bluuebunny/crossref_metadata_2025 huggingface dataset:
A new parasitic species of the holarctic lamprey genus Entosphenus Gill, 1862 (Petromyzonidae) from Klamath River, in California and Oregon
Authors: Vladykov Vadim D. , Kott Edward
Published: August 2008

A new parasitic lamprey is described from 29 metamorphosed specimens in feeding stage. The holotype (No. NMC 75-1550) is deposited in the National Museum of Natural Sciences. Ottawa, Canada. It is easily separable by its functional intestinal tract and strong dentition from the three nonparasitic species: Entosphenus folletti, E. hubbsi, and E. lethophagus. From the parasitic E. tridentatus it is distinguishable by (1) fewer myomeres, (2) greater disc length, (3) smaller eye diameter, (4) differences in dentition, and (5) differences in number and morphology of velar tentacles. From another parasitic species, E. minimus, it differs by (1) larger size, (2) greater disc length, (3) smaller eye length, (4) stronger dentition, and (5) differences in velar tentacle number.
Effect of precocene II on alate production in the pea aphid, Acyrthosiphon pisum
Authors: Mackauer M. , Nair K. K. , Unnithan G. C.
Published: August 2008

After topical application of 1 μg precocene II, young apterous viviparous pea aphids produced alate offspring under conditions favouring the exclusive production of apterous offspring. It is suggested that precocene has antiallatotropic effects in the pea aphid, although it did not cause sterility of adult females. The morphogenetic effect of precocene was reversible, at least in part, by the subsequent application of juvenile hormone I. Some aspects of wing polymorphism in aphids are discussed.
Rencular morphology and renal vascular system of the harbour porpoise Phocoena phocoena (L.)
Authors: Hedges N. A. , Gaskin D. E. , Smith G. J. D.
Published: August 2008

The kidneys of 35 harbour porpoises, Phocoena phocoena (L.), from the western North Atlantic were studied. Kidneys are large (0.84% of body weight) and multirenculate (approximately 300 renculi per kidney). Renculi have well developed medullary papillae (71–80% of rencular thickness) which correlates well with an ability to produce concentrated urine. Zonation of the vascular system within the medulla is also present, another characteristic of mammals producing concentrated urine.The intrarencular vascular supply is typically mammalian and similar to other cetaceans. As a result of excellent injection techniques, we found greater complexity and variability in the vascular system in our specimens than has been previously reported.Vascular control is discussed in relation to diving bradycardia. Parasympathetic nerves may stimulate vasodilation to quickly restore rencular circulation at the end of a dive.
Functions of display flights by males of the least sandpiper, Calidris minutilla (Vieill.), on Sable Island, Nova Scotia
Authors: Miller Edward H.
Published: August 2008

Display flights (.DF's) in the least sandpiper, Calidris minutilla (Vieill.), are described and their relations to ecological anti social variables assessed. DF activity is highest in early spring and in the morning, and is low in strong winds and poor visibility (fog). DF's are given only by males and generally cease upon pairing. Unpaired males maintain exclusive DF areas from which they chase other unpaired males. Each male's DF area includes his eventual nest site, but only includes foraging and brood-rearing areas occasionally. Nesting areas are defended by males sometimes, but foraging sites and brood-rearing areas are not. The DF area of a paired male may be taken over by a later male who pairs and nests nearby, so nests may be quite close together; this suggests that the primary function of DF's in C. minutilla is not to space out nests to reduce predation. The ultimate function of DF's is probably mate attraction, and thus sexual selection has been an important force in their evolution. This may be true of scolopacids and charadriids, which nest at high latitudes, in general.
Overlap among cohabiting ciliates in their growth responses to various prey bacteria
Authors: Taylor William D.
Published: August 2008

The growth responses of 8 cohabiting species of bactivorous ciliates to 13 potential prey species (12 bacteria and 1 yeast) were examined in monoxenic cultures. Growth responses were scored simply as positive or negative. The mean number of prey species to which the ciliate species showed a positive growth response was 9.625 out of 13 or 74%. However, this proportion differed significantly among the ciliates. The observed pattern of responses did not reduce overlap among ciliates more than would be expected if the responses were independent.
Regional distribution of blood flow during diving in the duck (Anas platyrhynchos)
Authors: Jones David R. , Bryan Jr. Robert M. , West Nigel H. , Lord Raymond H. , Clark Brenda
Published: August 2008

The regional distribution of blood flow, both before and during forced diving, was studied in the duck using radioactively labelled microspheres. Cardiac output fell from 227 ± 30 to 95 ± 16 mL kg−1 min−1 after 20–72 s of submergence and to 59 ± 18 mL kg−1 min−1 after 144–250 s of submergence. Mean arterial blood pressure did not change significantly as total peripheral resistance increased by four times during prolonged diving. Before diving the highest proportion of cardiac output went to the heart (2.6 ± 0.5%, n = 9) and kidneys (2.7 ± 0.5%, n = 9), with the brain receiving less than 1%. The share of cardiac output going to the brain and heart increased spectacularly during prolonged dives to 10.5 ± 3% (n = 5) and 15.9 ± 3.8% (n = 5), respectively, while that to the kidney fell to 0.4 ± 0.26% (n = 3). Since cardiac output declined during diving, tissue blood flow (millilitres per gram per minute) to the heart was unchanged although in the case of the brain it increased 2.35 times after 20–75 s of submergence and 8.5 times after 140–250 s of submergence. Spleen blood flow, the highest of any tissue predive (5.6 ± 1.3 mL g−1 min−1, n = 4), was insignificant during diving while adrenal flow increased markedly, in one animal reaching 7.09 mL g−1 min−1. The present results amplify general conclusions from previous research on regional distribution of blood flow in diving homeotherms, showing that, although both heart and brain receive a significant increase in the proportionate share of cardiac output during diving only the brain receives a significant increase in tissue blood flow, which increases as submergence is prolonged.
DNA in rat hepatocyte nuclei: effects of treatment with low levels of carbon tetrachloride and (or) chlordane
Authors: Mahon D. C. , Nair K. K. , Oloffs P. C.
Published: August 2008

