bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of the life cycles, reproductive ecologies, and size–weight relationships of Helisoma anceps, H. campanulatum, and H. trivolvis (Gastropoda, Planorbidae)
Authors: Boerger Hans
Published: August 2008

Helisoma anceps, H. campanulatum, and H. trivolvis were studied separately in three ponds near Waterloo, Ontario, and were found to differ in the following parameters, respectively: life span, 2.1, and 2 years; mean growth rate during the first 2 months after hatching, 0.2, 1.0, and 0.06 mm/week; minimum size at which snails laid eggs, 8, 10, and 18 mm shell diameter; number of breeding periods during the life cycle, 2, 1, and 1: length of the spawning season, 18, 10, and 8 weeks; date by which 50% of the eggs had been laid, July 2, May 14, and May 15; mean number of eggs per egg capsule, 14, 14, and 24. Although mature H. trivolvis occurred throughout the pond during the spawning season, eggs were laid only along the margin. The average number of eggs laid during the life span of a snail was 300 for H. campanulatum and 590 for H. anceps. Linear regression equations relating size to live weight, shell weight, and shell-free dry weight were calculated for each species. Differences between the three species in geographic distribution, tolerance to environmental perturbations, and frequency of congeneric associations seem to be related to differences in their life histories.
Multiple stability and maximum stability in a model population
Authors: McQueen Donald J.
Published: August 2008

Using a modular demographic model this work attempts to mechanistically explain how multistability levels might occur, to explain how a population might move from one level to another, and to investigate the combination of forces which leads to maximum stability within a local stability range. The work showed that unique stability levels for single populations are created by unique combinations of rates such as birth, natural mortality, emigration, immigration, and interference, and that because these rates depend upon factors such as climate and resource availability, stability levels constantly change and arc constantly chased by the population. The simulations also showed that, as rates changed, stable and unstable equilibrium points approached and met one another causing the population to shift from one stability level to another. The work also suggested that there was an inverse relationship between the numerical stability of the population and the number of feedback forces influencing its demographic structure. Maximum stability was achieved by excluding all but one feedback force, and among the simulations of this type that were performed, natural mortality acting alone produced the optimal damping effect.
Effects of dispersion, travel, and environmental heterogeneity on populations of the earwig Forficula auricularia L.
Authors: Lamb R. J.
Published: August 2008

Local earwig populations were increased by the addition of artificial shelters which protected them against an inhospitable microclimate and predation by birds. The spacing of shelters and the availability of nearby food limited the use of shelters and thus the size of populations, through intraspecific competition for food. This competition was increased by the active aggregation of earwigs in shelters. Aggregation probably assists in the location of suitable shelter and provides a focus for social interaction. Enhanced growth and early initiation of foraging were observed for earwigs reared in groups.Foraging earwigs showed intraspecific aggression, especially at feeding sites. Earwigs that had not fed during the current foraging period were less likely to join aggregations early in the night. Foraging earwigs showed no ability to home to shelters or locate aggregations from a distance of more than a few centimetres, but were capable of travelling many metres in one night. These factors resulted in the exclusion of new occupants when shelter use reached a maximum.
Relation entre les plantes aquatiques et les gastéropodes (Mollusca, Gastropoda) dans la région de la centrale nucléaire Gentilly I (Québec)
Authors: Lacoursière Estelle , Vaillancourt Guy , Couture Richard
Published: August 2008

This study is based on a sampling of the gastropods present in the vegetation of the St. Lawrence riverside zone at Gentilly. A total of 536 plant specimens belonging to 20 species as well as 37 239 specimens grouping 10 different species of gastropods were sampled. A comparison of the plant species – mollusc data was carried out. The analysis of the results indicates that prosobranchs have no affinity whatsoever for any plant species in particular. The pulmonates, however, are found mainly on emergent plants.
Paratylenchus projectus (Paratylenchinae: Nematoda) and some closely related species
Authors: Wu Liang-Yu
Published: August 2008

Paratylenchus projectus collected from various areas in Canada and 10 populations, each propagated from a single larva, were studied. Spear length varied from 24 to 28 μ, rarely 29 μ. Sides of head region were straight with a truncate front. Tail terminus varied from conically rounded, rounded, digitate, to subacute. Its differences from Paratylenchus neoprojectus are discussed. A study of the topotypes and lectotype of P. nanus indicates that these are different species. The lectotype is judged to be consistent with the original description, while the topotypes are closely related to P. projectus. A key to the Canadian species of Paratylenchus is presented.
Erratum: Reproductive timing by the polychaetes Clymenella torquata and Praxillella praetermissa in Passamaquoddy Bay, New Brunswick
Authors: Rowe V. Leslie , Hynes H. B. N. , Tyler A. V.
Published: August 2008

not available
Croissance en longueur et en poids des barbottes brunes Ictalurus nebulosus (Le Sueur) capturées à la frayère de la rivière aux Pins, près de Montréal (Québec)
Authors: Harvey Gilles , Fortin Rejean
Published: August 2008

Seine and dip net samples taken on the spawning grounds in Rivière aux Pins were used to describe the growth of young-of-the-year brown bullhead (Ictalurus nebulosus Le Sueur). One-year-old and older bullheads were aged by counts of annual growth marks on sections of their pectoral fin bony ray. Several aspects of the growth of these fish were determined: a faster growth in length and weight in ma les than in females; the presence in Rivière aux Pins of two groups of bullhead, one more slowly growing and one more rapidly growing; the effects of tagging on growth; the isometric length–weight relationship; and variations of condition during the few months when spawners occupy Rivière aux Pins.
Polar bear locomotion: body temperature and energetic cost
Authors: Hurst R. J. , Leonard M. L. , Watts P. D. , Beckerton P. , Øritsland N. A.
Published: August 2008

