bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of forced renesting and hand-rearing on growth of young captive American Kestrels
Authors: Bird David M. , Laguë Paul C.
Published: August 2008

During 1974 to 1977, 78 pairs of captive American Kestrels (Falco sparverius) were forced to renest and the hatchlings from the artificially incubated first clutches were hand-reared to fledging age. Sexual size dimorphism, i.e., heavier females, became evident at some undetermined point between the 6th and 12th day of growth. Overall, hand-reared kestrels exhibited significantly slower growth rates and smaller body weights on the 24th day than did parent-raised birds. They did tend to "catch up" to the parent-raised ones, as there were no significant differences later with respect to juvenile and adult weights. Antebrachium and manus length, tarsus length and diameter, and skull width were significantly smaller in hand-reared kestrels.
The developmental cycle of Caryospora bubonis Cawthorn and Stockdale 1981 (Protozoa: Eimeriidae) in the great horned owl, Bubo Virginianus (Gmelin)
Authors: Cawthorn Richard J. , Stockdale P. H. G.
Published: August 2008

The purpose of the study was to describe some parameters of oocyst production in direct and indirect transmission studies, endogenous development, and attempts at cross transmission of Caryospora bubonis (Protozoa: Eimeriidae) of great horned owls, Bubo virginianus (Gmelin). Three great horned owls were given sporulated oocysts of C. bubonis orally. Three more great horned owls were each fed two mice which had been given sporulated oocysts of C. bubonis orally, 4 weeks previously. Feces were examined daily by flotation and daily oocyst production was estimated. One great horned owl was given sporulated oocysts of C. bubonis and killed 12 days after infection when oocysts were first detected in feces. Tissues were examined histologically. Two long-eared owls (Asio otus (Pontoppidan)) and one short-eared owl (Asio flammeus (L.)) and domestic chicks (Gallus domesticus L.) were given sporulated oocysts of C. bubonis orally and their feces examined as above. Mice were given varying doses of sporulated oocysts of C. bubonis orally and killed sequentially after infection. Tissues of mice and chickens were examined histologically.The prepatent period was 12 days, the patent period was 4–11 days long and maximal oocyst production occurred from 12 to 17 days after direct infection of great horned owls with C. bubonis. The prepatent period was shortened by 48 h in owls indirectly infected with C. bubonis in mice. Endogenous development occurred in the posterior third of the small intestine. Caryospora bubonis was not transmitted to other species of birds.
The behaviour of Rhodnius prolixus (Stål) during the imaginal ecdysis
Authors: Ampleford E. J. , Steel C. G. H.
Published: August 2008

The behaviours during the imaginal ecdysis in Rhodnius prolixus (Stål) have been distinguished into three phases. The first phase is characterized by cessation of locomotion coupled with activity of localized regions such as the head or legs (rubbing and wiping). During the second (preecdysial) phase, behaviours such as rubbing and wiping continue with the addition of bursts of locomotor activity and head bobbing. In the third (ecdysial) phase, physical emergence from the exuviae occurs. The three phases differ in their degree of stereotyping. All behaviours which commence after the onset of air swallowing (late preecdysis) are stereotyped both in performance and in the sequence in which they occur. Prior to air swallowing the individual behaviours are stereotyped in performance but not in sequence. Argument is presented that the second and third phases are each initiated by a separate "decision." The first "decision" probably results from sensory information gained during the performance of the first phase and determines competence to proceed with the preecdysial phase. The second "decision" irreversibly commits Rhodnius to the ecdysial attempt and is made during the preecdysial phase prior to the onset of air swallowing. The second "decision" may evoke the stereotyped behavioural sequence observed throughout the ecdysial phase.
Redescription of Paracuaria adunca (Creplin, 1846) (Nematoda: Acuarioidea) from Larus delawarensis Ord (Laridae)
Authors: Wong P. L. , Anderson R. C.
Published: August 2008

Paracuaria adunca (Creplin, 1846) Anderson and Wong, 1981 from the oesophagus of Ring-billed Gulls (Larus delawarensis Ord) of Lake Ontario, Canada, is redescribed. The following synonyms are recognized: Paracuaria tridentata (Linstow, 1877); P. macdonaldi Rao, 1951; Rusguniella transcaucasica Solonitsin, 1932; Streptocara rissae Kreis, 1958. Paracuaria adunca, now generitype of the genus, is apparently a widely distributed species in fish-eating birds. Paracuaria formosensis (Sugimoto, 1930) is transferred back to the genus Streptocara. The status of P. soricis Jancev, 1972 of shrews is doubtful; it is not likely a member of Paracuaria. Paracuaria adunca is the only recognized member of Paracuaria.
Report of the metacestode of Paradilepis simoni Rausch, 1949 (Cyclophyllidea: Dilepidae) from fish in British Columbia
Authors: Ching Hilda Lei
Published: August 2008

Larval stages of tapeworms were found encysted in the livers of the following fish: 77% of 87 Oncorhynchus nerka (Walbaum), kokanee; 22% of 111 Salmo gairdneri (Richardson), rainbow trout; 13% of 113 Ptychocheilus oregonensis (Richardson), northern squawfish; 3% of 98 Prosopium williamsoni (Girard), mountain whitefish; and 2% of 85 Cottus asper (Richardson), prickly sculpin. The metacestodes were identified to be that of Paradilepis simoni from the number, size, and shape of the rostellar hooks.
Responses of the salamander inner ear to vibrations of the middle ear
Authors: Ross R. J. , Smith J. J. B.
Published: August 2008

