bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultraviolet Treatment of Water for Destruction of Five Gram-Negative Bacteria Pathogenic to Fishes
Authors: Bullock G. L. , Stuckey H. M.
Published: April 2011

Filtration (25 nm) and ultraviolet irradiation dosages of 13,100–29,400 microwatt seconds per square centimetre (μW∙s∙cm−2) effected a 99.98–100% reduction of five gram-negative fish pathogens — Aeromonas salmonicida, A. hydrophila, Vibrio anguillarum, Pseudomonas fluorescens, and the enteric redmouth organism in 12.5 °C clear spring water or spring water containing particulate matter. Filtration and a dosage of 4500 μW∙s∙cm−2 killed 99.83–100% of test strains in spring water and 4000–4750 μW∙s∙cm−2 killed 99.33–99.99% in water with particulate matter. Irradiation of unfiltered water containing particulate matter was less effective, especially at dosages of 5000 μW∙s∙cm−2 or less, which killed 97–99.94% of strains. Filtration and 13,100 μW∙s∙cm−2 irradiation of water containing A. salmonicida prevented transmission of furunculosis. Key words: ultraviolet irradiation, bacterial fish pathogens, water disinfection
Suppression of the Primary Immune Response in Rainbow Trout, Salmo gairdneri, Sublethally Exposed to Tritiated Water During Embryogenesis
Authors: Strand J. A. , Fujihara M. P. , Burdett R. D. , Poston T. M.
Published: April 2011

Antibody synthesis, in response to vaccination with a 0.1-ml (1.8 × 108 cells/ml) intraperitoneally injected, heat-killed strain of Flexibacter columnaris, was employed to investigate the effect of tritium irradiation (0, 0.04, 0.4, 4.0, 40 rads total dose for 20 days during embryogenesis) on development of the primary immune response in 5-mo rainbow trout, Salmo gairdneri, reared under essentially pathogen-free conditions. Specific agglutinins to F. columnaris, determined 1-wk pre vaccination, and 3, 5, 7, 9, and 11 wk postvaccination increased rapidly in both control and irradiated fish following vaccination. Agglutinin levels in irradiated fish were suppressed to 50% of control levels at 40 rads during the 9th wk, and 50% of control levels at 4.0 rads during the 11th wk. Electrophoretic separation of serum proteins of both control and irradiated–vaccinated fish demonstrated four major protein fractions. Densitometry analyses demonstrated that fraction IV increased significantly in percent of total protein following antigenic stimulation, suggesting that fraction IV represents the specific humoral antibody to F. columnaris. The relative percent of total protein contained in fraction IV was significantly reduced in irradiated–vaccinated fish. Key words: antibody synthesis, agglutination assay, vaccination, Flexibacter columnaris, tritium, Salmo gairdneri, electrophoresis, serum protein, densitometry, primary immune response
Nearctic and Palaearctic Paracladopelma Harnisch and Saetheria n.gen. (Diptera: Chironomidae)
Authors: Jackson George A.
Published: April 2011

New descriptions, redescriptions, taxonomical and ecological comments, and distribution records are given for known stages of 14 species of Paracladopelma Harnisch and 3 species of Saetheria n.gen. Seven species are described in all stages. Saetheria reissi n.sp., Paracladopelma winnelli n.sp., the immature stages of Saetheria tylus (Townes), Paracladopelma galaptera (Townes), Paracladopelma nereis (Townes), a larval-pupal association placed in Saetheria, and two larvae placed in Paracladopelma are new to the literature. The immature stages of Paracladopelma nais (Townes), Paracladopelma loganae Beck and Beck and Paracladopelma undine (Townes) are redescribed.Keys are provided for the known Nearctic larvae and pupae and for both Nearctic and Palaearctic adult males of Saetheria and Paracladopelma. Key words: Chironomidae, Paracladopelma, Saetheria. Great Lakes
Survival of Infectious Hematopoietic Necrosis Virus Held Under Various Environmental Conditions
Authors: Pietsch John P. , Amend Donald F. , Miller Christine M.
Published: April 2011

Dehydration of infectious hematopoietic necrosis virus (IHNV) from water at 4 and 10 °C resulted in only partial inactivation, but dehydration from Hanks' balanced salt solution (HBSS) and homogenized fish tissue resulted in total loss of virus infectivity within 7 days. Survival was not affected by pH between 6 and 8, but virus infectivity was significantly reduced at pH 5 and 9. Water hardness from 20 to 250 mg/ℓ (as CaCO3) did not significantly reduce virus infectivity. Salinity distinctly affected IHNV survival: storage in artificial seawater, filtered ocean water, HBSS. and Earle's balanced salt solution (EBSS) equally reduced virus titers. The addition of protein to deionized water and EBSS and HBSE resulted in increased survival. Survival of IHNV was inversely proportional to HBSS concentration and was highest when it was frozen in media supplemented with 10% calf serum. Virus survival was good at −70 and −20 °C, but virus infectivity decreased sharply with an increase of temperature above 4 °C; increasingly poor survival occurred at 15. 21, 28, and 32 °C. Freezing and thawing of IHNV had no effect if the media contained 10% protein; however, freezing in deionized water resulted in a significant loss of virus infectivity. Key words: virology, virus survival, laboratory storage, environmental effects
Reproduction of Planted Lake Trout, Salvelinus namaycush, in Gamitagama, a Small Precambrian Lake in Ontario
Authors: Olver C. H. , Lewis C. A.
Published: April 2011