The metabolic response of a 190-kg polar bear was tested at four different walking speeds within a respiration chamber mounted on a treadmill. Regressions of deep body temperature and oxygen consumption as a function of walking speed were determined. Equilibrium deep body temperature increased exponentially with speed of locomotion and indicated a relative inability to dissipate metabolic heat at high walking speeds. Metabolic rate, as measured by weight-specific oxygen consumption, was also best fit by a curvilinear equation and was twice that predicted by a general equation for quadruped locomotion. The apparent inefficiency of locomotion in polar bears suggests a compromise between thermoregulation, hunting strategies, and economy of transport.
Infestations of the nematode Skrjabingylus nasicola (Leukart 1842) in Mustela frenata (Lichtenstein) and M. erminea (L.) and some evidence of a paratenic host in the life cycle of this nematode
Authors: Gamble R. Lloyd , Riewe R. R.
Published: August 2008

Examination of 153 Mustela frenata and 16 Mustela erminea from Manitoba revealed 100% parasitism of both hosts by Skrjabingylus nasicola. Cranial damage was significantly less in M. frenata than in M. erminea. In M. frenata, cranial damage was less in adult females than males and greater in adults than in subadults. Adult males and females had a greater degree of damage than subadult males and females. Percentage infestation and damage was related to diet. Data suggest that rodents, particularly the myomorphs, shrew, amphibians, and reptiles are paratenic hosts for S. nasicola. The condylobasal length of the skull of M. frenata apparently is not affected by parasite invasion, though the interorbital breadth is affected and becomes unreliable as a taxonomic measurement. Cranial damage was frequently asymmetrical. Despite repeated invasions, the definitive host is still active and therefore must tolerate the damage.
Helminth parasitism in raccoons, Procyon lotor hirtus Nelson and Goldman, in Saskatchewan
Authors: Hoberg Eric P. , McGee Steven G.
Published: August 2008

Thirty-one raccoons, Procyon lotor hirtus Nelson and Goldman, from southern Saskatchewan, Canada, were examined for helminths. Six species were recovered: Plagiorchis cf. cf. elegans (Rudolphi, 1802); Alaria marcianae (LaRue, 1917); Pharyngostomoides adenocephala Beckerdite, Harkema and Miller, 1971; Microphalus sp.; Atriotaenia procyonis (Chandler, 1942); and Physaloptera sp. Comparisons were made with findings in a series of 25 raccoons from the midwestern United States and with published results and surveys in other regions. Notable variation exists in species diversity and intensity of infection of parasites in raccoons from different geographic regions. This is a consequence of diverse ecological conditions in different geographic regions. Since P. lotor is extending its range in Saskatchewan, it is suggested that the low diversity of its helminthic fauna may be attributable to dispersal of animals into regions where they persist in low numbers and where conditions are not suitable for completion of life cycles of helminths that elsewhere occur commonly in raccoons. The trematodes P. elegans and A. marcianae have not been previously reported from raccoons.
Reproductive parameters and nesting behavior of the Amazon turtle Podocnemis expansa (Testudinata: Pelomedusidae) in Brazil
Authors: Alho Cleber J. R. , Pádua Luiz F. M.
Published: August 2008

The Amazon River turtle Podocnemis expansa was studied during the nesting and hatching seasons (October and December of 1978, 1979, and 1980) at a protected site in a Biological Reserve on the Trombetas River, a tributary of the Amazon. Mean carapace length of nesting females was 66 cm and mean carapace width 59 cm. Mean clutch size was 91.5 eggs (with 95% hatching success) and was positively correlated to carapace length, carapace width, plastron length, and plastron width. Carapace width was positively correlated to egg chamber height, and egg chamber diameter was positively correlated with nest depth, clutch size, and plastron width. There is a synchronization between low water and nesting.
Observations on some poorly known syllid polychaetes from the Gulf of Maine
Authors: Riser Nathan W.
Published: August 2008

Amblyosyllis cincinnata (Verrill, 1874), a subtidal syllid polychaete associated with sponges, is described from the mouth of the St. Croix River. Distinguishing features are the dentition of the blades of the compound setae and the multicuspid pharyngeal teeth. Biological and morphological data on the common interstitial syllid, Sphaerosyllis brevifrons Webster and Benedict 1884, are presented. This species occurs intertidally in coarse sand in the northern Gulf of Maine and is subtidal in the southern part of the Gulf.
The biology of Trypanosoma andersoni n. sp. and Trypanosoma grylli Nigrelli, 1944 (Kinetoplastida) from Hyla versicolor LeConte, 1825 (Anura)
Authors: Reilly Brian O. , Woo P. T. K.
Published: August 2008