The effects of low-level, chronic feeding of the insecticide chlordane on the cytochemistry of the hepatocyte nuclei of male nits, with or without liver cirrhosis, were determined. Chlordane was given orally at 0.1 mg kg−1 day−1. Cirrhosis was induced by exposure of the animals to carbon tetrachloride (CCl4) vapours twice weekly for 10 weeks. The animals were killed after 20 weeks and the Feulgen-stained hepatocyte nuclei examined microspectrophotometrically for nuclear size, DNA content, and the degree of chromatin condensation. The five experimental groups were: (A) control; (B) chlordane only for 20 weeks; (C) cirrhosis only (CCl4 weeks 0–10); (D) chlordane (weeks 0–20) plus cirrhosis; (E) cirrhosis (CCl4, weeks 0–10) followed by chlordane (weeks 10–20). All treatments significantly (p < 0.01) increased nuclear size. Although DNA contents were not affected by chlordane alone, in cirrhotic animals treatment with chlordane caused significantly higher DNA contents than that in cirrhotics not receiving chlordane. This suggests that hepatic dysfunction increases the liver's sensitivity to respond to chlordane. Chromatin condensation was decreased by chlordane in both healthy and cirrhotic animals; animals with cirrhosis, but not receiving chlordane, had more condensed chromatin than the controls.The results of this study show that computer analysis of images of Feulgen-stained nuclei is a highly sensitive technique to detect the effects of chemicals on the degree of chromatin condensation even at dosage levels below the no-effect levels previously reported.
Tree climbing by the snail Cepaea nemoralis (L.): a possible method for regulating temperature and hydration
Authors: Jaremovic Renata , Rollo C. David
Published: August 2008

Three sheltering strategies employed by the snail Cepaea nemoralis are described: climbing objects, aestivating on the soil surface, and returning to underground refuges. The number of snails that climbed bushes was analysed by correlation regression. An equation incorporating maximum daily temperature, rainfall for the last 3 days, and the interaction of these factors explained 95% of the variation observed (P < 0.0001). Snails more than 1.8 m above the ground were significantly more dehydrated than those individuals found lower (P < 0.05). The distance climbed by snails, however, was not related to their size (P = 0.4112). The interrelationship of habitat structure, sheltering behavior, and microclimate is discussed in relation to selection of color morphs.
Fitting the von Bertalanffy growth equation to polar bear age–weight data
Authors: Kingsley Michael C. S.
Published: August 2008

Heavy sea ice in the Canadian Arctic in the winter of 1973–1974 reduced seal populations; polar bears, preying principally on seals, consequently lost weight. The nature and degree of this weight loss was investigated by examining the parameters of von Bertalanffy growth curves, fitted by direct minimization of a sum of squares using the simplex algorithm of Nelder and Mead. Growth rates were lower for both males and females tagged in 1974–1975 than for bears tagged in 1971–1973. Weights of mature bears were unaffected.
Incubation temperatures of the northern shoveler
Authors: Afton Alan D.
Published: August 2008

Egg air cell and nest air temperatures, measured in nests of wild northern shovelers near Delta, Manitoba, Canada, averaged 36.1 and 32.0 °C, respectively. Mean brood patch temperature of one captive incubating hen was 39.5 °C. Body temperature of 16 wild incubating hens averaged 41.1 °C. An egg cooling rate of 0.22 °C/1 °C h−1 was calculated from temperature records of 170 incubation recesses. Factors affecting egg cooling during recesses were investigated using multiple regression analysis. Statements in the literature that incubation by Anatidae begins upon termination of laying are not supported by available data. Incubation by waterfowl, as in passerines, apparently begins gradually during the laying period. Air and ground temperatures, by influencing egg cooling rates during incubation, may have been important ultimate factors determining the breeding range and timing of the breeding season for the northern shoveler.
Substratum heterogeneity, crypsis, and colour polymorphism in an intertidal snail (Littorina mariae)
Authors: Reimchen T. E.
Published: August 2008

On the British and Irish coasts, Littorina mariae showed extensive shell colour variation; the brown morph, dark reticulata, was common in exposed conditions, and the bright yellow morph, citrina, was common in shelter. Fucus serratus, the major substratum of L. mariae, contained a number of discreet colour backgrounds when viewed from the hunting position of Blennius pliolis, a predator on juvenile L. mariae. These backgrounds corresponded closely to the colours of the principal morphs. The opaque stem is dark brown, while the lamina, when viewed with reflected light, is olive–brown. With light transmitted through the lamina, that is. when viewed from beneath the fronds, it appears a brilliant yellow. In predation experiments with B. pholis, citrina was taken preferentially to dark reticulata on the stem and on the lamina perceived by reflected light; with transmitted light, dark reticulata was preferred.Examination of microdistributions showed juveniles prevalent on the lamina in sheltered shores but located on the stem and holdfast in exposed shores. The differences in adult morph frequencies between shores corresponded to the abundance of specific backgrounds on which juveniles were found. Stability in frequencies is discussed with reference to the heterogeneous backgrounds and density-dependent predation.
Feeding ecology of ring-billed gull (Larus delawarensis) chicks
Authors: Kirkham Ian R. , Morris Ralph D.
Published: August 2008

