bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of noradrenaline in the central nervous system of Phocanema decipiens and its possible role in the control of ecdysis
Authors: Goh S. L. , Davey K. G.
Published: March 2009

The cells of the cephalic papillary ganglia and of the lateral nerves, together with varicosities in the nerve ring which have previously been demonstrated to fluoresce after treatment with formaldehyde vapour, exhibit an emission spectrum characteristic of catecholamines. An analysis of the excitation spectrum of this fluorescence reveals peaks at 412 nm and at 320 nm. The former peak disappears after exposure of the tissues to HCl vapour and is replaced by a transient peak at 370 nm, while the 320 peak becomes more prominent. This behaviour is diagnostic of noradrenaline. The content of noradrenaline in the varicosities of the nerve ring and in the cells of the cephalic papillary ganglia as determined by quantitative fluorescence microscopy decreases after exposure to stimuli which initiate ecdysis. Application of noradrenaline to third stage larvae brings about ecdysis. Injection of noradrenaline into intact worms results in an increase in water content of the excretory cell, a phenomenon which is known to be an early event in the process of ecdysis. This increase in water content does not occur in worms which have been ligatured at the anterior end. Application of noradrenaline directly to exposed excretory cells fails to stimulate an increase in water content.
Effect of flightlessness during moult on the iron content in the pectoralis muscle of the Giant Canada Goose (Branta canadensis maxima)
Authors: Rosser B. W. C. , George J. C.
Published: March 2009

Adult male Giant Canada Geese, collected from a nonmigratory wild population during their premoult, moult, and postmoult periods were studied for changes in the pectoralis muscle. A significant (p ≤ 0.0001) drop in the lean dry weight of the pectoralis muscle during the moult period when the birds were flightless was attributed to disuse atrophy. The concentration of iron in the pectoralis muscle increased significantly (p ≤ 0.0054) during the moult, but the total amount of iron in the muscle remained constant during the three periods. It was revealed that iron was not lost during disuse atrophy, but that it became more concentrated as muscle mass decreased. The diverse results reported in the literature need to be reevaluated in light of concurrent changes in muscle under different experimental conditions and also the different fiber type composition of the muscles studied.
A morphometric study of geographic variation in the snowshoe hare (Lepus americanus)
Authors: Nagorsen David W.
Published: March 2009

Geographic variation in Lepus americanus was studied by multivariate analyses of 15 cranial measurements. A total of 1494 specimens from the entire geographic range were grouped into 37 geographic samples of males and females. Principal component analyses demonstrated that hares are largest in eastern North America, Alaska, and northwestern Canada, and smallest in the Pacific Northwest. Size clines exist in the Appalachian Mountains and western North America but size is relatively uniform throughout central Canada and the Great Lakes. A multiple regression of size with 16 climatic variables factors demonstrated that size and climate are strongly correlated; the size trends may reflect environmental selection. The differentiation of hares from the western Cordillera and Pacific coast, the similarity of populations from central Canada and the Great Lakes, and the clines in the Appalachians and western North America were evident in discriminant analyses. These patterns of variation among populations can be attributed to both gene flow and local selection. There is no evidence from the morphometric analyses for classifying populations into the 15 subspecies currently recognized.
Seasonal occurrence, recruitment, and maturation of Allocreadium lobatum Wallin, 1909 (Digenea: Allocreadiidae) in the fallfish, Semotilus corporalis Mitchell, in a New Brunswick, Canada, lake system
Authors: Rand Thomas G. , Burt Michael D. B.
Published: March 2009

The seasonal occurrence, recruitment, and maturation dynamics of Allocreadium lobatum (Digenea: Allocreadiidae) infecting the fallfish, Semotilus corporalis, from the Magaguadavic Lakes system, New Brunswick, Canada, were studied from May 1978 through July 1978 and from February 1979 through November 1980. Allocreadium lobatum has an annual cycle with both low mean intensity and low prevalence of infection occurring from July through September and increasing to high levels from November through May. Parasite recruitment, marked by the presence of a high percentage (≥ 58%) of immature and mature worms in fallfish, is greater from August through November but occurs intermittantly throughout the year. From February through July at least 60% of the parasite population is composed of gravid individuals which die after oviposition. The seasonality of parasite occurrence, recruitment, and maturation cycles is discussed in relation to temperature changes of the water, host diet, and trends in the occurrence of amphipods which are the second intermediate hosts of A. lobatum.
Effect of water depth on costs of aerial respiration and its alternatives in tadpoles of Rana pipiens
Authors: Feder Martin E. , Moran Catherine M.
Published: March 2009

Tadpoles of Rana pipiens were reared in shallow (25 cm depth) and deep (140 cm depth) hypoxic water and in shallow normoxic water. Food was available ad libitum on the bottom of the tadpole containers. Although the frequency of aerial respiration averaged 75% greater in the shallow hypoxic group than in the deep hypoxic group, the deep hypoxic group nonetheless travelled a 345% greater distance in breathing air than the shallow hypoxic group. Many tadpoles in the deep hypoxic group hung from the container's sides near the water's surface and thus were separate from food. Hypertrophy of cutaneous capillarization was evident in some (but not all) of the tadpoles in the deep hypoxic group. In the aggregate, these costs of aerial respiration or alternatives to it (e.g., swimming to the surface for aerial respiration, time spent away from food, tissue commitment to hypoxia acclimation) affected development and growth. Tadpoles in the shallow hypoxic treatment developed and metamorphosed more rapidly than tadpoles in the deep hypoxic treatment. The masses of tadpoles in the various treatment groups differed significantly in the first and last weeks of experimentation. Thus, even if food is available ad libitum, the costs associated with aerial respiration and its alternatives are significant.
Rythme nycthéméral de la synthèse protéique ovarienne chez le crustacé oniscoïde Porcellio dilatatus Brandt et rôle du protocérébron
Authors: Gohar M. , Souty-Grosset C. , Juchault P.
Published: March 2009

