bluuebunny/crossref_metadata_2025 huggingface dataset:
Biochemical and Structural Characterization of Cathepsin L-Processed Ebola Virus Glycoprotein: Implications for Viral Entry and Immunogenicity
Authors: Hood Chantelle L. , Abraham Jonathan , Boyington Jeffrey C. , Leung Kwanyee , Kwong Peter D. , Nabel Gary J.
Published: January 2010

Ebola virus (EBOV) cellular attachment and entry is initiated by the envelope glycoprotein (GP) on the virion surface. Entry of this virus is pH dependent and associated with the cleavage of GP by proteases, including cathepsin L (CatL) and/or CatB, in the endosome or cell membrane. Here, we characterize the product of CatL cleavage of Zaire EBOV GP (ZEBOV-GP) and evaluate its relevance to entry. A stabilized recombinant form of the EBOV GP trimer was generated using a trimerization domain linked to a cleavable histidine tag. This trimer was purified to homogeneity and cleaved with CatL. Characterization of the trimeric product by N-terminal sequencing and mass spectrometry revealed three cleavage fragments, with masses of 23, 19, and 4 kDa. Structure-assisted modeling of the cathepsin L-cleaved ZEBOV-GP revealed that cleavage removes a glycosylated glycan cap and mucin-like domain (MUC domain) and exposes the conserved core residues implicated in receptor binding. The CatL-cleaved ZEBOV-GP intermediate bound with high affinity to a neutralizing antibody, KZ52, and also elicited neutralizing antibodies, supporting the notion that the processed intermediate is required for viral entry. Together, these data suggest that CatL cleavage of EBOV GP exposes its receptor-binding domain, thereby facilitating access to a putative cellular receptor in steps that lead to membrane fusion.
Territorial behavior of the female brown-headed cow bird (Molothrus ater)
Authors: Darley James A.
Published: January 2010

The territorial behavior of the female brown-headed cowbird (Molothrus ater) was studied at London, Ontario, in 1966 and 1967. The cowbirds arrived in the study area during the last week of March and the first 2 weeks of April. Adult birds arrived about 2 weeks before the yearlings. Forty-six resident and 56 nonresident females were observed in the study area; these nonresidents appeared to use the area for feeding. The breeding residents established home ranges mainly through the use of threat displays. The defence of these home ranges suggest that they might be classified as territories. Thirty-nine breeding resident females, 17 yearlings, and 22 adults had home ranges ranging from 0.9 to 13.4 ha (average 4.5 ± 0.4 ha).
Production of filter-feeding Trichoptera in an impounded and a free-flowing river
Authors: Parker Charles R. , Voshell Jr. J. Reese
Published: January 2010

Production was estimated (size frequency method) for five species of Hydropsychidae and two species of Philopotamidae at two sites on the impounded North Anna River and two sites on the free-flowing South Anna River. Total production was highest (3250.0 g dry weight (DW)∙ha−1∙year−1 at the site immediately below the dam. At the other sites total production ranged from 94.0 to 515.1 g DW∙ha−1∙year−1. An attempt was made to determine the influence of various factors on production. From an analysis of the trophic dynamics of production, seston energetics, and rates of consumption we conclude that the zooplankton released from the reservoir greatly enriches the seston in a narrow size range (105–864 μm) that corresponds to the size of the zooplankton released from the reservoir and the capture net mesh size of the hydropsychids. The extremely high density of filter feeders below the dam reduces the food quality of the seston and limits production downstream. Ecological interactions also were found to influence production, requiring detailed knowledge of the biology of individual species to understand the dynamics of a system.
Influence of current velocity, density, and detritus on drift of two mayfly species (Ephemeroptera)
Authors: Ciborowski Jan J. H.
Published: January 2010

Drift responses of Baetis tricaudatus Dodds and Ephemerella inermis Eaton larvae to manipulations of benthic density, sterile detritus, and current velocity were monitored in laboratory streams. The proportion of larvae departing from the substrate was independent of benthic density, amount of detritus, and interactions between these two variables. In spring, departure of larvae of both species was a positive linear function of current velocity during daylight hours. In darkness, departure of B. tricaudatus larvae became a negative linear function of current velocity. Nocturnal drift of E. inermis larvae was minimal at a mean current velocity of 25 cm∙s−1 and greater at both higher and lower velocities. None of the factors tested influenced departure of B. tricaudatus larvae in autumn experiments. Dead larvae were eroded from the substrate in much smaller proportions than were their live counterparts. This suggests that appearance in the water column of live animals is the direct or indirect consequence of individuals' behaviour. Departure of animals during daytime is largely passive in nature, whereas a substantial proportion of nocturnal drift probably results from active desertion of the substrate.
Group size and predator surveillance in foraging house sparrows (Passer domesticus)
Authors: Studd Michael , Montgomerie Robert D. , Robertson Raleigh J.
Published: January 2010

