls in the central part of lakes. Twenty-eight species of crustaceans were found in the 45 lakes studied. The highest number of species as well as the highest numbers of individuals (per unit of area) usually occurred in the largest deepest lakes with most transparent water.The most common species were: Bosmina longirostris, Tropocyclops prasinus mexicanus, Mesocyclops edax, Diaptomus minutus, Holopedium gibberum, and Cyclops bicuspidatus thomasi. Daphnids were rather scarcely represented.Senecella calanoides, Limnocalanus macrurus, and Diaptomus sicilis were confined to rather deeper lakes, whereas Diaptomus oregonensis was found mostly in smaller shallower lakes and Diaptomus leptopus in very small, but relatively deep lakes. Diaptomus minutus and C. b. thomasi, though widely distributed, showed a preference for deeper lakes, whereas T. p. mexicanus tended towards smaller shallower lakes.In particular lakes, the number of dominants ranged between 1 and 5, but three dominants per lake was the most commonly encountered case. The simplest community was composed of one cyclopoid, though the most common consisted of one cyclopoid, one diaptomid, and one cladoceran.Four types of communities were distinguished, each of them characteristic for a group of lakes of specific size and depth: (I) in the largest and deepest lakes (389–1007 ha of area, 30–117 m maximum depth); (II) in lakes of medium size and depth (6.5–200 ha, 4.8–33 m); (III) in small and very shallow lakes (3.1–28 ha, 2.7–7.3 m); (IV) in very small lakes with medium depth (1.3–3.7 ha, 6.1–12.8 m).The high degree of similarity between the plankton communities of the Experimental Lakes Area (ELA) and southern Ontario, as well as of some Great Lakes, suggest that they all basically belong to the same zoogeographical area.The fact that most species were distributed evenly throughout ELA may indicate the relative uniformity of the area. In ELA, lake morphology is mainly responsible for defining the type of community.
Zoobenthos of Fifteen Lakes in the Experimental Lakes Area, Northwestern Ontario
Authors: Hamilton Andrew L.
Published: April 2011

The composition of the profundal and sublittoral zoobenthos of 15 lakes in northwestern Ontario was closely related to morphometric features of the individual lakes. The amphipod Pontoporeia affinis Lind., and the sphaeriid Pisidium conventus Clessin, were the dominant species in the larger deeper lakes whereas species of Chironomidae and Chaoborinae were the dominant forms in all lakes with mean depths of less than 10 m. Dissolved oxygen concentration and temperature of the bottom water, two characteristics that are largely a function of lake morphometry, are probably the primary factors limiting the distribution of individual species.
Trimethylamine-Producing Bacteria on Haddock (Melanogrammus aeglefinus) Fillets during Refrigerated Storage
Authors: Laycock R. A. , Regier L. W.
Published: April 2011

All of the psychrophilic groups of organisms isolated from haddock (Melanogrammus aeglefinus) fillets during storage at 3 C included organisms capable of producing trimethylamine (TMA) from trimethylamine oxide (TMAO). The percentage of TMA-producing isolates in the flora remained nearly constant during storage to spoilage, although the composition altered markedly. All Pseudomonas putrefaciens isolates were TMA producers and this organism was the most numerous TMA producer during storage. It was concluded that in this investigation P. putrefaciens was largely, if not wholely, responsible for observed TMA production. Achromobacters, although initially forming over half the TMA-producing flora, formed a decreasing percentage during storage and were not considered to contribute significantly to observed TMA production. Coryneforms were the only group to show an increase in percentage of TMA producers during storage.
Comparison of the Pectoral and Pelvic Skeletons and of some other Bones and their Phylogenetic Implications in the Aulorhynchidae and Gasterosteidae (Pisces)
Authors: Nelson Joseph S.
Published: April 2011

Study of the pectoral and pelvic skeletons and some other bones in recognized species of the seven genera comprising the related families Aulorhynchidae (tubesnouts) and Gasterosteidae (sticklebacks) showed that the two families differ in several respects, with no one living species appearing to be intermediate. The genera Aulorhynchus, Aulichthys, Spinachia, Apeltes, and Gasterosteus each have distinctive characteristics not found in any other genus of the two families. Gasterosteus wheatlandi is the only species of the two families that lacks both the posttemporal and the supracleithrum. The interrelations of the genera form a mosaic pattern and there is no acceptable basis in the characters examined for postulating a phylogeny within the Gasterosteidae or for selecting a living species as being a primitive form or the most closely allied to the Aulorhynchidae.
World Distribution of Brook Trout, Salvelinus fontinalis: Further Observations
Authors: MacCrimmon Hugh R. , Gots Barra L. , Campbell J. Scott
Published: April 2011

