bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of long day length on liver antifreeze mRNA in the winter flounder, Pseudopleuronectes americanus
Authors: Fourney Ron M. , Fletcher Garth L. , Hew Choy L.
Published: December 2009

The effect of photoperiod on the seasonal accumulation of winter flounder (Pseudopleuronectes americanus) antifreeze polypeptide (AFP) mRNA in the liver was examined. AFP mRNA levels were identified and measured by cytoplasmic dot hybridization and Northern blot hybridization procedures utilizing a nick-translated antifreeze genomic clone. Flounder maintained under conditions of 15-h long day length have both a delayed appearance and decreased accumulation of AFP mRNA. December flounder maintained under long day length had the most significant decrease in AFP mRNA levels. It was estimated that these fish contained less than 0.6% of the AFP mRNA normally found in control fish. The seasonal fluctuation of AFP mRNA in both the experimental and control fish matched closely but preceded the rise and fall of plasma AFP levels. These results suggest that long day length suppresses the rate of transcription of antifreeze genes and supports the hypothesis that photoperiod may act as the initial cue for entraining the precise activation of AFP synthesis. A pituitary hormone may be the mediator.
Effect of ligation and ecdysone on total haemocyte count in the tobacco caterpillar, Spodoptera litura (Noctuidae: Lepidoptera)
Authors: Rao C. G. Prasada , Ray Aparna , Ramamurty P. S.
Published: December 2009

Total haemocyte numbers in Spodoptera litura were studied under normal conditions and after ligation and subsequent injection of β-ecdysone. In late fifth stage larvae, ligation just behind the thorax resulted initially in a decrease of the total haemocyte count (THC) in both anterior and posterior halves, but 48 h postligation cell numbers increased in the anterior half, probably because of the presence of prothoracic glands in this region and also the elaboration of new cells from the anteriorly situated haemopoietic organs. The THC continued to remain low in the posterior half because of the deficiency of β-ecdysone and lack of haemopoietic organs. Injection of 50 μg of β-ecdysone into the "hormone-deficient" posterior half resulted in a significant increase in the haemocyte count, presumably because of direct or indirect hormonal stimulation of mitotis in circulating haemocytes.
Effects of substrate water potential and fluctuating temperatures on sex ratios of hatchling painted turtles (Chrysemys picta)
Authors: Paukstis Gary L. , Gutzke William H. N. , Packard Gary C.
Published: December 2009

Sex ratios of hatchling painted turtles (Chrysemys picta) are influenced by the hydric environment when eggs are exposed to fluctuating temperatures similar to those encountered in natural nests. When temperature varies between 18 and 30 °C over the course of a single day, nearly equal numbers of males and females hatch from eggs held on wet substrates, but, primarily, males emerge from eggs on dry substrates. The influence of the hydric environment on sex ratios of painted turtles developing in natural nests has important ecological implications, and may be a factor influencing both selection of nest sites by gravid females and sex ratios of hatchlings.
Influence of thiol substances on in vitro and in vivoL-thyroxine deiodination in rainbow trout, Salmo gairdneri
Authors: Eales J. G. , Shostak Shirley , Flood Catherine G.
Published: December 2009

The effects of the thiols DTT (dithiothreitol) and GSH (reduced glutathione) on hepatic in vitro and in vivo T4 (L-thyroxine) deiodination by rainbow trout held at 11 °C were studied. Hepatic deiodination increased progressively over the DTT range of 0.02–20 mM. GSH was less potent than DTT at low concentrations and strongly inhibited deiodination at high concentrations (> 1 mM). Hepatic deiodination was not increased by 1 mM NADPH or anaerobic conditions and was enhanced and not inhibited by the GSH inhibitor, diamide (2.5 mM), indicating that the low T4 deiodination in the absence of DTT is not due to endogenous GSH deficiency. Intraperitoneally injected GSH consistently increased plasma levels of 125I and [125I]-3,5,3′-triiodo-L-thyronine (T3) in fed or starved [125I]T4-injected trout, suggesting a GSH stimulation of extrahepatic T4 deiodination. However, injected GSH did not elevate plasma T3 concentrations. This was probably due to a demonstrated GSH stimulation of plasma T4 and T3 clearance. Force-fed GSH did not increase [125I]T4 deiodination. It is concluded that exogenous thiols can enhance T4 deiodination both in vitro and in vivo. However, availability of neither endogenous nor dietary GSH appears to regulate T4 deiodination under physiological conditions, including altered nutritional state.
Morphology and territory acquisition in willow ptarmigan
Authors: Hannon Susan J. , Roland Jens
Published: December 2009

Indices of body size, condition, and reproductive status were compared among willow ptarmigan (Lagopus lagopus alexandrae Grinnell) yearlings that held territories and those that replaced them in response to an experimental removal. We wished to determine whether these morphological factors had influenced the acquisition and retention of territories by residents. There was no difference in body size between residents and replacements in either sex, nor was there a difference in comb height, a correlate of hormonal status and aggression. Early replacements were in a condition similar to residents in females, but in poorer condition in males. There was a marked loss in condition in later replacements but this was more likely a consequence of nonterritoriality than a reason for it. We suggest that other factors such as prior familiarity with the breeding area or arriving before others may influence successful territorial establishment.
Honeydew as a source of host-searching kairomones for the aphid parasitoid Aphidius nigripes (Hymenoptera: Aphidiidae)
Authors: Bouchard Yves , Cloutier Conrad
Published: December 2009

