bluuebunny/crossref_metadata_2025 huggingface dataset:
The sand-burrowing amphipod Amphiporeia virginiana Shoemaker 1933 in the tidal plankton
Authors: Hager Richard P. , Croker Robert A.
Published: December 2009

The abundance of Amphiporeia virginiana in the tidal plankton over a high energy sandy shore in southern Maine increased to maximum values 1 to 1.4 m above mean low water (MLW) with no clear evidence of a diurnal cycle affecting swimming activity. The species undergoes daily tidal migrations over the shore with swimming activity increasing just before high tide and generally peaking during ebbing tides. Results of experiments with laboratory-held animals supported these conclusions, although swimming rhythms disappeared rapidly after 24 h in the laboratory. The swimming behavior of the species assists reproductive contact of sexes that are segregated in the sand, contributes to short-term fluctuations in distribution and abundance, and assists the species in maintaining dominance on high energy sandy shores.
On the validity of Diorchis maroccana Dollfus, 1975 (Cestoda: Hymenolepididae)
Authors: McLaughlin J. Daniel , Burt Michael D. B.
Published: December 2009

Reexamination of cotype material of Diorchis maroccana Dollfus, 1975 has revealed that the length of the rostellar hooks reported (36–40 μm and 65 μm) are in error. No hooks 65 μm were found. The rostellar hooks described for D. maroccana are similar in both length and shape to those of Diorchis ransomi Johri, 1939. In addition, the measurements and shapes of the various internal structures of D. maroccana specimens closely resemble those described for D. ransomi. On this basis, D. maroccana is therefore considered a synonym of D. ransomi.
Mechanical and metabolic response of the perfused isolated fish heart to anoxia and acidosis
Authors: Turner Jeffrey D. , Driedzic William R.
Published: December 2009

Sea raven (Hemitriperus americanus) and ocean pout (Macrozoarces americanus) hearts were excised and perfused in an isolated system. The contractile response of hearts perfused with buffer equilibrated with 100% O2, 100% N2, or 99% O2: 1% CO2 was monitored and work was calculated from mean pressure development times cardiac output. Hearts subjected to either anoxia or hypercapnic acidosis could not sustain mechanical performance as well as hearts perfused with buffer equilibrated with 100% O2. The decrease in mechanical function was not due to an unavailability of ATP. Alternatively it is suggested that contractile failure is related to a decrease in intracellular pH.
Development of thermoregulation in Richardson's ground squirrel, Spermophilus richardsonii
Authors: Dolman Teresa M.
Published: December 2009

Development of thermoregulation in Spermophilus richardsonii was investigated by determining the ability of neonates to maintain a normal body temperature when exposed to 30 and 25 °C, to maintain an elevated oxygen consumption (cubic centimetre oxygen per gram per hour) at 21 °C compared with that at 35 °C, and to move toward a warm object and assume curling postures when exposed to the cold. Newborn animals were essentially poikilothermic but by day 5 showed strong thermotaxis. By 30 days, the age of emergence from natal burrows, homeothermy had developed to the point at which normal body temperature could be maintained for at least 2 h at an ambient temperature of 25 °C. This process was correlated with improvements in heat production and heat retention. Subsequent growth was marked by a decreased metabolic response to cold (21 °C) owing to decreasing thermal conductance.
Surplus yearlings and the regulation of breeding density in blue grouse
Authors: Zwickel Fred C.
Published: December 2009

An experiment in which yearlings of both sexes of blue grouse (Dendragapus obscurus fuliginosus) were removed from breeding range showed that about two times, or more, yearlings of each sex were identified here as compared with a nearby control area, though numbers of "surplus" yearlings varied among years. The removal of large numbers of yearlings from the experimental area did not reduce breeding density, except ephemerally in 1 year. Nor did the removal of these birds affect populations in the surrounding area. These data confirm results from earlier studies with blue grouse, that surplus yearlings of both sexes are present on the breeding range. Replacement yearlings of both sexes (those taking the place of birds removed) were able to breed, but those removed sequentially (1974 to 1976) were lighter in body weight than those captured on control areas or those that settled synchronously after a near-total removal experiment in the same area. I infer from these results that some form of behaviour keeps surplus yearlings from settling on the breeding range and that this behaviour is a key mechanism involved in the regulation of breeding density. The important behaviour may involve either yearling–yearling or adult–yearling interactions.
Diagnostic value of vagina structure in the taxonomy of Aphelenchus Bastian, 1865 (Nematoda: Aphelenchidae) with a description of A. (Anaphelenchus) isomerus n.subgen., n.sp.
Authors: Anderson R. V. , Hooper D. J.
Published: December 2009

Structural differences in the vagina, found in a comparative study of 110 populations of Aphelenchus from 30 countries are judged to be of diagnostic value in separating species and species groups. Aphelenchus avenae, the type species, and all females from Europe and Canada and those from most populations from other countries have a vagina of unequal proportions, termed anisomorphic. Females of a few populations, all from regions with warm climates, have a vagina of equal proportions, termed isomorphic; both vaginas are described and illustrated. Anaphelenchus n.subgen. is proposed to accommodate those species having females with an isomorphic vagina: Aphelenchus (Aphelenchus) is restricted to those that are anisomorphic. Aphelenchus (An.) isomerus n.sp. from Cuba is designated as the type species of Anaphelenchus and is described and illustrated. Its distinguishing characters are the isomorphic vagina, fine body annulation, and wide lateral field with at least 14 incisures.
Development of Chandlerella chitwoodae Anderson, 1961 (Filarioidea: Onchocercidae) in Culicoides stilobezzioides Foote and Pratt and C. travisi Vargas (Diptera: Ceratopogonidae)
Authors: Bartlett Cheryl M. , Anderson Roy C.
Published: December 2009