Yearling lake trout, Salvelinus namaycush, stocked in 1961 in Gamitagama, an Ontario lake previously without this species, established a self-reproducing population. Planted fish first spawned at age 4+ in 1964 to produce the 1965 year-class. Four year-classes of naturally reproduced lake trout were present in the lake by 1969.
Systematics and Zoogeography of the Fishes of the Family Percidae
Authors: Collette Bruce B. , Bănărescu Petru
Published: April 2011

Two phyletic lines are present in the Percidae: the Percinae, in which the anteriormost interhaemal bone is much larger than the posterior ones and the anal spines usually are well developed, and the Luciopercinae, in which the interhaemal bones are of uniform size and the anal spines are poorly developed. Parallel evolution has produced in each subfamily small, benthic, rheophilic forms with depressed or terete bodies and reduced or vestigial swimbladders. This differentiation is shown by dividing each subfamily into two tribes. Within the Percinae, the Etheostomatini (Percina, Ammocrypta, and Etheostoma) are interpreted as derivatives of the Percini (Perca, Gymnocephalus [=Acerina], and Percarina). The North American species Perca flavescens is distinguished from the Eurasian species P. fluviatilis and P. schrenki on the basis of the more posterior position of the predorsal bone. In the Luciopercinae, the Romanichthyini (Zingel [=Aspro] and Romanichthys) have evolved from the Luciopercini (Stizostedion [including Lucioperca]). Key words: Percidae, systematics, zoogeography, evolution
Sensory Organs of the Lateral-Line Canal System in Two Percids and Their Importance in Behavior
Authors: Disler N. N. , Smirnov S. A.
Published: April 2011

The early development of the lateral-line systems in Eurasian perch (Perca fluviatilis) and the ruff (Gymnocephalus cernua) is described and related to development of behavior patterns characteristic of the two species. Perch are active pelagic predators for whom vision is of greatest importance in obtaining food, whereas ruff are benthophages of slow-flowing waters and typically obtain their food as solitary ambush predators for whom the highly sensitive lateral-line system is extremely important. The less developed system of the perch seems to match its greater ecological plasticity. Key words: Percidae, Perca, Gymnocephalus, lateral line, development, behavior, sensory organs
Food and Feeding Relations of Eurasian Perch (Perca fluviatilis) and Pikeperch (Stizostedion lucioperca) in Various Waters of the USSR
Authors: Popova O. A. , Sytina L. A.
Published: April 2011

Eurasian perch, Perca fluviatilis, and pikeperch, Stizostedion lucioperca, are the most widely distributed of the 11 species of percids in the USSR. This literature review examines their feeding ecology in the USSR.The pikeperch is an ambush–pursuit predator. It can become piscivorous within a few months after hatching, when it begins feeding mostly on small pelagic schooling fishes. In contrast, the perch, a facultative ambush predator, hunts during the day, eating mostly invertebrates and young fish.The daily ration of pikeperch during the most intensive feeding period constitutes 4.5–5.5% of the body weight and decreases to 0.5% during periods of less intensive feeding. The annual ration is 200–250% of its body weight. About 60% of the annual ration is consumed during spring, 15% during summer, 22% during autumn, and 3% during winter. The daily ration of perch is similar to pikeperch — 1–4% of the body weight during spring and autumn and 0.5% during other months. The annual ration of perch is 175–200% of its body weight. About 40% of the annual ration is eaten during spring, 30% during summer, 15% during autumn, and up to 20% during the winter. The conversion of wet weight of food eaten to wet weight of predator is higher for pikeperch (19.6%) and perch (18.2%) than for other predators in our area.Due to different feeding conditions the biological roles of perch and pikeperch vary even within the same water body. Adult pikeperch are always piscivorous, but perch often compete with other fishes for food and are a source of food for pikeperch and other large predators. The abundances of perch and pikeperch are inversely related; a decrease in pikeperch leads to a sharp increase in perch. In some small lakes in the forested area of northwest USSR, the fish fauna is represented by only two sizes of perch: small ones feeding on zooplankton and benthos near shore and larger ones cannibalizing the small ones; these two forms have fluctuated with 17-yr cycles.Calculation of diel, monthly, and annual rations of predators made it possible to determine the total food consumed in a year by one fish and by an entire stock of these predators. Stocking with pikeperch to control smaller fish abundance has been successful in waters with rich food supplies, but in some lakes of Middle Asia it annihilated the native fish fauna. Key words: Percidae, feeding habits, Perca, Stizostedion, annual rations
Percids in Unperturbed Ecosystems
Authors: Kelso J. R. M. , Bagenal T. B.
Published: April 2011

A review, primarily of papers from the PERCIS symposium, indicated that growth of percids in unperturbed ecosystems, which are rare and tend to be under harsh climatic regimes, was variable but tended to be low. Also, since growth appears to follow a clinal trend, heavily controlled by temperature, available data for unperturbed systems may not represent normal variation in growth. Recruitment did not appear to be a regular annual event and was adequately described by a wave pattern whose period was related to species longevity. Survival, therefore, was variable depending upon age-class structure of the community. Biomass, however, appeared to be a conservative property of unperturbed percid populations. Unperturbed populations should not be considered as ideal and we consider that preservation and study of unperturbed aquatic ecosystems can greatly increase understanding of the response of ecosystems to perturbation. Key words: Percidae, unperturbed ecosystems, growth, recruitment, age-class structure, survival, biomass
Production of Chironomus, Procladius, and Chaoborus at Different Levels of Phytoplankton Biomass in Lake Memphremagog, Quebec–Vermont
Authors: Dermott R. M. , Kalff J. , Leggett W. C. , Spence J.
Published: April 2011