The parasitoid Aphidius nigripes spent more time searching on potato plants previously infested with aphids than on fresh plants, suggesting the presence of searching stimulants on infested plants. Water extracts of aphid honeydew applied to the surface of foliage or to filter paper discs increased searching time and affected the locomotory behavior of parasitoids. When crossing a honeydew-treated area on filter paper, female parasitoids exhibited arrestment, antennal examination, abdominal protraction, reduced walking speed, and increased turning. Upon losing contact with honeydew-contaminated substrate, parasitoids often exhibited a klinotactic response which drove them back to the treated area. The time spent by individual parasitoids within a honeydew-treated area on filter paper decreased with successive visits, but the initial response level was restored when the insect was prevented from contacting honeydew for 1 h. The retention response exhibited by parasitoids contacting a honeydew-treated area increased with honeydew concentration, but levelled off at high concentrations. Naive parasitoids were more responsive to the retention effect of honeydew than experienced individuals.
An intraerythrocytic virus and rickettsia of frogs from Algonquin Park, Ontario
Authors: Desser Sherwin S. , Barta John R.
Published: December 2009

Two prokaryotic microorganisms were observed in the erythrocytes of frogs in a survey of blood parasites of six species of amphibians from a sphagnum bog adjacent to Lake Sasajewun, Algonquin Park, Ontario. A cytoplasmic virus was observed in 12 of 75 Rana catesbeiana and 1 of 75 Rana septentrionalis. The virus particles were hexagonal in section, measured 300–370 nm in diameter, and occurred in groups that were often surrounded by lamellar arrays of stacked membranes. Large spherical inclusions were seen in the erythrocytes of 2 of 57 Rana clamitans. In the electron microscope these inclusions were found to contain numerous rod-shaped prokaryotes which measured 1–1.7 μm × 200–300 nm. These organisms were ultrastructurally indistinguishable from rickettsiae.
Patterns and scale of habitat use in two temperate-zone, small mammal faunas
Authors: Morris Douglas W.
Published: December 2009

Small mammals were livetrapped and habitat quantified in replicates of six macrohabitats in Alberta and in temporal replicates of four macrohabitats in Ontario, Canada. Similar patterns emerged in both locations. The relative abundances of small mammals depended upon macrohabitat; within macrohabitats, species differed significantly in microhabitat use. The patterns were dynamic and probably the result of habitat preference instead of species interactions. Macrohabitat differences may in part be outcomes of microhabitat selection, but are unlikely to be completely understood without superimposing colonization and extinction probabilities on habitat selection models. Field biologists must recognize both scales of habitat to interpret patterns of species distribution.
Mechanisms responsible for the niche shift of brook charr, Salvelinus fontinalis Mitchill, when living sympatrically with creek chub, Semotilus atromaculatus Mitchill
Authors: Magnan Pierre , FitzGerald Gérard J.
Published: December 2009

When brook charr, Salvelinus fontinalis Mitchill, are in allopatry in oligotrophic Québec lakes, they feed largely on macrobenthic invertebrates. However, when brook charr cooccur with creek chub, Semotilus atromaculatus Mitchill, they feed largely on zooplankton. In the present study, laboratory experiments showed that creek chub were more effective than brook charr in searching for hidden, patchily distributed prey. The searching efficiency of an individual chub feeding in a group was improved through social facilitation. In contrast, the high level of intraspecific aggression observed in brook charr prevents the formation of such feeding groups. In the laboratory, brook charr were able to displace creek chub from the food source because of interspecific aggression. Data are presented showing that chub are morphologically better adapted than charr to feed on benthos (subterminal orientation of the mouth and protrusible premaxillae), while the charr are better adapted than chub to feed on zooplankton (gill raker structure). Differences in feeding behaviour, morphology, and relative abundance between these species appear to be important in the observed niche shift of brook charr in nature.
Prey selection and distribution of a predaceous, net-spinning caddisfly, Neureclipsis bimaculata (Polycentropodidae)
Authors: Richardson John S.
Published: December 2009

Responses of Neureclipsis bimaculata larvae to potential prey intercepted by their capture nets were observed in laboratory streams. Some prey types, such as amphipods and mayfly nymphs, were consistently able to escape the capture net. Of the prey items caught in the net, all elicited a similar initial response from larvae. Daphnia and terrestrial white worms (enchytraeids) were the most frequently captured prey items in these experiments. Larvae responded most often to live prey, presumably by sensing vibrations on the capture net. Prey selection was more a result of capture-net design and prey escape ability than an active choice by larvae. The availability of abundant, easily captured prey appears to be one of the determinants of the distribution of N. bimaculata populations.
Antipredator tactics of calving caribou: dispersion in mountains
Authors: Bergerud A. T. , Butler H. E. , Miller D. R.
Published: December 2009