Microfilariae of Chandlerella chitwoodae Anderson, 1961 developed to the third stage in the thorax of Culicoides stilobezzioides Foote and Pratt and Culicoides travisi Vargas. Infective larvae were found in the mouth parts of midges fed on infected Corvus brachyrhynchos brachyrhynchos Brehm and kept at 32 °C for 5 days. Chandlerella chitwoodae may parasitize several species of woodland birds because it is apparently transmitted by vectors with opportunistic feeding habits.
Reproduction in a laboratory colony of bank vole, Clethrionomys glareolus
Authors: Gustafsson Torgny , Andersson Bertil , Westlin Lilian
Published: December 2009

Reproduction was studied in a laboratory colony of bank voles, Clethrionomys glareolus. Litter size was mainly dependent on parity, the mean being 4.3 in primiparous and 5.3 in multiparous females. Mortality of young during the nursing period was also affected by the order of litter, with a minimum in the third litter (14%). Most of this mortality took place during the first 3 days after birth. Gestation was 18.3 days in primiparous females. Postpartum estrus and mating was usual and the length of the resulting pregnancy was prolonged by lactation (19.1 days for zero sucklings vs. 22 days for four or more sucklings).
Photoperiodic induction of multiple breeding seasons in captive American kestrels
Authors: Bird David M. , Weil P. Gregory , Laguë Paul C.
Published: December 2009

Six out of 10 mated pairs of captive American kestrels (Falco sparverius) were induced by artificial photoperiod to undergo a successful out-of-season breeding period between two consecutive successful spring breeding periods. Light intensity had significant (r = −0.88, p < 0.05) negative effects on onset of egg laying. Eighteen of the 27 eggs produced were laid at ambient temperatures below freezing. Fertility (85.2%), hatchability of fertile eggs (47.6%), and fledging success (100%) in the winter season were all highly comparable with the two spring breeding seasons.
The outer retina and tapetum lucidum of the snook Centropomus undecimalis (Teleostei)
Authors: Eckelbarger K. J. , Scalan R. , Nicol J. A. C.
Published: December 2009

The snook Centropomus undecimalis is a nocturnal fish inhabiting turbid estuaries, bays, and inshore waters. Its retina is duplex, containing rods and short single, long single, and double cones. Cones are arranged in a square mosaic; the rods are extremely numerous and outer segments are short and staggered in depth. Ellipsoid mitochondria undergo morphological alterations along the vitreo–scleral axis including the appearance of elongate cristae and the development of electron-dense matrices which nearly obscure the cristae. Peripheral mitochondria give off tubular elements in the calycal processes. Pigment epithelial cells have long processes which extend vitread to the cone ellipsoids and contain tapetal spheres (0.3 to 0.5 μm). The processes form a diffusely reflecting tapetum about 80 μm thick. In the scotopic eye the tapetum is uncovered when the retinal pigment retreats into the cell bases. The reflecting material is a triglyceride, largely glyceryl tridocosahexaenoate. Its high refractive index (n = 1.50) and the close packing of the spheres cause light to be backscattered. Reflection from the white lipid tapeta is about 50%; quantal catch in the retina because of the tapetum is enhanced by a factor of about 1.5.
Use of space in relation to feeding areas by zygopteran nymphs in captivity
Authors: Baker Robert L.
Published: December 2009

Spacing behaviour by nymphs of Coenagrion resolutum (Odonata: Coenagrionidae) was studied in the laboratory. Solitary nymphs found and remained at feeding sites; when several nymphs were present some were excluded from feeding sites. Nymphal size had no effect on positioning of solitary nymphs at feeding sites, but when nymphs occurred together, large nymphs excluded smaller nymphs. Prior occupancy at a feeding site by a nymph did not enhance its chances of remaining there when an intruder was added. When presented with a number of feeding sites, solitary nymphs stayed at only one site as frequently as did nymphs presented with only one site. Results are discussed in relation to possible effects of spacing behaviour on zygopteran life history and predator–prey dynamics.
Ontogénèse du comportement de l'Ecureuil roux (Tamiasciurus hudsonicus)
Authors: Ferron Jean
Published: December 2009

A detailed analysis of the behavioural development of the red squirrel (Tamiasciurus hudsonicus) from birth to weaning is presented. For each behaviour pattern, the earliest and latest ages of emergence in a series of 14 young (from three litters) were registered and a mean was calculated. A review of the principal events of physical development is given first. The ontogeny of behaviour is then considered under five headings: locomotion, alertness and exploration, feeding, comfort, and social interactions. In the discussion, a general analysis of the development of behaviour with regard to the different periods of ontogeny (neonatal period, transition period, and socialization period) and the two leading events of the early life of the red squirrel (emergence from the nest and weaning) is given. It appears that the young are equipped with a minimum of behaviour patterns during the period of nest confinement and that close to emergence, a series of new behaviours come into effect with the exception of locomotion, which evolves gradually and regularly during ontogeny.
Serum gonadotropin levels in mature male goldfish in response to luteinizing hormone – releasing hormone (LH-RH) and des-Gly10-[D-Ala6]-LH-RH ethylamide
Authors: Peter R. E.
Published: December 2009