Time budgets of house sparrows (Passer domesticus) foraging at a bird feeder revealed that the time an individual allocated to scanning for predators was negatively correlated with the size of the foraging group. The frequency of both aggressive and scanning bouts per individual did not vary significantly with group size. Reduced scanning time by individuals in larger groups was achieved by shortening scan bouts, rather than by decreasing scan rate as found in most other studies. For all group sizes, scan and interscan (mostly feeding) bout lengths were randomly distributed. We show analytically that even these birds scanning independently for random lengths of time were able to maintain a high level of predator surveillance while increasing the proportion of time spent foraging as flock size became larger. We also demonstrate a time–energy advantage to longer scanning bouts when ecological conditions allow birds to spend a relatively high proportion of their time scanning.
The effects of body size and temperature on metabolic rate of organisms
Authors: Robinson W. Richard , Peters Robert Henry , Zimmermann Jess
Published: January 2010

Multiple regression analyses of previously published data were performed to describe the effect of variations in body mass (M, in grams) and temperature (t, in degrees Celsius) on the rate of oxygen consumption ([Formula: see text], in millilitres O2 per gram per hour). For homeotherms and poikilotherms, the resultant equations describing standard metabolic rate are [Formula: see text] and [Formula: see text], respectively. The metabolic rate of unicells was described by [Formula: see text], although the temperature term was not statistically significant. When solved at 39 °C, the homeotherm equation is essentially similar to previously published relations. At 20 °C, the poikilotherm relation is slightly higher, and the unicell relation considerably lower, than Hemmingsen's widely cited relations. Enough data were available to provide a statistical description of active reptiles and fish: [Formula: see text]; this relationship may be used to approximate the metabolic rate of actively foraging fish and reptiles. Equations for the standard metabolic rate can serve as components in the calculation of minimal metabolic rates of homeotherms and higher poikilotherms in nature; such values could then be increased by estimates of the additional demands associated with movement, feeding, growth, etc. For unicells and lower vertebrates, standard rates also serve as estimates of free-living rates.
Energetics of fasting and subsequent growth in weaned harp seal pups, Phoca groenlandica
Authors: Worthy Graham A. J. , Lavigne D. M.
Published: January 2010

Changes in body weight and proximate composition were monitored throughout the postweaning fast in 20 male harp seal pups. Subsequent growth after the commencement of feeding was also examined. Weaned pups lost weight at a rate of 0.43 kg/day during the 1st week of fasting, declining to 0.20 kg/day by the 10th week. During the initial 2 weeks of the fast the lean body mass accounted for 39.8% of total energy losses (14.0% from core proteins and 25.8% from core lipids). The importance of core energy reserves later diminished until, by the 6th to 8th week of the fast, blubber supplied over 90% of the total energy. Core proteins were again mobilized during the final 2 weeks of the fast. Animals which started feeding after 1 to 2 weeks of fasting gained weight at a mean rate of 0.17 kg/day; those which started after 4 weeks of fasting gained at 0.29 kg/day. The relative amounts of muscle and fat deposited appeared to vary with the time (or physiological condition) when feeding commenced.
Aggressive response to "self" songs by female Red-winged Blackbirds, Agelaius phoeniceus
Authors: Beletsky L. David
Published: January 2010

Female Red-winged Blackbirds responded aggressively to audio playback of their own ("self") songs and to "stranger" female songs. Response behaviors measured were song rate and approach to the loudspeaker. The aggressive responses of the females provided supportive evidence for the existence of female redwing territoriality, for the establishment of exclusive female "subterritories" on the male redwing's larger territory, and for the equivalency of function between typical male passerine "territorial" songs and one of the female redwings' song types.
Limb regeneration blastema cells in the adult newt, Notophthalmus viridescens, give aberrant response to colchicine
Authors: Coomber Brenda L. , Davidson Karin J. , Scadding Steven R.
Published: January 2010

This study was designed to investigate the effect of colchicine on the mitotic index (number of mitotic figures per 1000 cells) in the newt limb regeneration blastema. Colchicine doses from 0.1 to 1000 μg per gram body weight and treatment durations from 2 to 72 h were used to determine the dose of colchicine and treatment period resulting in optimum metaphase arrest. A preliminary experiment demonstrated that there was no circadian rhythm of mitosis in the newt limb regeneration blastema. A dose of 5 μg colchicine per gram body weight was found to give the maximum mitotic index; both higher and lower doses had less effect. Very high doses of colchicine resulted in a mitotic index the same as that of the controls. The mitotic index increased with increasing treatment time up to 36 h, after which there was no further increase. In other newt tissues such as duodenal mucosa and liver, a more typical dose–response relationship was observed in that increased colchicine dose led to increased mitotic indices up to the level of lethal doses of colchicine.
Burrowing ability and behavior of salamanders of the genus Ambystoma
Authors: Semlitsch Raymond D.
Published: January 2010

The burrowing ability and behavior of five species of fossorial salamanders of the genus Ambystoma were examined in the laboratory. Individual salamanders were subjected to three experimental treatments to test the hypothesis that salamanders do not actively dig their own burrows but alternatively enlarge cracks, crevices, and invertebrate or small mammal burrows for occupancy. One species, A. tigrinum, actively dug burrows under all experimental treatments while A. talpoideum actively dug 50% of the time. The other species (A. opacum, A. annulatum, A. maculatum) burrowed passively by using their snout and body to enlarge holes or cracks provided. Individual salamanders not able to burrow (actively or passively) underground incurred significant water loss (25–39%) and several died after a 24-h test period. Digging ability was not clearly related to snout–vent length, head width, or forelimb diameter. These data suggest that the digging ability of ambystomatid salamanders may be a behavioral adaptation and is not simply related to morphology.
Calcium sources for growth of Musculium securis (Bivalvia: Pisidiidae)
Authors: Mackie G. L. , Flippance L. A.
Published: January 2010