The caribou (Rangifer tarandus) in Spatsizi Provincial Park, northern British Columbia, seek high south slopes in mountains as calving locations as an antipredator tactic. By being dispersed in heterogeneous and rugged mountains and away from moose (Alces alces), they force wolves (Canis lupus) and bears (Ursus arctos) to search large areas, reducing their capture success. By remaining at high elevation for 2–3 weeks in June, females with calves had to forego foraging in plant associations with high phytomass and nutrient concentrations. The antipredator tactic of dispersion in mountains was only relatively successful in 1976 and 1977; 90% of the calves still died prior to 6 months of age, largely from predation. The relatively recent invasion of moose into northern British Columbia in the early 1900's has resulted in more wolves per unit area than formerly and their combined searching has reduced the utility of leaving valley bottoms and being dispersed in mountains as a tactic to increasing the searching effort of predators.
The morphology of postponed senescence in Drosophila melanogaster
Authors: Rose Michael R. , Dorey Maria L. , Coyle Anne M. , Service Philip M.
Published: December 2009

Five laboratory populations of Drosophila melanogaster which exhibit postponed senescence were compared with five control populations. Comparisons were made with respect to weights of whole bodies, body parts, and water content. Ovaries of young adults from populations exhibiting postponed senescence were approximately half the weight of ovaries of flies from control populations. This result was obtained in two experiments. Whole wet body weight was significantly greater for control populations in one experiment, but not in a second. Males from control populations had significantly less proportional water content than males from populations exhibiting postponed senescence. The reduction in young adult ovary weight in flies from populations with postponed senescence supports the concept of a trade-off between reproductive effort and longevity.
Geographic variation in Congrogadus subducens (Teleostei, Perciformes, Congrogadidae)
Authors: Winterbottom Richard , Reist James D. , Goodchild Cheryl D.
Published: December 2009

Congrogadus subducens, which is confined to the western Pacific ocean, is redescribed on the basis of 188 specimens. Differences were found between the Sahul and Sunda shelves populations. Although some of the differences could be the result of ecophenotypic effects, evidence is presented suggesting that at least part of the variation is best accounted for by genotypic components, which may be at least partly due to historical biogeographic events. Evidence for dispersal of C. subducens into the range of its sister species C. hierichthys is presented.
Rediagnosis of Urucuia Kloss, 1961 (Nematoda; Rhigonematina; Carnoyidae) with comments on morphology and host distribution of the Carnoyidae, parasites of diplopods
Authors: Adamson Martin L.
Published: December 2009

In this study, two superfamilies are recognized in the Rhigonematina sensu Inglis, 1983: the Rhigonematoidea (containing the Rhigonematidae and the Ichthyocephalidae) and the Ransomnematoidea (containing the Ransomnematidae, Hethidae, and Carnoyidae). The Carnoyidae are recognized by the fact that the oesophageal corpus of the female is divided into narrow anterior and broad posterior portions. The carnoyid, Urucuia incondita Kloss, 1961, sole species of Urucuia Kloss, 1961 is redescribed and the genus is redefined. Urucuia most resembles Brumptaemilius in the structure of the spicules and gubernaculum, shape of the caudal extremity and disposition of caudal papillae in the male. The genera are distinguished principally by the structure of the baccal capsule of the male: in Brumptaemilius it has a broad open lumen and three prominent lanceolate cuticular formations project from its base; in Urucuia the posterior two-thirds of the baccal capsule are thick-walled with a much restricted lumen and cuticular projections are absent. The close similarity between Urucuia, a South American genus, and Brumptaemilius, an African genus, may reflect the fact that these genera are unique among the Carnoyidae in that they occur essentially in the Spirostreptinae (Order Spirostreptida).
Functional morphology involved in intraspecific fighting of the beaked whale, Mesoplodon carlhubbsi
Authors: Heyning John E.
Published: December 2009

Numerous authors have attributed the linear scars on male beaked whales to intraspecific fighting. The species Mesoplodon carlhubbsi was examined from a structural viewpoint to describe functionally how such scarring may result. In this species, linear scars occur in two patterns: single scars and parallel scars. Parallel scars occur when both of the large teeth possessed by the aggressor male come in contact simultaneously with the inflicted whale. In mature males, the teeth project from the lower jaw outside the mouth up along both sides of the rostrum to a height greater than the top of the rostrum. This indicates that the teeth are used with the mouth closed by bringing the dorsal aspect of the rostrum in contact with the soon to be inflicted whale. The densely ossified mesorostral canal evident in mature males probably functions in reinforcing the rostrum as the males engage in fighting. Two evolutionary trends in Mesoplodon dentition are hypothesized: (i) the change in position of the teeth in the mandibles from an apical (primitive) position back to a more posterior position; (ii) once situated farther back on the mandibles, to raise the apex of the teeth above the level of the rostrum. Comments on other Mesoplodon species are noted for comparisons.
Lernaea cruciata from the pumpkinseed, Lepomis gibbosus, in southern Québec
Authors: Lewis David J. , Deveau Jean-Louis , Doucet G. Jean
Published: December 2009

Lernaea cruciata (LeSueur) is reported from Lepomis gibbosus (Linnaeus) collected in Lac Saint-Louis, Québec. This constitutes the first report of this parasite on the pumpkinseed in Canadian waters.
Surface changes in the intestinal mucosa of mice infected with Eimeria falciformis
Authors: Speer Clarence A. , Pollari Franklin L.
Published: December 2009