The feeding ecology of ring-billed gull chicks from hatching to fledging was studied on an insular colony near Presqu'ile Provincial Park, Ontario, during the summer of 1977. A principal objective was to determine changes in food type and frequency of feedings during chick development and among temporally spaced broods.Two daily peaks in chick feeding occurred with the first shortly after sunrise and the second just prior to sunset. The frequency at which chicks were fed peaked when they were 4 days old and declined steadily thereafter. Chicks younger than 5 days were fed insects and fish while chicks older than 5 days were fed mainly fish. Seasonal variation in food type fed to chicks changed from insects and fish early in the season to predominantly fish late in the season. The incidence of earthworms in feedings correlated with preceding periods of high humidity or rain.
Laboratory observations on oviposition by the predaceous tree-hole mosquito, Toxorhynchites rutilus septentrionalis (Diptera: Culicidae)
Authors: Trimble R. M.
Published: August 2008

The number and hatchability of eggs laid each day was observed for 15 consecutive days in 24 females isolated individually. During the first 5 days of oviposition, the proportion of females laying eggs varied from 0.45 to 0.82 and then decreased to an average value of 0.30. There was no relationship between female age and hatchability, and with one exception, unhatched eggs were not embryonated. For the 18 females surviving to day 15, the mean total number of eggs laid was 38.89 and the mean total number of retained mature eggs was 62.44. There was no relationship between the total numbers laid and retained.Oviposition was diurnal, with a minor peak during the 1st h of the photophase and a major peak during the hour preceding evening twilight.Females showed an oviposition preference for Aedes aegypti (L.) rearing medium over deionized water.Results are discussed in relation to the behaviour and ecology of Toxorhynchites mosquitoes.
Ixodiphagus texanus Howard (Hymenoptera: Encyrtidae) a parasite of the rabbit tick in Nova Scotia
Authors: Davis A. J. , Campbell A.
Published: August 2008

An encyrtid wasp, Ixodiphagus texanus, was found parasitizing larvae and nymphs of the rabbit tick, Haemaphysalis leporispalustris, that had engorged on snowshoe hares, Lepus americanus, in a study area in southwestern Nova Scotia. Laboratory experiments on the development of the wasp and observations on the seasonal occurrence on wild-caught hosts indicated the wasp has at least two generations per year.
Site utilization, activity budgets, and disturbance responses of Atlantic walruses during terrestrial haul-out
Authors: Salter R. E.
Published: August 2008

Terrestrial haul-out of Atlantic walruses (Odobenus rosmarus (L.)) was studied in relation to temporal, weather, and disturbance factors at a site on Bathurst Island, N.W.T., from 24 July to 23 August 1977. Counts at 6-h intervals showed that up to 129 walruses occupied the site between 25 July and 19 August, with strong fluctuations in numbers during this period. Both sexes and various age classes were represented. Numbers hauled out were weakly correlated with ambient temperature, precipitation, and possibly with wind. Walruses on land spent over 90% of their time recumbent and apparently sleeping during ten 24-h watches. There were no consistent patterns of diel variation in percentage of walruses engaged in broadly scaled activities, with the possible exceptions of suckling by young walruses and near-shore feeding by older animals. Walruses on land responded to 27% of 71 local flights by helicopters, to 35% of 31 flights by fixed-wing aircraft, and to none of 6 approaches by boats. Responses recognized were head-lifting, orientation toward the sea, and retreat into the sea; the level of response depended upon distance and altitude of disturbance approach.
'Stealing' of the symbiotic anemone, Calliactis parasitica, in intraspecific and interspecific encounters of three species of Mediterranean pagurids
Authors: Ross D. M.
Published: August 2008

The pagurids Dardanus arrosor, Paguristes oculatus, and Pagurus alatus occur together near Banyuls-sur-Mer in the Western Mediterranean with the anemone Calliactis parasitica on their shells. In intraspecific encounters, the transfer of Calliactis from one individual to another was an infrequent event, occurring in only 6% of tests between two D. arrosor and even less often in tests on P. oculatus and P. alatus. In interspecific encounters, D. arrosor stole Calliactis from P. oculatus in every test and from P. alatus in over 80% of tests. Neither of these species stole Calliactis from D. arrosor. Dardanus arrosor stole Calliactis from P. oculatus without interacting with the pagurid, but with P. alatus in a confined space it extracted the pagurid from its shell and then either transferred the anemone or took over the shell. In a less confined space P. alatus, being more agile and able to run faster, usually escaped capture by D. arrosor. The implications of the apparent dominance of D. arrosor over P. oculatus and P. alatus are discussed in relation to the distribution and the interactions of these species in their benthic habitat.
Hourly and total oxygen consumption by ova of Atlantic salmon, Salmo salar L., during embryogenesis, at two temperatures and three levels of dissolved oxygen
Authors: Hamor T. , Garside E. T.
Published: August 2008