In Lake Memphremagog a north–south gradient in algal production and biomass exists during the ice-free period, with highest production in the southern areas. In response, the mean annual benthic standing stock (dry weight) in the south basin was 2.8 times greater than in the north basin at comparable depth. Mean annual standing stock of Procladius denticulatus and Chironomus anthracinus were significantly (5.8 and 3.1 times, respectively) higher in the south, while that of Chaoborus punctipennus did not differ significantly between areas. Annual production of P. denticulatus was greater in the south (0.861 g/m2) than in the north (0.143 g/m2). Similarly for Chironomus anthracinus annual production was greater in the south (3.393 g/m2) than in the north (1.264 g/m2). Production of Chaoborus punctipennis was greater in the north (0.066 g/m2) than in the south (0.348 g/m2). P:B ratios were less variable. Key words: Lake Memphremagog, benthos, production, nutrient gradient, mortality
Seasonal Distribution, Abundance, and Growth of Larval Capelin (Mallotus villosus) in the St. Lawrence Estuary and Northwestern Gulf of St. Lawrence
Authors: Jacquaz Bernadette , Able Kenneth W. , Leggett William C.
Published: April 2011

Capelin (Mallotus villosus) larvae in the St. Lawrence estuary and northwestern Gulf of St. Lawrence were most abundant in 1974 and 1975 in the upper estuary in early June; this coincided with the spring peak in primary production. A spectacular decline (>99%) in larval abundance between June and September resulted principally from their downstream transport by currents. In October and November larval capelin were concentrated in a large counterclockwise gyre located in the northwestern Gulf between Anticosti Island and Pointe des Monts. This region is within the area of maximum primary production in the estuary and Gulf and may serve as an important feeding area for larval capelin. Length of capelin larvae at the end of the first growing season in the estuary and northwestern Gulf was greater than that of capelin from Newfoundland, Labrador, and Greenland. However, this difference may have resulted from sampling biases. Daily growth rates of capelin larvae from these areas were similar. Key words: capelin, Mallotus villosus, St. Lawrence, seasonal distributions, larval transport, growth, vertical distribution
Effects of Fry and Fingerling Introductions on Walleye (Stizostedion vitreum vitreum) Production in West Blue Lake, Manitoba
Authors: Schweigert Jacob F. , Ward F. J. , Clayton J. W.
Published: April 2011

Walleye (Stizostedion vitreum vitreum) were introduced into West Blue Lake, Manitoba, as fry in 1971 and as fry and fingerlings in 1972. Introduced fish were selected to possess malate dehydrogenase (MDH) isozyme phenotypes different from native walleye. The fingerlings were also fin clipped. During the summer months of 1973, 1974, and 1975 fish were recaptured by gill net. Muscle from recaptured fish was used for the determination of MDH isozyme phenotype whereby the contribution of the introduced fish to year-class abundance, biomass, and production was calculated.The 1971 introduction augmented the year-class by 38% but this brood provided only 1.3% of the total catch during the September 1974 to August 1975 period. In contrast, the 1972 introductions formed 99% of the year-class and contributed 37.8% of the total catch in the same 1974–75 period. The fingerling introduction formed only 7.0% of the 1972 year-class abundance in 1975.Introduced fish provided 54% of the total walleye production of 260 kg (wet weight) during the period September 15, 1974 to August 8, 1975. Production by introduced fish was apportioned as follows: 1972 fry 91%; 1972 fingerlings 7.4%; 1971 fry 1.7%. This investigation demonstrates the important contribution that introduced walleye fry may make to production and the utility of isozyme "tagging" in the evaluation offish introductions. Key words: walleye, Stizostedion, production, fry introductions, malate dehydrogenase, MDH, isozymes, fish, introduction evaluation
Assessment of the Arctic Marine Environment/Selected Topics.
Authors: Welch H. E.
Published: April 2011

not available
Dinoflagellate Toxins as Probable Cause of an Atlantic Herring (Clupea harengus harengus) Kill, and Pteropods as Apparent Vector
Authors: White Alan W.
Published: April 2011

Stomachs of Atlantic herring (Clupea harengus harengus) from a kill that occurred in the Bay of Fundy during a bloom of the toxic dinoflagellate Gonyaulax excavata contained pteropods, algal remains, and paralytic toxins. Experiments show that comparable amounts of G. excavata toxins can kill herring rapidly. It is likely that the kill was caused by paralytic dinoflagellate toxins, and that the pteropod Limacina retroversa, a planktonic herbivore, acted as a vector of the toxins. Key words: Dinoflagellate toxins, Gonyaulax excavata, herring kill, Clupea harengus harengus, pteropod, Limacina retroversa
Stream Habitats and Behavioral Interactions of Underyearling and Yearling Atlantic Salmon (Salmo salar)
Authors: Symons P. E. K. , Heland M.
Published: April 2011

From an examination of over 20 yr of data from the Northwest Miramichi River and some additional data from small tributaries to the Nashwaak River, highest densities of 100 underyearling and 80 yearling or older Atlantic salmon (Salmo salar) per 100 m2 were found at sites where water velocities averaged 50–65 cm/s. At sites with lower or higher water velocities maximum observed densities decreased. Experiments in laboratory streams demonstrated that underyearling Atlantic salmon < 7 cm (total length) occurred in shallow (10–15 cm) pebbly (1.6–6.4 cm diam) riffles of natural streams by choice. As they grew they began to prefer deeper (> 30 cm) riffles with boulders (> 25.6 cm diam). Yearlings > 10 cm reduced the numbers of underyearlings < 6 cm in these deeper habitats by chasing them, and occasionally by catching and eating them. Social interactions, such as displays used in territorial defence, did not occur between yearlings and underyearlings until the latter exceeded 6.5 cm, the size at which they began to move to deeper riffles. Planting densities for hatchery-reared salmon recommended in the literature were refined, taking the space and habitat requirements of different-sized juvenile salmon into account. Key words: spatial relations, rearing capacity, stocking density, stream ecology
Survival of Steelhead Trout (Salmo gairdneri) Eggs, Embryos, and Fry in Air-Supersaturated Water
Authors: Nebeker Alan V. , Andros James D. , McCrady Joel K. , Stevens Donald G.
Published: April 2011