This note supplements the original paper by MacCrimmon and Campbell (J. Fish. Res. Bd. Canada 26: 1699–1725, 1969) by presenting additional information on the native range, attempted introductions, and present world distribution of the brook trout.
Seasonal Calorific Values of Freshwater Zooplankton, as Determined with a Phillipson Bomb Calorimeter Modified for Small Samples
Authors: Schindler D. W. , Clark A. S. , Gray J. R.
Published: April 2011

A modified temperature sensing circuit for the Phillipson microbomb calorimeter allowed accurate calorific determinations on samples as small as 3 cal.Calorific values of copepods from three lakes in eastern Ontario varied with species, developmental stage, lake, season, and year. No such differences were observed in calorific values for the few species of rotifers and cladocerans tested.Similar calorific values were obtained for samples preserved by freezing, freeze-drying, and heat-drying, but preservation in formalin resulted in erroneously low calorific values.
Effects of Gamma Irradiation on Salmonella spp. in Smoked Lake Whitefish (Coregonus clupeaformis)
Authors: Ostovar K. , Pereira R. R. , Gallop R. A.
Published: April 2011

A dosage of 0.5 M rad was found sufficient to eliminate three species of Salmonella in smoked lake whitefish (Coregonus clupeaformis) regardless of the stage of processing at which steaks were inoculated with the bacteria. All three species survived smoking at temperatures up to 167 F. The dosages required for elimination of the bacteria when steaks were inoculated at various stages of processing were: before freezing at 0 F for 48 hr, 0.4 M rad for S. give, 0.3 for S. typhimurium, and 0.2 for S. java; before brining at 60 Salometer for 25 min, 0.4, 0.3, and 0.3; after smoking, 0.5, 0.4, and 0.35. Salmonella give was more resistant to heat than the other two species.
A Simulation Model of Lake Trout Growth
Authors: Kerr S. R.
Published: April 2011

Kerr (J. Fish. Res. Bd. Canada 28: 809–814, 1971) described an equation system based upon metabolic constraints and foraging limitations that predicts level of rations and growth efficiency as a function of the availability of the prey resource. An algorithm that extends the equation system to a growth model is described here. With reference to increasing predator size, and to the mean size and abundance of prey, the model computes successive growth increments while holding the equations to the configuration that maximizes the ratio of growth efficiency to rations. When given information on the mean size and density of prey organisms, the model accurately predicts observed patterns of lake trout growth.
Gillnet Selectivity on Sockeye (Oncorhynchus nerka) and Pink Salmon (O. gorbuscha) of the Skeena River System, British Columbia
Authors: Todd Ian St. P. , Larkin P. A.
Published: April 2011

Exploitation of Skeena River sockeye salmon has been conducted almost solely by drift gillnets since 1875. This study was designed to determine the selective properties of nylon gillnets presently in use; to compare these with properties of linen nets used prior to 1955; and, using statistics of catch and escapement, to estimate the selective action of the fishery as a whole on sockeye and pink salmon in 1968.Unique selectivity curves for nylon nets of [Formula: see text] mesh size could not be determined from sockeye catches. Mean size of age class 1.2 sockeye increased with mesh size but mean size of the predominant age class 1.3 sockeye demonstrated no trend. Age class 1.3 sockeye were among the largest on record and were too large to gill properly in all mesh sizes used.Comparison of [Formula: see text] mesh nylon gillnet with linen nets of [Formula: see text] mesh used in the historic fishery was also influenced by the large size of age class 1.3 sockeye. Nylon nets were 2.5 and 2.7 times as efficient as linen for sockeye, and 8.0 and 9.0 times for pink salmon. Nylon gillnets caught larger sockeye and pink salmon than did linen. Variances of mean size were also greater for catches in nylon.The statistics of catch and escapement for 1968 indicated that selection increased over the length range of age 1.2 sockeye but decreased over the length range of age class 1.3 sockeye. For pink salmon, which were extremely small in 1968, selection was increasingly large for larger size males and females. The length–girth relations of the species and sexes accounted for most of the difference between the selectivity curves. Retention by gillnets declined once the girth/mesh ratio exceeded 1.2 for sockeye. For pink salmon, no females were of a size to equal this ratio; the descending limb of the selectivity curve was due solely to males as the retention rates declined once girth/mesh ratio exceeded 1.0.These findings suggest that in most years the gillnet fishery on the Skeena River would tend to select relatively larger sockeye salmon. In years such as 1968, however, selection would be against smaller fish. This frequent reversal combined with the intense modern fishery, which tends to remove virtually all fish during a short period and allows almost complete escapement in periods between fishing, suggests that selective fishing has probably not been a significant factor in decreased production.
Effects of Feeding Level on Circulus Formation on Scales of Young Sockeye Salmon (Oncorhynchus nerka)
Authors: Bilton H. T. , Robins G. L.
Published: April 2011