Sexually mature male goldfish, acclimated to 12–14 °C, were injected intraperitoneally with luteinizing hormone – releasing hormone (LH-RH) or the superactive analogue des-Gly10-[D-Ala6]-LH-RH ethylamide (G-A-LH-RH-E). Treatments were a single injection, two injections 12 h apart, and three injections 24 h apart at dosages of 0.1, 0.5, and 1.0 μg/g body weight. Blood samples were taken at 1 or 1.5, 6, and 24 h after the last injection for measurement of serum gonadotropin (GtH) by radioimmunoassay. Serum GtH levels were highest following two injections of LH-RH or G-A-LH-RH-E given 12 h apart; a single injection of the peptides produced the smallest change in GtH levels. The analogue caused a response of longer duration than did LH-RH in certain circumstances. The data also demonstrate that self-potentiation and self-suppression of response can occur under certain treatment conditions with LH-RH and the analogue.
Progesterone levels in peripheral plasma of Rocky Mountain bighorn ewes (Ovis canadensis) during the estrous cycle and pregnancy
Authors: Whitehead P. E. , McEwan E. H.
Published: December 2009

Plasma progesterone levels of three Rocky Mountain bighorn ewes (Ovis canadensis) were determined during anestrus, estrus, and pregnancy. Eighteen-month-old ewes had "silent" heats with peak progesterone levels ranging from 1.0 to 2.2 ng/mL. At [Formula: see text] years of age, luteal activity preceded behavioural estrus and successful breeding. During the first 50 days of gestation, plasma progesterone levels increased to 8.5 ng/mL (8.0–9.2 ng/mL). From 50 to 80 days, progesterone levels decreased, followed by an increase to peak values of 13.3 to 23.2 ng/mL. A rapid decline in progesterone levels occurred about the time of parturition.
Effects of brain extracts on oocyte maturation in Helisoma (Pulmonata:Mollusca)
Authors: Saleuddin A. S. M. , Wilson Laurie E. , Khan Hamidur R. , Jones Gwyneth M.
Published: December 2009

Normal oocyte development and the effects of brain extract injections on egg laying and on oocyte ultrastructure have been investigated in two populations of Helisoma: an egg-laying population (H. duryi) and a non-egg-laying, overwintering population (H. trivolvis). Oocyte development in H. duryi resembles that in other pulmonate molluscs. Endocytotic profiles occur in maturing oocytes but not in young (previtellogenic) oocytes. Injected horseradish peroxidase (HRP) and ferritin can be found in the follicular space and between follicle cells 2–3 h after injection. Ultrastructural evidence indicates that these tracers are taken up by maturing oocytes, but not by young oocytes or follicle cells. In non-egg-laying H. trivolvis large oocytes lack endocytotic profiles although a follicular space and many yolk granules may be present. Injection of extracts of dorsal bodies or suboesophageal ganglia from H. duryi induces egg laying in H. trivolvis within a few days. Injection of dorsal body extract into non-egg-laying animals also induces the appearance of many endocytotic profiles in large oocytes. It is suggested that endocytotic uptake of yolk components is stimulated by dorsal body extract in these animals.
Ultrastructural localization of peroxidase activity in neutrophil leukocytes of Ictalurus punctatus
Authors: Cannon M. Samuel , Mollenhauer Hilton H. , Cannon Anita M. , Eurell Thomas E. , Lewis Donald H.
Published: December 2009

The cytoplasmic granules of the blood neutrophil leukocyte of the teleost, Ictalurus punctatus, have been shown to exhibit peroxidase activity at the light and electron microscopic levels when exposed to the 3,3′-diaminobenzidine tetrahydrochloride peroxidase procedure. Erythrocytes also show activity. The addition of cyanide to the incubation medium has no apparent effect on peroxidase reactivity in neutrophils, but inhibits pseudoperoxidase reactivity in erythrocytes. The presence of peroxidase-positive granules in the neutrophil serve as a marker for identification of this cell and strongly indicate antibacterial and phagocytic functions for the neutrophil.
Geographical variation in some representatives of Haematoloechus Looss, 1899 (Trematoda:Haematoloechidae) from Canada and the United States
Authors: Kennedy Murray J.
Published: December 2009

A total of 2162 lung flukes constituting eight species of Haematoloechus from freshly killed frogs in addition to 422 preserved specimens borrowed from private and institutional collections were examined.Data on the prevalence and extent of extracaecal loops, shape and orientation of testes and ovary, ratio between the transverse diameter of the oral sucker to that of the acetabulum (O/A ratio), ratio between the transverse diameter of the oral sucker to that of the pharynx, and egg size were studied.The extent of the extracaecal loops used in conjunction with orientation of testes and O/A ratio were considered reliable as indicators of some species (H. longiplexus, H. breviplexus, and H. medioplexus) but not for others (H. varioplexus, H. buttensis, H. parviplexus, and H. coloradensis and H. complexus). Too much interspecific overlap in these characters was noted, such that identification of the latter five species would be difficult and inaccurate. It is suggested that the specific status of the latter species be reevaluated.
A device for observing wild beavers in their lodge
Authors: Patenaude-Pilote Françoise , Oertli Erwin F. , Bovet Jacques
Published: December 2009

