bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic origin of 3,4-dihydroxyphenylacetic acid in Tenebrio molitor and differences in its content in larval, pupal, and adult cuticle
Authors: Barrett F. M.
Published: December 2009

Pupal exuviae from Tenebrio molitor differ from larval exuviae and adult cuticle in that they lack 3,4-dihydroxyphenylacetic acid (3,4-DPA), a phenolic compound thought to be characteristic of coleopteran cuticle. This difference is not due to an absence of all cuticular o-dihydricphenols since all three cuticles yield comparable amounts of ketocatechol. The significance of this previously unreported stage difference is discussed in the light of the various functions proposed for 3,4-DPA in insect cuticle. Tyrosine is shown to be the primary precursor of 3,4-DPA in adult cuticle. Dopamine and N-acetyldopamine appear to make only a minor contribution to its formation.
Remote sensing of drained ice areas around the breathing holes of ice-inhabiting seals
Authors: Digby Susan A.
Published: December 2009

Drainage of surface meltwater into the breathing holes of seals creates characteristic patterns on undeformed, landfast first-year ice in the Arctic during the melt season. The drained ice areas in the vicinity of Mould Bay, Northwest Territories, have been observed on aerial photography, as well as on imagery from the LANDSAT satellite multispectral scanner, side-looking airborne radar (SLAR), and airborne synthetic aperture radar (SAR). Imagery for the Prince of Wales Strait suggests that the drained areas are also visible on imagery from a space-borne radar. The accuracy of remotely sensed data for detecting seal holes has yet to be determined. Further studies and quantification may lead to use of remotely detected drained ice areas around seal holes as an indicator of the winter resident population of the ringed seal, Phoca hispida.
Larval growth in three sympatric Ambystoma salamander species: species differences and the effects of temperature
Authors: Keen W. Hubert , Travis Joseph , Juilianna John
Published: December 2009

Differences in the larval growth of three Ambystoma salamander species that breed in close proximity to each other in space and time in north Florida were investigated under standardized regimes of controlled food levels and temperature. The order of species growth rates was as follows: Ambystoma tigrinum > A. talpoideum > A. opacum. This order is exactly the reverse of the order in which the species breed. Growth of A. talpoideum larvae was strongly dependent on temperature, whereas A. opacum larval growth was only weakly affected by temperature. Based on these growth rate differences, it is unlikely that A. talpoideum larvae could survive to metamorphosis without special behavioral mechanisms for predator avoidance in habitats with the rapidly growing predatory A. tigrinum larvae. Furthermore, A. opacum larvae would be favored in their growth over those of A. talpoideum at low temperature, while the reverse would be true at higher temperature.
Differences in skeletal characters between the disjunct eastern and western populations of ring-billed gulls (Larus delawarensis)
Authors: Termaat Beatrice M. , Ryder John P.
Published: December 2009

Univariate analyses of variance, multivariate analyses of variance (Manova), and discriminant function analyses were performed on measurements of 51 skeletal characters of adult males and females from the disjunct eastern and western populations of the ring-billed gull (Larus delawarensis) in Canada. The analyses established sufficient differences in skeletal characters to permit correct identification of the origin of 34 of 38 males (90%) and 40 of 42 females (95%). The populations are now expanding in range to the extent where new colonies are established in the Lake of the Woods, Ontario region, the historical hiatus between the two populations. Further expansion and contact may well erase the existing skeletal differences of individuals in these populations.
Gyrodactylus fryi n. sp. (Monogenea) from Esox masquinongy Mitchill in Ontario
Authors: Cone D. K. , Dechtiar A. O.
Published: December 2009