Feeding level exerted a significant influence on scale growth of young sockeye salmon (Oncorhynchus nerka) maintained for 2 months at a temperature of 13.98 ± 0.29 C and a constant photoperiod of 12 hr light and dark. The number and spacing of circuli, scale radius, and length and weight of the fish were all correlated with the feeding level. Two checks at most were observed on scales of fish in the experimental populations. At midpoint of the experiment, incidence of a first check was highest among fish that had been held at a high feeding level. At the end of the experiment a second check was apparent only on scales of fish that had the feeding levels raised at midpoint of the experiment. There were significant correlations between the nucleus radius of the scale and length and weight of the fish.
Enolase from Lobster (Homarus americanus)
Authors: Chapman M. John , Chin Christopher , Wold Finn
Published: April 2011

Enolase has been isolated from lobster muscle by acetone fractionation, heat treatment, ammonium sulfate fractionation, gel filtration, and ion-exchange chromatography. Preliminary characterization of the pure enzyme shows that the catalytic properties are very similar to those of the enolases from rabbit and fish.
Discreteness of Atlantic Herring (Clupea harengus harengus) Populations in Spring and Autumn Fisheries in the Southern Gulf of St. Lawrence
Authors: Messieh S. N. , Tibbo S. N.
Published: April 2011

Evidence was obtained that spring and autumn herring fisheries in the southern Gulf of St. Lawrence are supported by two discrete stocks. Samples from the two fisheries taken in 1965 through 1969 differed in length- and age-frequency distributions, year-class composition, growth rate, spawning time, and mean numbers of pectoral and dorsal fin rays.
Fecundity of the Left and Right Ovaries of Grand Bank Capelin (Mallotus villosus)
Authors: Winters G. H.
Published: April 2011

Fecundity estimates of the left and right ovaries of Grand Bank capelin (Mallotus villosus) revealed a considerable disproportion in egg counts, with the left ovary being on the average nine times more fecund than the right. For each ovary the relation between fecundity and length was curvilinear, and between fecundity and age was linear, with the left ovary increasing in fecundity with length and age at a faster rate than the right. Capelin fecundity is related more to age than length, and this was attributed to the inhibition of growth due to spawning and to the presence of repeat spawners in the older fish.
Maturity and Fecundity of the White Seaperch (Phanerodon furcatus) from Tomales Bay, California
Authors: Banerjee Tapan
Published: April 2011

The embryonic development of Phanerodon furcatus was found to be very similar to that of other members of the Embiotocidae; the smallest embryo (16.2 mm) had developed scales on the body and pigments in the eye. The embryos at birth measure approximately 43.5 mm. The average number of embryos for all females during the study was 19.6, and the embryos varied from 8 in a female measuring 196 mm to 33 in one measuring 262 mm in fork length. The number of embryos generally increases with an increase in size of the female parent. The breeding season of white seaperch, Phanerodon furcatus, in Tomales Bay, California, starts from the early part of May and extends to the middle of August.
Calorie-to-Protein Ratio for Brook Trout (Salvelinus fontinalis)
Authors: Ringrose R. C.
Published: April 2011

Based upon a kilogram of feed, the results suggested that the brook trout (Salvelinus fontinalis) required approximately 75 kcal of metabolizable energy for each 1% of protein in the feed. Additional feed energy, resulting in greater calorie-to-protein ratios, reduced weight gained but did not significantly increase fat content of the dry carcass.The carbohydrate and protein of wheat middlings were utilized by the trout. A toasted cereal product composed of 80% corn and 20% wheat was metabolized for energy. Delactosed dried whey was found less effective than glucose as an energy source for trout.
Comment: Gould's The case for accurate labeling of superchilled fish
Authors: Freese M.
Published: April 2011

This note comments on a misleading statement in Gould's (J. Fish. Res. Bd. Canada 27: 2101–2103) paper about the cost of instrumentation and the nature of the sample for distinguishing thawed, frozen fish from fresh fish (ultrasonic backscatter method of Freese and Makow (J. Fish. Res. Bd. Canada 25: 605–606)).
A Notacanthid Macdonaldia challengeri Collected off the Oregon Coast
Authors: Stein David , Butler John
Published: April 2011