In order to determine the primary source of calcium for a pisidiid, Musculium securis was grown in the laboratory in dishes with autoclaved or unautoclaved leaves and sediment and with or without algae. Results show that although both leaves and sediment provide calcium, the calcium from leaves is more readily available than calcium from sediment. It is suggested that molluscs which exhibit correlations between calcium contents of the shell and environment utilize calcium from the bedrock, whereas molluscs (e.g., M. securis) which exhibit no such correlations utilize calcium from other sources such as allochthonous material (e.g., leaf litter).
Growth rates and prey selection of two congeneric predatory caddisflies (Trichoptera: Rhyacophilidae)
Authors: Martin Ian D. , Mackay Rosemary J.
Published: January 2010

Rhyacophila fuscula (Walker) and R. melita Ross inhabit cool southern Ontario streams, often together. In laboratory experiments, R. fuscula and R. melita showed significant weight gains in 2 weeks on four common prey taxa occurring in the field (Diptera: Chironomidae and Simuliidae; Ephemeroptera: Baetidae; and Trichoptera: Hydropsychidae). Rhyacophila melita grew significantly less than R. fuscula on three prey, but significantly better on Chironomidae. The prey eliciting highest growth rates from R. fuscula (Prosimulium, Baetis) and R. melita (Chironomidae) are most abundant in the habitats occupied by each of these predators. Prosimulium and Baetis are common on the surface of rocks in headwater regions where R. fuscula are at high densities, and chironomids are the most abundant prey organism in the marl (travertine) microhabitat of R. melita farther downstream. Where the two predators co-occur, they may compete for foraging areas in the spring, when prey and microhabitat resources are reduced by flood scour.
Impact of two microsporidia, Nosema pyrausta and Vairimorpha necatrix, in Nosema pyrausta infected European corn borer (Ostrinia nubilalis) larvae
Authors: Lewis L. C. , Cossentine J. E. , Gunnarson R. D.
Published: January 2010

Larvae of the European corn borer, Ostrinia nubilalis (Hübner), infected with the microsporidium Nosema pyrausta (Paillot) or free of N. pyrausta infection, were fed either additional N. pyrausta, or Vairimorpha necatrix (Kramer), or a combination of N. pyrausta plus V. necatrix spores. Nosema pyrausta and (or) V. necatrix spores increased the number of tissues infected and the intensity of infection. In laboratory studies, V. necatrix, alone or in combination with N. pyrausta, killed more larvae than did N. pyrausta alone. Significantly fewer insects pupated and emerged in the V. necatrix plus N. pyrausta treatment than in the V. necatrix or N. pyrausta treatments alone. There was a correspondingly greater percentage of dead pupae in the V. necatrix plus N. pyrausta treatment. Nosema pyrausta was more detrimental under field conditions than under laboratory conditions. Of larvae surviving the winter, those that had been fed V. necatrix had significantly fewer spores per milligram of infected tissue than did larvae that had been fed N. pyrausta. These data suggest that the larvae with a higher intensity of V. necatrix spores did not survive the winter.
The problem of unequal catchability in mark–recapture estimation of small mammal populations
Authors: Jolly G. M. , Dickson J. M.
Published: January 2010

The problem of unequal catchability among individuals in an open population is discussed in regard to estimates of population size. Properties of the Jolly–Seber (J–S) estimate are clarified and comparisons are made with minimum number alive (MNA) techniques which attempt complete enumeration of the population. The MNA is shown to be seriously biased under the assumption of equal catchability and to have a proportionately much larger negative bias than the J–S estimate under unequal catchability. Suggestions are made for future work.
Hematology distinguishes coastal and offshore forms of dolphins (Tursiops)
Authors: Duffield Deborah A. , Ridgway Sam H. , Cornell Lanny H.
Published: January 2010

Bottlenose dolphins, Tursiops truncatus, can be separated into coastal and offshore ecotypes based upon hemoglobin levels, packed cell volumes, and red blood cell counts, the offshore form having higher values for all three measures. Captive-bred crosses between coastal and offshore types produce animals with intermediate hematologic profiles suggesting a significant genetic basis for these differences.
Variation of repertoire use in the eastern meadowlark, Sturnella magna
Authors: d'Agincourt Lorraine G. , Falls J. Bruce
Published: January 2010

The singing behavior of nine eastern meadowlark (Sturnella magna) males was examined over the 1980 breeding season for changes in versatility (use of different song types and switching between song types). The greatest degree of versatility occurred during territorial defense; the use of one-song bouts rose from 33.1% during nonchase periods to 64.9% during intraspecific encounters. Versatility also showed a seasonal trend, peaking during courtship and decreasing through the incubation, nestling, and fledgling stages. No relationship was evident between versatility characteristic of a male and the number of females obtained. Thus, while versatility may have increased during encounters with both sexes, it apparently did not influence mate attraction. These results are consistent with the hypothesis that repertoires reduce habituation in listeners. The data also support a derivative explanation that song variety serves as a graded signal indicating the tendency of a singer to interact with other males and females.
Structural basis of jaw protrusion in the largemouth bass, Micropterus salmoides: a microscopic analysis
Authors: Dutta Hiran M. , Chen E-Kwan
Published: January 2010