In Porcellio dilatatus, ovarian protein synthesis shows a diurnal rhythm with a maximum at the onset of night. Sham-operated females maintain this rhythm, which disappears after the ablation of the central part of the protocerebron. This operation also induces a decrease in the mean level of ovarian protein synthesis. Protocerebron implantation, before the removal of the brain, does not prevent the loss of that rhythm but maintains the same synthesis level as in sham-operated animals. Control of the ovarian protein synthesis rhythm by the central nervous system and the existence of a stimulating neurohormone for that synthesis are discussed.
Clam storage in a Northwestern Crow (Corvus caurinus): dispersion and sequencing
Authors: James Paul C. , Verbeek Nicolaas A. M.
Published: March 2009

An experimental study of clam storage by a Northwestern Crow (Corvus caurinus) was carried out on Mitlenatch Island, British Columbia, Canada. The crow was trained to take clams from a feeding table. His dispersion of the clams was studied using nearest-neighbour distance (NND). The distance clams were carried and the sequence of storage and recovery was also quantified. Median NND was significantly correlated with storage sequence position, as was NND with distance carried. The crow tended to recover the clams in the same order as he stored them, as storage sequence position was significantly correlated with recovery sequence position. The results were compared with other spatiotemporal studies of avian food hoarding. Recovery success of the crow was very high, he appeared to use memory to relocate his caches, as the majority of them were made in new sites, and he never revisited those already emptied.
Histology of moose (Alces alces andersoni) interdigital glands and associated green hairs
Authors: Chapman David M.
Published: March 2009

The interdigital glands of the moose (Alces alces andersoni) are distinguished from the neighboring skin by the lighter epidermis, green hairs, and huge sebaceous and sweat glands. In the glandular area is a shallow fore pocket and deep hind pocket in both sexes and all ages. Special 250 μm thick sections helped reveal the pilosebaceous–sweat gland unit in both the gland and general body surface. The secretory cycle of the apocrine cells and the cycle's relationship to the lipofuscin cycle are described. Macrophages ingest lipofuscin from moribund apocrine cells. The site of the dead apocrine cell is replaced by neighboring epithelial cells spreading out to fill the gap. The green hairs have a transmittance peak at 515 nm. The chemical nature of the coloring matter is unknown but is probably an organic compound covalently bonded to keratin. The green secretion of the sweat gland in some way dyes the hair. In both sexes the sebaceous gland volume of the gland increases at the rut.
Herring gulls prey upon female willow ptarmigan
Authors: Martin Kathy
Published: March 2009

On 12 June 1984 at La Pérouse Bay, Manitoba, Canada, 1 saw three herring gulls attack, kill, and consume an incubating adult hen willow ptarmigan and her clutch despite vigorous defence behaviour by her mate. Possible attacks by gulls or jaegers occurred also on two incubating hens in 1983.
Territorial behaviour of male Nannothemis bella (Uhler) (Anisoptera: Libellulidae)
Authors: Hilder Barbara E. , Colgan Patrick W.
Published: March 2009

Male Nannothemis bella (Uhler) dragonflies are territorial at the breeding site. On the basis of the male behavioural time budgets, the species can be regarded as a territorial percher. Those acts involved in territorial maintenance (patrolling and fighting) are more closely related to territorial dimensions than are those not concerned with the territory (feeding). Territoriality appears closely related to some aspect of the water area within a territory, as maintenance and defence behaviour vary most consistently with the size of this area. Territorial size increases as the season progresses. Defensive behaviour is directed at both conspecifics and a heterospecific, Leucorrhinia frigida. The usefulness of a marking technique for dragonflies was tested statistically.
A method of estimating diet digestibility in wild meadow voles
Authors: MacPherson Sandra L. , Servello Frederick A. , Kirkpatrick Roy L.
Published: March 2009

Regression equations for estimating diet digestibility in meadow voles (Microtus pennsylvanicus) were developed using laboratory digestion trials and chemical analyses of diets and stomach contents. These equations were used to obtain estimates of the apparent digestible dry matter (DDM) and apparent digestible energy (DE) in the diets of wild meadow voles. The estimated DDM and DE in the diets of two wild meadow vole populations varied between 62.9 and 75.2% and 62.0 and 74.2%, respectively, and were similar to those reported previously for pine voles (Microtus pinetorum).
Digestibility of ringed seals by the polar bear
Authors: Best Robin C.
Published: March 2009