A fifth specimen of a rare deep-sea spiny eel, Macdonaldia challengeri, is reported, extending the known range in the North Pacific Ocean to the Oregon coast.
A New Polychaete Species of the Genus Macellicephaloides from the Aleutian Trench
Authors: Levenstein R. Ya.
Published: April 2011

A new species of polychaete, Macellicephaloides berkeleyi, is described. The description is based on two specimens collected at a depth of 7000 m from the Aleutian Trench. The species is thought to be an intermediate link between the genera Macellicephala and Macellicephaloides.
Bioluminescence in Pelagic Polychaetes
Authors: Dales R. Phillips
Published: April 2011

Of six holopelagic polychaete families, the Tomopteridae and Alciopidae are the only ones having representatives that appear to be photogenic. Previous investigators localized the site of photogenic organs to certain parapodial glands in the tomopterids. Photogenic organs have not been demonstrated in the alciopids, but some species have been reported with little substantiation to be luminescent. The structure and function of the photogenic organs and the nature of the luminescent products are incompletely known, exemplifying gaps in the knowledge of the anatomy and life history of pelagic polychaetes.
Evolution of the Chondrophora: Evidence from Behavioural Studies on Velella
Authors: Fields W. Gordon , Mackie G. O.
Published: April 2011

The chondrophore Velella shows concert behaviour closely resembling and presumably homologous to that described for Porpita, Pelagohydra, and for the sessile tubularian hydroids Tubularia and Corymorpha. The movements consist of orally directed tentacular flexions, accompanied by retraction of the blastostyles, along with muscular contractions in the mantle and in the crest surmounting the sail. Concerts may consist of single contractions or sequences of contractions, the latter sometimes summing to produce a sustained declination of the tentacles or contraction in the other parts. Concerts are repeated periodically at intervals of between 1 and 3 min.Electrical potentials (concert pulses) are recorded from all parts of the body surface at each concert contraction. The potentials are through-conducted at 30–35 cm/sec in parts of the aboral surface. Feeding changes the concert pattern, introducing a type of event called a feeding pulse. Peristalsis in the proboscis, as in Tubularia, is exhibited without electrical concomitants.The observations support the view of Velella as a large individual hydroid in no way comparable to a siphonophore. It is regarded as a floating tubularian hydranth with inverted stem. Velella and Porpita (family Velellidae) are assigned to the superfamily Tubularoidea. The freshwater hydra shows a type of behaviour resembling modified tubularian concerts, and its possible affinity with the tubularoid group is discussed.
Ribonucleotide Reductase in Immature Testes of Salmon
Authors: Tarr H. L. A. , Gardner Linda
Published: April 2011

When cell-free extracts obtained by ultracentrifugation of homogenates of immature salmon testes were incubated with radioactive ribonucleoside di- or triphosphates, the corresponding deoxyribonucleosides were isolated from the reaction mixtures. The specific activities of the crude enzyme extracts were between 15.8 and 54 picomoles of deoxyribonucleoside formed per milligram of protein per hour at 25 C. All attempts to purify the enzyme, which lost activity quite rapidly at 0 C, were unsuccessful. Acid hydrolysis of guanosine deoxyribosides of constant specific radioactivity formed by enzymic reduction of tritiated guanosine triphosphate (GTP) or guanosine diphosphate (GDP) yielded radioactive guanosine of similar specific radioactivity. The crude nature of the preparation, which possessed phosphoribokinase and phosphatase activities, made it impossible to decide whether nucleotide reduction occurred at the mono-, di-, or triphosphate level. Evidence was obtained that allosteric effectors are required for ribonucleotide reduction, as with mammalian and bacterial ribonucleoside diphosphate reductase. The enzyme required dithiothreitol and iron, was strongly stimulated by ethylenediaminetetraacetate (EDTA) and was inhibited by dADP.
Effects of Starvation, Feeding, and Light Period on Circulus Formation on Scales of Young Sockeye Salmon (Oncorhynchus nerka)
Authors: Bilton H. T. , Robins G. L.
Published: April 2011

Young sockeye salmon (Oncorhynchus nerka) survived a starvation period of 20 weeks with no change in their mean length and weight and with no record of this starvation period on their scales. Fish offered an ad libitum diet for more than 4 weeks in the 20-week period had significant increases in body and scale growth. The number of checks on their scales was correlated with the number of weeks fish were offered an ad libitum diet and not with the number of weeks they were starved. Thus, a significant increase in food induced the formation of a check. Light period appeared to have some influence on body and scale growth.
Preliminary Description of an Unusual Gonatid Squid (Cephalopoda: Oegopsida) from the North Pacific
Authors: Fields W. Gordon , Gauley Veronica A.
Published: April 2011