The patterns of articulation between premaxilla and maxilla, maxilla and vomer, palatine and ethmoid, and maxilla and palatine are shown in microscopic cross sections of Micropterus salmoides. How the rostral cartilage, the ligaments, and articulations are involved in jaw protrusion is described. Fibrocartilage discs are found in all the joints involved in jaw protrusion. The maxilla rotates about its articulation with the vomer, apparently as a result of the stretching of the anterior ligamentum mandibulomaxillary. Anteroventral movement of the maxilla initiates movement in the lacrimoethmoidal joint. Jaw protrusion is also assisted by movement of the palatine, which is transmitted into the swing of the maxilla.
Differences in parental contribution among pair types in the polymorphic White-throated Sparrow
Authors: Knapton R. W. , Falls J. B.
Published: January 2010

We compared relative contributions to nestlings between male and female parents among different pair types in the White-throated Sparrow (Zonotrichia albicollis). The amount of parental contribution between the two main pair types, white-striped (WS) male × tan-striped (TS) female and TS male × WS female, did not differ. However, we found that (a) pairs consisting of TS males and WS females showed biparental care in which the partners made approximately equal investment in feeding nestlings; (b) males of WS male × TS female pair types contributed far less than the female, and far less than a TS male; (c) in WS pairs, males and females contributed about the same as did WS birds in mixed pairings; and (d) secondary TS females nested in territories of already paired WS males, and these females raised young unassisted by a male. We suggest explanations for these differences in contribution to nestlings between the sexes and between morphs, and we discuss optimal reproductive strategies for each sex and morph.
Swimming in the electric eels and knifefishes
Authors: Blake R. W.
Published: January 2010

The kinematics of steady forward swimming in six species of Gymnotidae and three species of Notopteridae are described. All the gymnotids and one notopterid (Xenomystis nigri) are propelled by the action of an undulatory anal fin (gymnotiform mode). Notopterus notopterus and Notopterus chilata employ the body and anal fin as a single propulsive unit and generate a body wave. Rapid bouts of burst swimming activity (e.g., escape responses) are generated by large amplitude motions of the entire body in all species studied. Experimentally determined drag coefficients exceed the theoretical rigid body predicted minimum values for the case of a laminar boundary layer and reasons for this are suggested. Values of the drag coefficient inferred from hydromechanical theory are within 20% of the experimental values. It is concluded that fish swimming in the gymnotiform mode may be subject to significantly less viscous drag than fish of equivalent size swimming at the same speed in the subcarangiform mode. Hydromechanical theory indicates a significant enhancement of fin added mass (due to the presence of a rigid body) over that of an isolated fin. The hydromechanical efficiency of the undulating fin system ranged from about 0.6 to 0.9 over a speed range of 0.2–5.0 lengths∙s−1 (corresponding to a Reynolds number range of about 103–105). It is suggested that undulatory median fin propulsion in the electric eels and knifefishes is an adaptation to swimming with high hydromechanical efficiency at low absolute forward speeds. Similarities and differences in body form between the species and the evolution of gymnotiform swimming are discussed.
Embryo survival and alevin emergence of brook charr, Salvelinus fontinalis and brown trout, Salmo trutta, relative to redd gravel composition
Authors: Witzel Larry D. , MacCrimmon Hugh R.
Published: January 2010

Effects of three homogeneous gravels (2.7, 6.2 and 9.2 mm in diameter) and five heterogeneous gravel mixtures (with 0, 20, 40, 60 and 80% sand; geometric mean diameters = 14.2, 10.1, 7.2, 5.1, 3.7 mm, respectively) on embryo survival and subsequent emergence of brook charr (Salvelinus fontinalis) and brown trout (Salmo trutta) were examined in the laboratory using vertical flow incubators. Differences in survival to emergence, temporal components of emergence and developmental stage of emergents are significant [Formula: see text] among gravel types within and between species. Alevin survival, time interval to first and 50% emergence and duration of emergence period vary directly with gravel size and inversely with sand concentration. Survivals of 0 to 20% occurred in unigranular gravels 6.2 mm or finer and in multitextured gravels with 60% or more sand and rates of 60 to 96% were found in 9.2-mm gravel and gravels with 20% or less sand. Emergent survival increased from 14 to 79% in gravels of 6.2 to 9.2 mm and from 2 to 96% in sand concentrations between 60 and 20% because of reduced entrapment. Period of emergence was longest in 9.2-mm gravel (mean for charr, 381 day degrees; mean for trout, 423 day degrees) and in 0% sand–gravel mixture (mean for charr, 232 day degrees; mean for trout, 179 day degrees). Premature emergence of alevins over a shortened emergence period in finer gravels is identified as a stress response. Larger gravel and lower sand concentrations produced the largest and most advanced alevins at emergence. Ecological implications of the results are examined.
The wax-secreting glands of Eriocampa ovata L. (Hymenoptera: Tenthredinidae): ultrastructural observations and chemical composition of the wax
Authors: Percy Jean E. , Blomquist Gary J. , MacDonald J. A.
Published: January 2010