Weighted mean hourly rates of oxygen consumption in embryonated ova of Atlantic salmon, Salmo salar L., during embryogenesis, were reduced significantly by levels of dissolved oxygen below air saturation and by a temperature of 5 °C, relative to those for ova incubated at 10 °C. Total oxygen consumption during embryogenesis also was reduced significantly by the lower levels of dissolved oxygen, but not by temperature. The decrease in the pace of embryogenesis in the lots of ova at 5 °C extended the developmental time so that the lower rate of oxygen uptake was offset. Thus, within each level of dissolved oxygen there was no appreciable difference in the products of time units and units of oxygen uptake. At 5 °C, 100% air saturation, mean hourly uptake was 0.0141 mg O2/ovum, and total uptake was 28.153 mg O2/ovum. At 10 °C, 100% air saturation, these values were 0.0270 mg O2/ovum, and 27.974 mg O2/ovum, respectively. Values for ova incubated at 50 and 30% air saturation were correspondingly lower.
Birth rate of planktonic rotifers in relation to food concentration in a shallow, eutrophic lake in western Canada
Authors: Baker Robert L.
Published: August 2008

Population dynamics and birth rates of Keratella quadrata, Keratella cochlearis, Keratella earlinae, Pompholyx sulcata, and Brachionus angularis were studied in a shallow eutrophic lake of western Canada during 1975–1976. The Keratella species were collected throughout the year with maximum population densities in spring and fall. Pompholyx sulcata and B. angularis were common only during summer months.An extensive correlation analysis involving 'lagged' variables was performed to ascertain relations between birth rates and environmental parameters (temperature and food). Birth rates of all five species were positively correlated with temperature. Concentrations of certain phytoplankton (Rhabdomonas, Rhodomonas, Chlamydomonas, and Ankistrodesmus) were positively correlated with Keratella birth rates. Birth rates of K. cochlearis and P. sulcata were positively correlated with concentration of bacteria. Correlations involving 'lagged' variables were often different from those using 'simultaneous' variables.
Effect of antimicrosporidian and antibacterial drugs on Nosema disstriae (Microsporida) infection in Malacosoma disstria (Lepidoptera: Lasiocampidae) cell cultures
Authors: Sohi S. S. , Wilson G. G.
Published: August 2008

Continuous hemocyte cultures (IPRI-MD-66) established from Malacosoma disstria (Lepidoptera: Lasiocampidae) and persistently infected with Nosema disstriae were treated separately with two antimicrosporidian drugs, fumagillin and benomyl, and an antibacterial drug, gentamicin. Treatment with fumagillin (2, 5, and 10 μg/mL) or benomyl (25 μg/mL) for 35 days permanently eliminated the microsporidium without adversely affecting the host cells. The use of benomyl for 7 days considerably reduced infection, but infection levels increased to that of the untreated controls when the drug treatment was discontinued. Gentamicin (50 and 100 μg/mL) used for 35 days had no adverse effect on Nosema or the host cell.
Fatty acid composition of Pacific walrus skin and blubber fats
Authors: West George C. , Burns John J. , Modafferi Marilyn
Published: August 2008

The fatty acid composition of skin and blubber lipids was analyzed from four apparently healthy adult Pacific walrus (Odobenus rosmarus divergens) taken in the Bering Sea and one moribund walrus from the vicinity of Barrow in the northern Chukchi Sea. All specimens had similar fatty acid complements; 13 fatty acids predominated ranging from chain lengths of 14 to 22 carbons with zero to six double bonds. There were no major differences between males and females nor between the one lactating and the nonlactating female. There were specific differences from inner blubber to outer blubber and skin and between the four healthy and one moribund animal. Double-bond indices (indicating degree of unsaturation) were relatively high in all samples, which reflects the large amount of long-chain polyunsaturated acids in the skin and blubber lipids. Inner blubber lipids were more highly unsaturated than outer blubber or skin lipids similar to the patterns observed in baleen whales. Melting points of blubber lipid ranged from 2.2 to −6.8 °C for some components; all components melted below 21.5 °C. Fatty acid composition of hind flipper tissues did not differ significantly from those in the trunk skin and blubber.
Echolocation and feeding behaviour in four species of Myotis (Chiroptera)
Authors: Fenton M. Brock , Bell Gary P.
Published: August 2008

We have compared the echolocation and feeding behaviours of Myotis lucifugus, M. californicus, M. volans, and M. auriculus based on observations and recordings of bats in the field. Myotis lucifugus and M. californicus appeared to detect prey at close range (≤ 1 m) and regularly made several attempts to capture insects over short distances; both used similar frequency-modulated echolocation calls. Myotis volans detected prey at greater distances (5–10 m), made only one attempt to capture insects per pass through a feeding area, and used an echolocation call with a distinct constant-frequency component. Myotis auriculus fed mainly on resting insects, mostly moths. The echolocation calls of this species were of shorter duration, lower intensity, broader frequency range with a higher frequency of maximum energy, and showed an initial upward sweep in frequency relative to the calls of the other Myotis we studied. Myotis auriculus did not increase their pulse repetition rate as they closed with stationary prey, and they appeared to fix on resting insects from about 2 m. This species rarely made more than one attempt to capture an insect per pass through a feeding area.
Fly catching as a deceptive behavior in solitary vireos (Vireo solitarius)
Authors: James Ross D.
Published: August 2008

A fly-catching action is used by the solitary vireo, apparently to deceive potential nest predators. The fly-catching action has been only slightly altered from true foraging behavior in that the food-gathering function is omitted in most cases. During the nestling stage of reproduction, the frequency of the original foraging behavior has also been increased to coincide with the appearance of this derived behavior.
Body temperature dynamics of the red squirrel (Tamiasciurus hudsonicus): adaptations for energy conservation
Authors: Pauls Ronald W.
Published: August 2008