From May 1979 to July 1980, the blood of 196 mature Hyla versicolor LeConte from six sites in southern Ontario and southeastern Manitoba was examined for trypanosomes using the haematocrit centrifugation technique. Trypanosoma andersoni n. sp. and Trypanosoma grylli Nigrelli were found in 5.2 and 5.6% of the frogs examined. Three frogs (1.5%) were infected with both species of trypanosomes. Blood trypomastigotes of both species were monomorphic. Blood trypomastigotes of T. andersoni n. sp. were long and slender, tapering at both ends, whereas those of T. grylli were pyriform with a rounded posterior and tapered anterior.Both blood and culture forms of these trypanosomes were infective to laboratory-raised H. versicolor and Hyla crucifer Wied. Trypanosoma grylli was also infective to a field-collected Acris gryllus (LeConte). Neither trypanosome was infective to laboratory-raised Rana catesbeiana Shaw, Rana clamitans Rafinesque tadpoles, Rana pipiens Schreber, Rana sylvatica LeConte, or Xenopus laevis Daudin. Trypanosoma andersoni n. sp. was also not infective to laboratory-raised Bufo americanus Holbrook, Pseudacris triseriata (Wied), or to field-collected Hyla cinerea (Schneider) and Osteopilus septentrionalis Dumeril and Bibron. Neither species was infective to field-collected Notophthalmus viridescens (Rafinesque).
The ultrastructure of an anuran trypanosome, Trypanosoma andersoni Reilly and Woo, 1982 (Kinetoplastida)
Authors: Reilly Brian O. , Woo P. T. K.
Published: August 2008

The blood trypomastigote of Trypanosoma andersoni Reilly and Woo has an amorphous surface coat and trilaminar pellicle with a series of subpellicular tubules. A long, tubular mitochondrion with many platelike cristae is present. The cytoplasm is rich in ribosomes and vacuolar elements. The surface coat of T. andersoni is similar to those of the stercorarian mammalian trypanosomes, whereas the undulating membrane and mitochondrion resembled those of avian trypanosomes.
Metazoan parasites and food of short-tailed weasels and mink in Newfoundland, Canada
Authors: Jennings David H. , Threlfall William , Dodds Donald G.
Published: August 2008

Forty short-tailed weasels (Mustela erminea Linnaeus, 1758) and 48 mink (Mustela vison Schreber, 1777) were collected, between January 1978 and February 1979, in three areas of insular Newfoundland and examined for metazoan parasites. Eight genera of parasites were recovered. Two findings constitute new host records. Forty (100%) of the M. erminea and 17 (35%) of the M. vison were infected. The effect of one species, Skrjabingylus nasicola (Leuckart, 1842), on the skull of the weasels was examined, and comments are made on its increase in prevalence with the introduction to insular Newfoundland of the masked shrew (Sorex cinereus Kerr, 1792) in 1958.Gut contents of both M. erminea and M. vison were identified and the percentage occurrence of different food items was calculated. In the case of the former species a marked change in diet, from lagomorphs and passerines to insectivores, was noted when the present (1978–1979) sample was compared with a 1956–1958 sample.
The effect of the stress of forcible submergence on the diving response in muskrats (Ondatra zibethica)
Authors: Jones David R. , West Nigel H. , Bamford Owen S. , Drummond Peter C. , Lord Raymond A.
Published: August 2008

The effect of the stress of forced submergence in the laboratory on a number of cardiovascular adjustments to diving was examined. Free muskrats, diving in large holding tanks, always displayed bradycardia and heart rate fell from a predive rate of 320 ± 6 to 34 ± 3 beats∙min−1 after 20 s submergence. In the laboratory this degree of bradycardia was only seen during whole-body submergence of anesthetized animals; restrained unanesthetized muskrats showed significantly less bradycardia. Forced submergence of only the head caused about half the bradycardia seen during whole-body submergence in both unanesthetized restrained and anesthetized muskrats. Decerebrated animals gave identical responses to those of anesthetized muskrats. Cardiac output was redistributed in forced diving to favour the heart and brain even when diving heart rate was three times that in free dives. However, many other tissues still received a significant proportion of cardiac output and must have placed a drain on the blood oxygen store which restricted apnoeic tolerance. Struggling during forced submergence was frequent and has a reflex or unconscious component since even decerebrated animals struggled during a dive. The present data suggest that the additional stresses imposed on muskrats during forcible submergence in the laboratory reduce rather than potentiate the cardiovascular adjustments to diving.
Scanning and transmission electron microscopy of ovine mesenteric arteries infected with first-generation meronts of Sarcocystis tenella
Authors: Speer Clarence A. , Dubey J. P.
Published: August 2008

First-generation meronts of Sarcocystis tenella were found within subendothelial cells between the endothelium and internal elastic membrane of mesenteric arteries. At 14 and 16 days postinoculation (DPI), host cells with mature meronts were enlarged, measuring 25.6 × 22 μm (16.4–35 × 4.4–28.5 μm; n = 17), which caused the endothelium to protrude into the vessel lumen. In mesenteric arteries, protuberances measured 37.4 × 29.7 μm (32–57 × 16.5–47 μm; n = 15) and extended 16.8 μm (12–27 μm; n = 12) into the vessel lumen. Merozoites in meronts measured 5.3 × 1.7 μm (4.5–5.5 × 1.5–1.8 μm; n = 20); free merozoites were 5.5 × 1.5 μm (4.8–6 × 1.3–1.7 μm; n = 18). At 16 DPI many of the endothelial cells covering protuberances as well as many of the host cells had sloughed from the tunica intima of the mesenteric arteries which exposed relatively large areas, 189.5 μm (50–350 μm; n = 15) in diameter, of the internal elastic membrane.
Superoxide dismutase activity in dauerlarvae of Caenorhabditis elegans (Nematoda: Rhabditidae)
Authors: Anderson Gary L.
Published: August 2008