Scanning electron microscopy (SEM) was used to study changes in the mucosa of the cecum and colon of mice infected with Eimeria falciformis. Pieces of the cecum and colon were removed from mice that had been inoculated 1–12 days earlier with 106 or 2 × 104 sporulated oocysts, and then processed for SEM. Alterations of the mucosal surface of infected mice were restricted to the cecum and upper half of the colon. At 2–8 days postinoculation (DPI), the apical area of absorptive enterocytes gradually increased to more than 4 times normal, and goblet cells initially increased in number, then declined and eventually disappeared. Lesions in the epithelium which exposed the basal lamina were most severe at 6–8 DPI. Repair of the epithelium occurred at 9–12 DPI.
A contribution to the knowledge of Chondracanthidae (Copepoda: Poecilostomatoida) parasitic on fishes of British Columbia
Authors: Kabata Z.
Published: December 2009

The paper discusses morphological criteria by which species of the genus Acanthochondria Oakley, 1930 (Copepoda: Poecilostomatoida) can be conveniently identified. It contains redescription of Acanthochondria rectangularis (Fraser, 1920) and descriptions of three new species of Acanthochondria: A. margolisi, A. dojirii, and A. vancouverensis, all from marine fishes of British Columbia, Canada. It proposes relegation of A. holocephalarum Kabata, 1968 to synonymy with A. epachthes (Wilson, 1908). Chondracanthus deltoideus Fraser, 1920 is redescribed and its affiliation to the genus Chondracanthus de la Roche, 1811 is defended.
Identified neurosecretory cells in the brain of female Rhodnius prolixus contain a myotropic peptide
Authors: Kriger F. L. , Davey K. G.
Published: December 2009

Extracts of 10 identified neurosecretory cells in the pars intercerebralis exhibit myotropic activity when added to the medium bathing an isolated ovary of Rhodnius. The myotropic activity of the preparation, expressed as the power in joules per second, increases linearly over a 100-fold range of concentrations but is not further affected by higher concentrations. The activity in the extracts is stable after heating to 90 °C for 5 min, and is reduced by incubation with trypsin. Comparison with the effects of proctolin demonstrates that the neurosecretory myotropin is not proctolin.
Seasonal histochemistry of the renal sexual segment in male common water snakes, Nerodia sipedon (L.)
Authors: Weil Michael R.
Published: December 2009

The histochemistry of the renal sexual segment of male common water snakes, Nerodia sipedon (L.), was studied throughout the active season. This segment is hypertrophied in early spring and late autumn, coinciding with peaks in plasma androgen levels. Secretory granules, present in epithelial cells lining the kidney tubule lumen of the sexual segment, are most evident at these times. Granules stain most intensely with periodic acid – Schiff, Sudan black B, and Oil red O from snakes collected in early spring and nearly as strongly from snakes collected in late autumn. Mercuric bromphenol blue and the Millon reaction stain granules most intensely from autumn captured animals. Granules from midsummer animals stained weakly with all of the above stains. It is suggested that the renal sex segment secretion plays a dual role, one of sperm transport and capacitation (final sperm maturation in the female reproductive tract) in autumn and another related to sexual behavior in the spring.
Effect of growth temperature on the steady-state fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene incorporated into flight muscle mitochondrial membranes of houseflies (Musca domestica)
Authors: Plaskon R. Richard , Anderson Gary L.
Published: December 2009

This study reports steady-state measurements of the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) within flight muscle mitochondrial membrane fragments from adult houseflies (Musca domestica) grown at 15 and 25 °C. Growth temperature of the houseflies is shown to have no effect on the polarization of DPH's fluorescence, whereas the temperature sensitivity of fluorescence polarization (Δ polarization) is 16% higher in flies grown at 25 °C than in those grown at 15 °C. Since the fluorescence polarization of DPH gives an indication of the degree of order within membranes, these results suggest that houseflies have the ability to alter the temperature dependence of their flight muscle mitochondrial membrane structure in response to a change in temperature. Little attention has been directed to the effects of growth temperature on Δ polarization values and this study suggests a procedure for detecting the existence of changes in this quantity.
Effects of crowding on fecundity in barnacles: Semibalanus (Balanus) balanoides, Balanus glandula, and Chthamalus dalli
Authors: Wethey David S.
Published: December 2009

Phenotypic plasticity of relative investment in shell, eggs, and somatic tissue was examined with experimental population density manipulations in field populations of the intertidal barnacles Semibalanus (Balanus) balanoides from Massachusetts and Balanus glandula and Chthamalus dalli from Washington State, U.S.A. Individuals of S. balanoides of comparable somatic tissue weights produced larger clutches of eggs when crowded and columnar than when conical and uncrowded. Individuals of C. dalli showed a similar pattern. Individuals of B. glandula showed the opposite pattern: at comparable somatic tissue weights, conical uncrowded individuals made slightly larger clutches of eggs than did crowded, columnar individuals. In all cases the greatest shell investment per unit somatic tissue weight was associated with the greatest clutch investment per unit somatic tissue weight.
Meadow vole cycles within fences
Authors: Tamarin Robert H. , Reich Lawrence M. , Moyer Carol A.
Published: December 2009

To test the idea that dispersal is necessary for cycling and to develop an enclosure that would permit vole population cycling, we partially and fully fenced grids that included woodland areas (dispersal sinks) that were continually trapped out. We studied three populations of the meadow vole, Microtus pennsylvanicus, in Massachusetts from 1978 to 1982. The control population and both fenced populations exhibited virtually identical demographic trends, which encompassed a vole cycle. Analysis of demographic parameters suggested that the major effect of the fence was to increase survival within. We attributed this increased survival to reduced dispersal because a dispersal sink attracted only 98 dispersers throughout the study, We suggest that there is a continuum of individual thresholds to disperse with only a very few animals motivated enough to enter a woodland dispersal sink.
Recent dynamics and mortality rates of the Kaibab deer herd
Authors: Barlow Jay , McCulloch Clay Y.
Published: December 2009