Descriptions are given of two specimens of an unusual type of gonatid squid taken from the North Pacific Ocean. A discussion is made of their relationship to two existing genera, Gonatus and Berryteuthis, of the family Gonatidae, and a note is included on a North Pacific gonatid larva that may be a related earlier stage of these two specimens. Because of their size and condition, neither a new genus nor a new species is declared; however, on the basis of these records, it is suggested that there is a need for a redefinition of the genera of the family Gonatidae.
Estimating Distances Between Fish Schooling in an Aquarium
Authors: Symons Philip E. K.
Published: April 2011

Distances between fish schooling in an aquarium can be estimated easily from simultaneous photographs, one taken from overhead and the other from the side. No special equipment is required, and the method is accurate to within 2 or 3 mm.
New Records of Lymphocystis Disease in Four Eastern Pacific Fish Species
Authors: McCosker John E. , Nigrelli Ross F.
Published: April 2011

Four new records of lymphocystis viral disease are described for gobiid and diodontid fishes. Spontaneous infection was found in Diodon holocanthus and Gobiosoma paradoxum from the Gulf of Panamá and in Gillichthys seta from the upper Gulf of California. Infection was intragenerically transferred to Diodon hystrix in a cohabitation experiment.
A Dispenser for Winkler's Dissolved Oxygen Reagents
Authors: Duedall I. W. , Coote A. R. , Knox D. F. , Connolly G. F.
Published: April 2011

A new dispenser for delivering Winkler's oxygen reagents simultaneously is described.
The Solubilizing Effect of Lysolecithin on the Extractability of Various Tissues of Rainbow Trout (Salmo gairdneri)
Authors: Jonas R. E. E.
Published: April 2011

Liver homogenate treated with and without lysolecithin (LL) and centrifuged at 1600 g and the supernatant portion centrifuged again at 20,000 g showed disintegration of organelles with disruption of their membranes in the pellet fractions of that which was treated with LL, whereas the organelles of the others were normal. This was seen from the electron micrographs of the pellet fractions. The amino acid composition of the protein fraction of the white skeletal muscle soluble in 0.9% NaCl and of the larger fraction extractable in 0.9% NaCl with LL added were similar. The total nitrogen found in the supernatant fraction of brain, kidney, and liver homogenates reached approximately 44, 59, and 63% in 0.9% NaCl and ≈ 88, 95, and 89% in 0.9% NaCl containing 4 mg/ml LL; whereas the total N present in heart muscle and white muscle homogenates reached approximately 39 and 31% in 0.9% NaCl and ≈ 61 and 51% in 0.9% NaCl containing 4 mg/ml LL. LL destroyed the ability of liver tissue and liver mitochondria to oxidize 14C palmitate. It was concluded that the effect of LL in increasing the amount of protein extractable from fish tissue homogenates arises from its ability to lower surface tension and disrupt membranes and not by affecting protein solubility.
Factors Affecting Respiration Rates of Winter Flounder (Pseudopleuronectes americanus)
Authors: Voyer R. A. , Morrison G. E.
Published: April 2011

In one series of experiments, average rates of oxygen consumed by winter flounder at 10 C were 35 and 55 mg O2/kg of body weight per hour at 3.5 and 8.6 mg dissolved oxygen (DO)/liter, respectively. At 20 C the average rates of oxygen uptake were 70 at 3.2 mg DO/liter and 97 at 6.3 mg DO/liter. Oxygen consumption rates were significantly greater (P <.05) at 20 C than at 10 C. In two of the three experiments, rates of oxygen uptake were significantly lower (P <.05) among groups of winter flounder maintained at the reduced dissolved oxygen concentrations for 15–23 hr. No dissolved oxygen–temperature interactions were apparent.Results of a second series of experiments indicated respiration rates of winter flounder increased linearly with weight along regression lines having slopes of 0.792 (20 C — 6.9 mg DO/liter), 0.785 (20 C — 4.3 mg DO/liter), 0.720 (10 C — 8.7 mg DO/liter), and 0.746 (10 C — 4.3 mg DO/liter).
Distribution and Abundance of Planktonic Crustacea in Sturgeon Bay and Shawanaga Inlet, Georgian Bay, Ontario
Authors: Carter John C. H.
Published: April 2011