Egg, embryo, fry, and swim-up stages of steelhead trout (Salmo gairdneri) were exposed to water at total gas saturation levels ranging from 130 to 115%. Eggs, embryos, and newly hatched fry were not affected at 126.7%, but at about day 16 posthatch when the fish began swimming up deaths occurred rapidly, and at the end of the test post button-up mortality ranged from 99% at 126.7% saturation to 45% at 115.3% saturation. Bubbles in the mouth, gill cavity, and yolk sac caused flotation and severe respiratory difficulties. Rupture of yolk-sac membranes also caused death. No differences were noted in survival between fish exposed from egg to fry, and those exposed only from swim-up to fry stage. In summary, there were differences in susceptibility among steelhead life stages to air-supersaturated water; eggs, embryos, and pre-swim-up larvae were more resistant than swim-up and later fry stages. Key words: trout, steelhead, supersaturation, gas-bubble disease, Salmo gairdneri, temperature, fish culture
Environmental Biogeochemistry. Volume 1: Carbon, Nitrogen Phosphorus, Sulfur and Selenium Cycles. Volume 2: Metals Transfer and Ecological Mass Balances.
Authors: Brunskill G. J.
Published: April 2011

not available
Ichthyology.
Authors: Cahn Phyllis H.
Published: April 2011

not available
Population Estimates of Sockeye Salmon (Oncorhynchus nerka) in a Fertilized Oligotrophic Lake
Authors: Robinson D. G. , Barraclough W. E.
Published: April 2011

Pelagic juvenile sockeye salmon (Oncorhynchus nerka) populations were studied in Great Central Lake, British Columbia, during 1969–76 to determine the effect of nutrient enrichment upon their growth and survival. Data for population estimates were collected concurrently by a high-frequency echosounder, and a midwater trawl whose efficiency was inversely related to ambient light above about 1.9 × 10−5 lx. Echogram counts supplemented by trawl catches yielded estimates with low variance, good resolution between age-groups, and indicated close correlation between numbers of spawners and resultant progeny within respective treatments. Survival to the fall for the treated 1969–72 brood years averaged 11.65% (range 11.11–12.81%) of potential egg deposition compared to 3.5% for the pretreatment 1968 brood year fish; 2.73 and 6.29% for the posttreatment 1974 and 1975 brood year fish. A carry-over of fertilization effects on the immediate posttreatment 1973 brood year may have induced a cyclic pattern on the survival of the two succeeding year-classes. The relatively consistent annual production of age 0+ sockeye may be due to the inherent stability of inlake spawning and incubation coupled with the low predation rates. The conservative estimate of a 2.5 increase in survival relative to the natural level indicates a positive response to enhanced feeding conditions caused by the fertilization of this oligotrophic lake. Key words: sockeye, survival, Great Central Lake, fertilization, enhancement, acoustic estimates, townet efficiency
Chemical and Sensory Analysis of Ungutted Offshore (Nonspawning) Capelin (Mallotus villosus) Stored in Ice
Authors: Botta J. R. , Noonan P. B. , Lauder J. T.
Published: April 2011

Based on changes in chemical and sensory variables, the keeping time of ungutted offshore capelin (Mallotus villosus) stored in ice was ~ 12 d, which was superior to other pelagic fish such as inshore (spawning) male capelin, Atlantic herring (Clupea harengus harengus) and Atlantic mackerel (Scomber scombrus). Free fatty acid, hypoxanthine, trimethylamine, and moisture content as well as iodine number and muscle pH significantly (P ≤ 0.05) changed during 16 d of iced storage. Although changes in lipid content and peroxide value were statistically significant (P ≤ 0.05), it is questionable whether these changes were chemically significant. Hypoxanthine and trimethylamine appeared to have the most potential for use as indices of sensory quality deterioration during iced storage. Key words: capelin, flavor, free fatty acids (FFA), hypoxanthine, iced storage, odor, overall acceptability, peroxide value, texture, trimethylamine (TMA)
Ammonia Quotient in Sockeye Salmon (Oncorhynchus nerka)
Authors: Kutty M. N.
Published: April 2011

Ammonia quotients (A.Q., ratio of ammonia excreted to oxygen consumed) were computed from data on daily-fed and starved sockeye salmon (Oncorhynchus nerka). In 22-d starved salmon, where a diel pulse in oxygen consumption, but not in ammonia excretion, persisted, the A.Q. was 0.125 at the prepulse stage (0.11 in fed fish); the lowest A.Q. was 0.06 (0.05 in fed fish) at peak oxygen consumption. The highest A.Q. of 0.24 was obtained in fed fish at the peak of ammonia output. Based on a theoretical estimate of an aerobic maximum A.Q. of 0.33, it is estimated that protein oxidation changes from 18 to 38% in starved sockeye and 15 to 73% in fed fish. The latter value is possibly an overestimate because of the involvement of nonoxidative protein breakdown, but this anaerobic involvement in routine metabolism of sockeye may be negligible. Key words: ammonia excretion, ammonia quotient, Oncorhynchus nerka, daily metabolic pattern, protein catabolism, starvation effect, energy utilization, nitrogen-excretion ratio, Rhinomugil corsula
Effects of the Polychlorinated Biphenyl Aroclor® 1254 on Growth, Survival, and Bone Development in Brook Trout (Salvelinus fontinalis)
Authors: Mauck Wilbur L. , Mehrle Paul M. , Mayer Foster L.
Published: April 2011