Larvae of the red-backed alder sawfly, Eriocampa ovata, in all instars except the last, exhibit external accumulations of wax. Approximately 93% of the hexane-extractable wax consists of primary alcohols ranging in chain length from 20 to 32 carbons. The major component is hexacosan-1-ol. Wax is secreted from specialized cuticular modifications found only on tergites and distinguishable from surrounding cuticle by the presence of cupular papillae. A single thread of wax exudes from the apical crater of each papilla. One feature peculiar to cuticle lining the craters is the presence of vast numbers of epicuticular filaments. These may represent channels for the transport of wax. The underlying glandular cells are modified columnar, ductless epidermal cells which, during wax secretion, exhibit organelles characteristic of lipid-producing cells. There are no wax secreting areas or similarly modified epidermal cells in the last larval instar.
Metabolism of arginine, proline, and ornithine in tissues of the squid, Illex illecebrosus
Authors: Mommsen Thomas P. , Hochachka Peter W. , French Christopher J.
Published: January 2010

Interconversions of arginine, ornithine, and proline were studied in the squid Illex illecebrosus, by supplying tissue homogenates from kidney, digestive gland, heart, brain, gill, middle and outer mantle with 14C-labelled substrates. Production of 14CO2 and distribution of label in various intermediates were measured for each tissue. Activities of enzymes catalysing the interconversions were also assessed. 14CO2 production was highest in middle and outer mantle with arginine as substrate, in kidney with ornithine, and in heart with proline. Urease was absent from all tissues. All tissues utilised arginine at reasonable rates, the highest being observed in middle and outer mantle and digestive gland. In heart, γ-guanidinobutyrate was the main product of arginine metabolism. In all other tissues, ornithine was the first product. Kidney utilised ornithine at the fastest rate, while proline was utilised and oxidised best by heart and brain. The results suggest that the capacity of all tissues to metabolise arginine rapidly is a means for maintaining low concentrations of this compound. In some tissues (brain, kidney) the products of arginine metabolism may be fully oxidised in situ whereas in others (digestive gland, gill) produced ornithine may be exported for utilisation elsewhere.
High incidence of limb skeletal variants in a peripheral population of the red-backed salamander, Plethodon cinereus (Amphibia: Plethodontidae), from Nova Scotia
Authors: Hanken James
Published: January 2010

A single population of Plethodon cinereus from northwestern Nova Scotia shows a high incidence of limb skeletal variants, which is exceptional for this morphologically conservative species. Included are nine carpal patterns and five tarsal patterns, which result from the variable occurrence of 11 different combinations of fused adjacent mesopodial elements, and frequent absence of one or more ossified phalanges; one instance of increased phalangeal number also is noted. Primitive plethodontid carpal and tarsal patterns, which characterize P. cinereus from other parts of its range, occur in 69 and 71% of the carpi and tarsi examined, respectively. Modal phalangeal formulae also are those typical of P. cinereus generally. Several mesopodial variants resemble those seen in other plethodontid genera; they may have appeared independently in P. cinereus. Others are unique to this population. Both the genetic basis and geographical extent of this variation are unknown.
Effects of starvation and refeeding on plasma T4 and T3 levels and T4 deiodination in rainbow trout, Salmo gairdneri
Authors: Flood Catherine G. , Eales J. G.
Published: January 2010

Plasma T4 (L-thyroxine) and T3 (3,5,3′-triiodo-L-thyronine) levels were decreased by starvation in both terminally sampled and serially sampled rainbow trout held at 11 °C, significant changes in T3 occurring by day 6. Diel variation in plasma T4 was confirmed for fed trout and could explain the previous inability to detect differences in plasma thyroid hormone levels between starved and fed states. Significant elevations in plasma T4 and T3 could be obtained 4 h after feeding previously starved trout. Based on studies with [125I]T4 it is concluded that the food-induced elevation in plasma T3 is due, in part at least, to increased extrathyroidal T4 deiodination to T3.
An energy budget for northern pike (Esox lucius)
Authors: Diana James S.
Published: January 2010

Allocation of energy by northern pike (Esox lucius) to maintenance, growth, and reproduction was estimated by a combination of laboratory and field techniques. Parameters were fitted to a bioenergetics model to determine the energy budgets of pike from Lac Ste Anne, Alberta. A poor fit was obtained when comparing the predicted ration and growth (from the model) to the estimated ration and growth (in the field), indicating that estimates for some budget components were in error. Further examination indicated that field ration data were probably inaccurate, and budgets were then calculated avoiding these data. The relative cost of maintenance was very low for age 0 fish (~60%) and increased with age. Relative allocations to reproduction and growth were similar from ages 1 to 3, although the relative energy allocated to growth declined from age 0 to 1. There were differences between energy budgets of males and females; females ingested 1.1- to 1.3-fold more energy annually than did males, and this extra energy was diverted into ovary growth, since total body growth was similar in the two sexes. There were also large differences in the seasonal timing of body and gonad growth between the sexes. Males increased in body energy over the summer and winter, while all testicular growth occurred in August. Females increased in body energy over summer only, while ovarian growth occurred mainly during the winter. Both sexes declined in energy stores over the spawning interval (March to May).
The occurrence of the shipworm, Lyrodus sp. in Ladysmith Harbour, British Columbia
Authors: Popham J. David
Published: January 2010