Gyrodactylus fryi n. sp. (Monogenea) is described from the body surface of Esox masquinongy Mitchill in Ontario. Gyrodactxlus fryi resembles most closely G. lingulatus Rogers, 1968 from the cyprinid Hypentelium etowanum (Jordan) in Alabama in having well-developed hamuli, a compact ventral bar with no anterolateral processes, a tongue-shaped ventral bar membrane, and a penis with small spines in two arched rows. Gyrodactylus fryi is easily distinguished from G. lingulatus by marginal hook size (11 to 14 μm long. 7 to 8 μm wide proximally, 14 to 16 μm wide distally) and shape (relatively small base with a long thin blade). Gyrodactylus fryi resembles at least nine other Gyrodactylus species known from cyprinid and catostomid fishes. The study concludes that a close ecological association between a piscivorous ancestral E. masquinongy and cyprinid and (or) catostomid fishes led eventually to evolutionary radiation of a gyrodactylid lineage from prey to predator.
Cephalids in the taxonomy of Scutellonema Andrássy, 1958 and the description of Scutellonema cephalidum n. sp. (Nematoda: Hoplolaimidae)
Authors: Anderson R. V. , Handoo Zafar A. , Townshend J. L.
Published: December 2009

Scutellonema cephalidum n. sp., a parasite of the rubber plant, Ficus elastica 'Decora,' is described and illustrated. Its primary distinguishing characters are the irregular size and shape of four to nine segments of the basal head annule, parthenogenetic females which lack a spermatheca, and distinctiveness of the cephalids, hemizonid, and hemizonion in permanent glycerine and temporary 4% Formalin totomounts. The absence of cephalids in S. brachyurum (Steiner, 1938) Andrássy, 1958, demonstrated experimentally, proved a reliable character for separating these closely related species. The importance of cephalids in the taxonomy of Scutellonema is discussed.
Ultrastructural studies on mitosis in Trypanosoma danilewskyi (Mastigophora: Zoomastigophorea)
Authors: Paterson W. Brockley , Woo Patrick T. K.
Published: December 2009

Mitosis of Trypanosoma danilewskyi was studied using transmission electron microscopy. The basal body replicates prior to the kinetoplast. Nuclear division is coincident with the first part of cytokinesis. The kinetoplast DNA appears to disaggregate and then recondense as two strands. In the early phase of mitosis the chromatin and nucleolar material also disaggregate, but the nuclear membranes persist throughout mitosis. Electron-dense plaques, possibly kinetochores, were observed on the spindle microtubules in the polar regions of dividing nuclei. Additional electron-dense material was observed on the inner nuclear membranes adjacent to the plaques and microtubules but without connection to these latter structures. Daughter nuclei migrate but remain temporarily connected by a bridge composed of spindle microtubules enclosed by both nuclear membranes. During the final stages of karyokinesis the inner nuclear membrane reorganizes to exclude the microtubules of the bridge from the nucleoplasm. The nucleolus and chromatin reform, with the nucleolus being temporarily connected to the inner nuclear membrane by a chromatin strand. Cytokinesis is accomplished by transverse symmetrogenic fission, and the daughter cells are temporarily connected by a cytoplasmic isthmus.
Density and agonistic behaviour in young-of-the-year largemouth bass (Micropterus salmoides)
Authors: Fleming Ian A. , Johansen Peter H.
Published: December 2009

Laboratory studies were carried out to investigate the influence of density on agonistic behaviour and dominance relations in juvenile largemouth bass (Micropterus salmoides). We report here that high densities result in fewer agonistic interactions and fewer as well as less stable dominance relations. Increased numbers of potential interactions may render the continued maintenance of dominance inefficients.
The spring decline in the meadow vole, Microtus pennsylvanicus: the effect of density
Authors: Rodd F. Helen , Boonstra Rudy
Published: December 2009

The densities of six Microtus pennsylvanicus populations were reduced by removing large, sexually mature adults 6 months prior to (fall removal manipulation) and just prior to (spring removal manipulation) anticipated spring declines. When the spring decline on the control grid was a result of short distance dispersal, the manipulations had no effect; when it was a result of in situ mortality and (or) long distance dispersal, the fall removal manipulation produced a significant improvement in the survival rates of adult males. Adult female survival rates were high and unaffected by the manipulations. Adult reproductive rates were high and similar on all grids. The onset of the females' breeding season was advanced by the manipulations in two trials. Home range sizes were similar for all animals during the nonbreeding period. During the breeding period, males and females on the experimental grids had larger home ranges than those on the control grids.
Life cycles and drift of Trichoptera from a woodland stream in Minnesota
Authors: Krueger Charles C. , Cook Edwin F.
Published: December 2009