Eyed eggs of brook trout (Salvelinus fontinalis) were exposed to Aroclor® 1254 (0.43–13 μg/L) for 10 d before hatching and the fry for 118 d after hatching. Median hatching time, egg hatchability, and sac fry survival were not affected by Aroclor 1254. At 48 d after hatching, growth was significantly (P < 0.05) decreased by Aroclor 1254 concentrations ≥ 1.5 μg/L, but no significant differences in growth of surviving fry were observed at the end of the 118-d exposure. Mortality occurred in fry exposed to 13 μg/L within 48 d of exposure, and after 118 d of exposure significant mortality occurred in the three highest concentrations. Biochemical constituents in brook trout fry related to growth and development were affected by Aroclor 1254. Hydroxyproline and vitamin C concentrations in sac fry (38 d old) were decreased by ≥ 3.1 μg/L. Backbone development in fry exposed for 118 d was significantly altered. Collagen was significantly decreased in the backbone as was the phosphorous concentration, while the calcium concentration increased. Hydroxyproline concentration in collagen isolated from the backbone was also decreased. The no-effect exposure concentration on backbone composition was < 0.43 μg/L. Whole body residues in fry exposed for 118 d were 40 000 to 47 000 times the concentration in water. Key words: brook trout, Salvelinus fontinalis, Aroclor® 1254, polychlorinated biphenyls, PCB, growth, bone development, vitamin C, collagen
Acoustic Detection of Demersal Fish Closer than 15 Centimetres to the Bottom in 80 Metres of Water
Authors: Orr M. H. , Hays E. E. , Hess F. R.
Published: April 2011

Records from an acoustic backscattering system operating at 200 kHz are presented which show that demersal fish can be individually detected closer than 15 cm to the ocean bottom in 88 m of water. Key words: acoustic, demersal fish
Ultrastructural Aspects of the Causative Agent and Renal Histopathology of Bacterial Kidney Disease in Brook Trout (Salvelinus fontinalis)
Authors: Young Charity L. , Chapman George B.
Published: April 2011

The renal histopathology of bacterial kidney disease in both naturally and experimentally infected brook trout (Salvelinus fontinalis) was investigated here on the ultrastructural level. Abnormal changes in the glomerulus and renal tubule during the experimental infection are described chronologically and compared with the changes observed in the fully developed natural infection. These abnormalities are similar to those occurring in mammalian renal disease. Evidence of a host immune and inflammatory response is presented. The bacterial strains involved in the two infections are compared in cell size, internal morphology, and manner of division to help characterize the as yet unclassified causative agent. Key words: morphology, fine structure, pathology, Corynebacterium, renal, bacterium, trout, disease, Salmonidae
Lag Adjustment Between Estimated and Actual Physiological Responses Conducted in Flow-Through Systems
Authors: Niimi A. J.
Published: April 2011

The results from physiological experiments that use a flow-through or open system may be biased because of lag. The nature of this discrepancy is attributable to a delay between the actual response of an organism and the measured response of the system. An equation is presented that would adjust the measurement for lag. This procedure is especially important when measuring time-dependent uptake and depuration rates like those reported in respiratory and toxicological studies. Key words: lag, flow-through systems, open systems, time-dependent uptake, depuration rate, respiration, toxicology
Histopathological and Hematological Changes in Mummichogs, Fundulus heteroclitus, Infected by a Pseudomonad
Authors: Li M. F. , Traxler G. S. , Clyburne S.
Published: April 2011

The hematological and histopathological changes in mummichogs infected by Pseudomonas reptilivora included a dramatic reduction in hematocrit values; massive structural lymphoid necrosis with formation of edematous spaces in the splenic tissue; empty and degenerate hepatic veins and sinusoids; and necrosis of the renal tubules in naturally and experimentally infected fish. Electron microscopy of the renal tissue revealed clumps of chromatin in the nuclei, disintegration or degeneration of organelles, and an increase of digestive vesicles or autophagic vacuoles in the cells. This is the first description of the pathology of this bacteria in a marine fish. Key words: fish disease, Pseudomonas, bacteria, hemorrhagic septicemia
Mating Behavior of the Rock Crab, Cancer irroratus
Authors: Elner R. W. , Stasko A. B.
Published: April 2011

A pair of rock crabs, Cancer irroratus, in mating embrace an hour after being placed in a laboratory tank, was observed intermittently until ecdysis of the female and copulation of the pair, and then until escape of the female 27 d after ecdysis. When separated from the mating embrace, the hard-shelled female sought out the male. Approach of female ecdysis was indicated by protrusion of a soft spherical bulge at the rear of the epimeral line. Details of the immediate pre- and postcopulatory behavior were observed continuously from 26 min before to 150 min after copulation. The female was first noted separated from the male 7 h after copulation. Periods of separation increased until mating interactions were completely abandoned 5 d after copulation. A second pair subsequently observed confirmed the above. Mating embrace was also observed between a hard-shelled male and a hard-shelled female that already had sperm plugs. Key words: Crustacea, crabs, copulation, molt indicators
Precocious Induction of Oocyte Maturation and Ovulation in Coho Salmon, Oncorhynchus kisutch
Authors: Jalabert Bernard , Goetz Frederick W. , Breton Bernard , Fostier Alexis , Donaldson Edward M.
Published: April 2011