Distribution and abundance of 27 planktonic crustaceans in an inshore area of Georgian Bay characterized by horizontal differences in temperature and electrolyte concentrations are described on the basis of duplicate vertical hauls on eight dates at six stations during ice-free months of 1970 and on one date at four stations through the ice in 1971. Most species were found at all stations on at least some occasions in 1970, although some differences in periods of maximum abundance between stations, probably related to temperature, were noted. Daphnia ambigua and Diaptomus reighardi were confined to the inner stations. Limnocalanus macrurus and Diaptomus sicilis were absent during periods of highest water temperatures. Eubosmina coregoni, although found throughout the system in February 1971, was restricted to the outer stations in 1970. A marked late-summer drop in populations of all species except Bosmina longirostris and Tropocyclops prasinus mexicanus in 1970 might have been due to either normal seasonal fluctuations or heavy predation by planktivorous fish.
Growth Per Moult of Tagged Lobsters (Homarus americanus) in Bonavista Bay, Newfoundland
Authors: Ennis G. P.
Published: April 2011

The suitability of the sphyrion tag for lobster growth studies is demonstrated by comparing growth of ferromagnetic- and sphyrion-tagged lobsters. Carapace length and total weight increments in one moult of 54 males (52–92-mm carapace length) tagged with sphyrion tags averaged 11.4 mm (15.7%) and 185.9 g (60.8%). For 56 females 57–89-mm carapace length they averaged 9.8 mm (13.3%) and 136.3 g (42.5%). Differences in growth per moult between sexes increased with size. For both sexes percent carapace length increment decreased with increase in carapace length but more rapidly for females. Carapace length increment increased with increasing carapace length for males, but for females there was no significant change over the size range considered. Incidence of moulting for sphyrion-tagged lobsters was 83.1% and comparable with an observed estimate (85.2%) from field samples obtained shortly after the moulting season.
Biology of Rock Crab (Cancer irroratus) in Northumberland Strait
Authors: Scarratt D. J. , Lowe Robert
Published: April 2011

Divers hand-collected 342 rock crabs (Cancer irroratus) ranging from 4.2 mm carapace width to 97 mm (females) and 127 mm (males). The sex ratio (1.37:1) was biased in favour of males. Of 2929 crabs taken in commercial lobster fishing gear, 92% were above the minimum commercial size of 89 mm, and of these 99.1% were male. Smallest size at maturity was 60 mm for females and 69 mm for males. Breeding occurred in late summer and fall. Larvae were present in surface waters from June to September. Prey of crabs > 25 mm consisted principally of polychaetes, mussels, starfish, and sea urchins. Crabs less than about 65 mm inhabit rocky areas; larger crabs move out onto sand and mud. The fishable population is probably not in significant competition with lobsters for food or space.
Initial Studies on a Method of Algal Assay for Nutrient Parameters in Water
Authors: Cullimore D. R. , McCann A.
Published: April 2011

A bioassay technique was outlined for estimating the impact of supplementation of the nutrients carbon, nitrogen, and phosphorus on algal growth. One of the main problems was the monitoring of algal growth using lengthy techniques of chlorophyll extraction with acetone. An alternative system involving filtration and reflectometric readings at 600 nm is described and found to be satisfactory when five readings were taken per filtered disk.
Occurrence of Eukrohnia bathypelagica Alvariño 1962 (Chaetognatha) in the Atlantic Waters of Canada
Authors: Figueira Armando J. G.
Published: April 2011

The chaetognath Eukrohnia bathypelagica Alvariño 1962 is recorded for the first time in the waters of eastern Canada. Some remarks on the morphology of the only specimen obtained are included. It is suggested that this species may not be rare in the region.
The Interrelation of Biting and Filtering in the Feeding Activity of the Northern Anchovy (Engraulis mordax)
Authors: O'Connell Charles P.
Published: April 2011

A previous study showed that the northern anchovy (Engraulis mordax) captures Artemia adults (3.7 mm long) by biting and Artemia nauplii (0.65 mm long) by filter feeding. This study shows that the ratio of biting to filtering activity in small schools varies with the relative concentration of Artemia adults and nauplii in the water. Activity was half biting and half filter feeding when Artemia adults were 2% by dry weight of the available biomass, but was entirely biting when Artemia adults exceeded about 7% of the biomass.It is estimated that when feeding activity is half biting and half filtering, Artemia adults and nauplii would contribute equal dry weights to ingestion, and that the sum of the two would be the same as that possible if total activity had been filtering. When relative concentration of Artemia adults is high enough to induce total biting activity, the dry weight ingested per unit time would be double that possible by filtering alone on the nauplii present.Ratios of large-to-small crustaceans are relatively high near the surface at night off southern California, which suggests that biting activity could often exceed 50% of total feeding activity. If the plankton does support a high percentage of biting activity, a large part of the area should usually provide the anchovy with its daily nutritional needs.
Prolactin and Growth Hormone Concentrations in the Serum and Pituitary Gland of Adult Migratory Sockeye Salmon (Oncorhynchus nerka)
Authors: McKeown B. A. , Overbeeke A. P. van
Published: April 2011