Dauerlarvae are reportedly adapted to withstand adverse environmental conditions. Current knowledge of the mechanisms underlying the unique characteristics of dauerlarvae is limited. This study characterizes superoxide dismutase (SODase) activity in several developmental stages of Caenorhabditis elegans (originally described by E. Maupas in 1900). Extracts of dauerlarvae have 17.1 units SODase per milligram protein, as compared with 4.3 and 3.8 units per milligram for obligate larvae and young adults, respectively. Since oxygen consumption in dauerlarvae is lower than that of young adults, the ratio of SODase to oxygen consumption is markedly higher in dauerlarvae than in young adults. The elevated SODase might contribute to an increased resistance to a variety of environmental stresses, including radiation. Furthermore, the elevation of this activity relative to metabolic rate could account for the long life-span of dauerlarvae.
Circannual cycles of thyroid hormones in plasma of winter flounder (Pseudopleuronectes americanus Walbaum)
Authors: Eales J. G. , Fletcher G. L.
Published: August 2008

Seasonal changes in plasma concentrations of L-thyroxine (T4) and 3,5,3′-triiodo-L-thyronine (T3) were measured by radioimmunoassay for flounder bled shortly after capture (field fish) or after 7 days retention in the laboratory at seasonal temperatures and photoperiods (laboratory fish).In field fish plasma T4 was highest from April to June and lowest from November to February, whereas plasma T3 was highest from September to January and lowest in May to June. T4/T3 molar ratios increased markedly from March to June and fell to very low values during July to early February.Laboratory fish showed generally similar seasonal patterns, except that for most of the year their T4 levels were consistently higher and T3 levels consistently lower than their field counterparts, resulting in much higher T4/T3 ratios in plasma of laboratory fish.The above seasonal trends are discussed in relation to environmental and physiological parameters and stress.
How cranefly larvae breathe
Authors: Pritchard Gordon , Stewart Mary
Published: August 2008

Aeropyles in the spiracles of the larvae of the terrestrial Tipula paludosa and the aquatic but air-breathing Pedicia parvicellula and an unidentified Tipula are illustrated. In T. paludosa these aeropyles are present and open throughout larval life and through the pharate pupal phase. By contrast, the aeropyles of the aquatic T. sacra and T. abdominalis are essentially closed and, in T. sacra at least, appear not to function during the larval stage. Gas exchange must be effected cutaneously in these latter species and, in T. sacra, the spiracular lobes and perhaps the smaller lobes along the body are principal sites of oxygen uptake. However, the larval spiracles of T. sacra do function during the terrestrial pharate pupal phase, when the central scar plug of the spiracle breaks down. Tipula paludosa has a well-developed "tracheal lung" emanating from the spiracular atrium, but this is absent in T. sacra. It is suggested that this lung functions as a tracheal gill when terrestrial habitats become flooded.
Attraction to and selection of prey by immature lobsters (Homarus americanus)
Authors: Carter J. A. , Steele D. H.
Published: August 2008

This study was concerned with the relative attractiveness of prey extracts and metabolites and ninhydrin-positive compounds (NPCs) offered to immature lobsters (Homarus americanus). Extracts of rock crabs were the most attractive. Those of sea urchins and starfish were the least attractive. Immature lobsters showed significant preference for rock crab extract when offered those of various species. Only rock crab metabolites elicited significant food-searching responses from lobsters. Proline and ammonia were the most attractive of the NPCs tested.Selection of intact prey by immature lobsters was observed. Brittlestars, nereids, and polynoids were attacked more often than other prey, including rock crabs, starfish, mussels, sea urchins, and periwinkles. Polychaetes were almost always completely consumed when attacked. Immature lobsters ate smaller proportions of larger prey. Small rock crabs and large starfish, sea urchins, and mussels tended to avoid predation.An analysis of prey NPCs implicated the higher levels of NPCs, such as proline and ammonia, as a reason for the significant attractiveness of rock crabs.
Properties and distribution of a chymotryptic-like enzyme from the sipunculan, Phascolopsis gouldii
Authors: Brown Carolyn Lee , Michel Catherine , DeVillez Edward J.
Published: August 2008

Homogenates of digestive tract, digestive fluid extracts, and a partially purified enzyme from Phascolopsis gouldii demonstrated activities toward N-benzoyl-L-tyrosine ethyl ester (BTEE) and N-glutaryl-L-phenylalanine p-nitroanilide (GPANA) at pH 7.8. The chymotryptic component showed optimal BTEE activity from pH 7.7 to 8.2 and was found to be stable at pH 5.0–9.0 with immediate and irreversible loss of activity at pH 4.0. BTEE activity was inhibited by L-1-tosylamide-2-phenylethyl chloromethyl ketone (TPCK), phenylmethylsulfonyl fluoride (PMSF), and phenothiazine-n-carbonyl chloride (PCC) and demonstrated affinity for 4-phenylbutylamine on a Sepharose 4B column. The molecular weight of the digestive fluid component as determined by gel chromatography was approximately 23 400. Gel chromatography of the eluant demonstrating pheynlbutylamine affinity yielded additional low molecular weight components. The posterior loop, which forms the junction between descending and ascending intestine, demonstrated highest BTEE and GPANA activities. In contrast, secretory cells are concentrated in the anterior descending intestine and granules appear to be emitted as an apocrine secretion.
Effect of coronary artery ablation on exercise performance in Salmo gairdneri
Authors: Daxboeck Charles
Published: August 2008