Coho salmon (Oncorhynchus kisutch) were induced to ovulate 3–5 wk ahead of the normal time using partially purified salmon gonadotropin (SG-G100) alone or in combination with 17αhydroxy 20β dihydroprogesterone (17α-20βP). Treatment with 17α-20βP alone induced final oocyte maturation but not ovulation and was associated with a negative feedback upon endogenous gonadotropin. The most successful treatments consisted of a "priming" injection of 0.1 mg/kg SG-G100 followed within 2–3 d by an injection of either 1 mg/kg SG-G100 or 3 mg/kg 17α-20βP. Ova from the ovulated fish were successfully fertilized. This is the first occasion in which the time of spawning has been controlled in adult migrant Pacific salmon. Key words: coho salmon, Oncorhynchus kisutch, induced ovulation, final maturation, SG-G100, gonadotropin, 17α-20β dihydroprogesterone
Modification of Phosphorus Retention Models for Use with Lakes with Low Areal Water Loading
Authors: Ostrofsky M. L.
Published: April 2011

Existing phosphorus retention models are shown to overestimate retention in lakes where the areal water load (qs) is < 10 m/yr, thereby leading to low predictions of phosphorus concentration. This is caused, in part, by inconsistent assumptions in the overall modeling sequence. New empirical equations are presented that give better predictions of phosphorus for lakes with qs < 10 m, and equally good predictions for lakes with qs > 10 m. Key words: retention, phosphorus, empirical model, areal water load
Loss Rates of Suspended Material Sedimented in a Marine Bay
Authors: Taguchi S. , Hargrave B. T.
Published: April 2011

Loss rates for particulate carbon, nitrogen, chlorophyll a, and phaeophytin during the year in a coastal marine bay were calculated by comparison of sedimentation rates and suspended concentration of particulate matter available for deposition. Daily loss of carbon and nitrogen at various depths (1–6% with maximum values during late summer and autumn) generally decreased with depth and was highest when fecal pellet deposition increased during late summer. Loss rates of plant pigments were an order of magnitude lower than those of carbon and nitrogen, except when algal cells settled directly during winter. The observations substantiate previous assumptions that on a daily basis only a small proportion of suspended material is sedimented. Loss rate is dependent on the nature of the suspended particulate matter and physical structure of the water column. Key words: sedimentation, suspended particulate matter, settling velocity, coastal embayment
Seasonal Changes in Oxygen Uptake by Settled Particulate Matter and Sediments in a Marine Bay
Authors: Hargrave B. T.
Published: April 2011

Oxygen consumption by material deposited in sediment traps suspended at different depths in a coastal marine bay was highest during summer. Seasonal changes in respiration (Formalin sensitive oxygen uptake) were significantly correlated with organic content and highest rates on a dry and organic weight basis occurred during summer. There was no consistent depth-related change in oxygen uptake but seasonal changes in respiration were significantly correlated over consecutive 10-m depth intervals between 20 and 60 m. Rates of respiration and chemical oxidation by undisturbed sediment cores from 60 m, which were maximum during late summer, were not related to seasonal changes in temperature or dissolved oxygen concentration. A 1–2-mo delay existed between the deposition of particulate matter with maximum rates of oxygen consumption and maximum oxygen uptake by bottom sediments. Similar seasonal changes and calculation of the carbon equivalent of sediment respiration, however, show that oxidation of settled organic matter is largely complete within the year of deposition. Key words: sedimentation, particulate matter, biological and chemical oxidation, marine sediments
Survival and Growth of Juvenile American Lobsters (Homarus americanus) After Eyestalk Ablation
Authors: Trider D. J. , Mason E. G. , Castell J. D.
Published: April 2011

The effect of size at the time of ablation on postoperative survival was assessed by removing the eyestalk from 4th, 5th, and 6th stage juvenile American lobsters (Homarus americanus) 6 d postmolt. The 6th stage juveniles exhibited significantly higher survival (72.8%) through three postoperative molts than the 5th or 4th stage lobsters (45 and 30% survival, respectively). Survival of control lobsters through the same number of molts was 90%. The feeding of a nutritionally adequate diet (frozen brine shrimp) was of prime importance with regard to survival of both ablated and control lobsters. The mean percent total weight gains for these three postablation molts were 610, 571, and 642% for 4th, 5th, and 6th stage lobsters, respectively, while the weight gain for control lobsters was 407%. The data suggest that eyestalk ablation should not be performed earlier than 6th stage for maximum survival and growth. Key words: eyestalk ablation, American lobster, survival, growth
Uptake from Seawater and Clearance of p,p′-DDT by Marine Planktonic Crustacea
Authors: Harding Gareth C. H. , Vass W. Peter
Published: April 2011