A device is described that allows direct visual observation of wild beavers within their original lodges.
Coelomomyces infection of the adult female mosquito Aedes trivittatus (Coquillett) in Manitoba
Authors: Taylor B. W. , Harlos J. A. , Brust R. A.
Published: December 2009

Adult females of Aedes trivittatus collected near Winnipeg, Manitoba, were found to be infected with a Coelomomyces sp. The level of infection, as expressed by the formation of sporangia within the haemocoel of the adult, was as high as 56% in blood-fed female mosquitoes. No sporangia were found in females or males that were fed only carbohydrates. Mature sporangia were visible through the abdominal wall of the infected adult at time of death. None of the infected females was able to reproduce. Coelomomyces infection was found to be initiated during the fourth larval instar and (or) pupal stage in artificial pools. Two species of copepods were present in the pools; however, the role of these organisms in the life cycle of the Coelomomyces sp. is not known at this time.
A biological explanation for the differences in infectivity of geographical isolates of Trichinella
Authors: Sukhdeo M. V. K. , Meerovitch E.
Published: December 2009

Isolates of Trichinella from Alaska, Canada, and Kenya were compared during the intestinal and muscle phases of infection in the A/J mouse. It was found that, whereas the adults of the three isolates occupied similar sites along the intestine, the durations of their sojourns in the intestine differed from each other. Histological examination of the small intestine during this period revealed that the inflammatory response of the A/J mouse to infection by the three isolates was similar in times of onset. Histological examination of the diaphragm muscle 30 day s after infection revealed that the most severe inflammatory response was found around cysts of the Canadian isolate whereas the inflammation surrounding the cysts of the other isolates was mild.These results suggest that the differences in infectivity determined from previous studies on these isolates are not related to the host inflammatory response to either intestinal or muscle phase. It is postulated that isolate infectivity is a function of the duration of the sojourn by the adult worms in the small intestine or of the fecundity of the adult worms.
Selective predation upon pelvic phenotypes of brook stickleback, Culaea inconstans, by northern pike, Esox lucius
Authors: Reist James D.
Published: December 2009

Laboratory and field work assessed the importance of Esox lucius predation in maintaining pelvic skeletal phenotypes in a population of Culaea inconstans. Individuals possessing a pelvis and pelvic spines (with) have a selective advantage over those lacking these parts (without). The latter are preferentially preyed upon in the lab by small northern pike due to this morphological difference. The advantage conferred by the spines depends upon relative size of predator to prey and likely has no effect upon predation by larger pike. Preferential selection of with individuals whose pelvic spines were removed, rather than without individuals (i.e. morphologically similar prey), suggests withouts compensate behaviourally for their morphological disadvantage. Analysis of food of large wild pike indicated that these postulated behavioural differences contributed to selective predation of individuals of the with phenotype in Wakomao Lake, Alberta, Canada. The frequency of these phenotypes in any situation represents a balance between counterselective forces, some of which are due to predation. Additional predatory species present in the lake and additional uses of pelvic spines probably also influence the phenotypic frequencies.
Breeding success of the black-crowned night heron in the St. Lawrence Estuary
Authors: Tremblay Jacqueline , Ellison Laurence N.
Published: December 2009

Reproductive success of black-crowned night herons (Nycticorax nycticorax) was studied on two islands during 2 years in the St. Lawrence Estuary. The mean size of complete clutches was 4.1 eggs. The mean number of young fledged per active nest varied from 0.5 to 2.1 young according to year and to island. The mean number of young fledged per successful nest varied from 2.1 to 3.0. Toxic chemical residues in eggs were relatively low, and we found no evidence of eggshell thinning. We conclude that reproduction was normal and probably sufficient to maintain a stable population.
Innervation of sheath cells of an insect sensillum by a bipolar type II neuron
Authors: Zacharuk R. Y.
Published: December 2009

A multiterminal bipolar type II neuron is situated centrally in each mandible of an elaterid larva. It is ensheathed by a glial cell to the base of the two terminal scolopophorous sensilla in the terminal mandibular tooth but its terminal branches are naked. These branches extend along the outer surfaces of the inner and outer sheath cells of and the adjacent surfaces of the epidermal cells around both sensilla. The dendrite and its branches contain longitudinal microtubules, peripheral mitochondria, and clear and variously dense vesicles. It has no ciliary region. The dense vesicles are more numerous in newly molted than in intermolt larvae. Unique plates of endoplasmic reticulum and vesiculating bodies occur in the sheath and epidermal cells adjacent to the naked dendritic branches. This neuron may control the secretory activities of the sensillar sheath cells and adjacent epidermal cells through release of appropriate chemical mediators.
Late summer time budget and feeding behaviour of marbled godwits (Limosa fedoa) in southern Manitoba
Authors: Wishart Richard A. , Sealy Spencer G.
Published: December 2009