When sockeye salmon entered the Fraser River the prolactin content of the serum and the pituitary gland was reduced by 27 and 36%, respectively. During migration to the spawning grounds the serum concentration increased considerably (81%), while the pituitary concentration was gradually restored to that of the first seawater sample. Serum concentration of growth hormone gradually increased during the migration (29%), while growth hormone in the pituitary glands initially decreased (13%) then increased (12%) as the fish approached the spawning grounds. The changes in prolactin concentrations appear to be related to a change in salinity, whereas growth hormone changes were unaltered at this time.
Laboratory Rearing of Spot Shrimp Larvae (Pandalus platyceros) and Descriptions of Stages
Authors: Price Vincent A. , Chew Kenneth K.
Published: April 2011

Spot shrimp (Pandalus platyceros) were cultured in the laboratory from ovigerous females and eggs detached from females caught in Dabob Bay of Hood Canal, Washington. A tank was designed specifically to incubate the detached eggs in a recirculating seawater system. After hatching, the larvae were cultured in beakers in a water bath and fed newly-hatched Artemia.Morphological descriptions of the larval stages were made and discussed. The fifth stage was considered the megalopa (post-larval).
Clostridium botulinum in Sediments from the Canadian Atlantic Seaboard
Authors: Laycock R. A. , Longard A. A.
Published: April 2011

The presence of Clostridium botulinum types B, C, and E has been detected off the coast of Nova Scotia. Whereas types B and E were found only in low concentration on the Scotian Shelf, localized areas of high concentration of type C were found inshore in the Halifax–Dartmouth area and offshore in the deeper waters of Emerald Basin and the edge of the Shelf. Type E only was found off the coast of Newfoundland with a high incidence of the organism as far as 150 miles off the northeast coast. In general, C. botulinum appeared to be absent from the shallower bank areas but present in the deeper waters within and bordering upon the Continental Shelf.
Food and Starvation as Factors Affecting the Time to Death of the Lobster Homarus americanus Infected with Gaffkya homari
Authors: Stewart James E. , Zwicker B. M. , Arie B. , Horner G. W.
Published: April 2011

Among lobsters infected experimentally at 15 C with the pathogen Gaffkya homari, fed animals died much earlier and with higher bacterial numbers than did animals starved for several months. The shorter times to death were attributed to a more rapid development of the pathogen in the fed host, due to the richer nutrient supply in the circulatory system bolstered by substantial reserves. Infected lobsters ate only during the very early stages of infection.
Relation of Egg Number to Carapace Length of Sidestripe Shrimp (Pandalopsis dispar) from Dabob Bay, Washington
Authors: Harris Colin , Chew Kenneth K. , Price Vincent
Published: April 2011

A linear relation was found between egg number and carapace length in a sample of 244 sidestripe shrimp, Pandalopsis dispar. There was an average error of 6% in estimates of egg number. Ovigerous sidestripe shrimp from Dabob Bay are smaller than those of Vancouver Island, and have lower egg counts than those of Alaska.
Some Effects of Group Housing Upon the Aggressive Behavior of the Lobster Homarus americanus
Authors: Dunham Philip J.
Published: April 2011

Lobsters maintained in a group housing tank for 36 days were less aggressive than lobsters maintained in individual tanks. A measure of activity indicated that differences in aggressive behavior could not be explained in terms of activity differences between the two groups.
The Systematics of Salmonid Fishes of Recently Glaciated Lakes
Authors: Behnke Robert J.
Published: April 2011

The systematics of the subfamilies Salmoninae and Coregoninae of recently glaciated regions are reviewed. Interrelation between systematics and fisheries biology are stressed, pointing out the abundance of intraspecific genetic diversity of some salmonid fishes manifested in ecological and behavioral specializations, but not necessarily by morphological divergence. Innate, reproductive homing behavior of salmonid fishes may allow closely related populations to exist in sympatry and maintain reproductive isolation. Examples are cited to support the contention that many sympatric "sibling species" have evolved from a common ancestor in postglacial times. Closely related, sympatric populations are a major taxonomic problem, but this phenomenon which allows a species to consist of genetically discrete units with reproductive isolation between the stocks is of great significance for fisheries management. Postglacial salmonid communities are typically fragile and highly susceptible to disruption or destruction by introductions, eutrophication, and exploitation. Every effort should be made to protect the genetic diversity of a species.
A Compact Recirculation Unit for the Rearing and Maintenance of Fish
Authors: Scott K. R. , Gillespie D. C.
Published: April 2011