Life cycles of Trichoptera from a stream riffle were determined from analyses of monthly size–frequency distributions of larvae, pupal densities, and observations of adult emergence. Two types of univoltine life cycles were observed (H. B. N. Hynes' classification): slow seasonal for Brachycentrus americanus, Brachycentrus occidentalism and Micrasema kluane, and fast seasonal for Lepidostoma bryanti. The life cycle for Glossosoma intermedium was primarily bivoltine with summer and winter generations; however, some larvae of the summer generation were suspected to overwinter as pupae or terminal instar larvae and emerge in the spring. Larval B. americanus and L. bryanti showed peak drift prior to pupation and emergence which thus appeared seasonally associated with life cycle. Stream drift of M. kluane and G. intermedium was low and exhibited no clear association with life cycle or season. Drift of B. americanus, M. kluane, L. bryanti, and G. intermedium was not correlated to standing stocks (p < 0.05).
Description of Caryospora colubris sp.n. (Apicomplexa: Eimeriidae) from the western whip snake, Coluber viridiflavus (Serpentes: Colubridae)
Authors: Matuschka Franz Rainer
Published: December 2009

A new coccidian parasite of the genus Caryospora is described from the western whip snake (Coluber viridiflavus). The size of the spherical to slightly subspherical oocysts from Caryospora colubris n.sp. range from 16.2 to 27.9 μm and do not possess micropyle or oocyst residuum. The ovoid sporocysts are 13.2–19.1 μm long and 10.3–14.7 μm wide. The sporocyst residuum and a distinct Stieda body are present. The oocyst wall is approximately 1 μm thick. The sporulation is completed in about 48–72 h at 23 ± 2 °C. Within the given range the oocysts could be subdivided into three categories of size as follows. The predominating part of oocysts measured ca. 25.7 (23.5–27.9) μm, while usually less than 10% were 20.8 (20.6–22.1) μm or 17.4 (16.2–18.2) μm. The corresponding measurements of sporocysts were 17.9 (17.6–19.1) × 12.7 (11.8–14.7) μm; 15.0 (14.7–16.2) × 11.8 and 14.5 (13.2–14.7) × 11.0 (10.3–11.8) μm.
Feeding ecology of breeding Long-eared Owls in southwestern Idaho
Authors: Marks Jeffrey S.
Published: December 2009

Feeding ecology of Long-eared Owls (Asio otus) was investigated in the Snake River Birds of Prey Area, southwestern Idaho, during the breeding seasons of 1980 and 1981. The owls preyed mainly on five genera of small mammals: Peromyscus, Perognathus, Dipodomys, Microtus, and Reithrodontomys. There was considerable variation in prey composition among sites but not between years. In both years the proportion of Perognathus in the diet increased after the young owls fledged. Compared with other North American studies, Long-eared Owls in the Snake River Birds of Prey Area had a wider feeding niche and preyed more extensively on nonmicrotines. The range of prey sizes in Long-eared Owl diets was similar to that in other areas, with most prey weighing less than 100 g. Interlocality differences in the Long-eared Owl feeding niche probably reflect differences in the composition of small mammal faunas. Long-eared Owls in the Snake River Birds of Prey Area appeared to feed opportunistically on a diversity of available small mammals; prey size, rather than prey type, was the most important factor in food selection.
Life history and abundance of the predaceous psammophilous mayfly Pseudiron centralis McDunnough (Ephemeroptera: Heptageniidae)
Authors: Soluk Daniel A. , Clifford Hugh F.
Published: December 2009

Aspects of the life history and abundance of Pseudiron centralis McDunnough were examined in the Sand River in east central Alberta. The population exhibited a univoltine summer life cycle, spending 9 to 10 months of the year in the egg stage. Eggs were large (0.33 × 0.41 mm; mean dry weight, 0.005 mg). Larvae were associated with three types of substrate in the river bed: shifting sand, marginal sand, and gravelly sand. Larvae were active epibenthic predators, feeding primarily on psammophilous chironomid larvae. Larval density was low (< 4 larvae/m2); however, larval mortality also appeared to be low. Stage III and IV larvae exhibited a random dispersion pattern. Annual production (instantaneous growth method) was estimated to be 28.70 and 11.24 mg∙m−2∙year−1 in 1980 and 1981, respectively. The relatively large size of first-instar larvae may allow them to cope with the dynamics of sandy substrates, or may be the minimum size that can effectively capture and consume chironomid larvae. Although chironomid abundance in sandy substrates remains high throughout the year, P. centralis larvae exploit this resource for only a short period.
Functional characterization of limb muscles involved in locomotion in the Canada goose, Branta canadensis
Authors: Weinstein G. N. , Anderson C. , Steeves J. D.
Published: December 2009