A simple exponential model is used to interpret the simultaneous uptake and clearance of p,p′-DDT by euphausiids and copepods to and from seawater,[Formula: see text]where [C] and [W] are the concentrations in the organism and seawater, respectively. The clearance rate constant for euphausiids, kj = 0.043/d, is not significantly different from that observed for copepods, 0.048/d. No trend in ki values is detected over the range of p,p′-DDT concentrations in seawater used, 27.8–1388 ng/L. Furthermore, there is a great deal of overlap in the uptake rate constant values between organisms. Uptake rate constants range from 0.76 to 1.21 × 104/d for euphausiids and from 1.04 to 2.51 × 104/d for copepods. There appears to be no need to use a surface-area term if the concentration of p,p′-DDT in the organism is expressed per unit dry weight even though the euphausiids are 2 orders of magnitude larger than copepods. Knowing levels of ΣDDT present in planktonic crustaceans in nature, back calculations suggest that there must be [Formula: see text] ΣDDT/L in seawater. A considerable amount of the ΣDDT reported in seawater must therefore be unavailable to plankters because it is "bound" to particles. Key words: p,p′-DDT, uptake, clearance, surface area, euphausiids, copepods
Freshwater Benthic Invertebrate Life Histories: Current Research and Future Needs: Introduction
Authors: Rosenberg David M.
Published: April 2011

not available
Agricultural Engineering.
Authors: Sutterlin A. M.
Published: April 2011

not available
Detritus and Juvenile Salmon Production in the Nanaimo Estuary: III. Importance of Detrital Carbon to the Estuarine Ecosystem
Authors: Naiman R. J. , Sibert J. R.
Published: April 2011

Sources of autotrophic and allochthonous organic carbon available to the Nanaimo Estuary delta, British Columbia, were studied from 1974 to 1978. Annually, benthic microalgae produce 4–55 g C∙m−2, phytoplankton ~7.5 g C∙m−2, and macroalgae 0.9–7.5 g C∙m−2. Zostera marina (26.8 g C∙m−2∙yr−1) and Carex (~564 g C∙m−2∙yr−1) are productive but enter the food web as detritus. Allochthonous sources are most important with organic matter from the river, especially dissolved organic carbon (~2000 g C∙m−2∙yr−1) and fine particulates (56 g C∙m−2∙yr−1), contributing greatest amounts. The standing crop of organic detritus in the top 5 cm of sediments averages from 58 to 233 g C∙m−2, depending upon the station. The timing of organic inputs are important, however. Seventy to 93% of total annual river inputs occur during autumn freshets, Zostera enters the food web during winter, Carex may contribute in early spring, and algae are productive over summer months. Activity and biomass of microbes are high most of the year in surface sediments but in the water column microbes are relatively active only during warmer months. Surface sediment ATP concentrations range seasonally from 3 to 36 μg∙g sediment−1; and concentrations in the water column range from < 0.2 to 1.5 μg∙L−1. Microbial activity, measured with 14C-glucose, ranges seasonally from 4 to 20% uptake per hour for surface sediments and from < 1 to nearly 40%∙h−1 in the water column. These results are compared with those from other studies and coupled to concurrent studies of meiofauna and salmon ecology to show a link between detritus, microbes, harpacticoid copepods, and the food, growth, and production of juvenile chum salmon (Oncorhynchus keta). Key words: detritus, Nanaimo Estuary, primary production, carbon, microbes, salmon, algae, ATP, chlorophyll, Zostera
Seiche Excitation in Port San Juan, British Columbia
Authors: Lemon D. D. , LeBlond P. H. , Osborn T. R.
Published: April 2011

Seiche motions observed in San Juan Harbour with a bottom-mounted pressure gauge have been Fourier-analyzed and interpreted in terms of a theoretical model of oscillations in a rectangular basin with an exponential depth profile. Two of the observed periods (at 14.6 and 38.5 min) are identified with resonances of the basin; two other significant low frequency peaks (at 21 and 55 min) do not coincide with resonant periods of the basin and must be due to strong external forcing. Higher frequency fluctuations (20–160 s) are attributed to swell and to its subharmonic interactions with edge waves. Key words: water waves, seiches, mathematical model, Juan de Fuca Strait, British Columbia
Le contrôle de la variabilité à court terme du phytoplancton estuarien: stabilité verticale et profondeur critique
Authors: Fortier L. , Legendre L.
Published: April 2011

Hourly series of summer phytoplankton biomass (ATP and chlorophyll a) and photosynthetic capacity (14C assimilation and ATP increase in saturating light) were sampled in the lower St. Lawrence Estuary during the summer of 1977. Vertical stability of the water column was estimated by the Richardson number. From the results it is concluded that the mean level of biomass is an inverse function of critical depth, likely linked to the neap-spring tidal cycle (Mf). On the other hand, the fine fluctuations of biomass and photosynthetic activity were related to vertical stability, which varies according to the semi-diurnal tidal cycle (M2). A simple model was developed on the basis of Sverdrup's critical depth, combining the M2 fluctuations in stability (degree of vertical mixing) to Mf variations in critical depth. Net biomass increases, observed in a nonturbid stabilized water column, cannot be explained by the growth rates computed from 14C assimilation, but they are consistent with the measured rates of ATP production. Spectral analyses of time series of temperature and Richardson number suggest that low frequency water column stability variations amplify the spatial heterogeneity of a reacting parameter such as phytoplankton. On the other hand, a passive scalar such as temperature does not respond to these low frequency variations of stability. It follows that the study of stability spectra may give some insight into the low frequency control of phytoplankton dynamics. Key words: phytoplankton, St. Lawrence Estuary, variability, vertical stability, critical depth, Richardson number, Kendall's cross correlation, spectral analysis
New Information on the Longevity of Pacific Ocean Perch (Sebastes alutus)
Authors: Beamish Richard J.
Published: April 2011