Microphonic and action potentials were recorded from the inner ear and eighth cranial nerve respectively of Notophthalmus viridescens, supine in air, while the exposed operculum of the middle ear was vibrated. Microphonic potentials were double the frequency of the vibrating source and were produced for a range of vibrations from 30 to at least 700 Hz. Sensitivity functions were irregular. Action potentials were obtained for a range of vibrations from between 30 and 60 Hz up to 550 Hz depending on the recording site. Populations of neurons were found that were narrowly tuned to a range of frequencies and that had peak sensitivities representing almost the entire range of frequencies to which responses were obtained (50–400 Hz). The most sensitive preparation required only 0.003 μm (peak to peak) with a peak sensitivity at 400 Hz to obtain a response. Vibration energy applied to a part of the middle ear can activate inner ear sense organs and at least part of this information can reach the central nervous system.
Reproduction et force des classes d'âge du Grand Brochet (Esox lucius L.) dans le Haut-Richelieu et la baie Missisquoi
Authors: Fortin Réjean , Dumont Pierre , Fournier Henri , Cadieux Claude , Villeneuve Diane
Published: August 2008

Captures of northern pike on the spawning grounds and measures of egg deposition showed that from 1975 to 1978 spawning occurred in April, after the onset of spring high waters and the warming of the water above 5–6 °C. Maximal egg deposition occurs on abandoned meadows, pastures, and shrub–grass areas, in water 60 cm or less. In the Bleury Stream area, these substrates lie mostly between elevations 30 and 30,5 m. Water temperature influences the length of the spawning and incubation periods. Spawning, egg incubation, and growth of the young to a mean length of 20 mm require approximately 40 days. From 1970 to 1977, two strong year classes (1973 and 1976) were produced; they were both followed by a weak year class. Air temperatures in June, summer water levels (June–September), and also the strength of the preceding year class, had a determining effect on year class strength.
Axotomy increases excitability in crayfish fast flexor motoneuron somata
Authors: Wiens Theodore J. , Atwood Harold L.
Published: August 2008

Somata of crayfish fast flexor motoneurons whose axons had been cut several days previously were found to display much greater electrical excitability than intact contralateral controls. This increased excitability was evidenced by the consistent appearance in intracellular (soma) recordings of overshooting action potentials during antidromic stimulation, in contrast to the decremented passive antidromic potentials usually seen in control cells. The excitability increase was apparently shared by all fast flexor motoneurons whose axons pass out through the severed (main third) root (arising from three major clusters of somata in two ganglia); it also occurred when only one of the first two major branches of the root was cut. These findings corroborate and extend similar results from crayfish and other arthropods, and may find application in the study of central motoneuron circuitry.
Effect of Blarina brevicauda on trap response of Microtus pennsylvanicus
Authors: Boonstra Rudy , Rodd F. Helen , Carleton David J.
Published: August 2008

The response of Microtus pennsylvanicus to traps with or without various prior occupants is described. Microtus were most frequently captured in traps previously visited by Microtus, but they showed a significant avoidance of traps previously visited by Blarina brevicauda. However, the probability of entry into such traps was no lower than into traps previously visited by other rodent species (Mus musculus, Peromyscus leucopus, or Zapus hudsonicus). There was an even lower probability of entry into traps which were previously empty. Blarina had a significantly higher probability of entering traps previously capturing Blarina than traps previously capturing Microtus or no one. We conclude that this evidence gives no support for the hypothesis that Blarina is a significant predator of Microtus pennsylvanicus.
Some remarks on the occurrence and development of philometrid nematodes infecting the white sucker, Catostomus commersoni Lacépède (Pisces: Catostomidae), in Ontario
Authors: Molnar K. , Chan G. L. , Fernando C. H.
Published: August 2008

During a study on the parasitofauna of white sucker (Catostomus commersoni) in Laurel Creek, Ontario, three philometrid nematodes were found. Gravid and subgravid females completing the life cycle occurred very infrequently (Philometroides huronensis: 4.3%, Philometroides nodulosa: 1.6%, Philometra kobuleji: 1.1%). In comparison, males and retarded females infected the eyeball and the peritoneum around the swim bladder very often (43.1 and 31.6% in total, respectively). Less frequently, developmental stages were found in the abdominal cavity. Specimens found in the eyeball were identified as belonging to P. nodulosa, while the swim bladder forms could belong to P. huronensis or to P. kobuleji. The eyeball and the peritoneum around the swim bladder are regarded as refuges for retarded forms, where they can survive for more than a year. No evidence was found of a direct cause of retardation.
Host and geographic records of ectoparasites from Alaskan seabirds (Charadriiformes: Alcidae and Laridae)
Authors: Hoberg Eric P. , Wehle D. H. S.
Published: August 2008

Host and geographic records are presented for ectoparasites collected from seabirds in Alaska. Ectoparasites of three major groups were recovered: Mallophaga, represented by the genera Saemundssonia (S. fraterculae, S. montereyi, and Saemundssonia sp.) and Quadraceps (Q. antigua, and Quadraceps sp.); Siphonaptera, represented by a single specimen of Ceratophyllus v. vagabundus; and Acari, represented by the genus Ixodes (I. uriae and I. signatus). These ectoparasites along with specimens of unidentified free-living oribatid mites were found infesting species of Alcidae and Laridae (Charadriiformes) at localities in the Gulf of Alaska and the Bering and Chukchi seas.
Range extensions for some ectoparasites from rodents of southeastern Quebec
Authors: Gyorkos Theresa W. , Hilton Donald F. J.
Published: August 2008