Ablation of the coronary artery of the rainbow trout does not affect the level of exercise performance attained in a Brett-type water tunnel, when compared with intact or sham-operated fish. Arterial blood supply to the myocardium is maintained, following artery ablation, by small patent vessels in the adventitia of the bulbus–ventral aorta. The significance of the arterial vascular pattern of trout hearts is discussed.
Energy consumption and subsequent partitioning in lactating black-tailed deer
Authors: Sadleir R. M. F. S.
Published: August 2008

The voluntary feed intake of lactating Odocoileus hemionus columbianus does was measured to 4 months after parturition. Similar measures of consumption by nonlactating does showed average dry matter intakes of 67 g∙kg−0.75∙day−1 (247 kcal digestible energy∙kg−0.75∙day−1; 1 cal = 4.1868 J). At peak consumption rates, 4–5 weeks after parturition, lactating does with twin fawns consumed 170% of the intake of nonlactating does. For does with single fawns the rate was 135%. Body weight changes in early lactation varied between does, with some individuals utilizing body reserves to maintain milk production whereas others remained in a positive caloric balance. For the rest of lactation, voluntary feed intakes were sufficiently high to allow all does to both produce milk and increase in body weight.
Blood parasites from fish of the Gulf of Maine to Cape Hatteras, Northwest Atlantic Ocean, with notes on the distribution of fish hematozoa
Authors: Khan R. A. , Newman M. W.
Published: August 2008

Examination of blood smears from 657 marine fish collected from the continental shelf off the east coast of the United States, Cape Hatteras to the Gulf of Maine, revealed hematozoa in 19 of 39 species. Among the infected fish species, hemogregarines were more prevalent (17%) than trypanosomes (5%), piroplasms (4%), or trypanoplasms (1%). Ten species were infected with the virus that causes piscine erythrocytic necrosis. Prevalence of hemogregarines was higher in pleuronectiform and gadiform fish than among perciform species. Sedentary benthic species, especially flatfishes, and some demersal fish, were infected more often than pelagic species. Comparison of this survey with previous studies in the Northwest Atlantic suggests that hematozoa are more prevalent among fish in areas north of Newfoundland and decrease towards the equator. Piroplasms are reported only from fish occurring in temperate Atlantic waters. Piscivorous species of leeches, which are suspected or proven vectors of hematozoa, are more prevalent in the arctoboreal than in the neotropical Atlantic Ocean, and might account for the higher prevalence of piscine hematozoa in the northern latitudes.
Effect of hypophysectomy on thyroxine deiodination in rainbow trout, Salmo gairdneri
Authors: Levin G. B. , Eales J. G.
Published: August 2008

The tendency for [125I]thyroxine (T4) to be deiodinated to 125I− and 3,5,3′-[125I]triiodothyronine is reduced in rainbow trout within 5–8 days of hypophysectomy, indicating pituitary influence by either direct or indirect intervention upon extrathyroidal T4 monodeiodination.
Métabolisme périphérique de la testostérone en relation avec le cycle annuel de la testostérone et de la 5α-dihydrotestostérone plasmatiques chez le Blaireau européen (Meles meles L.) et le Renard roux (Vulpes vulpes L.)
Authors: Maurel D. , Boissin J.
Published: August 2008

Seasonal variations in plasma contents of testosterone, 5α-dihydrotestosterone (5α-DHT) and other parameters related to the peripheral metabolism of testosterone have been determined in adult foxes and badgers, in natural climatic conditions.In both species, testosterone reaches peak levels in winter, but whereas the fox takes a sexual break beginning in spring (April), the badger has high concentrations of hormones until the summer. The mean annual concentration of testosterone is four times higher in the badger than in the fox; the annual mean value of 5α-dihydrotestosterone is identical in both species and levels of 5α-DHT are significantly higher during the breeding period.The annual cycle of testosterone peripheral metabolism in the fox is characterized by a decreased rate during summer and fall and an increased rate during winter (breeding period). In the badger, the metabolic clearance rate is high at the end of the fall and at the onset of the breeding period (October to January) and low during the peak reproduction period (February to April) and then increases as the period of sexual break approaches.The annual cycle of testosterone production rate is characterized in both species by a fall or prewinter increase; in the fox, this increase is followed by a decrease at the end of the winter, whereas the badger keeps pretty well the same rate of production until the summer.Seasonal variations of hormone peripheral metabolism are examined and discussed in relation to the fluctuations in testosterone levels and the hormone-specific protein linkage capacity.[Journal Translation]
Stages of the intermoult cycle in the terrestrial isopod Oniscus asellus and their relation to biphasic cuticle secretion
Authors: Steel C. G. H.
Published: August 2008

The intermoult cycle of Oniscus has been divided into 15 stages, recognizable by changes in the appearance of the anterior sternites. The stages are related to concurrent microscopical changes in the integument. The normal stimulus which initiates premoult is followed by a period when no tissue changes are discernible. Apolysis occurs about 7 days after premoult initiation. Thus, use of apolysis to recognize premoult (as in many crustaceans) would result in 44% of premoult passing undetected. Storage of calcium in sternal deposits and the general cuticle of the anterior region during the latter half of premoult is associated with an arrest of cuticle secretion in this region; at the time of posterior ecdysis (Ep) the anterior region has no new exocuticle. The anterior region is thus functionally similar to the decapod gastrolith. Stored calcium is resorbed and the anterior exocuticle secreted during the 24 h following Ep, enabling ecdysis of the anterior region to follow. The accumulation of calcium in the anterior cuticle while the posterior cuticle is undergoing resorption and the secretion of exocuticle at different times in the two regions both imply that the integuments of anterior and posterior regions differ in their responses to the moulting hormone.
Polymorphism in the White-throated Sparrow: habitat occupancy and nest-site selection
Authors: Knapton Richard W. , Falls J. Bruce
Published: August 2008