Specimens of the teredo, Lyrodus sp. (probably Lyrodus takanoshimensis Roch), were found in sunken driftwood collected at low tide from the head of Ladysmith Harbour, British Columbia. The introduction of this exotic species to Ladysmith Harbour may have occurred during the time when oyster seed was packed in wooden boxes and shipped to the harbour for subsequent culture.
Diel haul-out patterns of Weddell seal (Leptonychotes weddelli) females and their pups
Authors: Thomas Jeanette A. , DeMaster Douglas P.
Published: January 2010

Radio-frequency transmitters were used to determine the diel haul-out pattern of Weddell seal (Leptonychotes weddelli) females and their pups during the breeding season in McMurdo Sound, Antarctica. Individual and seasonal variations in haul out are reported. There was no significant difference in the haul-out pattern among parous females or among pups. Females spent increasingly more time in the water as weaning of their pups commenced. About 6 weeks after parturition, females hauled out for significantly shorter periods, which probably indicated the onset of mating.
Cellular reactions of the field cricket (Gryllus pennsylvanicus (Burmeister)) to Turgida turgida (Rudolphi, 1819) (Nematoda: Physalopteroidea)
Authors: Gray J. B. , Anderson R. C.
Published: January 2010

Cellular reactions to infections of Turgida turgida (Rudolphi, 1819) in field crickets (Gryllus pennsylvanicus (Burmeister) (=Acheta pennsylvanicus Burmeister)) were studied. Most larvae reached the epithelial cells of the ileum. These larvae caused little cellular destruction or haemocytic response until 18 h after infection. Syncytia of epithelial cell origin had formed around larvae by 28 h after infection. Initially, each syncytium was surrounded by haemocytes and later, by a wall with two well-defined layers. The epithelial layer of the alimentary tract had regenerated beneath the capsule by 48 days. Occasionally larvae penetrated directly into the haemocoel and were surrounded by haemocytes and(or) became melanized.
New species of Bathydrilus Cook (Oligochaeta; Tubificidae) from British Columbia
Authors: Baker H. R.
Published: January 2010

Bathydrilus litoreus n. sp., from intertidal habitats of British Columbia and Washington, is distinguished from other members of the genus by the combination of possessing histologically bipartite atria, atrial ducts, bilobed glandular sacs about the penial setae, patches of glandular epithelium between the dorsal setal bundles, and thickened epidermal pads ventrally in X. Bathydrilus torosus n. sp., from the intertidal of southwest Vancouver Island, is the only known shallow-water species of Bathydrilus to lack modified penial setae; it lacks dorsal patches of glandular epithelium and thickened epidermal pads ventrally in X but does possess atrial ducts and histologically bipartite, very muscular atria. Both B. litoreus and B. torosus lack copulatory sacs and pseudopenes. These are the first species of the genus to be described from the Northeast Pacific.
Geographic variation in the aerial song of the Short-billed Dowitcher (Aves, Scolopacidae)
Authors: Miller E. H. , Gunn W. W. H. , Harris R. E.
Published: January 2010

The complex aerial song of the Short-billed Dowitcher (Limnodromus griseus) is described, and recordings from northern British Columbia (subspecies caurinus), northern Manitoba (hendersoni), and Labrador (griseus) are analyzed. The song is a stereotyped sequence of one to five units that are repeated rapidly and increase successively in duration. Each song unit consists of three readily distinguished element types (I, II, III), which form graded series occurring in fixed sequence. Song structure and element types are similar in all subspecies, but significant quantitative differences exist; the central subspecies (hendersoni) is clearly distinguished from the other two, in particular. These geographic differences are slight in comparison with primary song in many species of Oscines.
Swim bladder gas composition and control of buoyancy by fathead minnows (Pimephales promelas) during exposure to hypoxia
Authors: Chiasson Alyre G. , Gee John H.
Published: January 2010

In normoxic water, swim bladder gases of the fathead minnow consisted of 1.5% CO2, 10.2% O2, and 89.2% N2, and remained unchanged over 24 h. Fathead minnows were exposed to hypoxic water with and without access to the surface and changes in swim bladder lift and gas composition were recorded. After 12 h of hypoxia with surface access, mean swim bladder lift (buoyancy) increased from slightly negative to strongly positive with extreme variation between individuals. Lift declined slightly between 36 and 60 h in hypoxia. O2 and CO2 proportions were maintained at levels similar to those found in normoxic waters for 12–36 h but then these declined such that N2 was 96% of the swim bladder volume after 60 h of hypoxia. Without surface access, swim bladder lift and gas composition remained unchanged. Changes in swim bladder lift were due to addition and (or) losses of gases and were not due to changes in internal pressure of swim bladder gas. Mechanisms of controlling swim bladder volume (lift) in hypoxic water and the significance of changes in swim bladder gas composition are discussed.
The annual migrations of three species of West African fruit bats (Chiroptera: Pteropodidae)
Authors: Thomas Donald W.
Published: January 2010