As part of the qualitative component of an ectoparasite survey of wild rodents in southeastern Quebec, range extensions are documented for 4 species of Anoplura and 11 species of Acari. These supplement existing records of ectoparasites of mammals from Canada.
Two new species of Hirschmanniella Luc and Goodey, 1963 (Nematoda: Pratylenchidae) with a key to the nominal species
Authors: Ebsary B. A. , Anderson R. V.
Published: August 2008

Hirschmanniella anchoryzae n. sp. from Canada and Hirschmanniella areolata n. sp. from Hong Kong are described and illustrated. The former is characterized by a flattened head, stylet length of 16–17 μm, an elongate–conoid tail with 60–88 annules, ending in an axial mucro, and location of the phasmids 37–57 μm from the tail terminus. Hirschmanniella areolata n. sp. has a hemispherical head, stylet length of 24–27 μm, complete areolation of the lateral field, a tail with 48–61 annules, ending in a ventral mucro, and phasmids 22–29 μm from the tail terminus. Spicule lengths from both species range from 28 to 31 μm. A key is presented to 24 nominal species of the genus.
The effect of acid stress on survivorship and reproduction of Daphnia pulex (Crustacea: Cladocera)
Authors: Walton W. E. , Compton S. M. , Allan J. D. , Daniels R. E.
Published: August 2008

Laboratory simulation of acid stress to a common cladoceran, Daphnia pulex, was conducted in pond water of varying acidity due to addition of H2SO4. An acute test using exposure times of 1 to 96 h and pH levels of 3.7 and 6.5 revealed virtually no effect at 4.3 and higher, while 4.2 and lower severely reduced survivorship. Very short (3-h) exposures caused nearly complete mortality at pH 3.7, while > 12 h exposure caused high mortality at pH of 4.0–4.2. A chronic 21-d life table test indicated a gradually increasing impairment of population growth rate potential (r) at pH 5.0 and below. This was due primarily to reduced survivorship and delayed onset of reproductive maturity. Those individuals which survived at lower pH levels produced broods equivalent to unstressed daphnids. While the tolerance of D. pulex to low pH does not appear to have been reported from field surveys, our results are in close agreement with the observed effects of increasing acidity on the distribution of other zooplankton species.
The relationship between fertility and fat reserves of Peary caribou
Authors: Thomas Donald C.
Published: August 2008

There was a close association between pregnancy rates and levels of fat reserves and body weights in Peary caribou (Rangifer tarandus pearyi) collected in the late winters of 1974 through 1977 on several islands in the Canadian Arctic. Pregnancy rates were <8% in adult (>2 years) females weighing <53 kg in March and April, >75% in those weighing >57 kg, and 100% in those >67 kg in weight. Pregnancy rates increased progressively from 7 to 100% as the percentage marrow fat increased from 43 to 79% and the kidney-fat index increased from 24 to 41%. Only heavy (>46 kg) yearling (21 month) females with high fat reserves were pregnant. Reproduction virtually ceased from 1973–1974 to 1975–1976 in Peary caribou on the western Queen Elizabeth Islands because their physical condition was poor. Pregnancy rates were as high as 100% in females in a second population located on Somerset and Prince of Wales islands, and in 1974–1975 four of five yearling females were pregnant. The adjustment of fertility to energy reserves is viewed as an adaptation to conserve energy. It is well developed in Peary caribou whose environment is characterized by a highly variable and often harsh climate in which negative energy balances probably prevail for 8 to 10 months of the year.
Experimental studies on acarine predator–prey interactions: the effects of predator density on prey consumption, predator searching efficiency, and the functional response to prey density (Acarina: Phytoseiidae)
Authors: Eveleigh Eldon S. , Chant D. A.
Published: August 2008

Experiments on the responses of two species of predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, to their own density revealed that, with the exception of adult female P. persimilis, the individual predation rates of all instars of both species increased as predator and prey densities were increased within certain fixed predator to prey ratios. "Interference" between adult female P. persimilis was suggested as a possible reason for this result, and this was confirmed by the application of Hassell and Varley's model to data from an experiment where predator density was increased within various prey densities. Interference did not influence the predation rates for other instars of either species and other factors are considered to account for the results obtained.Increasing predator density caused the functional response of all instars of both species to increase over an increasingly wider range of prey densities. However, due to interference between adult female P. persimilis the functional response curves increased curvilinearly and reached plateaux at progressively lower levels of prey killed per predator as predator density increased. With the other instars of both species the responses became less curvilinear with increasing predator density, and trends in the data suggested that plateaux would be reached at similar levels of prey killed for different predator densities provided sufficient prey are present.
Experimental studies on acarine predator–prey interactions: the response of predators to prey distribution in an homogeneous area (Acarina: Phytoseiidae)
Authors: Eveleigh Eldon S. , Chant D. A.
Published: August 2008