Survival rates and expected sex ratios are estimated for the Kaibab mule deer (Odocoileus hemionus) of north central Arizona from harvest age–frequency distributions. During the study period (1972–1979) the population was declining at 9% per year. Annual survival rates for females older than 1.4 years were 0.63 and 0.62 for the eastern and western overwintering herds, respectively. For males older than 3.4 years, the corresponding rates were 0.50 and 0.44, respectively. These survival rates did not change appreciably with age beyond 1.4 years for does and 3.4 years for bucks. When survival rates were adjusted by subtracting reported firearm harvests, the rates show only a small difference between the sexes. Sex ratios estimated from the survival rates differed markedly from field estimates. Possible biases in both the field methods and in the use of harvest age distributions to infer population age structure are examined. The potential value of analyses of age distributions is discussed with regard to augmenting and independently verifying field data.
The savannah sparrow territorial system: can habitat features be related to breeding success?
Authors: Bédard Jean , LaPointe Gisèle
Published: December 2009

We studied the biology of the savannah sparrow (Passerculus sandwichensis) in a tidal marsh – abandoned fields ecotone at Isle Verte, Québec, from 1976 to 1981 in an attempt to relate habitat features of the territories (size, vegetation structure and height, food abundance, and an index of foraging opportunities) with breeding success (success in attracting a mate and in fledging at least one young). The height of plant cover did not influence the selection of nesting areas by females. The index of foraging opportunities was highly variable and could not be related to the age of the territory holder (yearling or older), his mating status (breeder or bachelor), or to his breeding success (success in fledging at least one young). Territory size was not consistently influenced by these factors. We propose several reasons for the lack of relation between breeding performance and those features of habitat quality that we studied.
Normal and multiple eggshells in batagurine turtles and their implications for dinosaurs and other reptiles
Authors: Ewert Michael A. , Firth Susan J. , Nelson Craig E.
Published: December 2009

The fine structure of normal and abnormally thick eggshells of the turtles Melanochelys trijuga and Rhinoclemmys areolata (Emydidae: Batagurinae) are described through the use of scanning electron microscopy. Eggshells of R. areolata differ from those reported for other turtles in having complex pores with basal openings partially occluded with crystallites. Each of the abnormally thick eggshells has the usual membrane and mineral layer encased within a second membrane and mineral layer and, in one case, within yet a third membrane and mineral layer. Information on oviducal function and the structure of these and most previously reported multiple-shelled turtle eggs allow the hypothesis that such eggs arise from oviducal retention of normally shelled eggs of one clutch that become reshelled during shelling of eggs ovulated to form the next clutch. This is likely only in species that lay more than one clutch per season. Our evidence suggests that dietary inadequacy causes the retention. We propose that dinosaurs that laid multiple-shelled eggs also had two or more clutches per season and that this multiple shelling was produced also by abnormal retention of eggs which, in turn, may have been induced by changes in diet.
The prevalence and pathogenicity of gizzard nematodes of the genera Amidostomum and Epomidiostomum (Trichostrongylidae) in the lesser snow goose (Chen caerulescens caerulescens)
Authors: Tuggle Benjamin N. , Crites John L.
Published: December 2009

Three species of trichostrongylid nematodes were removed from the gizzards of 25 lesser snow geese, Chen caerulescens caerulescens, collected at Winisk, Ont. A 100% prevalence of infection was noted in the sampled population with each bird harboring two or more of the following species: Epomidiostomum crami (prevalence, 92%; mean intensity, 18.7 ± 13.3), Amidostomum anseris (prevalence, 84%; mean intensity, 9.6 ± 9.8), and Amidostomum spatulatum (prevalence, 84%; mean intensity, 11.2 ± 9.8). When large burdens (>30) of both A. anseris and A. spatulatum were present in the mucosal lining of the gizzard, progressive degeneration of the epithilium and koilin linings was noted in 16% of the geese examined. Severe necrotic granulomata observed in the gizzard muscle of 36% of the geese were associated with sizable burdens (>25) of E. crami which were found burrowed in the gizzard muscle.
Liparis rufescens Burke 1930, a junior subjective synonym of Liparis gibbus Bean 1880
Authors: Vogt K. D.
Published: December 2009

A discussion of the status of Liparis rufescens Burke is presented along with a table of measurements and meristic values which indicates that no morphological differences appear to exist between L. rufescens and L. gibbus Bean. It is suggested that L. rufescens be considered a junior subjective synonym of L. gibbus.
Anatomy and adrenergic pharmacology of the coronary vascular bed of Pacific blue marlin (Makaira nigricans)
Authors: Davie Peter S. , Daxboeck Charles
Published: December 2009