The musculature of the Canada goose, Branta canadensis, was examined anatomically, physiologically, and behaviorally to determine which muscles best define the normal locomotor cycles for flying and walking. Muscle selection was based on a muscle outlining a distinct phase of normal locomotion, as well as being readily accessible for percutaneous implantation of electromyographic recording electrodes. In the hindlimb, the iliotibialis cranialis (ITC) and flexor cruris lateralis (FCL) are superficial muscles which clearly define the swing and stance phases, respectively, during walking. Similarly, the deltoideus major and pectoralis muscles clearly delineate the elevator and depressor movements of the wings. A compendium of synonymous muscle names is included to reduce the confusion surrounding avian nomenclature.
Systematic revision of the African mongoose genus Crossarchus (Mammalia: Viverridae)
Authors: Goldman Corey A.
Published: December 2009

Morphometric variation in external and cranial measurements of 152 specimens of Crossarchus was analyzed by means of univariate and multivariate statistical procedures. From the results of the analyses, four species of Crossarchus are recognized: C. obscurus from Sierra Leone to Ghana, C. alexandri from Zaire and Uganda, C. ansorgei known from the holotype from Angola and a second specimen from western Zaire, and Crossarchus platycephalus n. sp. from Cameroon, Nigeria, and Benin. Crossarchus obscurus and C. platycephalus are considered monotypic, whereas two subspecies are recognized in C. alexandri: C. alexandri alexandri from northern and central Zaire and C. alexandri minor n. ssp. from extreme eastern Zaire and Uganda. Significant secondary sexual variation was lacking in all taxa studied. Little individual variation was present in geographic samples. Geographic distributions of all taxa are plotted based upon specimens examined and literature records.
Arctic fox denning behavior in northern Alaska
Authors: Garrott R. A. , Eberhardt L. E. , Hanson W. C.
Published: December 2009

The behavior of nine families of denning arctic foxes was studied from blinds erected near occupied dens from June to August 1976 in the Prudhoe Bay area and from June to August 1978 and 1979 in the Colville River Delta area of northern Alaska. Six hundred and forty-eight hours of data representing 27 continuous 24-h observation periods were analyzed. Pups first appeared above ground in June, when they were 3–4 weeks old. Observability of pups at dens increased until they were 8 weeks old, at which time they began spending time away from dens. Both the adult female and male returned to the den periodically with prey for pups; however, the adult female provided a larger proportion of their food than adult males. As pups grew older, the adults returned to the den less frequently. Adult interactions with pups were generally limited to the transfer of food which was relinquished to the first pups to reach the adult. Interactions between adults were rare, as both adults were seldom in the vicinity of the den at the same time. Social behavior was most frequently observed between littermates and usually involved some form of play; however, the most prevalent pup behaviors observed were nonsocial. Aggression between siblings was uncommon and never led to serious injury of the participants.
Evolution and host specificity: a study of the invasion success of a specialized bumblebee social parasite
Authors: Fisher Richard M.
Published: December 2009

Species of Psithyrus (Hymenoptera: Apidae) are obligate social parasites of bumblebees. They range from monospecificity to species which have many Bombus hosts. Much of the reported variation in host–parasite behaviour which occurs during attempted nest usurpations may be explained in the context of host specificity. Psithyrus ashtoni is a relatively specialized bumblebee social parasite. The ability of P. ashtoni females to successfully enter laboratory colonies of Bombus affinis and Bombus terricola was tested. Female Psithyrus were introduced into more than 100 host colonies containing 0–58 workers. Parasites and host queens never fought, but in both hosts, invasion success decreased with increasing worker numbers. The passive nest usurpation behaviour of P. ashtoni differs from that of other, nonspecialized species of Psithyrus, which may kill or displace the host queen, and from that of completely specialized parasites, which may cohabit with both host queens and host workers. Host specialization may allow Psithyrus females to evolve behavioural and physiological features which minimize host defenses. Thus, while the number of available host species is limited, there is an increased probability of successful usurpation in nests of the appropriate host.
Pitfalls in the use of ground squirrels for research on hibernation
Authors: Davis David E.
Published: December 2009