A laboratory study was conducted to determine the effects of prey distribution in an homogeneous area on the searching success and functional response of two species of phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans. The results indicated that the spatial distribution of the prey affected the searching success and functional response of P. persimilis but not of A. degenerans. More prey were killed by the former predator when prey were clustered, followed by random and uniform distributions. In contrast to A. degenerans, the degree of prey aggregation at a given prey density also affected the number of prey killed by P. persimilis. With both predators, prey depletion affected the comparative success of the predators at certain prey distributions. It is concluded that P. persimilis is adapted to search for prey which aggregate, whereas A. degenerans is not. The results are discussed in terms of their potential importance in predation and biological control studies.
Siphonaptera from mammals in Alaska. Supplement III. Western Alaska
Authors: Haas Glenn E. , Wilson Nixon , Zarnke Randall L. , Barrett Richard E. , Rumfelt Tim
Published: August 2008

Nineteen taxa of mammal fleas were recorded from 93 collections from western Alaska. Oropsylla alaskensis (Baker) and O. arctomys (Baker) are additions to this series of reports. The other 17 taxa were recorded from 71 new localities; 46 records were from remote localities. Many range extensions resulted and noteworthy were Ctenocephalides f. felis (Bouché) north to Fairbanks, Corrodopsylla c. curvata (Rothschild) west to the Bering Sea coast, Megabothris abantis (Rothschild) northwest to the lower Yukon River Valley, and Chaetopsylla tuberculaticeps (Bezzi) north of the Arctic Circle. Six hosts were not in our previous records: masked shrew, woodchuck, meadow vole, collared lemming, black bear, and wolverine. In all, 14 species of wild mammals, domestic dog and cat, and man were recorded hosts. Records from bat roosts were included.
Diet and feeding of Neomysis mercedis Holmes (Crustacea, Mysidacea) from the Fraser River Estuary, British Columbia
Authors: Johnston N. T. , Lasenby D. C.
Published: August 2008

Neomysis mercedis in the Fraser River estuary is a predator on the meiobenthos, especially harpacticoid copepods. There are no clear seasonal differences in its utilization of food resources. The consumption rate of N. mercedis feeding from natural sediments varies with body size and temperature as C = 3.81 W0.782T0.515, where C is the consumption rate of meiofauna in micrograms dry weight per animal per hour, W is the mysid size in milligrams dry weight, and T is the temperature in degrees Celsius. The weight dependence of the ingestion rate is identical to that of the metabolic rate but the temperature dependence is significantly lower. The mysid selectively feeds on the organic fraction of the sediments but only one-half of the ingested material (by weight) is of biological origin. In mid-April, mysid predation may result in a 12% per day mortality rate on harpacticoid copepods. Thus, mysid predation may strongly influence meiofaunal densities.
Octopamine-sensitive adenylate cyclase in haemocytes of the forest tent caterpillar, Malacosoma disstria Hubner (Lepidoptera: Lasiocampidae)
Authors: Gole J. W. D. , Downer R. G. H. , Sohi S. S.
Published: August 2008

Injection of octopamine into the haemocoel of third instar larvae and pupae of the forest tent caterpillar, Malacosoma disstria, results in a rapid elevation of haemolymph cyclic AMP levels. The elevated cyclic AMP levels are due, at least in part, to the action of octopamine on haemocytes, as evidenced by the octopamine-induced stimulation of adenylate cyclase in an established haemocyte cell line (Md 66). The effect is simulated by the adrenergic agonist, synephrine, and inhibited by the α-adrenergic blocking agent, phentolamine. The insect haemocyte receptor–enzyme system resembles equivalent vertebrate systems in being activated by sodium fluoride and requiring GTP for expression of effector-induced activation of the enzyme.
Ploidy and genetic diversity in Ontario salamanders of the Ambystoma jeffersonianum complex revealed through an electrophoretic examination of larvae
Authors: Bogart James P.
Published: August 2008

Salamander larvae from 13 breeding ponds were subjected to chromosomal and electrophoretic analyses. Both triploid and diploid members of the Ambystoma jeffersonianum complex were polymorphic for a malate dehydrogenase locus (MDH-3) and a lactate dehydrogenase locus (LDH-2). Sympatric A. maculatum larvae were electrophoretically distinctive from A. jeffersonianum complex larvae at both loci. Two genetically distinctive triploid clones were fixed heterozygotes. Most diploid larvae were homozygous, but a few diploid heterozygotes were found for both polymorphic loci. All the offspring of a sperm-carrying single triploid female which produced eggs in the laboratory were genetically identical to each other and to the mother but the tadpoles from some naturally occurring egg masses from one pond contained both diploid and triploid individuals. Tadpoles from two different egg masses contained representatives of both triploid genetic clones. Two different triploid genotypes were found to occur in a pond in Parry Sound District. This provides evidence for a northern extention of the known range for Ontario triploids. The genetic information derived from A. jeffersonianum complex triploids suggests that there exists genetic interaction among certain members of this complex.
Correct scientific names for the least brook lamprey and the American brook lamprey (Petromyzontidae)
Authors: Vladykov Vadim D. , Kott Edward
Published: August 2008

Among students of lamprey taxonomy, there has been agreement on the common names for the least brook lamprey and American brook lamprey, two nonparasitic species of eastern North America. However, there still is a disagreement as to their scientific names. On the basis of a critical study of original descriptions and drawings of American authors of the last century, we reached the conclusion that the length of the urogenital papilla in spawning males is a very important taxonomic character. Therefore, we propose that the name for the least brook lamprey, which has a long urogenital papilla, is Lampetra lamottenii (Lesueur); and for the American brook lamprey, with a short papilla, is Lethenteron wilderi (Gage).
Electrophoretic analysis of Euplotes crassus stocks from populations differing in their breeding systems
Authors: Dini Fernando , Giorgi Franco
Published: August 2008