We analysed several vegetational variables in four populations of White-throated Sparrows (Zonotrichia albicollis) to determine if differences exist between the white-stripe (WS) and tan-stripe (TS) morphs at the level of the macrohabitat (territory) and the microhabitat (nest site). Univariate and discriminant function analyses revealed that trees were farther apart, more light penetrated to the forest floor, and fewer shade-tolerant plants occurred in territories of WS than TS males. There was little difference between females of the morphs in selection of nest sites. The distribution of territories of WS males along the discriminant function axis (macrohabitat analysis) was narrower than that of TS males, and was concentrated toward the "open" habitat end of the axis. The distribution of territories of TS males spanned the length of the axis, from "open" to "dense" habitat. The question why WS male × TS female pairs occupy a relatively narrow range of habitat whereas TS male × WS female pairs occupy a much broader range is discussed.
Changes in reproductive parameters in aging females of solitary phase Schistocerca gregaria
Authors: Dale J. F. , Injeyan H. S. , Tobe S. S.
Published: August 2008

The proportion of resorbing basal oocytes was higher in aging than in young solitary female Schistocerca gregaria and the haemolymph vitellogenin available to the maturing oocytes in late gonotrophic cycles was undiminished or even increased in comparison with early gonotrophic cycles. Nevertheless eggs in late pods from solitary females showed only a very modest size increase over those from early pods, particularly in comparison with the size increase which resulted from crowding solitary females. Hatchlings emerging from late pods, like those from early pods, were largely of the solitary phase.A remarkable cyclicity of haemolymph vitellogenin titres was observed during gonotrophic cycles in aging females, the maximal titre almost always following closely upon the oviposition which marked the beginning of the cycle.
The effect of drying temperature on extraction of petroleum ether soluble fats of small birds and mammals
Authors: Kerr David C. , Ankney C. Davison , Millar John S.
Published: August 2008

The effect of drying temperature on subsequent fat extractions was investigated. Equal aliquots of homogenized house sparrow (Passer domesticus) were dried to constant weight at 40, 75, 100, and 120 °C and by freeze-drying, and equal aliquots of homogenized meadow vole (Microtus pennsylvanicus) were dried to constant weight at 40 and 120 °C. Total fat, extracted in a Goldfisch fat extractor with petroleum ether, did not differ among temperature treatments. We suggest that loss of volatile fatty acids is similar at the temperatures we used.
Misuse of orientation statistics
Authors: Childs Stephen B. , Buchler Edward R.
Published: August 2008

Improved statistical techniques for the analysis of circular data have increased our awareness of certain invalid procedures in earlier orientation research. Even now, however, the current literature contains many examples of inappropriately analyzed data sets. In experiments where a number of individuals are each observed more than once, second-order statistics must be used. Twice repeated, first-order statistics do not allow valid conclusions in experiments of this type.
Movements and diel activity of the coast mole Scapanus orarius True
Authors: Schaefer Valentin H.
Published: August 2008

A coast mole, Scapanus orarius True, was labelled with Iridium 192. Its activities were monitored for a total of 50 h and 48 min. The mole spent most of its time in the vicinity of the nest, but was active over an area of 39 × 39 m. The mole was active for 5-h periods (three observations) and did not confine its activity to any particular part of the day.
The defense function: a measure of territorial behavior
Authors: Melemis Steven M. , Falls J. Bruce
Published: August 2008

The defense function is defined as the relationship between the location of an intrusion and the level of territorial defense it stimulates. To investigate this property we used eight measures of responses of territorial male white-throated sparrows (Zonotrichia albicollis) to playback of recorded song at three points inside and two points outside territorial boundaries. Variables associated with first reactions and movement reflected a fairly constant level of response when playback was located inside the territory and a significant drop when it was outside; song variables showed a steady decline in response from the center outward. The concept of a defense function is used to develop an alternative definition of a territory and to suggest further experiments for investigating territoriality.
Description of germinal sacs of a gymnophallid trematode, Cercaria margaritensis sp. n., in the extrapallial fluid of subtidal snails (Margarites spp.) in British Columbia
Authors: Ching Hilda Lei
Published: August 2008

Asexually reproductive stages equivalent to the cercaria and the metacercaria, with oral and ventral suckers, bifurcate caeca, and forked tails were found between the mantle and shell of subtidal snails collected in 1977 and 1978. The parasites were found in 77% of 336 Margarites costalis (Gould), 59% of 27 Margarites pupillus (Gould), and 59% of 37 Margarites olivaceous (Brown). With heavy infections, the extrapallial fluid of the snail is increased and the gonad and digestive gland may be destroyed. Host amoebocytes increase in the extrapallial fluid and the larvae may become encapsulated by melanin and nacreous secretions. Unusual crystals within the intestine of the parasites may be by-products of the ingested medium.
Canadian species of Merlinius Siddiqi, 1970 and a diagnosis and description for Mulveyotus hyalacus n. gen., n. sp. (Nematoda: Tylenchorhynchidae)
Authors: Anderson R. V. , Ebsary B. A.
Published: August 2008