A comparison of ages determined from surfaces of otoliths and from sections of otoliths showed that ages were similar up to a section age of 22–24 yr. The growth pattern observed on thin sections of otoliths and from broken and burned otoliths from the region of the nucleus was interpreted to indicate that Pacific ocean perch probably live much longer than previously thought. Because the criteria used to identify annuli from otoliths sections appeared valid for younger fish, there was no justification to reject the application of these criteria for estimating ages of older fish and thus no reason to reject the possibility that Pacific ocean perch might live to be older than 70 yr. Ages determined from sections of otoliths from other rockfish species found off the west coast of Canada such as Sebastes fiavidus and Sebastes brevispinis have ranged from 30 to 60 yr indicating that many species of rockfish may live longer than previously thought. Key words: age determination, otolith, maximum age, age determination errors, Pacific ocean perch, otolith sections
Fluoride in Antarctic Krill (Euphausia superba) and Atlantic Krill (Meganyctiphanes norvegica)
Authors: Soevik T. , Braekkan O. R.
Published: April 2011

Samples of Antarctic krill (Euphausia superba) and Atlantic krill (Meganyctiphanes norvegica) were analysed for fluoride using a selective fluoride electrode method. Both species showed very high concentrations, a total of 1330–2400 mg F−/kg on fat free dry weight basis in raw samples whereas deep sea prawns (Pandalus borealis) showed a total of 18–91 and red feed (Calanus finmarchicus) 10–37 mg F−/kg. Sections of Antarctic krill were analyzed, and the highest concentration was found in the carapace, 4260 mg F−/kg fat free dry matter, compared with 570 and 750 mg F−/kg in raw and boiled muscle. Biological availability was measured in a chick assay, and showed fluoride in krill to be equally utilized as sodium fluoride added to the diet. Key words: krill, red feed, deep sea prawn, fluoride
Relationships Between RNA–DNA Ratio, Prey Density, and Growth Rate in Atlantic Cod (Gadus morhua) Larvae
Authors: Buckley L. J.
Published: April 2011

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod
Ecology of Benthic Epifauna of the Estuary and Gulf of St. Lawrence: Factors Influencing Their Distribution and Abundance on Buoys
Authors: Fradette Pierre , Bourget Edwin
Published: April 2011

The invertebrate fauna on 200 buoys moored in the Estuary and Gulf of St. Lawrence was sampled from May through December from 1975 to 1976. A total of 45 species (13 sessile, 32 motile) was collected. The distribution of the most abundant sessile species (Obelia longissima, Mytilus edulis, Hiatella arctica, Balanus crenatus, and Balanus balanoides) was studied in detail. Numbers of organisms and biomass decreased markedly on passing from the Gulf of St. Lawrence to the Lower Estuary and from the Lower Estuary to the Upper Estuary. Numbers of species showed stepwise diminution along with a stepwise increase in turbidity, while community densities decreased progressively with salinities. No sessile species and four motile species were observed in the riverine portion of the Estuary. In the upper portion of the Estuary, freshwater species were found along the south shore whereas euryhaline species were observed on the north shore. Water outflow from the Saguenay Fjord coincided with the limit of penetration or with discontinuities in the distribution of all sessile species within the Estuary. In the Upper Estuary, patches of M. edulis, B. crenatus, and the hydroids O. longissima and Clytia sp. were observed in regions of upwelling. Similarly, in the Gulf, O. longissima was very abundant on buoys near Mingan Islands where there is also an upwelling. The relatively high abundance of hydroids where conditions were generally unfavorable for settlement of sessile organisms was due to their capacity to colonize substrata from the budding of a few individuals. Mytilus edulis was the most abundant species elsewhere in the Gulf, except along the Lower North Shore. Low water temperature influencing larval development of M. edulis in this region best explains low community densities. Variations of growth indices (maximum lengths and mean weights per individual) for M. edulis were related to water temperature and to relative abundance of suspended organic matter in seawater.Key words: benthic epifauna, St. Lawrence Estuary, Gulf of St. Lawrence, ecological distribution, biomass, population density, Mytilus edulis, Balanus crenatus, B. balanoides, Hiatella arctica, Obelia longissima, buoys
A New Approach for Differentiating Flexibacteria Isolated from Cold-water and Warmwater Fish
Authors: Pyle Stephen W. , Shotts Jr. Emmett B.
Published: April 2011

Seventeen strains of flexibacteria associated with fish disease were evaluated with the API 20E system of biochemical tests. The results differentiate between isolates from warmwater fish, which utilize arabinose, melibiose, and sucrose; and isolates from cold-water fish, which are negative on these tests. Cold-water fish isolates may be further divided into subgroups on the basis of gelatin hydrolysis. The API system appears to provide the first biochemical differentiation of this group of poorly defined organisms.Key words: API 20E, flexibacteria, differentiate
Elemental Composition of Bone from White Sucker (Catostomus commersoni) in Relation to Lake Acidification
Authors: Fraser Grant A. , Harvey Harold H.
Published: April 2011

Bone was decalcified in fish from three acid lakes and manganese was increased greatly in bone of fish from the most acid lake. The mean centrum calcium content of white suckers (Catostomus commersoni) captured in George Lake (pH 4.65) was 16% lower than in white suckers from three lakes with near-neutral pH levels. In two other acid lakes, King (pH 5.08) and Crosson (pH 5.36), centrum calcium was reduced significantly in white suckers. Centrum manganese was elevated fivefold in white sucker from recently acidified George Lake, and tended to be elevated in this species from King Lake. White suckers from George Lake exhibited shorter caudal vertebrae and some of these fish had deformed caudal fins. These anomalies may be indicative of bone demineralization. All of the study lakes were located in south-central Ontario, including the La Cloche Mountains, North Bay, Algonquin, Haliburton, and Muskoka.Key words: lake acidification, bone composition, calcium, manganese, white sucker