Abdominal temperatures (Tb) of two captive female red squirrels (Tamiasciurus hudsonicus) in a natural outdoor environment were monitored by radiotelemetry at air temperatures (Ta) from −33 to 28 °C. Abdominal temperature ranged from 35.9 to 41.4 °C with values usually less than 39 °C when an animal was in the nest and greater than 39 °C when outside. An increase of Tb to about 39 °C usually occurred before an animal left the nest. In the nest Tb was positively correlated with Ta. Outside the nest there was a weak positive correlation at Ta less than 15 °C and a stronger negative correlation at higher Ta. During subnivean activity a rapid decline in Tb usually occurred. It is suggested that in the nest a low Tb is adaptive in that it results in energy conservation while a higher Tb is required outside the nest for rapid and coordinated motor activity.
Osmotic regulation and osmotically induced changes in the neurosecretory cells of the pulmonate snail Helisoma
Authors: Khan Hamidur R. , Saleuddin A. S. M.
Published: August 2008

Helisoma duryi and H. trivolvis are hyperosmotic regulators within a range from distilled water to 20% sea water (0.5–200 mosmol/L). Ultrastructurally three types of neurosecretory cells can be recognized in the visceral and left parietal ganglia. Type 1 and 2 cells correspond to the paraldehyde fuchsin (PAF) positive group 1 cells of visceral and medium sized parietal cells of left parietal ganglia. Type 3 cells are located in the visceral ganglion; they are PAF negative. Type 1 and 2 cells stain intensely with PAF in snails kept in distilled water but stain faintly in snails kept in isosmotic saline. Perikarya and axon endings of type 2 cells contain more granules and appear synthetically active when snails are kept in distilled water but less synthetically active when snails are kept in isosmotic saline. The response of type 1 cells is comparable with that of type 2 cells but less pronounced. The response of type 3 cells to media of different osmotic concentration is opposite to that found in type 2 cells. The possible roles of the cell types are discussed, and it is suggested that type 2 cells may be involved in diuresis.
Elaphostrongylus cervi Cameron 1931 (Nematoda: Metastrongyloidea) in caribou (Rangifer tarandus caribou) of Newfoundland
Authors: Lankester Murray W. , Northcott Tom H.
Published: August 2008

Elaphostrongylus cervi Cameron 1931 is identified for the first time in North America from woodland caribou (Rangifer tarandus caribou) in Newfoundland where up to 88% of animals were infected. First-stage nematode larvae identical to those of E. cervi occur in faeces of barren ground caribou (R. t. groenlandicus) of the Kaminuriak herd and of woodland caribou in northern Labrador, Ontario, and Manitoba, suggesting that the parasite is widespread in Rangifer in Canada.In clinically normal caribou, adult E. cervi were found beneath the skin and in fascia of the thoracic musculature. Verminous pneumonia caused by nematode eggs and larvae in the lungs and diffuse lymphocytic leptomeningitis over the brain and spinal cord were consistent aspects of infection. A 10-month-old caribou calf exhibiting neurologic signs had numerous E. cervi among thoracic and cervical muscles but none in the central nervous system. Accumulations of lymphocytes, eosinophils, and histiocytes in the subarachnoid and perineurium of lateral nerves in the posterior region of the spinal cord and destruction of axons in the cauda equina may explain the clinical signs observed.
The effects of glyphosate herbicide on food preference and consumption in black-tailed deer
Authors: Sullivan Thomas P. , Sullivan Druscilla S.
Published: August 2008

The use of herbicides is an important part of forestry management practices in the Pacific Northwest because the regeneration of coastal forests is hampered by many species of deciduous shrubs and weeds. The herbicide glyphosate is used to control these undesirable species. Some effects of glyphosate on black-tailed deer have been investigated by analyzing food preference and consumption under simulated field conditions. Deer given a choice of control or glyphosate-treated alder and alfalfa browse showed no preference or ate more of the treated foliage. The ingestion of treated browse did not affect the consumption of laboratory chow by the deer. These results indicate that spraying with the herbicide glyphosate should not prevent deer from feeding on foliage in the affected area.
The mouthparts and digestive tract in the larval stages of Homarus americanus
Authors: Hinton D. J. , Corey S.
Published: August 2008

The early planktonic larval stages have spinous-type gastric armature, simple cardiac channels, mysid-like mouthparts, functional exopodites on the thoracic appendages, and specialized midgut, suggesting that these stages are adapted for feeding on suspended food material, which is relatively soft and has a high fat content. The presettling and settling larval stages are characterized by the metamorphosis of these structures from the planktonic form to the adult form, which coincides with a change in diet from the planktonic larval stages to that of the benthic adult; the adult diet consists of relatively hard food with a possible low fat content. A similar relationship between the structure and metamorphosis of the mouthparts and the digestive sytem to a change in diet and environment in other decapod larvae is discussed.
Anatomie comparée des racines des rhizocéphales Sacculina carcini Thompson et Loxothylacus panopei (Gissler) parasites respectifs des brachyoures Carcinus maenas (L.) et Rhithropanopeus harrisii (Gould); étude ultrastructurale des racines libres
Authors: Hubert Michelle , Payen Geneviève G. , Chassard-Bouchaud Colette
Published: August 2008