The digestive efficiency of polar bears (Ursus maritimus) feeding on their principal prey, the ringed seal (Phoca hispida) is high. Apparent digestibilities of 83.7 ± 10.3% for dietary protein, 97.3 ± 2.1% for dietary fat, and an assimilation of dietary energy of 91.7 ± 5.8% were found for the five diets. Presence of hair and bone in the diet significantly reduced the apparent digestibility of protein N. Gastrointestinal transit times were affected principally by the fat (energy) content of the diet and varied between 12.3 ± 1.9 to 38.0 ± 8.0 h. The results explain the apparent preference for seal blubber by polar bears in the arctic as well as demonstrate that any seal > 1 month of age would satisfy the bear's daily energy requirements. The limiting factors in energy intake at a given feeding are the stomach capacity of the bear and the relative proportion of blubber and meat ingested.
Nutritional ecology of a fossorial herbivore: protein N and energy value of winter caches made by the northern pocket gopher, Thomomys talpoides
Authors: Stuebe Miki M. , Andersen Douglas C.
Published: March 2009

Northern pocket gophers (Thomomys talpoides) are fossorial herbivores that excavate belowground plant parts for food. In subalpine areas during autumn and winter, pocket gophers hoard plant parts in caches placed in or under snow. We examined the size and composition of 17 nival caches and tested the hypotheses that (i) cached food can provide complete energy and protein N sustenance during typical periods when burrowing is precluded by soil conditions, and (ii) cached food is a random sample of items encountered by burrowing gophers during tunnel excavation. Our data indicate that caches provide substantially more energy than protein in terms of a pocket gopher's daily maintenance requirements. Nevertheless, quantities stored are sufficient to allow individuals to endure commonly encountered adverse environmental conditions without entering negative energy or protein balance. Analysis of stomach contents and a comparison of cache composition to availability of plant species suggests that gophers consume high-protein items as they are encountered, and store low-protein items in caches.
Paramphistomum cervi and Paramphistomum liorchis (Digenea: Paramphistomatidae) in moose, Alces alces, from Ontario, Canada
Authors: Kennedy Murray J. , Lankester Murray W. , Snider J. Barry
Published: March 2009

Two species of Paramphistomum were found in moose in Ontario. Paramphistomum liorchis Fischoeder, 1901 can be distinguished from P. cervi (Zeder, 1790) by the presence of cuticular papillae, in having longer papillae lining the anterior one-quarter of the inner surface of the pharynx, and having more median external circular muscle bundles.
The vertical distribution of hydropsychid larvae and pupae (Trichoptera: Hydropsychidae) in stream substrates
Authors: Rutherford Jane E. , Mackay Rosemary J.
Published: March 2009

Vertical stratification of benthic samples at three stations on the Credit and Humber rivers revealed significant between-layer differences in the physical structure of riffles and abundances of larvae and pupal cases of Cheumatopsyche Wallengren and four species of Hydropsyche Pictet (Trichoptera: Hydropsychidae). Rock size and total rock surface area decreased from the top layer to the bottom (surface areas of pebbles excluded). Larvae of all five instars of H. sparna Ross were significantly more abundant (P < 0.05) in the top layer than in the bottom, but pupal cases were more numerous in the middle and bottom layers. Similar patterns were found for larvae and pupal cases of Hydropsyche bronta Ross, Hydropsyche slossonae Banks, and Cheumatopsyche. Pupal cases as well as larvae of Hydropsyche morosa Hagen were more numerous in the top layer. Depth and current conditions influenced sedimentation. Mean current velocities and total accumulation of fine material were greater at downstream stations. Significant variation in deposition of fine and coarse materials was found within the riffle at each station, suggesting that local streambed conditions govern sediment deposition at the microhabitat level.
Two new aquatic species of Ironus Bastian, 1865 (Nematoda: Ironidae) from Canada
Authors: Ebsary B. A.
Published: March 2009

Two new species of Ironus from freshwater river bottom samples are described and illustrated from Canada. Ironus sphincterus n. sp. is recognized by the refractive sphincter between the oviduct and uterus, and the short, elongate conoid tail. Ironus terranovus n. sp. is most similar to I. paramacramphis but differs by shorter body length, narrower head, more anterior vulva, and smaller c value.
Ultrastructure of the caudal muscle cells in the larva of a polyclinid ascidian
Authors: Cavey Michael J. , Strecker Harvey D.
Published: March 2009

Two paraxial bands of somatic striated muscle occur in the tail of the larva of the compound ascidian Aplidium ?constellatum. The mononucleate muscle cells of each band align in longitudinal rows between the epidermis and the notochord. The cross-striated myofibrils, originating and terminating at intermediate junctions on the transverse cellular boundaries, are indiscrete. They follow a spiral course through the subcortical and medullary sarcoplasm, bypassing the nucleus and the other organelles and inclusions in the center of the cell. Cisternae of the sarcoplasmic reticulum envelop the myofibrils, forming compact fenestrated sheets that are continuous between the sarcomeres and locally undifferentiated with respect to the myofibrillar striations. Cisternae of the perifibrillar sarcoplasmic reticulum near each sarcomeric Z-line establish dyadic interior couplings with a network of tubular invaginations of the sarcolemma. The sarcolemmal tubules can originate from any surface, including the transverse cellular boundaries. Near the half I-bands of the terminal sarcomeres at the intermediate junctions, the perifibrillar cisternae frequently leave the fenestrated sheets and extend to the overlying sarcolemma, becoming the sub-sarcolemmal cisternae of dyadic peripheral couplings.
Naididae (Oligochaeta) as hosts for mermithid nematodes (Enoplida: Mermithidae)
Authors: Smith Michael E.
Published: March 2009