Marbled godwit (Limosa fedoa) foraging, social behaviour, and habitat use were studied in late summer in southern Manitoba. The flocks spent most of their time using three small potholes on the study area. Time budget activity changed cyclically over the day; birds spent 61.3% of the day feeding. Over 22% of foraging time was spent handling food and in pauses. It is suggested that the birds feed primarily by contact rather than sight and foraging may occur at night. Feeding was less efficient during strong wind and wave action and birds avoided exposed areas. This permitted them to feed at efficiencies characteristic of those of calm conditions. Birds were wary of marsh hawks (Circus cyaneus), but flocking and the use of open areas may have reduced their vulnerability to predation. Several factors including food availability, protection from wind, and vulnerability to predators probably influenced the way godwits used the habitat.
The flower-visiting behaviour of bumble bees: floral complexity and learning
Authors: Laverty T. M.
Published: December 2009

Videotape records of flower-visiting behaviour of bumble bees (Bombus spp.) without previous foraging experience were compared with records of experienced foragers on flowers of six plant species representing a range of morphological complexity. Although the behaviour of experienced bees was relatively consistent, those without previous experience made many types of "errors" on their first flower visits. These included landing on inappropriate areas of flowers, assuming incorrect positions, and probing into areas of flowers other than in the vicinity of the nectary. The proportion of inexperienced foragers achieving a success criterion, defined as three sequential "errorless" visits, differed significantly among plant species. The time spent in trial and error learning before the criterion was obtained was significantly greater for flowers of high structural complexity than for those of intermediate and low complexity.The initial probing response of inexperienced bumble bees is mainly instinctive behaviour. However, exploitation of flowers also involves a learning component during which initial responses are modified according to the location of rewards in flowers of different plant species.f
Ticks from mammals from Prince Edward Island, New Brunswick, northern Nova Scotia, and Gaspé Peninsula, Quebec
Authors: Jones Gwilym S. , Thomas Howard H.
Published: December 2009

Four species of ticks were recovered from small mammals collected in Prince Edward Island. New Brunswick, northern Nova Scotia, and the Gaspé Peninsula, Quebec. Included among these were the following new host records: Ixodes marxi ex Sorex cinereus, I. muris ex. Clethrionomys gapperi, and Haemaphysalis leporispalustris ex. Tamias striatus. New provincial records were Ixodes marxi, I. muris, and Haemaphysalis leporispalustris from Prince Edward Island and Ixodes muris from New Brunswick.
Moose winter browsing patterns on clear-cuttings in northern Ontario
Authors: Hamilton G. D. , Drysdale P. D. , Euler D. L.
Published: December 2009

Winter browsing patterns by moose (Alces alces) were studied on three cutovers in northern Ontario during spring and summer of 1975 and 1976. The three cutovers were 5 to 6 years old and ranged from 24 to 525 ha in area. Browse patterns were determined by examining 2 m × 4 m plots spaced at 25 m intervals along selected cruise lines. The distance from cover for each plot was calculated from large scale maps. No correlation was found between distance from cover and browse abundance, and moose browsing was independent of food distribution. In 1975, it was found that 95% of all browsing activity was confined to within 80 m of cover. Browse use tended to be greater in 1976, with significant use extending as far as 260 m from cover in one cutover. Food abundance and snow depths up to 75 cm apparently did not determine moose distribution.
Besoins qualitatifs en acides aminés chez la punaise de l'asclépiade, Oncopeltus fasciatus (Dallas) (Hemiptera, Lygaeidae)
Authors: Levesque Claire , Levesque Gilles-Y.
Published: December 2009

Qualitative amino acid requirements of Oncopeltus fasciatus (Dallas) larvae reared on holidic diets were studied. All experiments began at the third instar. Amino acids are required in the diet for the growth and survival of the large milkweed bug larvae. By omitting each amino acid individually from the basic holidic diet, we showed that the 10 amino acids generally essential for the insects are also all required for growth of O. fasciatus. In contrast with the observations recorded for most insects, none of the amino acids tested was individually required for the survival of the larvae of this hemipteron. Simultaneous omission of aspartic acid, glutamic acid, asparagine, and glutamine from the diet did not result in a reduction of growth of the milkweed bug. D-Alanine in the holidic diet was neither beneficial nor toxic to the insect.
The brown lemming, Lemmus sibiricus (Rodentia, Arvicolidae), in the late Pleistocene of Alberta and its postglacial dispersal
Authors: Burns James A.
Published: December 2009

The first fossil remains of Lemmus sibiricus south of Beringia are reported from a rock shelter called January Cave in the Front Ranges of the Rocky Mountains, southwestern Alberta, Canada. The 45 specimens were excavated along with several thousands of isolated small mammal teeth and fragmentary bones. Dated by both radiocarbon and thermoluminescence methods to span the last 22 000 – 23 000 years, a late Pleistocene-through-present sequence is provided. Argument is made for the existence of a southern relict population of this lemming prior to a northward, postglacial dispersal into British Columbia and the Yukon Territory.
Growth dynamics of mosaic muscle fibres in fingerling rainbow trout (Salmo gairdneri) in relation to somatic growth rate
Authors: Weatherley A. H. , Gill H. S. , Rogers S. C.
Published: December 2009

We examined the effects of varying water temperature (5, 12, 20 °C), ration size (ad libitum, and 3–4% of dry body weight per day), and injection of bovine growth hormone, on the growth characteristics of the epaxial muscle in laboratory-reared rainbow trout. Although the experimental conditions resulted in differences in growth rate, condition factor (K = W/L3 × 102) and dry weight, we found that, below a fork length of 18–20 cm, an increase in the cross-sectional area of the epaxial muscle occurs mainly by the addition of new fibres. However, between 20 and 25 cm the increase evidently results mainly from an increase in diameter of existing fibres. The relationship between fibre diameter frequency and fork length is characterized, and the implications of this relationship in limiting growth of this species is discussed.
Feeding of ribbon seals (Phoca fasciata) in the Bering Sea in spring
Authors: Frost Kathryn J. , Lowry Lloyd F.
Published: December 2009