A comparative examination of the free roots of Sacculina carcini, parasitizing Carcinus maenas, and Loxothylacus panopei, parasitizing Rhithropanopeus harrisii, shows numerous similar ultrastructural features as well as a few specific variations. Proceeding inwards from the outside, the following structures can be seen: (1) a thin and uncalcified exoskeleton with irregular processes fitted with vesicules forming a dense network and opening in the host's haemocoel; the whole may also display deep infoldings, these characters promote an important increase of the root surface; (2) subcuticular spaces sometimes particularly developed; (3) root cells that show a double aspect.In periphery, the electron-lucent cytoplasm with microtubules and free ribosomes, show apical villi which can penetrate the exoskeleton; mitochondria are abundant and possess a dense matrix with parallel cristae. Near the axis of the root, an electron-dense cytoplasm contains numerous rough-surfaced endoplasmic reticulum cisternae and large reserve inclusion bodies. Pictures of cytolysis are visible at the edge of cells. Middle lumen seem to appear after degeneration of some axial cells. Peculiarities of the described structures and their respective role in the absorption of substances, storage of reserves, or excretion of metabolites are discussed with regard to the host–parasite relationships.
Ecology of southeastern Arizona whiptail lizards (Cnemidophorus: Teiidae): population densities, resource partitioning, and niche overlap
Authors: Mitchell Joseph C.
Published: August 2008

Four species of whiptail lizards, two bisexual (Cnemidophorus inornatus and C. tigris) and two unisexual (C. sonorae and C. uniparens), were examined for ecological differences during the 1975 activity season in the desert–grassland of southeastern Arizona.Density estimates indicate the decreasing order of abundance was C. uniparens, C. inornatus, C. tigris, and C. sonorae. Daily activity was generally bimodal. Most active lizards were encountered away from plant cover and utilization of shade patches differed among species, Termites, coleopterans, orthopterans, and various larvae dominated whiptail diets and a wide variety of other prey types were consumed in small quantities. Monthly variations of arthropod biomass and prey diversities between years are presented and discussed.Niche breadths and two measures of niche overlap were calculated and compared for temporal, spatial, and trophic niche components for syntopic species pairs. Ecological differences between bisexual and unisexual species were determined to be minimal.Comparisons of data and niche overlaps indicate the order of importance in separating southeastern Arizona whiptail niches is macrohabitat, microhabitat, time, and food. However, due to higher than average niche overlap and noted similarities among these four species, it is concluded that southeastern Arizona whiptails form a guild of similar lizards.
Prevalence of heartworm, Sarconema eurycerca, Wehr, 1939 (Nematoda), in whistling swan, Cygnus columbianus columbianus
Authors: Seegar William S.
Published: August 2008

From 1973 to 1976, 795 whistling swans, Cygnus columbianus columbianus, were surveyed for microfilariae of the heartworm, Sarconema eurycerca, by blood test. Swans were captured on their east coast wintering grounds in Maryland and North Carolina, and on their breeding grounds on the North Slope, Alaska. Prevalence of heartworm in winter was 18, 9, 27, and 19% in 1973, 1974, 1975, and 1976, respectively. Prevalence was 32% in adults on the breeding grounds, 1974. Overall prevalence during 4 years was 20%; prevalence was 19% in adults and 24% in juveniles. Microfilariae were not found in cygnets 4 to 6 weeks of age on the breeding grounds.
Cuckoldry in sunfishes (Lepomis: Centrarchidae)
Authors: Gross Mart R.
Published: August 2008

Male sunfishes build nests and provide care for eggs spawned therein. It is shown here that small non-nesting male pumpkinseed (Lepomis gibbosus) and bluegill (L. macrochirus) will intrude during conspecific spawnings, to fertilize eggs. Such behaviour cuckolds the males which care for the brood.
Ampharetidae (Polychaeta) from British Columbia and Washington
Authors: Banse Karl
Published: August 2008

Morphological and distributional observations on 11 of the 19 ampharetid species and subspecies recorded from British Columbia and Washington are presented. Hobsonia new genus and Sosanopsis hesslei new species are described, and remarks made on the generic diagnosis of Sosanopsis. Amage anops is studied from type material. Ampharete labrops, A. goesi brazhnikovi, Hobsonia florida, and Samytha californiensis are newly recorded for the Oregon biogeographic Province. Ampharete gagarae is shown to be restricted to deep water of the northeast Pacific and adjacent seas.
Cytotaxonomic studies on some cyclopoid copepods (Copepoda, Crustacea) from Ontario, Canada
Authors: Chinnappa C. C. , Victor Reginald
Published: August 2008

The cytology of 10 Ontario species of cyclopoid copepods has been investigated. The chromosome number and meiotic chromosome behaviours are described for the females of Acanthocyclops vernalis (2n = 8), Acanthocyclops vernalis ssp. Parcus? (2n = 6), Tropocyclops prasinus mexicanus (2n = 11), Eucyclops setrulatus (2n = 13), Eucyclops speratus (2n = 13), Mesocyclops leuckarti (2n = 12), Mesocyclops edax (2n = 14), Macrocyclops albidus (2n = 14), Macrocyclops ater (2n = 22), and Diacyclops bicuspidatus thomasi (2n = 18). Cytotaxonomic implications in relation to the evolution in this group are discussed.
Plasma concentrations of prolactin during egg laying and incubation in the ruffed grouse (Bonasa umbellus)
Authors: Etches R. J. , Garbutt A. , Middleton A. L.
Published: August 2008