Naidid species Chaetogaster diaphanus, Chaetogaster diastrophus, Chaetogaster limnaei limnaei, Dero digitata, Dero nivea, Nais communis, Nais simplex, Nais variabilis, Pristina leidyi, Slavina appendiculata, and Stylaria lacustris were observed as paratenic and possibly intermediate hosts for larval mermithid nematodes from field collections. Mermithids were generally found in the anterior, dorsal region of the oligochaetes. Individual naidids were at most infected with two nematodes. No seasonal prevalence patterns could be firmly established owing to the sporadic occurrence of mermithid infections in the naidids.
Growth responses of the brown bullhead (Ictalurus nebulosus) to temperature
Authors: Keast Allen
Published: March 2009

Groups of year 0 and year 2 brown bullhead (Ictalurus nebulosus) that had concluded the summer's growth, were exposed to six different temperatures between 5 and 30 °C for 8 weeks. For both size classes, ration (grams of food per fish per day) increased with temperature. Instantaneous growth (percent body weight per day) was best at 20–30 °C. In the small size class it was higher at 30 °C than at 20–25 °C. Conversion efficiency results were highest at 10–30 °C and 15–25 °C for the small and large size classes, respectively. Relative to seasonal water temperatures in Lake Opinicon, the period of greatest expected growth was June to September. Instantaneous growth (percent total length per day) was high from June to August in the field population. Times of greatest prey biomass, however, were in May and September. Despite the times of maximum temperature and growth not coinciding with that of greatest prey abundance, the field growth rates were comparable to laboratory values. This suggested that food was not limiting in Lake Opinicon and that the brown bullheads achieved their potential growth relative to length of the growth season.
Ichthyofilaria canadensis n.sp. (Nematoda: Dracunculoidea) from eelpouts (Lycodes spp.)
Authors: Appy R. G. , Anderson R. C. , Khan R. A.
Published: March 2009

Ichthyofilaria canadensis n.sp., from the eelpouts Lycodes lavalaei Vladykov and Tremblay, 1936 and Lycodes vahlii Reinhardt, 1838 from the northwest Atlantic off Newfoundland and Labrador, is distinguished from Ichthyofilaria dasycotti Yamaguti, 1935 by its smaller size, the presence of well-developed vulva and vagina, the more anterior extent of the anterior ovary and uterus, and the host and geographic distribution. The first-stage larva is microfilarioid and occurs in the blood of the host.
Parental behavior in the Least Sandpiper (Calidris minutilla)
Authors: Miller Edward H.
Published: March 2009

Breeding Least Sandpipers were studied in Nova Scotia (1975–1976), Manitoba (1978), Yukon Territory (1979), and British Columbia (1982–1984). The most detailed study was on Sable Island, Nova Scotia, which is near the southern limit of the breeding range. The nesting period there was relatively long, and the species was strictly monogamous. Males tended to incubate during daylight hours and females, at night. There was a weak (insignificant) trend for males to increase their role in incubation as it progressed. Shortly after hatching, broods moved to undefended foraging areas, where they tended to remain throughout the period of parental attendance. Chicks could fly strongly by 14 – 16 days of age but were attended by parents for longer: females attended broods for 0 – 22 days (average 6) after hatching and males for 14 – 27 (average 20). After their parents left, chicks slowly drifted away from where they had been reared. Diversionary behavior of incubating birds, and of parents attending young chicks, was similar in all study areas. "Alarm" behavior and vocalizations of parents were also very similar in all localities and included four types of calls during brooding and undisturbed attendance and two types when disturbed by humans.
The influence of benthic tundra pond vegetation and prey behavior on Zooplankton predation by the flatworm Mesostoma lingua
Authors: MacIsaac Hugh J. , Hutchinson Thomas C.
Published: March 2009

Experiments were conducted at the Smoking Hills and Tuktoyaktuk, N.W.T., to determine if Mesostoma lingua, a common pond inhabitant, preys selectively on co-occurring Zooplankton, and whether predation rates are affected by the presence of pond vegetation. Experiments were conducted in 250-mL containers at the sites. Mesostoma fed heavily on Daphnia pulex and Chironomus riparius, but not on Branchinecta paludosa or Diaptomus arcticus. The presence of alternative prey led to significant reductions in Daphnia predation rates, while the presence of the pond plants Cladophora insignis and Drepanocladus aduncus, which provide shelter and cover, significantly increased predation rates. The advantage of the moss and algal habitat was largely to the predator.
An experimental test of simultaneous settlement in the vole, Microtus townsendii
Authors: Taitt Mary J.
Published: March 2009

I attempted to induce simultaneous settlement in populations of Microtus townsendii over two spring periods. Male and female voles were removed from field populations, held, and then rereleased in two ways: sequentially (three or four pairs every 3–4 days) or simultaneously (all released at one time). There was no significant difference between the two treatments. Striking differences in demography were observed between years on unmanipulated control populations. The failure of this initial attempt to demonstrate simultaneous settlement in voles may have resulted from the technique used. Experiments are suggested to test for the forms of simultaneous settlement believed to be important in contributing to vole outbreaks.
Seasonal dynamics of body mass of insectivorous passerines breeding on the forested dune ridge, Delta Marsh, Manitoba
Authors: Biermann Gloria C. , Sealy Spencer G.
Published: March 2009