Stocks of sympatric autogamous (A+) and nonautogamous (A−) populations of the ciliate Euplotes crassus have been analysed using sodium dodecyl sulfate – polyacrylamide gel electrophoresis. These stocks differ markedly in the protein contents of their particulate cell fractions. The results agree with breeding tests and studies on the physiological tolerance to various stresses in suggesting some degree of genetic differentiation between A+ and A− stocks. A plausible hypothesis is that they constitute separate "subspecies" within the same morphological species E. crassus.
The susceptibility of the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae), to Heterorhabditis heliothidis (Nematoda: Heterorhabditidae) in the laboratory
Authors: Finney Jean R. , Lim K. P. , Bennett Gordon F.
Published: August 2008

Exposure of 4th, 5th, and 6th instar Choristoneura fumiferana to Heterorhabditis heliothidis (120 nemas per larva) resulted in 100% mortality within 48 h at 24 ± 1 °C. At 17 °C, 100% mortality was achieved within 120 h. Reduction of the dose to 15 nemas per 5th–6th instar larva caused 70% mortality at 24 ± 1 °C and 15% mortality at 17 °C within 120 h. At the higher temperature, mortalities of 80 and 73% were recorded for pupae exposed to 150 and 60 nemas per pupa, respectively. When 6th instar larvae on foliage of balsam fir or blue spruce were treated with the nematode suspension (120 nemas per larva) 100% mortality was obtained within 72 h at 24 ± 1 °C. The potential of using this nematode in biological control of spruce budworm is discussed.
A new species of Haploops (Amphipoda, Ampeliscidae) from the Bay of Fundy
Authors: Wildish D. J. , Dickinson J. J.
Published: August 2008

Haploops fundiensis n. sp. is described and figured in immature and mature life-history stages, inclusive of the pelagic male, from samples taken at 80 m in the Bay of Fundy. Taxonomic affinities and distinguishing characteristics of H. fundiensis n. sp. are discussed and a key is provided for distinguishing the presently known species of Haploops from the northwestern Atlantic and Arctic regions.
Allozyme analysis of the hybrid Phoxinus eos × Phoxinus neogaeus (Pisces: Cyprinidae) in Nebraska
Authors: Joswiak Gerard R. , Stasiak Richard H. , Moore William S.
Published: August 2008

Twenty-three fish from two localities in Nebraska were electrophoresed for three marker loci that distinguish Phoxinus eos and P. neogaeus. Seven had patterns of pure P. eos and 16 were heterozygous at all three markers. Of these, two were morphologically similar to P. eos, while the rest more closely resembled neogaeus. All hybrids were female. Two hypotheses are suggested: (1) The F1 hybrids fall into two morphological groups, dependent on the species of the maternal progenitor and (2) the hybrids are a parthenogenetic species. No introgression was detected in this study and the question of hybrid reproduction remains unresolved.
Effects of pulsatile perfusion on flow distribution within an isolated saline-perfused trout head preparation
Authors: Daxboeck Charles , Davie Peter S.
Published: August 2008

Increasing the input pulse pressure to the gills of an isolated, saline-perfused trout head preparation significantly increased the anterior venous–venolymphatic flow returning to the heart. This increased flow could have been brought about by the mechanical interaction between afferent–efferent vessel pulse pressures being transmitted to the low pressure venolymphatic system. Alternatively, these pressure pulses may have increased lymphatic drainage from the gill tissues. Changes in perfusate oxygen tension across these gills were consistent with data from other saline-perfused preparations, but were not comparable to in vivo data from Salmo gairdneri. The measured values for gill resistance and general head circulation resistance to flow were similar to other saline-perfused preparations, but again were not comparable to in vivo data. The possible roles of increased venolymphatic flow to gill function were discussed.
Polymorphism for plate morphs in Gasterosteus aculeatus on the east coast of Canada and an hypothesis for their global distribution
Authors: Hagen D. W. , Moodie G. E. E.
Published: August 2008

In the threespine stickleback (Gasterosteus aculeatus) three plate morphs, controlled by major genes, are easily distinguished: the low-plated, partially plated, and completely plated morphs. We give the results of a geographic survey for these morphs, with 177 samples from New Brunswick, Prince Edward Island, and adjacent regions. The low-plated morph is virtually absent. Most sites are either monomorphic for the completely plated morph or polymorphic with high frequencies of that morph. Polymorphic sites are most frequent in fresh water where the frequency of partials is much higher. Polymorphic sites are also more than twice as frequent on Prince Edward Island than on the mainland. But sites with high frequencies of the partial morph, with one exception, occur only on the mainland. Populations with high frequencies of partials predominate in lakes and their tributaries near the sea. Hybridization between the low-plated leiurus and completely plated trachurus cannot account for most of the polymorphism in North America. The global distribution of plate morphs shows an association with climate, and the virtual absence of the low-plated morph in this survey can be accounted for by the action of climatic selection or an associated variable.
Incidence and intensity of Cyathocephalus truncatus and Schistocephalus solidus infection in Gasterosteus aculeatus
Authors: Reimchen T. E.
Published: August 2008