The use of a compact recirculation system for rearing rainbow trout is described. An 8-month experiment showed that up to 75 kg offish could be maintained in a healthy condition in a 1600-liter tank using a make-up water rate of only 1.0 liter/min. Temperature, oxygen, pH, ammonia nitrogen, and nitrate nitrogen levels were satisfactorily controlled. An average weight gain of 8% per week was achieved with a feed rate of 2% of body weight per day. Fish mortality was insignificant.
Effect of Smoke-Processing on Muddy Odor and Taste in Rainbow Trout (Salmo gairdneri)
Authors: Iredale D. G. , Rigby D.
Published: April 2011

Because of problems with a "muddy" odor and taste occurring in rainbow trout being reared commercially in some small prairie lakes in central Canada, full production potential has not been realized. The possibility of masking the undesirable condition by smoke-processing was investigated and this was found to be a valid method of utilizing the majority of the affected fish.
Migration of Yearling Sockeye Salmon (Oncorhynchus nerka) as Determined by Time-Lapse Photography of Sonar Observations
Authors: Groot C.
Published: April 2011

The seaward migration of sockeye salmon smolts through the Babine Lake system to its outlet was examined by taking film records of the Plan-Position-Indicator display of a high-frequency sonar whereby each frame of film was exposed during one scan of the sonar unit. Frame-by-frame analysis of the films revealed information on speed, direction, and diurnal timing of migration of sockeye smolts during a 24-hr period.Migratory activity in the lake centered around dusk and dawn, a similar pattern to that near the outlet for smolts entering the river on their way to sea.Speeds of movements were 19–51 cm/sec (mean 30 cm/sec). Greatest velocities occurred at dusk and dawn. They were close to the maximum sustained swimming speeds determined under laboratory conditions for sockeye smolts of the same size and within similar temperature ranges as in the field.The most direct movements of targets were found at twilight, when migration activity was highest. In general, directional tendencies were consistent with the shortest route to the outlet. In some observations near the junction of Main Lake and Morrison and North arms, movements were observed which would lead the smolts away from the outlet. Consequences of such movements are discussed and compared with data from tagging operations.
The Behavior of Adult American Shad (Alosa sapidissima) During Migration from Salt to Fresh Water as Observed by Ultrasonic Tracking Techniques
Authors: Dodson Julian J. , Leggett William C. , Jones Robert A.
Published: April 2011

Five of seven adult American shad (Alosa sapidissima), tracked continuously with ultrasonic transmitters in the lower estuary of the Connecticut River in 1968 during their spawning migration to fresh water, exhibited extensive meandering, ranging 24–53 hr in duration in the region of the saltwater–freshwater interface. The salinity in the Connecticut River is like a wedge; its daily position is dependent on upland discharge, and its hourly position is dependent on tidal activity. The fish were observed during all tidal conditions and at several discharge rates, and in all cases they remained near the leading edge of salt water during the meandering phase. This behavior pattern was not a result of handling nor was it a typical behavioral response to tidal cycle. It was concluded that the meandering observed in the region of the saltwater–freshwater interface was due to physiological adaptation of the fish to fresh water. Of the remaining two shad tagged, one proceeded directly upstream without meandering, and one moved downstream.
Sight Records of Right Whales (Eubalaena glacialis) and Finback Whales (Balaenoptera physalus) from the Lower Bay of Fundy
Authors: Arnold P. W. , Gaskin D. E.
Published: April 2011

At least five right whales (Eubalaena glacialis) were observed by the authors in the lower Bay of Fundy between August 22–31, 1971. Some limited notes on behavior and movements are recorded.
Temperature–Salinity Stress and Mercury Uptake in the Fiddler Crab, Uca pugilator
Authors: Vernberg Winona B. , O'Hara James
Published: April 2011

Uptake of 203Hg was determined in gill and hepatopancreas tissue from fiddler crabs (Uca pugilator) maintained under six temperature–salinity regimes. Although the total mercury was relatively constant under all experimental conditions, the percent of mercury in each of the tissues was markedly different. At higher temperatures the crabs seem able to transport mercury from gill tissue to the hepatopancreas more effectively than at lower temperatures. This could be a factor in the toxicity of mercury to fiddler crabs at low temperature.