Ground squirrels and marmots, which are popular animals for studies of hibernation and torpor, have endogenous (circannual) rhythms of mass, torpor, molt, nest building, water consumption, and probably other processes. Methods for physiological research must recognize the existence of endogenous changes. Many brief studies ignore these rhythms and thus produce ambiguous or misleading results. For valid results use only known-age individuals and keep them on natural day length (12 h light : 12 h dark is free runnng). In addition, determine the rhythms under wild conditions, the relation of torpor to sex and age, and the influence of disease on torpor.
The evolution of animal senescence
Authors: Rose Michael R.
Published: December 2009

Senescence, the endogenous deterioration of health at later ages, can be explained in terms of evolution. Senescence is not due to group selection but to the decline with age in the force of natural selection acting on individuals. This decline allows the spread of alleles with deleterious effects on late health. Such alleles do not appear to have effects confined to later ages. Instead, they are favoured by natural selection because of beneficial effects at early ages, in spite of later deleterious effects due to antagonistic pleiotropy. Manipulation of laboratory populations of Drosophila has shown that senescence can be postponed using selection. There are no absolute, universal, physiological causes of senescence. Laboratory populations with genetically postponed senescence can be used to study proximate physiological mechanisms of senescence in animals.
Redescription of Falcaustra duyagi (Tubangui &Villaamil, 1933) Freitas &Lent, 1941 (Nematoda: Cosmocercoidea) from Cuora amboinensis (Testudinidae) of Malaysia
Authors: Berry Jim F.
Published: December 2009

Falcaustra duyagi (Tubangui &Villaamil, 1933) Freitas &Lent, 1941 is redescribed based on specimens from Cuora amboinensis (Testudinidae) of Malaysia (new locality record). These specimens differ only slightly from the original description in dimensions and appearance of caudal pseudosuckers in males. This work elucidates details of cephalic morphology, the excretory system and the gubernaculum, which may provide useful taxonomic information. Falcaustra duyagi is distinguished from other Asian species by the number of pseudosuckers, short spicules bearing numerous prominent protuberances on the anterior portion, and by the large saccular excretory vesicle lacking lateral canals. Cephalic morphology of F. duyagi was studied from stained histologic sections. The cheilostome and oesophastome are similar to Falcaustra stewarti Baylis &Daubney, 1922. Falcaustra stewarti is reported from Cyclemys mouhoti (Testudinidae) of southern Viet Nam (new host and locality record).
Redescription and distribution of Xiphinema rivesi Dalmasso, 1969 and Xiphinema americanum Cobb, 1913 in Canada with a description of Xiphinema occiduum n. sp. (Nematoda: Longidoridae)
Authors: Ebsary B. A. , Potter J. W. , Allen W. R.
Published: December 2009

Xiphinema rivesi and Xiphinema americanum are redescribed and illustrated from several eastern Canadian localities. Xiphinema occiduum n. sp. is described and illustrated from western Canada. The new species is most closely related to X. utahense but differs by the shorter odontostyle, greater J length and width, more anterior guiding ring, smaller a value and less elongate tail. The distribution and hosts of each species in Canada are also provided.
Changes in the condition of dunlins and knots during short-term captivity
Authors: Davidson Nicholas C.
Published: December 2009

Dunlins, Calidris alpina, and knots, Calidris canutus, captured while roosting at Teesmouth in northeastern England, were held in captivity during ringing operations. During this time they lost up to 19% (dunlins) and 23% (knots) of their total mass. In dunlins, loss of mass occurred in two phases. During phase 1 (0–8 h after capture) mass was lost at a similar, declining, rate regardless of conditions or frequency of handling. During phase 2 (>8 h after capture), frequently handled birds continued to lose mass rapidly, but the mass of less disturbed birds decreased at a lower, constant, rate. Knots had a similar two-phase mass loss. Changes in body condition were analysed in less disturbed birds. During phase 1 much of the loss was due to dehydration. Fat catabolism began within 4 h of capture at a rate of 2.2 to 2.4 times basal metabolic rate (BMR) in dunlins and 2.4 times BMR in knots. Dunlins also lost lean dry muscle tissue concurrently and at a constant rate. After 24 h, dunlins had lost 27.4% of the protein reserve available in their pectoral muscles. The consequences of the stress of capture and handling on rates of loss of mass, particularly muscle protein, are discussed, as are the implications of short-term loss of mass for the accurate measurement of body condition in live and killed samples of birds.
Rate of digestion in three species of pinnipeds
Authors: Helm Roger C.
Published: December 2009