The plasma concentration of prolactin was measured following experimental photostimulation, during oviposition and during incubation in plasma from ruffed grouse by heterologous double-antibody radioimmunoassay. A slight increase in plasma prolactin was noted after photo-stimulation and a much larger increase was observed as subsequent eggs were laid. When the last egg was laid, plasma prolactin was maximal. This high concentration was maintained throughout incubation and declined to basal values when incubation was terminated by removal of the eggs. In hens that failed to incubate, plasma prolactin declined after the last oviposition.Brood patch development began before the first egg was laid but was not completed until incubation was initiated. Therefore, the patch began to develop when plasma concentrations of prolactin were slightly elevated but it was not fully formed until high concentrations of prolactin were maintained for several days.
The effect of temperature on tail beat frequency of fish swimming at constant velocity
Authors: Stevens E. Don
Published: August 2008

Rainbow trout and largemouth bass were swum at fixed swim speeds from one to three body lengths per second at ambient water temperatures from 5 to 35 °C. Tail beat frequency was measured during steady swimming. Both tail beat frequency and stride length (distance moved per tail beat) increased with increased swim speed. In trout tail beat frequency was lower at higher water temperatures, whereas in bass tail beat frequency was higher at higher water temperatures. In both trout and bass tail beat frequency was lower in fish acclimated to a higher temperature. I suggest that when test temperature is above acclimation temperature the muscle operates high on the force–velocity curve; and when test temperature is below acclimation temperature the muscle operates low on the force–velocity curve.
Les marques de croissance des os et des écailles comme indicateur de l'âge chez Testudo hermanni et Testudo graeca (Reptilia, Chelonia, Testudinidae)
Authors: Castanet Jacques , Cheylan Marc
Published: August 2008

This work shows the value of osseous growth marks for age determination in two terrestrial chelonia, Testudo hermanni and Testudo graeca. Careful histological observation of long bones proves that concentric rings show a yearly growth pattern; we have already described similar findings in amphibians, snakes, and lizards.We confirm these data first by the observation of some wild turtles of known age and of a close correlation between the number of bone rings and the number of rings on the cornified scutes. We also confirm in both species that scutes have a yearly growth rhythm and we conclude that bone growth marks provide a good criterion for age determination. Resorption destroys some juvenile rings; we propose a calculation to evaluate the number of resorbed lines to obtain the true individual age.In our turtles, scute growth rings allowed age determination until sexual maturity. With osseous growth marks, we were able to extend accurate ageing until the 20th year. We also established that sexual maturity occurs when animals are 12 or 13 years old in both species, with little difference between males and females.
Some ultrastructural characteristics of mandibular cuticle in an elaterid larva (Coleoptera)
Authors: Zacharuk R. Y.
Published: August 2008

The cuticular walls of the mandibles of larvae of Ctenicera destructor (Brown) have a layer of nonlamellate procuticle with a preferred orientation of cuticular microfibrils and pore canals. This type of cuticle is characteristic of many pterygote adult cuticles but has not been noted in larval cuticles of other cephalic appendages or body sclerites and membranes. This nonlamellate layer is sandwiched between two layers of lamellate procuticle over most but not all of the mandibular base. There is no outer lamellate layer of procuticle in the walls of the mandibular teeth, but the layer of protein epicuticle is exceptionally thick here, comprising about two-thirds of the total wall thickness. These characteristics of the mandibular cuticle are discussed with respect to wall strength, tooth wear, function of mandibular mechanosensilla, and development.
Embryonic development of Romanomermis communensis (Nematoda:Mermithidae) at different temperatures
Authors: Thornton D. P. , Brust R. A.
Published: August 2008

Embryos of R. communensis completed their development to the late coil stage in 16.5 days at 20 °C, 22 days at 15 °C, and 32 days at 10 °C. Embryos failed to develop at 5 °C, although 10% did reach the two-cell stage by 32 days. About 5% of the eggs at 20 and 15 °C hatched after embryonation was completed. There was no further hatching during the 32-day period of observation. The nematode is probably univoltine in its natural habitat near Churchill, Manitoba.
Development of swim bladder nematodes (Cystidicola spp.) in their intermediate hosts
Authors: Smith J. D. , Lankester M. W.
Published: August 2008

It has been confirmed experimentally that Cystidicola farionis develops to the infective third-stage in amphipods. The third stage was reached more quickly in Gammarus fasciatus (5 weeks) than in Hyalella azteca (6 weeks) at 12–14 °C and required 7 weeks to develop in Pontoporeia affinis at 5–7 °C. Third-stage larvae were 437 μm long immediately after the second moult and grew up to 4.9 mm long. Cystidicola cristivomeri developed to the third stage in Mysis relicta but not in amphipods. Third-stage larvae were about 720 μm long after the second moult and grew up to 5.7 mm long. Third-stage larvae of C. cristivomeri up to 10.8 mm long were found in 0.8% of M. relicta from a lake where lake trout were infected with the parasite. Third-stage larvae of C. farionis and C. cristivomeri grew considerably in the intermediate hosts and the gonads became well developed. Similar development has been reported in other cystidicolids but suggestions that larvae moult to the fourth stage in the intermediate host cannot be accepted.
Stimulation of mitosis in Dugesia tigrina by a neurosecretory fraction
Authors: Friedel Thomas , Webb Rodney A.
Published: August 2008

A neurosecretory fraction, isolated from regenerating Dugesia tigrina, significantly stimulates the number of cells entering mitosis in the blastema of posterior worm pieces. When this fraction was applied to regenerating worms in the presence of colchicine, a doubling of the mitotic index was observed.
Siphonaptera from mammals in Alaska. Supplement I
Authors: Haas Glenn E. , Rumfelt Tim , Johnson Loyal , Wilson Nixon
Published: August 2008