Three new bisexual species of Merlinius Siddiqi, 1970, characterized by apically flattened heads and elongate–conoid tails with narrowly rounded or pointed ends, and a new genus and species (Tylenchorhynchidae) in Canada are described and illustrated. The distinguishing female characters of Merlinius plerorbus n. sp. are the constricted head, 16- to 17-μm-long stylet, 45- to 54-μm-long tail with 38–40 annules and a smoothly rounded terminus, and lobed spermathecae. Diagnostic for females of Merlinius circellus n. sp. are the continuous low head, 9- to 10-μm-long stylet, tail with 72–75 annules and a pointed terminus, and spherical spermathecae. The female of Merlinius tetylus n. sp. has a stylet length of 14 μm, a 98-μm-long tail with about 100 fine annules, and lobed spermathecae. Supplemental descriptive data for M. processus Siddiqi, 1979, a new species record for Canada, is provided, and included in a key to the species of Merlinius. Merlinius laminatus (Wu, 1969) Siddiqi, 1970 is transferred as a new combination to Scutylenchus Jairajpuri, 1971. Differential characters of Mulveyotus hyalacus n. gen., n. sp., are a body length of over 1 mm, alow, flattened continuous head, an areolated lateral field of three incisures, and a conoid tail over 100 μm long with a tapered smooth terminus of thickened cuticle comprising 24% of the tail length.
Distinguishing characteristics of the hairs of wild and domestic canids from Alberta
Authors: Kennedy Alan. J.
Published: August 2008

Dorsal, ventral, and lateral guard hairs were examined from 12 wolves (Canis lupus), 14 coyotes (Canis latrans), six domestic dogs (Canis familiaris), and six red foxes (Vulpes vulpes) to determine distinguishing features. Wolf and coyote hairs are not separable using present techniques. However, wolf–coyote hair can be identified by its total length, band number and size, and distinctive basal cuticle scale pattern. Red fox hair is characteristic in its length, color, tip region size, basal cuticle scale pattern, and medulla cross section. Domestic dog hair is identified by its length and basal cuticle scale pattern. Several macroscopic and microscopic hair characteristics of Alberta canids are different from those of eastern canids.
Changes in blood properties of fasting and feeding harp seal pups, Phoca groenlandica, after weaning
Authors: Worthy Graham A. J. , Lavigne D. M.
Published: August 2008

Physical blood properties and blood biochemistry were monitored in captive harp seal pups throughout the postweaning fast and during the onset of feeding. One group was fasted for a period of 10 weeks and three other groups commenced feeding after fasts of 8, 29, and 36 to 44 days, respectively.Calcium and phosphorus levels in fasting pups were lower than in feeding pups. Circulating levels of alkaline phosphatase, serum glutamic-pyruvic transaminase (SGPT), serum glutamic oxalo-acetic transaminase (SGOT), and creatinine phosphokinase (CPK) increased with the onset of feeding. Other monitored blood parameters exhibited no significant differences between feeding and fasting animals and were within the range of normal values previously reported for harp seals.Harp seal pups commence feeding within about 6 weeks after weaning. During this period they appear capable of maintaining homeostasis with respect to many blood parameters, prior to achieving nutritional self-sufficiency.
Aktedrilus locyi Erséus, 1980 and Aktedrilus oregonensis n. sp. (Oligochaeta, Tubificidae) from Coos Bay, Oregon, with notes on distribution with tidal height and sediment type
Authors: Strehlow David R.
Published: August 2008

Specimens of Aktedrilus locyi Erséus, 1980 (Oligochaeta, Tubificidae) from Coos Bay, Oregon, U.S.A., are compared with the original California material, and Aktedrilus oregonensis n. sp. is described. Aktedrilus locyi was found in the upper to middle intertidal in sands with [Formula: see text] silt. Aktedrilus oregonensis occurs lower on the beach than A. locyi and in the upper intertidal only in sand with 8% silt. An interaction of tidal height and sediment type affects the distributions of both species.
The searching behaviour of two species of phytoseiid mites, Phytoseiulus persimilis Athias-Henriot and Amblyseius degenerans (Berlese), in relation to the density and distribution of prey in an homogeneous area (Acarina: Phytoseiidae)
Authors: Eveleigh Eldon S. , Chant D. A.
Published: August 2008

Both Phytoseiulus persimilis and Amblyseius degenerans exhibited area-restricted searching after prey capture(s) regardless of the density and distribution of prey experienced. A reduction in searching speed and an increase in the absolute magnitude of turns following prey capture(s) contributed to area-restricted searching under all prey conditions with P. persimilis, whereas with A. degenerans, area-restricted searching was due to factors other than a consistent change in these searching parameters under all prey conditions. Phytoseiulus persimilis modified its overall searching behaviour to a greater extent at low than high prey densities and under clumped than uniform prey distributions, whereas A. degenerans showed similar postcapture behaviour under all prey conditions tested. The possible consequences of the behaviour of both predators on their searching success under different types of prey conditions are discussed.
Filter feeding in larvae of Simuliidae (Diptera: Culicomorpha): aspects of functional morphology and hydrodynamics
Authors: Craig Douglas A. , Chance Mary M.
Published: August 2008