Torpid bowels or an impaction obstruction significantly retards the rate of passage of digesta in an animal and can lead to serious clinical problems. In many captive animals the approximate rate of food passage is well-known, thus allowing for rapid diagnosis and treatment if an intestinal blockage occurs. Although pinnipeds are commonly kept in captivity, the rate of passage of digesta in these animals is not known. In this study, the time period that elapsed before the initial defecation of a dye-marked meal was determined for 20 pinnipeds representing three species. This initial defecation time (IDT) serves as a good indicator of the rate of passage of digesta. The mean IDTs determined for pinnipeds were very fast averaging 5 h or less. No other medium to large carnivore or omnivore has been shown to exhibit such a rapid rate of passage. The extraordinarily fast excretion rate of these animals is even more remarkable considering that their intestine to body length ratios are among the largest in the animal kingdom. It is hypothesized that the rate of passage of digesta in pinnipeds is strongly influenced by their high metabolic rate and the high water content of their digesta.
Présence de bactéries dans les caecums postérieurs de l'intestin moyen du Crustacé hypogé Niphargus virei (Gammaridae : Amphipoda)
Authors: Graf F.
Published: December 2009

Prokaryotic microorganisms were observed within the lumen of the posterior caeca in the midgut of the hypogean crustacean Niphargus virei. The observed ultrastructural features are those of bacteria, probably belonging to the family Spirillaceae. This constant association between these bacteria and the posterior caeca, described for the first time in crustaceans, is discussed in relation to the cavernicolous biology of Niphargus. As well, other prokaryotic microorganisms, probably Rickettsiales, were observed within the epithelial cells from the midgut of Niphargus.
A remarkable new caddisfly genus from northwestern North America (Trichoptera, Limnephilidae, Limnephilinae)
Authors: Wiggins Glenn B. , Winchester Neville N.
Published: December 2009

Adults of Sphagnophylax meiops gen. et sp. nov. are described from the Yukon and Northwest Territories of Canada. The habitat is small, low-lying tundra basins where water lies on the surface for brief periods in the spring, later receding into a saturated layer of organic debris. Affinity of Sphagnophylax with the four tribes of the Limnephilinae is questionable. Apomorph characters shared with the Chaetopterygini are open to conflicting interpretations, and others are discordant or unique in the Limnephilidae, indicating that Sphagnophylax is best assigned as Limnephilinae incertae sedis until more information is available.
A world review of the occidentalis species group in the genus Typhlodromus Scheuten (Acarina: Phytoseiidae)
Authors: Chant D. A. , Yoshida-Shaul E.
Published: December 2009

A revised concept of the occidentalis species group in the genus Typhlodromus Scheuten is proposed. Concepts of the group proposed by various earlier authors are reviewed. Keys are provided to the adult females of the eight species in the group, including a new species (T. annectens De Leon, T. ferrugineus (De Leon), T. helveolus Chant, T. longipilus Nesbitt, T. occidentalis Nesbitt, T. porresi McMurtry, T. superstus (Zack), and T. deceptus n. sp.), and each is described. Typhlodromus gratus Chant is designated as a junior synonym of T. helveolus.
Metazoan parasites of Northwest Atlantic redfishes (Sebastes spp.)
Authors: Bourgeois C. E. , Ni I.-H.
Published: December 2009