Cyathocephalus truncatus, a cestode usually found in salmonids, and plerocercoids of Schistocephalus solidus are reported from a population of Gasterosteus aculeatus on the Queen Charlotte Islands, British Columbia. Adult C. truncatus attached at the anterior of the intestine adjacent to the pyloric sphincter, whereas in salmonids the pyloric caeca is the usual attachment site. Mean intensities of infection for C. truncatus and S. solidus were 2.7 (maximum 26) and 3.4 (maximum 87), respectively, with intensities increasing in larger fish. The highest incidence of C. truncatus infection was from February to May (80%) and for S. solidus, from April to September (50%). Infection rates for C. truncatus during different seasons and among different length classes offish were directly correlated with the relative abundance of amphipods (the intermediate hosts of C. truncatus) in the fish stomachs. Possible modification of host feeding behaviour is indicated by a relative increase in the consumption of amphipods by infected fish.
The effect of temperature on facilitated oxygen diffusion and its relation to warm tuna muscle
Authors: Stevens E. Don
Published: August 2008

A system is described that permits a measure of the rate of diffusion of oxygen through a solution supported in a Millipore filter. The rate of diffusion of oxygen through distilled water in the membrane was the same at 25 °C as at 35 °C. The rate of diffusion of oxygen through a hemoglobin solution was considerably enhanced by the 10 °C increase in temperature.
The haemoglobins and respiratory enzymes in the ventral papillae of Notocotylus triserialis Diesing 1839 (Digenea: Notocotylidae)
Authors: MacKinnon Barbara M.
Published: August 2008

Ventral papillae of Notocotylus triserialis contain pyriform cells filled with mitochondria. To investigate the possible respiratory function of the papillae, N. triserialis was examined histochemically for numerous respiratory enzymes. α-Glycerophosphate, succinate, glutamate, lactate, and glucose-6-phosphate dehydrogenases and cytochrome oxidase were identified within the pyriform cells of the ventral papillae and lateral margins of the worm.Living N. triserialis are red, particularly the ventral papillae and lateral margins of the worms. Using spectroscopy, this pigment was identified as a true oxyhaemoglobin, with the α and β peaks at 570–580 and 530–540 nm, respectively, corresponding closely with those of its experimentally infected chicken host haemoglobin. Polyacrylamide gel electrophoresis showed three, possibly four, haemoglobins in N. triserialis, distinct from the two chicken haemoglobins. During in vitro experiments the bright red colour of the worms turned to a dull grey–blue when worms were deprived of oxygen and the red colour returned upon addition of oxygen to the culture medium. This suggested that the haemoglobins of N. triserialis had the ability to deoxygenate and reoxygenate in vitro.
Résistance thermique supérieure de Gammarus fasciatus, Say (Crustacea, Amphipoda) et son utilisation en situation de rejets thermiques
Authors: Thibault Y. , Couture R.
Published: August 2008

The upper thermal resistance limit (dose–time analysis of mortality at high temperatures) has been determined in the amphipod G. fasciatus on a time scale of up to 5 days. LTm's (median tolerance limit: 50% survival time) show a 1.12 mean multiplication factor for each degree of acclimation between 5 and 25 °C and a mean reduction factor of 2.06 for each degree of exposure between 25 and 38 °C. Toxicity curves relating LTm, acclimation, and exposure temperatures serve to establish short-term survival diagrams that can be used in various situations of thermal shock. Priority should be given to the ΔT (interval between exposure and acclimation temperatures) or its duration. Thus, a 10 °C ΔT seems to be tolerated during an indefinite period of time when the water temperature is 15 °C or less. Predicted survival times are only 2 days and 2 h, respectively, when temperatures reach 20 and 25 °C. The methods used in this study helped to establish some short-term protection criteria for this species. These methods are also applicable to the study of other species or groups of aquatic organisms.[Journal translation]
Distribution of the species of the genus Oxyloma (Mollusca, Succineidae) in southern Canada and the adjacent portions of the United States
Authors: Harris Stuart A. , Hubricht Leslie
Published: August 2008

Extensive collecting and dissecting of live material shows that eight species of Oxyloma occur in southern and western Canada. Oxyloma haydeni is the common species across the Prairies from northern Ontario to southern Alberta. Oxyloma kanabensis occurs west of Edmonton, east of the Continental Divide and north of Sundre, while O. nuttalliana occurs west of the Continental Divide in southern British Columbia. Oxyloma groenlandica is found in the Yukon Territory and in the intermontane valleys in interior British Columbia. Oxyloma hawkinsi occurs sparsely, centred in the Okanagan area, but also persists as a probable remnant of the Hypsithermal interval at Exshaw, Alberta. Oxyloma retusa and O. gouldi are confined to the southern portions of Ontario and Quebec.A new species, Oxyloma missoula, occurs in and adjacent to the areas occupied by the former Pluvial Lake Bonneville and Glacial Lake Missoula. All the species could have survived from before the last Wisconsinan ice advance since their distributions straddle the boundary of the glaciated area.
Demography of the longtail vole Microtus longicaudus in seral stages of coastal coniferous forest, southeast Alaska
Authors: Horne Beatrice Van
Published: August 2008