Coronary blood supply to the heart of Pacific blue marlin (Makaira nigricans) is derived principally from efferent branchial arteries of the third gill arch via the hypobranchial arteries. A single coronary artery courses caudally from the hypobranchial arteries along the dorsal aspect of the bulbus arteriosus to the ventricle wall in which it branches extensively. Arterial branches invest the compact myocardial shell, trabeculated myocardium, and the atrium. In common with coronary vascular beds of higher vertebrates, marlin coronary vascular beds contained α-constrictor adrenoceptors and β-dilator adrenoceptors.
The effects of diet and photoperiod on hibernation in the woodland jumping mouse, Napaeozapus insignis (Miller)
Authors: Collins Valerie E. , Cameron Duncan M.
Published: December 2009

Woodland jumping mice, Napaeozapus insignis, were held at 9 ± 3 °C under three photoperiods: short days (8 h light: 16 h dark), long days (16 h light: 8 h dark), and a naturally changing photoperiod that approximated naturally occurring day lengths. Half the animals under each photoperiod had access to a full diet of sunflower seeds, rolled oats, and Purina rabbit chow throughout the experiment. The remainder of the animals in each photoperiod received the full diet for the first 10 days of the experiment after which they were given only rabbit chow. The patterns of torpidity of the animals in each group were analyzed with respect to two dimensions of hibernation: timing and quality. Under all photoperiods, animals that were switched to the rabbit chow diet spent significantly more time in torpor than did those that remained on the full diet. Of the animals on a full diet, those on a natural photoperiod spent more time in the torpid state than did those on either long or short days. It is suggested that jumping mice in nature respond to both decreasing photoperiod and food to adjust the proportion of time spent in torpor.
Effets du chimiostérilisant ornitrol sur le développement testiculaire du Carouge à épaulettes traité en captivité
Authors: Lacombe Diane , Cyr André , Bergeron Jean-Marie
Published: December 2009

Male red-winged blackbirds were kept in captivity and fed cracked corn containing 0.1% ornitrol for a period of 10 days in order to determine the optimal timing of this treatment during gonad growth. Treatments were administered before and during testis growth under conditions of natural photoperiod and under conditions of artificial photoperiod that stimulate testis development (18 h light: 6 h dark). In both experiments we observed a great deal of individual variation in the response to treatments. In the first trial, treatments applied both before and during testes growth inhibited their development. In the second trial, the same trend was observed, but differences were not significant. This treatment will have maximum efficiency in a natural environment and be profitable as a method of control only if the reproductive state of male redwings is determined with precision.[Journal translation]
Effect of low pH on sodium regulation in two species of Daphnia
Authors: Havas Magda , Hutchinson Thomas C. , Likens Gene E.
Published: December 2009

The effect of low pH on sodium-22 influx and outflux of Daphnia magna and Daphnia middendorffiana was assessed. Experiments were conducted in both hard and soft water with experimental pHs ranging from 3.5 to 8.0. In hard water, at and below pH 4.0, there was a net loss of sodium from both species. The rate of sodium loss (outflux) increased significantly, while the rate of uptake (influx) remained constant at pH 4.0 compared with the reference pH 8.0. Only at extremely low pH (pH 3.5) was sodium influx inhibited in hard water. In soft water, D. magna responded quite differently. Sodium influx was inhibited by 23% at pH 5.0 and by 69% at pH 4.5 compared with the control (pH 6.5). Sodium outflux was stimulated to 125% of the control at pH 4.5. The net loss of sodium in soft water was due to both an increase in sodium outflux and a decrease in sodium influx, while in hard water the effect was primarily on sodium outflux. Daphnia magna and D. middendorffiana have problems with sodium regulation below pH 5.5 in soft water and below pH 4.5 in hard water, which indicates that they are considerably more sensitive to low pH in soft water than in hard water.
Furocoumarin resistance in the larvae of Phytomyza spondylii (Diptera: Agromyzidae) feeding on Heracleum lanatum is associated with the enzymatic breakdown of 8-methoxypsoralen
Authors: Ashwood-Smith M. J. , Ring R. A. , Liu M. , Phillips S. , Wilson M.
Published: December 2009

The larvae of Phytomyza spondylii feed and produce characteristic tunnels or mines on the leaves of Heracleum lanatum, a plant which is rich in both angular and linear furocoumarins. These molecules, in the presence of near ultraviolet light, photosensitize cells by producing DNA adducts which, unless repaired, arc lethal. Thus, many plants belonging to the Umbelliferaceae are often considered to be resistant to insect foraging because of the presence of furocoumarins. The larvae of Phytomyza spondylii rapidly break down 8-methoxypsoralen into photobiologically inactive compounds. This is an enzymatic reaction requiring the presence of an electron generating and accepting system not unlike that seen with the mixed function microsomal oxidases of mammalian liver microsomes. This reaction may be specific as it was not observable in the fall webworm (Hyphantria cunea) on red alder or in Papilio zelicaon feeding on dill or parsley. It is postulated, therefore, that the presence of this detoxifying system in Phytomyza spondylii is related to the host specificity and distribution of the insect.
Oviposition of Hydropsychidae (Trichoptera) in a large river
Authors: Deutsch William G.
Published: December 2009