A total of 4669 body mass estimates was obtained between 1976 and 1983 from nine insectivorous passerine species that nest in a riparian habitat in southern Manitoba. The mass of individuals of the following species were obtained: eastern kingbird (Tyrannus tyrannus), least flycatcher (Empidonax minimus), house wren (Troglodytes aedon), gray catbird (Dumatella carolinensis), American robin (Turdus migratorius), veery (Catharus fuscescens), warbling vireo (Vireo gilvus), yellow warbler (Dendroica petechia), and northern oriole (Icterus galbula). The mass of most of these species varied during the summer and changes were correlated with breeding activity. Yearly differences in mass were significant for some species, but males and females of the same species did not always show the same pattern of variation from year to year. In species where the sexes could be identified, males were usually heavier than females. Yearling yellow warblers were significantly lighter than older individuals, but this trend was not found in the northern oriole.
Exploitation of prey seasonality by a planktonic predator
Authors: Riessen Howard P.
Published: March 2009

The timing of the life history of the pelagic water mite Piona constricta in Heney Lake, Québec, allows this species to exploit the seasonality of its two most important prey, Bosmina longirostris and Chydorus sphaericus. The spring emergence of P. constricta adults coincides with a large maximum of Bosmina, while the summer maximum of P. constricta nymphs largely coincides with a "bloom" of Chydorus in the plankton. The spring ice melt appears to be an important event, initiating the seasonal dynamics of the various species and indirectly linking the life history of the predatory water mite to the seasonal population maxima of its prey. The unusual success of this water mite in the plankton community of Heney Lake appears to be largely due to its ability to fully exploit predictable prey seasonality.
Low levels of genetic variability in pikas from Colorado
Authors: Tolliver Deanna K. , Smith Michael H. , Johns Paul E. , Smith Michael W.
Published: March 2009

Genetic variability at 27 loci was analyzed in four populations of pikas (Ochotona princeps) from Colorado. Estimates of mean heterozygosity [Formula: see text] ranged from 0.5 to 1.4%. These results are among the lowest estimates of [Formula: see text] reported for a mammal having a broad distribution, and are the lowest reported for a lagomorph. Data from this study and others estimate [Formula: see text] as 0.71% for pikas from Colorado. Founder effect, followed by drift occurring in small isolated populations during postglacial shifts in the range of the pika, is the most likely explanation for low estimates of genetic variability in pikas from Colorado.
Meristic and morphometric identity of Baltic stocks of Atlantic salmon (Salmo salar)
Authors: MacCrimmon Hugh R. , Claytor Ross R.
Published: March 2009

Juvenile representatives of seven river stocks of Baltic salmon, Salmo salar, in northern, north-central, central, and southern Sweden are examined to determine if meristic and morphometric characters can be used to identify regional and home river origins. Morphometric features (> 80% accuracy) provide a better means of identification of salmon stocks than do meristic features. Both methods are congruent in identifying cohesive somatic salmon stocks based on river and regional geographic origin. Examination of within-stock differences between immature and mature (precocious) parr shows meristic homogeneity but significant morphological dichotomy. These significant morphological differences, involving different character sets, do not alter the capability to discern regional and river stocks containing disparate maturation stages of parr.
Comparison of the genetic variation in Svalbard and Norwegian reindeer
Authors: Røed K. H.
Published: March 2009

Polyacrylamide gel electrophoresis was used to score for genetic variation in 35 loci in Svalbard reindeer, Rangifer tarandus platyrhynchus, and in reindeer, Rangifer tarandus tarandus, from two localities in northern Norway. In R. t. platyrhynchus the proportion of polymorphic loci was 0.114 and the average heterozygosite was 0.030. In R. t. tarandus the proportion of polymorphic loci was 0.171–0.286 and the average heterozygosity was 0.043–0.045. Excluding the variability in the locus coding for transferrin from calculations reduced the average heterozygosity to 0.020 in R. t. platyrhynchus and to 0.021–0.025 in R. t. tarandus, suggesting that the amount of genetic variation in R. t. platyrhynchus is not very different from that in R. t. tarandus. Unique alleles in the loci coding for transferrin and acid phosphatase for the two subspecies indicate that there has been no interbreeding in recent time. The genetic distance between the two subspecies is within the same range as between subspecies of other organisms. Evolutionary divergence time based on the protein data indicates that either the divergence between these subspecies was initiated a very long time ago or R. t. platyrhynchus originates from other subspecies of reindeer.
Ligictaluridus posthon n. sp. (Monogenea: Ancyrocephalidae) from Noturus flavus Rafinesque (Siluriformes: Ictaluridae) in Ontario, Canada
Authors: Klassen G. J. , Beverley-Burton M. , Dechtiar A. O.
Published: March 2009