The seasonal movements of Eidolon helvum, Myonycteris torquata, and Nanonycteris veldkampi were studied over a 2-year period in West Africa. During the dry season, E. helvum roosts in at least one large colony (ca. 500 000 individuals) in the southern forest zone of Ivory Coast. Following the birth of young in February, males and females move into the savanna zones, and the progressive establishment and decline of colonies along a south–north axis indicates that E. helvum migrates at least to the Niger River basin by the middle of the wet season (July). During the dry season, both M. torquata and N. veldkampi are absent from savanna sites, but are common in the forest zone. With the onset of the rainy season in March, catch rates of both species increase first at a southern Guinea savanna site and subsequently at a savanna site 400 km to the north, indicating that both species migrate at least to the southern Sudanese savanna zone during the wet season. Both sexes of N. veldkampi migrate, but the migration of M. torquata is restricted to the immature male cohorts. I argue that the high amplitude of the seasonal fluctuations in fruit abundance at savanna sites creates a wet-season surplus of food which results in low intra- and inter-specific competition levels at these sites relative to the forest zone. This may provide the conditions leading to the observed annual migrations.
An emended description of Ditylenchus valveus Thorne &Malek, 1968 and description of D. filimus n. sp. (Nematoda: Tylenchidae) from mushroom compost in Canada
Authors: Anderson R. V.
Published: January 2010

Ditylenchus filimus n. sp., found in mushroom compost from western Canada with D. valveus Thorne &Malek, 1968, is described and illustrated. Main differential characters of the new species are a stylet length of less than 10 μm, narrow lateral field of four incisures, pyriform basal esophageal bulb without lobes or intestinal overlap, a posterior vulva at 83–85% of body length, short postuterine sac, and an attenuated tail ending in a filament. An emended description of D. valveus includes a stylet length of less than 10 μm in contrast to a reported 12 μm.
The influence of the zona radiata on the toxicity and uptake of cadmium in embryos of Atlantic salmon (Salmo salar)
Authors: Rombough P. J. , Garside E. T.
Published: January 2010

Eyed embryos of Atlantic salmon (Salmo salar) were significantly more resistant to cadmium if the zona radiata (capsule) was removed (10-day LC50, 4.80 mg Cd/L) than if the zona radiata was intact (10-day LC50, 3.20 mg Cd/L). Differences in resistance times were attributed to slower absorption of cadmium by decapsulated embryos than by encapsulated embryos. The metal content of naked embryos increased slowly and in direct proportion to the length of exposure. The metal content of encapsulated embryos was proportional to the logarithm of the exposure period and rapidly approached an asymptotic maximum. As a consequence, the cadmium content of naked embryos after a 24-h exposure to 8 mg Cd/L was less than 3% of that of encapsulated embryos. An opaque precipitate formed around the head and anterior portion of the body of encapsulated embryos but not of naked embryos exposed to acutely lethal cadmium concentrations. This material was probably cadmium carbonate and may have facilitated metal absorption by effectively exposing the encapsulated embryos to cadmium concentrations considerably greater than those in the ambient environment.
Découverte, dans le sud-ouest du Québec, d'une population de cisco de lac, Coregonus artedii, frayant au printemps
Authors: Pariseau Richard , Dumont Pierre , Migneault Jean-Guy
Published: January 2010

We report the discovery of a spring spawning population of cisco, Coregonus artedii, a first in North America, at lac des Ecorces in southwestern Quebec (Ottawa River basin). Two longer specimens with a higher number of gill rakers were also taken. These were probably autumn spawners. The 1st year's growth of the spring spawning ciscoes is very limited owing to their comparatively short growing period, but some catching up is done afterwards.
Acoustical repertoires and morphological differences in the ear of two Alsodes species (Amphibia: Leptodactylidae)
Authors: Penna M. , Contreras S. , Veloso A.
Published: January 2010

Vocalizations, the sound-conducting apparatus, and acoustical receptors of the inner ear in two species of the anuran genus Alsodes are described. Alsodes nodosus emits a mating call and has a complete middle ear. Alsodes tumultuosus has a weak vocalization that is apparently not involved in mate attraction. This species lacks a tympanic ring and columella. Inner ear receptors are similar in their gross morphology in both species. Anatomical differences in sound-conducting structures may determine interspecific differences in auditory function corresponding with signal divergence.
Ovarian steroid glucuronides function as sex pheromones for male zebrafish, Brachydanio rerio
Authors: Hurk R. van den , Lambert J. G. D.
Published: January 2010

Female zebrafish become attractive to male conspecifics by means of a specific sex attractant secreted by the ovaries. This sex attractant consists of steroid glucuronides; most likely a mixture containing oestradiol-17β- and testosterone glucuronide. Anosmic males are not attracted by the female pheromones and fail to court females with ovulated eggs in the abdomen. Male zebrafish thus detect the ovarian sex attractant, which motivates them to start a series of courtship actions, by olfaction.
Induction of diploid gynogenesis in Atlantic salmon and rainbow trout using irradiated sperm and heat shock
Authors: Refstie Terje
Published: January 2010

Three experiments were carried out to investigate the possibility of producing inbred lines of Atlantic salmon (Salmo salar) and rainbow trout (Salmo gairdneri) by gynogenesis using irradiated sperm and heat shock. In experiment I, tolerance of eggs to heat shock was investigated. In experiment II, eggs were inseminated with irradiated sperm and effects of temperature level, duration of shock, and time from insemination to heat shock were investigated. Heat shock administered for 10 or 20 min during the first 30 min after insemination increased the frequency of gynogenetic fry. Time from insemination to heat shock did not influence the results. The highest frequencies of gynogenetic fry were produced when Atlantic salmon and rainbow trout eggs were heat shocked at 24 and 26 °C, respectively. In experiment III, eggs from albino rainbow trout (recessive homozygote for a depigmentation gene) were inseminated with irradiated sperm from wild-type coloured males and heat shocked. All fry produced in this experiment were of the yellow albino phenotype. It is concluded that induction of diploid gynogenesis by heat shock is a rapid and practical method of producing high numbers of inbred lines in Atlantic salmon and rainbow trout.
Variations de la fécondité et de la structure des populations chez Bithynia tentaculata L. (Gastropoda: Prosobranchia)
Authors: Vincent B. , Gaucher M.
Published: January 2010