Digestive tracts of 61 ribbon seals (Phoca fasciata) collected in the seasonal pack ice of the Bering Sea during March to June 1976–1979 were examined. Very little fresh food was found in stomachs; however, hard parts of prey, particularly fish otoliths, were found in stomachs and (or) intestines of 28 seals. Based on counts of otoliths, the main prey were pollock in south-central and central Bering Sea, and arctic cod in northern Bering Sea. Weights and lengths of fishes consumed by seals were estimated from measurements of otoliths. On the basis of estimated whole weight of prey consumed, eelpout were a major food of these seals in south-central and central Bering Sea. Comparison of the species composition of fishes caught in trawls and eaten by seals suggests that seals in central and northern Bering Sea select for pollock and arctic cod, and against sculpins and capelin. In contrast, in south-central Bering Sea pollock was the most abundant fish in both seals and trawls. Seals were nonselective with regard to size of pollock consumed but appeared to select for large arctic cod. Our data suggest feeding conditions may be more favorable for ribbon seals in south-central Bering Sea than in more northern areas.
Vigisospirura potekhina (Petrow and Potekhina, 1953) (Nematoda: Spiruroidea) from the bobcat, Lynx rufus (Schreber), in the Southeastern U.S.A.
Authors: Wong P. L. , Watson T. , Anderson R. C.
Published: December 2009

Vigisospirura potekhina (Petrow and Potekhina, 1953) Chabaud, 1959 from the stomach of the bobcat, Lynx rufus (Schreber), in West Virginia, U.S.A., is redescribed. This is the first report of this nematode in North America and from the Felidae. It is suggested this species may have a wide distribution in carnivores in the U.S.S.R. and North America. The relationships between Vigisospirura Petrow and Potekhina, 1953, Didelphonema Wolfgang, 1953, and Spirocerca Raillet and Henry, 1917 are clarified by a study of cephalic structures in the three genera. Chlamydoprocta Chandler, 1954 is regarded as a synonym of Vigisospirura resulting in the new combination V. itascensis (Chandler, 1954) n.comb.
Patency of the follicular epithelium in Rhodnius prolixus: a re-examination of the hormone response and technique refinement
Authors: Huebner Erwin , Injeyan Hampik S.
Published: December 2009

The size of the extracellular spaces revealed by Evans' blue penetration into the follicular epithelium of Rhodnius prolixus increases with the stage of vitellogenesis. This was found to be true of follicles incubated in control media, as well as those whose spaces had been stimulated to expand by incubation in juvenile hormone (JH) or the analogue ZR515. An improved method of estimating hormonal effects in vitro utilizes a regression analysis of patency index relative to follicle length; with control follicles the slope was 0.44, whereas hormone- and analogue-treated follicles yielded slopes of 0.86 and 1.09, respectively. Some pitfalls of the dye penetration test are outlined.
The leech as a vector of a fish piroplasm
Authors: Khan R. A.
Published: December 2009

A piroplasm, Haemohormidium beckeri, is redescribed from two marine fish, Lycodes lavalaei and Lycodes vahlii (Zoarcidae). The parasite divided by both binary fission and schizogony. In the latter process, up to eight merozoites were produced and these developed within mature erythrocytes. Infections were prevalent among fish from areas off the Labrador coast. Parasitemias, which varied from light infections to estimates of 60 parasites/1000 erythrocytes, were recorded in 15 fish for about 6 months. Subinoculation of infected blood initiated infections in two perciform fish, Myoxocephalus octodecemspinosus and Anarhichas lupus, but not in a pleuronectiform, Pseudopleuronectes americanus, or a gadiform, Gadus morhua. Natural infections were present in three leeches, Platybdella olriki, that had fed on an infected L. lavalaei. Piroplasms were also observed in the gastrointestinal content of all 94 laboratory-reared leeches, Johanssonia arctica, dissected 7 through 109 days after engorgement on infected fish blood. Inoculations of gut contents from leeches after digestion of a blood meal produced infections in uninfected fish. Natural transmission occurred when leeches were fed again on susceptible fish, whereas pipetting entire leeches into the stomach of fish did not initiate infections. This is the first evidence that leeches transmit piroplasms in nature to fish.
The biology and energetics of Eogammarus confervicolus (Stimpson) (Amphipoda, Anisogammaridae) at the Squamish River Estuary, B.C.
Authors: Levings C. D.
Published: December 2009