Scuba observations in the Susquehanna River revealed that oviposition of Cheumatopsyche speciosa and Hydropsyche phalerata began 26–44 min (mean, 33 min) after sunset and lasted for 19–30 min (mean, 24 min). Females oriented into the current on acrylic plates and ociposited in 30–60 s. Cheumatopsyche (probably C. speciosa) and H. phalerata egg masses contained a mean of 265 (134–504) and 367 (116–679) eggs, respectively; masses were largest and most densely packed with eggs in mid-June. Cheumatopsyche egg masses (84% of the 15 000 hydropsychid masses collected in 1981) were found from 21 May to 30 September; up to 980 egg masses∙m−2∙day−1 occurred in mid-July. Hydropsyche phalerata egg masses (15% of the total) were found from 22 May to 14 September; up to 170∙m−2∙day−1 occurred in early June. Both species oviposited almost daily when river temperature exceeded 15 °C. During a 30-day period when river temperature and depth were stable, there was a highly significant (P < 0.01) positive correlation between the number of Cheumatopsyche egg masses and evening air temperature. Positive correlation between the number of egg masses and river current (10–47 cm/s) at eight sites was highly significant (P < 0.01) for H. phalerata but not for Cheumatopsyche (P > 0.05). Hydropsychid egg masses were widely distributed over an acrylic hemisphere in a slow (15 cm/s) current but were concentrated on the top, downstream portion in a strong (58 cm/s) current.
The effect of substrate on burrowing in freshwater mussels (Unionidae)
Authors: Lewis John B. , Riebel Philippe N.
Published: December 2009

The burrowing behaviour and rates of burrowing on sand, clay, mud, and gravel were determined for three species of freshwater mussels, Lampsilis radiata (Barnes), Anodonta grandis Say, and Elliptio complanata (Solander). Burrowing is achieved by a series of probing and digging movements by the foot, alternating with adduction or closing of the valves, and foot contraction, which cause the valves to be forced downwards into the substratum. Overall burrowing abilities were superior in sand in comparison to gravel in all three species, and E. complanata burrowed more rapidly than the other species in clay, sand, and gravel. Righting was not accomplished in soft liquid mud but burrowing was achieved by frequent, rapid adduction of the valves. Although righting by both E. complanata and A. grandis in a clay substratum was slower than in either sand or gravel, both species burrowed more rapidly in clay. Although there were differences in burrowing abilities between species and in the four substrata tested, the ultimate success in burrowing by all three species suggests that substrate is not the direct causal factor affecting local distribution of freshwater mussels.
Croissance et morphogénèse postnatales de la mandibule du vison (Mustela vison Schreiber): données sur la dynamique et l'interprétation fonctionnelle des dépôts osseux mandibulaires
Authors: Buffrénil V. de , Pascal M.
Published: December 2009

The postnatal growth and morphogenesis of the mink (Mustela vison Schreiber) mandible are described using 10 specimens of known age, the skeletons of which were labelled in vivo by fluorescein and alizarin. Growth is very active in all mandibular regions during the first 2 months of life. It slows down during the 3rd month. During the 4th month, the whole mandible undergoes resorption, the intensity of which varies locally. Growth resumes during or some time before the 9th month with a deposit of parallel bone fibres in some mandibular regions only. This deposit is still active but goes on at a very low rate in old animals. The structural organization of mandibular bone varies in time and space and the relationships between the structure of bone and its growth rate is clarified. The overall modalities of osteogenesis meet the geometrical requirements of mandibular growth and are obviously a transcription of a specific pattern. They probably integrate, as well, epigenetic factors related to the local mechanical conditions of manducation. The influence of these factors on osteogenesis disturbs the deposit of annual growth lines in periosteal bone, weakening the fundamental hypothesis of the skelettochronology. Thus, the conditions for which this technique should be used are discussed.
Histopathological effects of crude oil on Atlantic cod following chronic exposure
Authors: Khan R. A. , Kiceniuk J.
Published: December 2009

To assess the long-term effect on the tissues of marine fish, Atlantic cod, Gadus morhua L., were exposed to water-soluble fractions of Venezuelan and Hibernia crude oils at concentrations of 50–300 ppb for 12–13 weeks in a flow-through seawater system. Histopathological changes in oil-exposed fish included increased numbers of mucus-producing epithelial cells, capillary dilation, lamellar hyperplasia, and fusion of adjacent filaments in gills, microvesicular formation in hepatocytes, delayed spermatogenesis with intratubular multinucleated giant cells, and an increase of melanomacrophage centers in the spleen and kidney. Lesions were more prevalent and severe in fish exposed to Hibernia crude than to Venezuelan crude at a similar concentration.
Redescription of Dichelyne (Cucullanellus) cotylophora (Ward &Magath, 1917) (Nematoda: Cucullanidae) parasitic in freshwater fishes of eastern North America
Authors: Baker M. R.
Published: December 2009

Dichelyne (Cucullanellus) cotylophora (Ward &Magath, 1917) Petter, 1974, is redescribed based on specimens from 440 perch (Perca flavescens) collected in Lake Erie, Ontario, from May 10 to October 29, 1982. There is a dorsoventrally elongate mouth opening and enlarged oesophastome with an armature similar to that described for other species of Dichelyne and Cucullanus. Dichelyne cotylophora most closely resembles Dichelyne bullocki Stromberg &Crites, 1972, from which it can be distinguished by possessing a markedly thicker body cuticle and by sexual maturation at a larger body size. Dichelyne cotylophora is reported in P. flavescens from two new localities: St. Lawrence River at Montreal, Québec, and Lake Memphremagog, Eastern Townships, Québec. This species occurs in a wide variety of fishes in eastern North America, but its main host is P. flavescens. A five- to six-fold increase in size and morphological changes occur during growth of adult D. cotylophora. The oesophastome of small worms is relatively undeveloped, especially the processes extending from the oesophastomal ring which are conspicuous in large adult worms. The caudal pseudosucker, which is prominent in large males, is undeveloped in small specimens. Morphometric analysis indicated that measurements of body dimensions can be misleading in taxonomy of cucullanids.
Pauropoda (Myriapoda) from Canada
Authors: Scheller Ulf
Published: December 2009