In 1982, we studied three populations of the snail Bithynia tentaculata living in a cold environment in the upper estuary of the St. Lawrence River (Quebec), with particular emphasis on the population structure and the fecundity of the different generations. This and other studies show that large variations can occur in the age of sexual maturity from year to year; these are caused by variations in the growth rate and could cause important changes in the growth rate of the populations. Also, there does not appear to be an adequate mechanism to compensate poor recruitment in one year and thus an unbalance in the population structure can be seen for at least 7 years. Fecundity varies from one population to another and from one year to the next. Differences are greater between populations, but both phenomena often interact. These results show the relevance of long-term observations, still quite rare, in order to interpret spatial and temporal variations in the bionomics of iteroparous species.[Journal translation]
Molt, T4, and testosterone in adult male and female bar-headed geese, Anser indicus
Authors: Dittami John Philip , Hall Michael Robert
Published: January 2010

In order to examine the role of gonadal–thyroid interactions in controlling the molt, the ratio of circulating levels of testosterone and thyroxine were examined before and during the molt. The results in males fit the hypothesis that an imbalance between the two functions produce molt but the results from females do not.
Cadmium, copper, and zinc in soil animals and their food in a red clover system
Authors: Carter Alan
Published: January 2010

To evaluate the importance of soil macrofauna in the distribution and turnover of heavy metals, a red clover system was quantitatively sampled and the samples were analyzed for zinc, cadmium, and copper. Heavy metal levels in consumers were described in relation to the consumers' food web relationships. Cadmium was concentrated by earthworms, arthropod predators, and a herbivorous slug over the levels in their respective food items. Millipedes with highly calcareous exoskeletons had low amounts of Cd in their bodies but concentrated Cu and Zn. Earthworms and their faeces, millipedes, and carabid adults had low variability in Zn and Cd concentrations and could be used to monitor changes in levels of these metals in polluted soils.
Reproduction in the lizard Mabuya heathi (Scincidae): a commentary on viviparity in new world Mabuya
Authors: Vitt Laurie J. , Blackburn Daniel G.
Published: January 2010

The tropical Brazilian skink Mabuya heathi is viviparous, producing ova which increase in wet mass by 53 800% and in dry mass by 38 400% during gestation. Ovulation occurs during October–January, rapid growth in embryos takes place during June–October, and parturition occurs in September–November, between 9 and 12 months after ovulation. Female and male reproduction is cyclic and is synchronous between the sexes. Brood size is 2–9 [Formula: see text] and is significantly correlated to female size. Fat bodies of females are largest when embryos are small, and decrease in mass as embryos increase in size. Testes in males are largest during September–February, associated with a decrease in fat body size. Mabuya heathi is the second species of lizard in the caatinga herpetofauna shown to be strongly cyclical in reproduction and to reproduce only once per year.
An ultrastructural study of the culture forms of Trypanosoma (Schizotrypanum) myoti
Authors: Paterson W. Brockley , Woo Patrick T. K.
Published: January 2010

Trypanosoma myoti from the bat Myotis lucifugus was cultured in a diphasic blood-agar and saline medium and examined using transmission electron microscopy. Glutaraldehyde fixation revealed a pattern of kinetoplast DNA condensation in the epimastigote which is characteristic of the subgenus Schizotrypanum. Ferritin was used to demonstrate a functional cytostome–cytopharynx complex. Replication of the basal bodies, flagella, kinetoplast, and the nucleus during binary fission is described. Also present were cells which contain multiple sets of organelles and which undergo multiple fission. The ultrastructural features of Trypanosoma myoti resemble those of Trypanosoma cruzi.
Peripheral metabolism of testosterone during the annual reproductive cycle in the male hedgehog, a hibernating mammal
Authors: Saboureau M. , Boissin J.
Published: January 2010

The seasonal cycle of plasma testosterone levels in hedgehogs of midwestern France shows large variations and different successive sequences: a resting period in autumn, an increase during winter in January, continued high levels from midwinter to midsummer that are characterized by an important spring peak, a regular decrease in May–June, a shorter but regular summer peak, and an involution beginning at the end of summer. To elucidate (i) the increase of plasma testosterone levels in January during hibernation and (ii) the regular decrease of plasma testosterone levels in May–June during the activity period, the seasonal cycles of metabolic clearance and production rates of testosterone were studied, using [3H]testosterone in a single injection technique. The rate of peripheral metabolism of testosterone was reduced in autumn but increased in January during hibernation, simultaneously with the endocrine activity of the testis; it was maximum in February–March, then fluctuated but stayed at a high level during spring and summer, and decreased in September. In these hedgehogs there is a clear annual cycle of testosterone production with two maxima, and only the decrease of plasma testosterone levels observed in June can be explained by an increase of the metabolic clearance rate.