Data on the biology and energetics of the gammarid amphipod Eogammarus confervicolus (Stimpson) are presented from the Squamish River estuary in southwestern British Columbia. At low tide, E. confervicolus was most abundant under cover material, especially sedge rhizomes (Carex lyngbyei) and rockweed (Fucus distichus). Maximum biomass was observed in spring under the sedge mat (16.1 g dry weight m−2) and rockweed (16.8 g dry weight m−2). The minimum sized female bearing eggs was observed to be approximately 7 mm and egg number ranged up to 75. Incubation time (10 °C, 15‰) was 17 days. In 2 years of data, mature females were most abundant in samples from October to December and July to August. Oxygen consumption rates at 5 and 10 °C were lowest in fresh water and increased with higher salinities. At 15 °C, lower salinities increased consumption rates. Net growth efficiency (K2) was calculated from growth rates on four diets used in a previous study and for respiration under prevailing environmental conditions. The following are ranked diets: Enteromorpha linza (51.2%), Pilayella littoralis (44.2%), Navicula spp. (42.7%), and Carex lyngbyei debris (22.4%). The central sector of the estuary showed the highest K2 values when averaged over diets (53.2%).
Multivariate analysis of hybridizing Cyprinidae from the Kananaskis Reservoirs, Alberta
Authors: Butcher G. A.
Published: December 2009

Principal components and canonical variates analyses of hybridizing Couesius plumbeus (lake chub) and Rhinichthys cataractae (longnose dace) from Upper and Lower Kananaskis Reservoirs, Alberta, using 21 morphological characters, revealed two parental groups bridged continuously by an intermediate hybrid group. This morphological overlap between the hybrids and the parental species indicates that it is not always possible to positively identify "pure" parental individuals from the Kananaskis. Neither backcross nor hybrid F2 individuals could be identified from the analyses, although the Kananaskis R. cataractae showed effects suggestive of either selection or introgression, relative to known R. cataractae from widespread Alberta localities. Rhinichthys cataractae has also declined in numbers relative to C. plumbeus since last studied in 1961. Couesius plumbeus does not show similar effects suggestive of selection or introgression.
Development of pedicellariae in the pluteus larva of Lytechinus pictus (Echinodermata: Echinoidea)
Authors: Burke Robert D.
Published: December 2009

Three tridentate pedicellariae develop in the pluteus larva of Lytechinus pictus. Two are located on the right side of the larval body and the third is on the posterior end of the larva. The pedicellariae form from mesenchyme associated with the larval skeleton which becomes enclosed in an invagination of larval epidermis. The mesenchyme within the pedicellaria primordium aggregates into groups of cells that become skeletogenic tissues which secrete the pedicellaria jaws, and smooth and striated muscles. Nerves and sensory cells develop within the epidermis covering the pedicellariae. Pedicellaria formation takes 3 days and occurs about midway through the development of the adult rudiment. During metamorphosis the pedicellariae are shifted to the aboral surface of the juvenile.Pedicellariae that develop in the larvae are fully operable prior to metamorphosis and do not appear to be released from any rudimentary state of development by metamorphosis. At least 16 echinoid species are reported to form pedicellariae in the larva. The precocious development of these adult structures appears to be dispersed throughout the orders of regular urchins.
Impact of botfly parasitism on Microtus townsendii populations
Authors: Boonstra Rudy , Krebs Charles J. , Beacham Terry D.
Published: December 2009

The impact of botfly (Cuterebra grisea) parasitism on populations of Microtus townsendii was studied on four areas near Vancouver, British Columbia, from 1971 to 1978. Botfly larvae were found in voles during the period from late June to late November, with a peak occurring from mid-August to mid-September. There was a significant negative relationship between vole density and the proportion of the population infested. The percentage of voles infested changed in the following manner in the three weight classes: juveniles (18.5%) > adults (16.5%) > subadults (13.0%), with the sexes showing no differences between them. Overall, noninfested voles always survived better than infested ones did in the three classes. In both adults and juveniles, survival declined as botfly larvae number increased; subadults did not show this relationship. Infested adult male voles survived more poorly at high densities (r = 0.62); adult females did not. Infested large adult males (≥ 55 g) survived better than small adults did (40–54 g), but the two size classes in females showed no survival differences. Infested adult voles had significantly lower rates of reproduction: 8% fewer males were in breeding condition, 10% fewer females were lactating, and 4% fewer females were pregnant. Parasitism significantly depressed growth rates in all weight classes above 40 g. We conclude that botflies had a significant detrimental influence on vole survival, reproduction, and growth.
On the validity of the genus Musculium (Bivalvia: Sphaeriidae): electrophoretic evidence
Authors: Hornbach Daniel J. , McLeod M. J. , Guttman S. I.
Published: December 2009

Starch gel electrophoresis was used to examine the generic separation of the sphaeriid clams Musculium and Sphaerium. Twenty-five loci from 13 enzyme systems were resolved. Major differences in electrophoretic patterns were observed, and these appear to support the generic separation of Musculium and Sphaerium. Sphaerium occidentale, considered to be intermediate in form between Musculium and Sphaerium, is more closely related (electrophoretically) to other spieces of Sphaerium than to Musculium. The phenotypic convergence of S. occidentale with Musculium and its genotypic divergence from other species of Sphaerium can be related to habitat characteristics of these forms.
Rates of glucose and lactate oxidation by the perfused isolated trout (Salvelinus fontinalis) heart
Authors: Lanctin Henri P. , McMorran Lynn E. , Driedzic William R.
Published: December 2009

Isolated brook trout (Salvelinus fontinalis) hearts were perfused with buffer containing either [U-14C]glucose or [U-14C]lactate and the rate of 14CO2 production monitored. Lactate oxidation rates were higher than glucose oxidation rates when either substrate was provided individually. When glucose and lactate were offered simultaneously glucose oxidation was markedly inhibited whereas there was only a minor inhibitory effect upon lactate oxidation. It appears that the fish heart preferentially utilizes lactate as a metabolic fuel under aerobic conditions.
Dietary influences on sodium and potassium metabolism of reindeer
Authors: Staaland H. , White R. G. , Luick J. R. , Holleman D. F.
Published: December 2009