As a result of further studies following the review of the genus Ligictaluridus by G. J. Klassen and M. Beverley-Burton, we propose Ligictaluridus posthon n. sp. for ancyrocephalid monogeneans found on Noturus flavus (Siluriformes: Ictaluridae) taken in Ontario. Ligictaluridus posthon is most similar to the type species, L. pricei (Mueller, 1936) Beverley-Burton, 1984 but is distinguished by a stouter penis, with a diameter to length ratio of ~1:6 (~1:18 in L. pricei), larger hamuli, and an apparent specificity for stonecats (Noturus flavus).
Specialization by territorial hummingbirds on experimentally enriched patches of flowers: energetic profitability and learning
Authors: Gass Clifton Lee , Sutherland Glenn D.
Published: March 2009

On unmanipulated hummingbird feeding territories, time spent foraging in patches was directly proportional to the number of flowers they contained. After we added nectar to the flowers in some patches, foraging increased in those patches, decreased in other patches, and decreased overall relative to control conditions. Specialization on enriched patches and reduction in foraging effort quantitatively reflected the energy we added, but the reduced effort had little effect on overall energy expenditure. Nevertheless, rates of net energy intake increased under enrichment, because gross intake rates increased. These experiments provide evidence that hummingbirds allocate effort among patches, using memory of relative patch quality when they initiate bouts of foraging. The strongest evidence is that individuals begin each day of foraging as if it were the previous day. On mornings after control days, birds foraged among patches as they had the day before, even though there was an (undiscovered) bonanza on their territories. On mornings after days of enrichment, however, whether or not a patch was enriched again, birds specialized on it at first. If the patch was enriched again, they continued to exploit it; if not, they reverted to normal patterns of allocation.
Pathogenesis of Trypanosoma murmanensis in marine fish of the northwestern Atlantic following experimental transmission
Authors: Khan R. A.
Published: March 2009

The susceptibility of four species of marine fish (Gadus morhua, Pseudopleuronectes americanus, Myoxocephalus scorpius, and Myoxocephalus octodecemspinosus) to leech-transmitted Trypanosoma murmanensis was assessed 49–60 days after infection by comparing condition factor, organ somatic indices, parasitological, hematological, and histological findings with corresponding uninfected animals. The fish were maintained at temperatures (0–1 °C) to simulate the environment where transmission occurs naturally. High mortality occurred in juvenile Atlantic cod and winter flounder, but deaths decreased with increasing fish size. No adult fish died except flounder when fin rot was present. Anemia was the most common pathological feature observed in young fish at necropsy, but its severity was not always correlated with the level of parasitemia. The persistent anemia was probably associated with an inactive rather than an impaired hemopoietic system. Condition factor and somatic indices of liver, spleen, and heart were altered in some infected fish groups. It is concluded that T. murmanensis is a potential pathogen, especially to juvenile American plaice, Hippoglossoides platessoides, in which high prevalences of natural infections have been observed in some areas of the northwestern Atlantic Ocean.
The effect of digestibility values of resources on the reliability of food-habit studies from fecal analyses
Authors: Caron L. , Garant Y. , Bergeron J.-M.
Published: March 2009

The digestibility of 10 plant species was computed using the amount of food ingested and egested in laboratory experiments with meadow voles (Microtus pennsylvanicus). The plant species chosen for analysis can be found in old-field habitats and have low digestibility values. Digestibility coefficients of monocots and dicots did not differ. Digestibility values varied from 19% for Agropyron repens to 68% for Leontodon autumnalis and were not related to identifiable microscopic epidermal fragments in feces. The water content of plants influenced food ingestion, since the highest ingestion rates coincided with plants having the lowest water content. Observed differences in the number of identifiable microscopic epidermal fragments in feces among species were due to other factors than the differential digestibility.
Comparative study of the eggshell of the fruit flies Dacus oleae and Ceratitis capitata (Diptera: Trypetidae)
Authors: Margaritis Lukas H.
Published: March 2009

The eggshell of two fruit flies of economic importance has been studied by means of light and electron microscopy. The eggshell of the olive fruit fly, Dacus oleae, contains compact endochorion, whereas that of the Mediterranean fruit fly, Ceratitis capitata, exhibits a holey endochorionic layer. The eggshells of both species have an innermost chorionic layer which appears to be crystalline in substructure. The anterior pole in each case contains the micropylar canal but in addition it bears an elaborate "cup" in Dacus oleae. Both species exhibit peroxidase activity in most eggshell layers and, as in the case of Drosophila melanogaster, it is thought that the enzyme causes covalent cross-linking of the eggshell proteins producing a resilin-type configuration with rubberlike properties. The above features are related to specific structural functions of the eggshell during fertilization, oviposition, and respiration of the embryo. Biochemical analysis has revealed that the two species have very few eggshell proteins that are similar in molecular weight.
The Rotifera of the Canadian Arctic sea ice, with description of a new species
Authors: Chengalath R.
Published: March 2009

The rotifers found in ice from Frobisher Bay, Northwest Territories, Canada, are documented. A new species, Encentrum graingeri, and Proales reinhardti (Ehrenberg), a species recorded for the first time in Canada, are described and illustrated. Species assemblages found in ice are similar to those of marine interstitial habitats. The adaptations of these animals to life in ice are discussed.
Body condition in terms of anatomical and biochemical assessment of body fat in North Atlantic fin and sei whales
Authors: Lockyer C. H. , McConnell L. C. , Waters T. D.
Published: March 2009