This is the first supplement to Haas et al. Can. J. Zool. 56: 333–338, 1978. Nineteen species of fleas were collected from 10 species of wild mammals and man. Delotelis hollandi Smit and Ceratophyllus niger C. Fox. first collected in 1950 and 1937, respectively, were rediscovered. The ranges of four species were extended 500–975 km.
Methods of estimating total lipid content in the redhead duck (Aythya americana) and an evaluation of condition indices
Authors: Bailey Robert O.
Published: August 2008

Methods of estimating total lipid content in the redhead duck (Aythya americana) without performing time-consuming ether extractions are presented. The relationship between various condition indices and total lipid content was investigated. Weights of the whole skin and the abdominal fat depot were easily obtained, good predictors of total body lipids. Total length was the best predictor of fat-free carcass weight.
Resting and diel respiration rates for the burrowing wolf spider Geolycosa domifex (Hancock)
Authors: McQueen Donald J. , Jensen Ingrid M. , Dyer Brandon S.
Published: August 2008

Respiration rates were measured for the burrowing wolf spider Geolycosa domifex (Hancock) during 1977 and 1978. Most experiments were run for at least 24 h and respiration rates (micro-litres CO2 per hour) and activity were monitored continuously. Experiments were conducted at 14.5, 18, and 22 °C, and it was found that respiration (R) was related to both weight (W) (R = aWb) and temperature. A brief model relating respiration, weight, and temperature was compared with independently collected data (1978) fur animals exposed to 20 °C. The expected and observed mean respiration rates were not different (α = 0.05) but the slopes (b) were different (α = 0.05}. The diel respiration patterns suggested that there was a significant amount of variation between animals, but that the highest respiration patterns always occurred during the dark. The respiration rates recorded for G. domifex were lower than those found for other species. This was due to the fact that activity monitoring allowed resting respiration data to be collected exactly when the spider was resting. The data also showed that active respiration rates were several times higher than resting rates, and that active rates will be very important to the development of a complete respiration model.
The reproductive cycles of the sunflower beetle, Zygogramma exclamationis (Coleoptera: Chrysomelidae), in Manitoba
Authors: Gerber G. H. , Neill G. B. , Westdal P. H.
Published: August 2008

Field and laboratory studies showed that Zygogramma exclamationis (F.) has only one generation per year in Manitoba. New generation adults emerge in August, but do not copulate or develop any eggs before entering the soil to hibernate. They reemerge the following May. Vitellogenesis is initiated either before or shortly after emergence. The first mature oocytes appear 2–4 days after emergence. Oviposition is initiated soon after the first eggs are developed, usually within 1 week of emergence. Copulation is initiated by both males and females within 2 days of emergence and both mate many times during their life. Females lay almost every day during the oviposition period. In the laboratory in 1974, the average number of eggs per female was 1968 (range, 260–3587). In experiments out-of-doors in 1976 and 1977, the females laid 968 (range, 657–1400) and 636 (range, 132–1554) eggs per female, respectively. In these three studies, the average length of the oviposition period ranged between 42.5 days in 1977 and 60.7 days in 1974. In the field in 1975–1977, eggs were found from mid-May to mid-July and the total length of the oviposition period was estimated to be 6–7 weeks. The females normally die a few days after oviposition is completed. A system for classifying the stages of oocyte development is described.
Influence of orally administered L-thyroxine or 3,5,3′-triiodo-L-thyronine on growth, food consumption, and food conversion of underyearling coho salmon (Oncorhynchus kisutch)
Authors: Higgs David A. , Fagerlund U. H. M. , McBride J. R. , Eales J. G.
Published: August 2008

Between August and November, groups of underyearling coho salmon, held at 10 °C and on a natural photoperiod, were fed twice daily to satiation with Oregon moist pellets supplemented with 0, 20, 100. or 500 ppm of L-thyroxine (T4) or 3,5,3′-triiodo-L-thyronine (T3).The T3 significantly increased weight (20 and 100 ppm) and length (all doses), depressed condition factor (100 and 500 ppm), stimulated food consumption (20 ppm), improved food conversion (all doses), decreased thyroid follicle epithelial height (500 ppm), and influenced pituitary basophil and somatotrop number, size, and granulation.The T4 influenced neither growth nor food conversion, but did increase food consumption (20 ppm) and condition factor (500 ppm). and decreased thyroid follicle epithelial height (500 ppm).No breakdown of either added T4 or T3 was observed during prolonged food storage.It is concluded that T3 unlike T4, can be administered in the diet of coho held at 10 °C to enhance growth and improve food conversion.
Seasonal changes in serum thyroid hormone levels in ruffed grouse maintained under natural conditions of temperature and photoperiod
Authors: Garbutt A. , Leatherland J. F. , Middleton A. L. A.
Published: August 2008

Serum triiodothyronine (T3) and thyroxine (T4) concentrations were measured in a population of ruffed grouse, held outdoors under natural conditions of photoperiod and temperature. Blood samples were collected at monthly intervals, and at the solstices and equinoxes to test for variation through the light period. No changes in T4 or T3 levels were found during the light period but levels of T3 and T4 showed marked seasonal changes. Lowest T4 and T3 levels were found in birds during the winter months, with an increase in the concentration of both hormones in early spring concomitant with gonadal development in the adults. A lowering of serum T4 and T3 values was associated with the period of molt.