Sodium (Na) and potassium (K) concentrations in plasma, saliva, rumen liquor, urine, and feces were measured in reindeer, Rangifer tarandus, given diets high in Na and K (a commercial livestock ration), low in both minerals (lichens), and low in Na and high in K (summer range in interior Alaska). Sodium concentrations in plasma, urine, feces, and saliva were high in reindeer fed the commercial ration and were lower in reindeer grazing summer vegetation. Concentrations of Na and K in saliva were highly correlated with those in plasma. During summer, there was a decrease in saliva Na and an increase in K. The calculated salivary Na:K ratio for reindeer grazing summer vegetation (1.4:1 and 1.6:1) suggested Na insufficiency. Sodium concentrations were higher and within the normal range in saliva of reindeer fed lichens.
Echolocation and feeding behaviour of Taphozous mauritianus (Chiroptera: Emballonuridae)
Authors: Fenton M. B. , Bell G. P. , Thomas D. W.
Published: December 2009

Observations of free-flying bats in the field in Zimbabwe indicated that Taphozous mauritianus uses multiharmonic constant frequency (CF) search calls followed by multiharmonic approach and terminal calls that combine shallow and steep frequency modulated (FM) sweeps during approaches to targets. The three phases of calls all have rapid rise times to full amplitude, and most of the sound energy is in the second harmonic; the fundamental is usually present (11–13 kHz), making the calls clearly audible to the unaided human ear. This combination of characters, but particularly the CF search calls, serves to distinguish these echolocation calls from those of other insectivorous bats. One light-tagged individual hunting insects reacted to targets at distances of about 3 m, suggesting a long-range feeding strategy.
Similarity of olfactory receptor responses (EOG) of freshwater and marine catfish to amino acids
Authors: Caprio John
Published: December 2009

A comparison of olfactory receptor responses of three species of freshwater catfishes (family Ictaluridae) and one species of marine catfish (family Arridae) was performed. With the exception of the reduced response of the sea catfish (Arius felis) to L-glutamine, no distinctive species specific differences in the electro-olfactogram (EOG) responses were noted. The phasic EOG response increased exponentially with a logarithmic increase in amino acid concentration from threshold to 10−2M. The relative stimulatory effectiveness of the amino acids tested was similar among the four species. The olfactory receptors were highly responsive to L-cysteine and to amino acids containing five carbon atoms having unbranched and uncharged side chains. From phyletic relationships of the species tested, the present data suggest that the olfactory system of the North American catfishes has remained temporally conservative.
Sites and patterns of protein and amino acid utilization during the spawning migration of salmon
Authors: Mommsen T. P. , French C. J. , Hochachka P. W.
Published: December 2009

Some aspects of the biochemistry of sockeye salmon (Oncorhynchns nerka) were investigated during spawning migration in the Fraser River, B.C. Studies included measurements of the activities of metabolic enzymes, protein content, and free amino acid concentrations in various tissues. In white muscle, soluble and insoluble protein decreased by 70% during migration and the activities of most of the enzymes studied showed a similar pattern. In contrast, the activities of cathepsin D (EC 3.4.23.5) and carboxypeptidase A (EC 3.4.12A.1) increased considerably, whereas the activities of alanine aminotransferase (EC 2.6.1.2) and malic enzyme (EC 1.1.1.40) were unchanged during migration. In red muscle and heart there was little change in either protein levels or enzyme activities, with the exception of glucose-6-phosphate dehydrogenase (EC 1.1.1.4), which increased threefold to sixfold. In liver, the activities of metabolic enzymes and the levels of soluble protein decreased, whereas proteolytic enzyme activities increased slightly during migration.It is concluded that white muscle is the primary source of the amino acids utilized during migration. A model is proposed to account for the fate of the amino acids released by proteolysis in white muscle. It is suggested that most of the amino acids are collected as alanine and transported to other tissues in this form.
Population ecology of the taiga vole, Microtus xanthognathus, in interior Alaska
Authors: Wolff J. O. , Lidicker Jr. W. Z.
Published: December 2009

This study makes important contributions 10 our understanding of the life history and population dynamics or a little-known yet widespread member of the taiga community. A live trapping grid plus supplemental snaptrapping were used for 3 years. Less intensive efforts covered 3 additional years. Reproduction begins when the snow melts and continues to mid-July. Litters average 8.8, each female producing only two liners in a lifetime. Young do not mature in the year of their birth and adults do not survive a second winter. Body weights are reduced during winter and huddling reduces heat loss. In good microhabitat, densities were similar over a 6-year period, but progressively declined in marginal areas. No multiannual cycle was evident. Flank glands are active in both sexes during the reproductive season and for one additional ensuing month. There are two major dispersal periods; one in August dominated by juvenile males, and a second in spring in which both sexes participate equally. Feeding is opportunistic with horsetail, grasses, and berries predominating in summer and stored rhizomes in winter. Primary habitat requirements include a source of storable rhizomes for winter and good burrowing conditions. These resource needs explain the species' predilection for riparian forest edge and lightly burned forest.