Microtus longicaudus is atypical of its genus as it most often occupies a shrubby rather than grassy habitat where it exists at low densities. Populations were monitored by biweekly livetrapping in three logged habitats and in an old-growth area during three reproductive seasons in order to investigate the relationship between habitat and demography. The most consistently high population densities were observed on a 7 to 10-year-old clear-cut. Densities were positively correlated with log and shrub cover within and between grids and with herb cover at a between-grid scale only. Habitat selectivity was higher at low densities. Densities declined on all grids during the 3rd year of the study; this resulted from poor overwinter survival on three grids and poor recruitment on one grid. Adult males survived poorly in relation to adult females during the breeding season and over winter. Consistently low overwinter survival and low growth rates of adults and juveniles on the 23 to 26-year-old clear-cut were associated with low nitrogen content of shrub species; dicot leaves constituted 30% of the adult diet. Fruit and seeds comprised 67% of the juvenile diet, and their phenology may be an important determinant of reproductive patterns.
Fish embryo culture: observations on axial cord differentiation in presomitic isolates of the zebrafish Brachydanio rerio (Hamilton-Buchanan)
Authors: Laale Hans W.
Published: August 2008

Eighteen pre- and post-rhombencephalic axial isolates from zebrafish, Brachydanio rerio, presomitic embryos divested of epidermis and yolk were maintained in a nutrient medium for 14 days at 24 ± 2 °C. The paper focuses on the differentiation of the notochord and metamerism of axial somites in culture. The technique is proposed as a possible means for studying parameters pertaining to meristic variation in developing fish embryos.
Species differentiation of the glochidia of Anodonta cataracta Say, 1817 and Anodonta implicata Say, 1829 (Mollusca: Unionidae) by scanning electron microscopy
Authors: Rand Thomas G. , Wiles Michael
Published: August 2008

Morphology of shell valves, shell valve terminal plates, marginal and plate protuberances, sensory tufts, and valvular pores was studied for usefulness in congeneric differentiation of glochidia of Anodonta cataracta Say, 1817 and A. implicata Say, 1829 from two lakes in Nova Scotia. Investigation was with a Cambridge S150 scanning electron microscope operated at 10 kV. Shell valve and terminal plate structures and spatial and size frequency distributions of plate protuberances allow discrimination of these two species of Anodonta. The tubercle-like protuberances probably aid attachment to fish hosts, sensory tufts aid in detection of host and environmental stimuli, and valvular pores may function in nutrition and respiration of glochidia. Possible function of valvular pores was inferred from the observation that they penetrate mantle and valves completely.
Body composition of Svalbard reindeer
Authors: Reimers Eigil , Ringberg Tata , Sørumgård Rolf
Published: August 2008

Tissue and (or) chemical body composition was determined in 18 Svalbard reindeer, aged [Formula: see text] months prepartum to [Formula: see text] years, and in mainland Norway reindeer, aged [Formula: see text] months prepartum to [Formula: see text] years. At the end of the growing season, the fat content in the ingesta-free body was very high (27–40%) in Svalbard reindeer. Two mainland yearling males had 4.5% body fat as compared with 27.8% in a Svalbard male yearling. At the end of winter the weight decrease of Svalbard reindeer was close to 50%. The loss of ash, protein, water, and fat from the body was estimated at 16.8, 30.9, 34.3, and 76.3%, respectively. Animals that had starved to death showed an additional weight loss of 8% and a nearly complete loss of fat. Liver content of Fe increased from 97 mg/kg in late summer to 3463 mg/kg in late winter and 5075 mg/kg in animals that had starved to death. There were significant linear relationships between the percent water and percent fat in the ingesta-free body and between the weight of the fat-free and ingesta-free body and the weight of its components, namely water, protein, and ash.
Survival and delayed breeding in male blue grouse
Authors: Lewis Richard A. , Zwickels Fred C.
Published: August 2008

We present an analysis of survival of male blue grouse (Dendragapus obscurus) using known-aged individuals and examine the results in terms of the evolution of delayed breeding. Males had low rates of mortality and, among 2-year-olds, mortality rates of territorial and nonterritorial birds were the same. Up to 6 years of age, males had life expectancies of at least 2 years. Males that postponed breeding and survived had a 40–45% chance of eventually obtaining a high-quality site for a territory. If males had not delayed breeding they likely would have had to settle on areas where opportunities for breeding appear to be low. Thus, survival patterns of males are consistent with the hypothesis that it is advantageous for some males to delay breeding if high-quality sites cannot be obtained.
How dominance status of adult Japanese quail influences the viability and dominance status of their offspring
Authors: Boag David A.
Published: August 2008

Japanese quail (Coturnix coturnix) acquire an ability to dominate conspecifics of the same sex through inheritance and through experience during interactions with siblings of the same sex. The extent to which the former can mask the latter was investigated in both males and females of this species. The results suggest that when differences in dominance status of the parental stock are marked (winning >85% of interactions versus winning <25%) the ability to dominate, acquired through inheritance, overrides virtually all ability acquired through experience in the brood. All encounters among males were decisively won by young birds from dominant stock, whereas among females the results, although similar, were not as clear-cut. The production of young by the two parental stocks was compared; those of low dominance status produced both greater numbers of young as well as a significantly higher proportion surviving to adulthood.
Gregarine and microsporidan protozoa in Aedes polynesiensis, Tokelau Islands. Recent accidental importations?
Authors: Laird Marshall
Published: August 2008