Tissues from fin (Balaenoptera physalus) and sei (Balaenoptera borealis) whales taken off the coast of Southwest Iceland in July–August in 1978 and 1981 were analysed for percent lipid, protein, and ash contents. The tail region of the whales, especially the dorsal area, constituted the main area of lipid storage in both blubber and muscle. No significant differences (p > 0.05, ANOVA) were evident between reproductive classes, except that adult females appear to store more lipid in the tail muscles than other classes. Most sei whale tissues contained more lipid than those of fin whales, but the differences may be explained by variations in seasonal feeding and fattening. Seasonal variations and differences between reproductive classes were evident from girth and blubber thickness. Juvenile males were thinnest and adult females were thickest.
On the filarioid nematodes (Splendidofilaria spp.) from the pulmonary arteries of birds
Authors: Bartlett Cheryl M. , Anderson R. C.
Published: March 2009

Splendidofilaria caperata Hibler, 1964 was found in the pulmonary arteries of 1 of 7 red-winged blackbirds (Agelaius phoeniceus (L.) (Icteridae)), 2 of 30 common grackles (Quiscalus quiscula versicolor Vieillot (Icteridae)), and 1 of 2 American robins (Turdus migratorius L. (Muscicapidae)) collected near Guelph, Ontario, Canada. All are new host records and their epizootiologic importance in Ontario is discussed. Two of the three species of filarioids described from the pulmonary arteries of birds can be readily distinguished by cuticular morphology: S. caperata has a thick, striated cuticle which often appears wrinkled and inconspicuous lateral alae, whereas S. algonquinensis (Anderson, 1955) (= S. passerina Koch and Huizinga, 1971) has only a thin striated cuticle. A third species, S. periarterialis (Caballero, 1948), requires additional study.
Daily and seasonal variation in hydric conditions and temperature inside nests of common snapping turtles (Chelydra serpentina)
Authors: Packard Gary C. , Paukstis Gary L. , Boardman Thomas J. , Gutzke William H. N.
Published: March 2009

Water potential and temperature are interrelated variables that must be studied simultaneously to gain insight concerning the water relations of reptilian eggs incubating in subterranean nests. We measured these variables inside nests of common snapping turtles (Chelydra serpentina) using thermocouple psychrometry. Water potentials in nests were high after heavy rainfalls, but declined during periods of fair weather. Likewise, temperatures in nests increased progressively during intervals of warm weather, but declined abruptly during cool periods accompanied by overcast and precipitation. On clear days, diel cycles in temperature occurred at the top, in the middle, and at the bottom of nests, but the cycles were slightly out of phase and their amplitudes decreased with increasing depth. These cycles in temperature drove cycles in evaporation–condensation of water that led in turn to complex cycles in diffusion of vapour. Net movement of vapour was into nests on some occasions, but out of them on others. Transport of liquid occurred also in the vicinity of nests, but probably was less important than transport of vapour as a means for translocating water. The eggs themselves influenced water potentials and vapour pressures in the vicinity of their nests and thereby elicited different movements of water in their immediate surroundings than occurred in the soil at large.
Effects of a carbaryl-induced depression of arthropod abundance on the behavior of Parulinae warblers
Authors: Hunter Jr. Malcolm L. , Witham Jack W.
Published: March 2009

Aerial spraying of carbaryl in Maine's spruce–fir forest reduced the abundance of canopy arthropods and affected the distribution and behavior of Parulinae warblers. For 7 days following a 1980 spraying, fewer warblers foraged in the sprayed area; they foraged lower in the canopy and in a greater variety of trees. After a 1981 spraying there was no significant change in numbers or territorial behavior. It is suggested that patchy spray coverage in 1980 created "refugia" of unsprayed forest to which many birds may have moved, whereas uniform spray coverage in 1981 prevented a similar response.
The effects of density, food, and interspecific interference on home range size in Peromyscus leucopus and Peromyscus maniculatus
Authors: Wolff Jerry O.
Published: March 2009

Home ranges of Peromyscus leucopus noveboracensis and Peromyscus maniculatus nubiterrae were compared between species, sexes, and ages at high and low densities on (i) control grids with two species present, (ii) grids supplied with additional food, and (iii) grids from which one of the species was removed. In addition, aggressive behavior of mice from high and low densities was compared. Home ranges averaged 590 m2 and did not differ between species or ages, but males had slightly larger home ranges than females. Sizes of home ranges on food-supplemented grids did not differ significantly from control grids. Thus, food does not appear to be the major factor determining minimum size of home range in these Peromyscus species. Home ranges on removal grids did not differ significantly from home ranges on control grids. Interspecific aggression for space was indistinguishable from intraspecific aggression. Sizes of home ranges were marginally negatively associated with population density. At low densities, individuals of the same sex maintained exclusive home ranges by mutual avoidance. At high densities, home ranges became somewhat constricted, but reached a minimum size of about 500 m2. At this point, home ranges did not become smaller; instead the overlap increased and increased levels of aggression and territorial defense resulted. Aggression and territorial defense were density dependent and occurred only when populations exceeded 25 to 30 mice/ha.
Daphniopsis ephemeralis sp. n. (Cladocera, Daphniidae): a new genus for North America
Authors: Schwartz Steven S. , Hebert Paul D. N.
Published: March 2009