Twenty-three species of Pauropoda are reported from Canada. They belong to seven genera in two families, Pauropodidae and Brachypauropodidae. A new genus, Amphipauropus, is proposed for Cauvetauropus rhenanus Huther, a close relative of which has been found in Canada. Six species new to science are described and illustrated: Allopauropus remigatus n. sp., Allopauropus marshalli n. sp., Allopauropus tomlini n. sp., Allopauropus asperosus n. sp., Pauropus mixtus n. sp., and Stylopauropus canadensis n. sp. From a distributional viewpoint, the Canadian pauropods all belong to genera with very wide ranges: 52% of the species are known far beyond North America.
Alloparental care in the common murre (Uria aalge)
Authors: Birkhead T. R. , Nettleship D. N.
Published: December 2009

Common murres (Uria aalge) at the Gannet Islands, Labrador, were found to assist in the rearing of chicks which were not their own. This alloparental behaviour was most common among birds which had failed in their breeding attempt and mainly comprised brooding of well-grown chicks aged 18–22 days. Alloparental care occurred both when the chick's parents were present and absent from the colony. It is unusual for common murre chicks to be left unattended and occurs only when food availability is low: alloparents may increase the chances of survival of unattended chicks. There are several possible explanations for alloparental care in common murres, but at the present time we have insufficient information to enable us to distinguish between them. However, the most parsimonious explanation is that chicks take advantage of a nonadaptive residual hormone titre in failed breeders.
Exchangeable sodium pool size and sodium turnover in freshwater- and saltwater-acclimated ducks and gulls
Authors: Roberts Juliet R. , Hughes Maryanne R.
Published: December 2009

The exchangeable sodium pool size and its turnover rate were determined in ducks, Anas platyrhynchos, and gulls, Larus glaucescens, acclimated to freshwater and subsequently to 2/3 seawater. Saline acclimation led to a significant reduction in body mass in ducks but not gulls. Exchangeable body sodium per unit wet body mass was significantly greater for gulls (43 mmol∙kg−1) than for ducks (30 mmol∙kg−1) drinking freshwater. It was not significantly different between saltwater-acclimated ducks (48 mmol∙kg−1) and gulls (44 mmol∙kg−1). Saline drinking increased the sodium pool of ducks but not gulls. Similarly, the sodium flux per unit body mass was significantly higher for freshwater gulls (4.2 mmol∙kg−1∙day−1) than for ducks (2.1 mmol∙kg−1∙day−1). It was not significantly different between saltwater gulls (19 mmol∙kg−1∙day−1) and ducks (21 mmol∙kg−1∙days−1). Saline acclimation increased sodium flux by a factor of 4.5 for gulls and 10.4 for ducks. Freshwater-acclimated gulls had significantly higher levels of plasma sodium, chloride, and osmolality than did ducks. Saline acclimation increased the plasma osmolality of both species and the sodium and chloride concentrations of the plasma of ducks, and it decreased the hematocrit of ducks. Hematocrit and plasma osmotic and ionic concentrations were similar for saline-acclimated gulls and ducks.
A technique for the surgical removal of a kidney from individuals of a feral population of small rodents
Authors: Pavone Leo V. , Boonstra Rudy
Published: December 2009

A technique for the surgical removal of a kidney from small rodents is presented. It involves making two incisions, tying off the ureter and the renal blood vessels, removing the kidney, and stitching the incisions. Under laboratory conditions virtually all animals recuperated. A field test resulted in a 78% recovery rate for treated animals compared with their controls. The technique is simple, inexpensive, and quick making it a potentially useful tool in many areas including paternity studies and gene flow studies.
Histochemical properties of locomotory muscles of European hares and cottontail rabbits
Authors: Schnurr D. L. , Thomas V. G.
Published: December 2009

European hares (Lepus capensis) and cottontail rabbits (Sylvilagus floridanus) represent near extremes in the locomotory pattern encountered among leporids. Animals of both species were collected and four major hindlimb locomotor muscles were examined histochemically for succinic dehydrogenase and myosin adenosine triphosphatase activities. Muscle fibres were classified as fast-twitch glycolytic, fast-twitch oxidative glycolytic, or slow-twitch oxidative, and the percent composition and transverse area of the fibre types were obtained. Hare muscles had a much greater oxidative capacity than cottontail muscles as shown by 32–55% more fast-twitch oxidative glycolytic fibres than cottontail muscles. This correlates with the capacity of hares for high-speed endurance running and their inhabiting open, expansive environments. Cottontail muscles had a large proportion (45–54%) of fast-twitch glycolytic fibres of large transverse area resulting in the muscles being composed primarily of fast-twitch glycolytic fibres. This reflects the capacity of rabbits for quick bursts of activity and this type of locomotor pattern may restrict cottontails to densely covered deciduous habitats.