The microsporidan, Vavraia culicis (Weiser), was unrecorded from the Tokelau Islands (tropical Polynesia) until 1974, and gregarines (Ascogregarina sp.) have not previously been reported from these isolated atolls. Both now occur in larval Aedes (Stegomyia) polynesiensis Marks on the village islet of Nukunono. Conspicuous melanization of many of the spores and cysts of V. culicis and other data collected over a 27-year period support the speculation that these widespread protozoan parasites may have invaded the local population of A. polynesiensis (apparently pathogen-free until the mid-1960s except for the deliberately introduced Coelomomyces stegomyiae Keilin) following the recent accidental importation and establishment of Aedes (S.) aegypti (L.).
Changes in terrestrial animal activity of a forest community after an application of aminocarb (Matacil®)
Authors: Bracher G. A. , Bider J. R.
Published: August 2008

The effects of aminocarb on the activity of an animal community were investigated using two sets of sand transects, 25 km apart. Changes in the ratios of animal activity between the treatment and control transects, prespray and postspray, were used to identify impacts. Right after the aerial spray, lepidopteran and arachnid activity significantly decreased; avian activity along the forest floor increased. Chilopoda activity may have increased in response to less competition or predation from arachnids. An increase in food availability could have resulted in an increase in Diplopoda activity. The activity of Mollusca and Annelida decreased during the 2 months after the insecticide application. Bufo americanus and Thamnophis s. sirtalis activity could have been adversely affected by reduced prey availability. The change in bird behaviour appears to have initiated a significant increase in Mustela erminea activity. Reductions in Blarina brevicauda and Clethrionomys gapperi activity may have been related to the increased Mustela erminea activity.
Revision of the gammaridean amphipod family Ampithoidae using numerical analytical methods
Authors: Conlan K. E.
Published: August 2008

A revision of the tube-building amphipod family Ampithoidae on a world-wide basis, using numerical analytical methods, recognizes 13 genera of which 2 are newly described. Cluster analysis and principal components ordination reveal that the form of the first gnathopod is of basic significance in differentiation of genera within the family Ampithoidae. Phyletic relationships are examined and related to evolutionary sequences in morphology, behaviour, and zoogeography.
Changes in plasma insulin and carbohydrate metabolism of zinc-stressed rainbow trout, Salmo gairdneri
Authors: Wagner G. F. , McKeown B. A.
Published: August 2008

An experiment was conducted to determine if the hyperglycemia that is observed in zinc-stressed fish is also accompanied by changes in the levels of plasma insulin and liver glycogen. Juvenile rainbow trout were exposed to three concentrations of zinc sulphate along with a control group over 31 days. Plasma glucose levels were monitored in each group over the course of the experiment. The group demonstrating the most acute and sustained hyperglycemia (0.352 ppm zinc) was then analyzed along with the controls for changes in plasma insulin (using a teleost insulin radioimmunoassay) and liver glycogen levels. Significant depressions in plasma insulin and liver glycogen levels were observed in the zinc-exposed fish when compared with the controls. These changes are discussed with respect to possible influences of epinephrine, which is elevated in stressed fish, and (or) a direct effect of zinc metal on the pancreatic beta cells.
Entamoeba histolytica: the dynamics of penetrating a meniscus
Authors: Smith J. M. , Meerovitch E.
Published: August 2008

Using a closed-circuit television system, Entamoeba histolytica strain IP-106 was observed to penetrate through a meniscus separating a medium–nitrogen gas interface. Both the forces exerted on the amoeba by the surface tension of the liquid medium and the resultant forces applied by the amoeba, at various stages during penetration, were calculated. During penetration the force applied increased to a maximum of 3.3 × 10−6 N. However it was found that the shape of the amoeba allowed it to penetrate with a constant pressure. Intercellular movement due to active pseudopodial motion may play an important role in the process of penetration.
Thirteen-fold change in population size of Peromyscus leucopus
Authors: Sexton Owen J. , Douglass John F. , Bloye Robert R. , Pesce Andrea
Published: August 2008

A live-trapping study of a population of white-footed mice Peromyscus leucopus was carried out during the midsummers of 1976, 1977, 1979, and 1981. The trapping grid (60 × 120 m) was located in a lakeside forest in the northern portion of the lower peninsula of Michigan, U.S.A. Extremes in estimated population size were 11 individuals in 1979 and 139 in 1981.
A morphological comparison of muskrats (Ondatra zibethicus) from Newfoundland and New Brunswick
Authors: Rigby Michael D. , Threlfall William
Published: August 2008

Adult muskrats (Ondatra zibethicus) from Newfoundland (N = 44) and New Brunswick (N = 21) were measured and data obtained were analyzed using multivariate techniques. On the basis of skull measurements it was possible to accurately predict (P < 0.01) the site of origin of individual animals. Size differences were related to the availability of preferred foodstuffs. Ondatra zibethicus obscurus is considered a valid taxon for the Newfoundland muskrat.
Seasonality of Diplostomum spathaceum (Trematoda: Strigeidae) transmission to brook trout (Salvelinus fontinalis) in northern Quebec, Canada
Authors: Brassard Paul , Curtis Mark A. , Rau Manfred E.
Published: August 2008

The availability of cercariae of Diplostomum spathaceum, calculated as the product of the rate of cercarial release, the expected cercarial life span, and the prevalence of infection in snail host Lymnaea arctica, was determined between June and September at a pond near Schefferville in the Québec subarctic. Cercariae were present from late June until mid-September but were most abundant in July and August with a peak in early August. Cercarial availability coincided with the pattern of acquisition of metacercariae by sentinel fish (Salvelinus fontinalis).