The range of the cladoceran genus Daphniopsis is extended to North America with the description of a new species, Daphniopsis ephemeralis. Its morphological intermediacy suggests that Daphniopsis is ancestral to the genera Daphnia and Simocephalus. The genus appears to have a relict distribution and is restricted to marginal habitats.
Redescription of Liberonautes chaperi (A. Milne-Edwards, 1887) n. comb. (Brachyura, Potamonautidae) from Ivory Coast and Ghana
Authors: Cumberlidge Neil
Published: March 2009

Liberonautes chaperi (A. Milne-Edwards, 1887) n. comb. is redescribed from the holotype from Ivory Coast and from new material from Ghana. The present study introduces 12 newly discovered specimens, including 4 males, from the collection of the British Museum (Natural History), London. New evidence from comparisons of gonopod structure leads to a suggested reassignment of this species to the genus Liberonautes Bott, 1955. A key to distinguish between the species of the genus Liberonautes is provided.
Interactions of variation in food supply and kleptoparasitism levels on the reproductive success of Common Puffins (Fratercula arctica)
Authors: Rice Jake
Published: March 2009

Colonies of Common Puffins (Fratercula arctica), differing in numbers of breeding Herring Gulls (Larus argentatus) present, also differed in puffin numbers, burrow placement, and burrow activity rate. All differences indicated that puffins avoided gulls. Sites differing in gull numbers did not differ, however, in puffin fledging success or weights of fledged chicks. Chick weights and fledging success were low. The pattern of weight gain by chicks was irregular over the season, although consistent among sites for individual periods. These results imply that food usually was hard to find, although occasionally locally abundant. Pressures on puffin reproductive efforts due to variation in food supply and levels of kleptoparasitism do not appear to be additive; rather, low food availability decreases the effect of gull kleptoparasitism as well.
Calcitonin-induced body mass loss in the lizard Sauromalus obesus
Authors: Kline L. W.
Published: March 2009

Intracranial administration of 250 ng synthetic salmon calcitonin produced a significant loss of body mass in the lizard Sauromalus obesus.
Fat reserves and migration of Red-necked Phalaropes (Phalaropus lobatus) in the Quoddy region, New Brunswick, Canada
Authors: Mercier Francine M.
Published: March 2009

Arrival, length of stay, fat deposition, flight range, and migration strategy of Red-necked Phalaropes (Phalaropus lobatus) were studied during the 1981–1982 autumn migrations through the Quoddy region, New Brunswick, Canada. Arrivals at this staging ground reflected the sequence in departures from the Arctic breeding grounds reported in the literature. Females arrived first, followed by males and finally juveniles, based on overall population composition during the season and patterns of fat deposition. Fat was deposited at the rate of 1.0 g per day over a period of about 20 days and maximum fat reserves amounted to between 40 and 45% of fresh weight, yielding enough for potential flight ranges of 4300–5100 km. The probable wintering grounds for the Quoddy region population are the waters off Peru, with the most direct migration route from the Bay of Fundy being some 6000 km long. This distance considerably exceeds the calculated nonstop flight capacities of Red-necked Phalaropes, and precludes their arriving at the wintering grounds without making another feeding stop, possibly off Panama.
The effects of an Arctic winter on benthic invertebrates in the littoral zone of Char Lake, Northwest Territories
Authors: Andrews Daniel , Rigler Frank H.
Published: March 2009

A method was devised for sampling the frozen benthos in the littoral zone of Char Lake, Northwest Territories, a polar lake that was studied during the International Biological Program. Temperature probes indicated that during the winter benthic invertebrates in sediments at 0.5 and 1.75 m were exposed to temperatures as low as −18 and −8 °C, respectively. Mortality in animals that had overwintered in the frozen samples ranged from 13 to 84% (mean 46%) and was attributed mostly to sample processing. With the possible exception of chironomids, no conclusive evidence was found that benthic invertebrates avoid freezing by emigrating to deeper portions of the lake. Exposure to subzero temperatures for 8 months or more increased the synchrony in development of the population of the harpacticoid Attheyella nordenskioldii and shifted its peak reproductive period by about 4 months. These changes implied increases in the population's gross production, growth efficiency, and ecological efficiency. The exposure of shallow-dwelling benthic invertebrates to subzero temperatures is a widespread phenomenon, the effects of which on life cycles and population energetics are poorly known.
Pleiotropic effects of a regulatory gene (Pgm-1-t) on the social behavior of juvenile rainbow trout (Salmo gairdneri)
Authors: Ferguson Moira M. , Danzmann Roy G.
Published: March 2009

We compared the social behavior of juvenile rainbow trout with a regulatory allele, Pgm-1-t(b), to their full-sibs without this allele. Other studies have shown that this gene has many pleiotropic effects in the Arlee strain, the most obvious being an increase in developmental rate at about the time of hatching. The frequencies of two agonistic action patterns, charge and lateral display, and two nonagonistic measures, yawn and forage, were used to describe early social behavior. Pgm-1-t(b) was associated with significantly higher frequencies of charge and larger size in fish from the Arlee strain. However, fish from the DeSmet strain with Pgm-1-t(b) were no more aggressive or longer than their full-sibs lacking this allele. Length was the primary determinant of dominance status in both strains, regardless of Pgm-1-t genotype. In both strains, there was no significant difference between genotypes in the frequency of lateral display and forage. Our results show that genetic differences at a single locus can have pleiotropic effects on behavior with potential adaptive significance.