The feeding mechanism of simuliid larvae is further elucidated by detailed study of the nature and speed of cephalic fan and mouthpart movements, and examination of water flow around larvae. Photographic observations of artificial particles flowing past Simulium vittatum Zett. larvae show the body and head to be highly streamlined and water flow to be laminar over the larva. Dissections and cinephotography show cephalic fan closure to be initiated and controlled by rotation and medial movement of the torma. As the primary fan closes, the median and secondary fans close and form raised sides to the primary fan. Sharp movements made during opening and closing of the fan suggest the presence of "click mechanisms."One cephalic fan closes and adducts every 0.231 s, and for the period analyzed, one or other fan was closed 28% of the time. It is suggested that the time fans are closed should be included in calculations of simuliid larval feeding efficiencies. Larvae with slower mouthpart movements may filter more efficiently than those with faster movements.Laminar flow through and cross-sectional shape of fan rays produce optimal flow for filtration. Probably turbulent flow at higher velocity may explain observed decreases in feeding efficiencies. Behaviour, body shape, and structure of simuliid larvae are highly adapted for optimal water flow over body and fans, even when gross flow in the habitat is turbulent.
Spring roosting dynamics of red-winged blackbirds: biological and management implications
Authors: Greenwood Hamilton , Weatherhead Patrick J.
Published: August 2008

Monitoring of changes in size and composition of a spring blackbird roost near Beauharnois, Quebec, indicated that the roost became active in the middle of March and that most birds had dispersed by late April. Throughout the roosting period, red-winged blackbirds (Agelaius phoeniceus) constituted approximately 74% of the roosting population. The patterns of arrival and dispersal from the roost by the different age–sex cohorts of the red-winged blackbird reflected the intensity of sexual selection on this polygynous species. Older males were first to arrive but dispersed to establish breeding territories soon thereafter. Second-year males exhibited a less abrupt pattern of arrival and dispersal than older males while the pattern for females was even less abrupt. The implications of these patterns for management schemes aimed at reducing spring populations are discussed.
A revision of the congrogadid fish genus Halidesmus (Pisces: Perciformes), with the description of a new species from Kenya and a list of the species included in the family
Authors: Winterbottom Richard
Published: August 2008

The genus Halidesmus is unique within the Congrogadidae in the possession of three lateral lines. The three species are described, diagnosed, and illustrated, and a key to the species is provided. One of these species, from Kenya, is described as new and is distinguished from the other two species in lacking scales on the cheek and nape, in having 11 suborbital pores, and in the degree of development and form of the lateral lines and associated pores. A tentative hypothesis of relationships is proposed, based primarily on lateral-line structure, relating H. scapularis to Halidesmus polytretus n. sp. as sister species together forming the sister group of H. thomaseni.
Urine marking at food and caches in captive coyotes
Authors: Harrington Fred H.
Published: August 2008

Urine marking of food and caches was studied in a group of captive coyotes, Canis latrans. During feeding observations, coyotes frequently urine marked the food pile and individual food items that had been carried and dropped some distance from the pile. In addition, food items which had been stolen were often marked. However, marking of food did not reserve it for the marking animal. Others usually ignored the urine mark and ate the item. The significant increase in urine marking of food during the breeding season suggested that it was involved in the expression of dominance in intrasexual rivalries. Cache marking was quite different. Urine marking never occurred when food was cached and rarely occurred while the cache still contained food. However, once the cache was emptied, urine marking usually occurred. Thus at caches, urine marking evidently serves a "book-keeping" role, indicating that the caches are no longer worth investigating although food odors might still linger.
Changes in tissue and intestinal serotonin (5-HT) levels in the laboratory rat following feeding and the effect of 5-HT inhibitors on the migratory response of Hymenolepis diminuta (Cestoda)
Authors: Mettrick D. F. , Cho C. H.
Published: August 2008

Following withdrawal of food for 24 h, rats infected with ten 11-day-old Hymenolepis diminuta were given, via stomach tube, either 2 mL water, 1.2 mmol MgSO4 in 2 mL water, 1.2 × 10−3 mmol methysergide hydrogenmaleinate in 2 mL water, or 1.2 × 10−2 mmol methysergide in 2 mL water. Thirty minutes after treatment rats were again given access to food. In untreated control animals and in two further experimental groups which received either 2 mL water or 1.2 × 10−2 mmol methysergide in 2 mL water, food continued to be withheld after treatment.The amount of food ingested was determined, as well as changes in mucosal, luminal, and worm serotonin (5-HT) levels. Changes in worm biomass distribution were also monitored. The addition of the specific 5-HT antagonist methysergide resulted in over a 90% inhibition in worm migratory response; MgSO4 resulted in 67% inhibition indicating a direct relationship between intestinal 5-HT levels and the distribution and the migratory behaviour of H. diminuta within the intestinal lumen.
An addition to Krebs' restatement of the Chitty Hypothesis from an entomological perspective
Authors: Garland J. A.
Published: August 2008

The insect examples which Krebs used to illustrate the Chitty Hypothesis of self-regulation in animal population dynamics are updated. For the larch bud moth, Zeiraphera diniana, regulation still is best explained by environmental factors. With the several species of plague locusts, including Locusta migratoria, L. pardalina, and Schistocerca gregaria, locustol and two potential pheromones combine to produce an apparent perpetual state of gregarisation. On present evidence, self-regulation by means of microevolution does not appear to be involved in the action of locust chemical releasing stimuli; so that, for the moment, neither entomological test case can be said to support the Chitty Hypothesis.