A total of 443 specimens of three redfish species (209 Sebastes fasciatus, 123 S. marinus, and 111 S. mentella), obtained from Northwest Atlantic Fisheries Organization (NAFO) divisions 2H, 2J (Labrador area), 3K (Northeastern Newfoundland), 3L, 3O (Grand Banks) 3M (Flemish Cap), and 3Ps (St. Pierre Bank) during 1980–1982, was examined for metazoan parasites; 182 (87.1%) S. fasciatus, 120 (97.6%) S. marinus, and 103 (92.8%) S. mentella were infected. Seventeen species of parasites were recovered (12 from S. fasciatus, 16 from S. marinus, and 11 from S. mentella). 22 of which were new host records. Quantitative data, including prevalence and intensity of infection, are given for each parasite by host species and NAFO division. The zeogeography and host specificity of the parasites encountered in this study are discussed in relation to redfish and hypothetical stocks of Sebastes spp. are proposed based on the parasite data collected.
Some aspects of the foraging ecology of migrant juvenile sandpipers in the outer Bay of Fundy
Authors: Gratto G. W. , Thomas M. L. H. , Gratto C. L.
Published: December 2009

Thirty-seven sandpipers (29 semipalmated and 8 least) were collected in early September 1983 on an intertidal flat on the outer Bay of Fundy. Analysis of esophagus and gizzard contents revealed a variety of benthic invertebrates but the diets of both species were dominated by the amphipod Corophium volutator (Pallas). Females of both species ate larger Corophium than did males of the same species. Both least and semipalmated sandpipers were underutilizing a cohort of large (7–10 mm) Corophium. It is possible that the large amphipods have reached a size refuge from predation such that the energy required to handle and ingest these large prey offsets too great a portion of the energy obtained.
Secretion of progestogens during induced ovulation in goldfish
Authors: Peter R. E. , Sokolowska M. , Truscott B. , Walsh J. , Idler D. R.
Published: December 2009

Female goldfish (Carassius auratus L.) were held at 20 °C and ovulation was induced by injection of des-Gly10[D-Ala6] luteinizing hormone releasing hormone ethylamide (LHRH-A) plus pimozide, and 3 h later, LHRH-A. This treatment causes rapid onset of a prolonged surge of gonadotropin (GtH) release. At 6 h after the second set of injections, serum levels of GtH, 17α-hydroxyprogesterone (17α-P), and 17α-hydroxy-20β-dihydroprogesterone (17α,20β-P) are significantly higher than in control groups; oocytes have reached the germinal vesicle breakdown stage of maturation by this time. By 20 h after the second set of injections, seven of eight fish had ovulated in the LHRH-A and pimozide treatment group; the serum levels of GtH were greater than at 6 h, but serum concentrations of 17α-P and 17α,20β-P were decreased to control levels. The ovulated fish still retained ovulated oocytes. This indicates that goldfish have a preovulatory surge of secretion of progestogens, which may aid in induction of oocyte maturation and ovulation within a short time period, enabling the goldfish to synchronize ovulation with the photoperiod and to take advantage of favorable environmental conditions for spawning within a 24-h period.
A modified electronic shuttlebox for joint thermoregulatory and toxicological studies
Authors: Gregory Michael A. , Anderson Perry D.
Published: December 2009

This paper presents a modified electronic shuttlebox for studies of behavioral thermoregulation in fish. The apparatus incorporates continual water replacement, the water temperature being controlled by the fish. Such a design facilitates long-term studies, with or without a chemical agent. Additionally, the absence of a temperature gradient permits strict response-conditioning experimentation. Fingerling rainbow trout (Salmo gairdneri) maintained a mean temperature of 18.1 ± 0.6 °C, thermoregulating with a degree of regularity and precision similar to the findings of other workers using different devices. Fish have been able to successfully thermoregulate in this apparatus for periods of up to 6 weeks.
The free amino acid contribution to osmotic regulation in Acanthamoeba castellanii
Authors: Geoffrion Yves , Larochelle Jacques
Published: December 2009

In Acanthamoeba, a sudden rise in the medium osmolality from 240 to 500 mosmol/kg water was found to produce within 5 h a 2.7-fold increase in the cell free amino acid (FAA) content which accounted for 25% of the change in the solute content of the cell. While in general, modifications of the FAA pool were essentially completed within 1 h, Pro was accumulated linearly with time. Over the 5-h experimental period, the cell content in Pro increased by more than 10-fold to constitute 49% of the cell FAA content. Taken together, the variations of Pro. Ala, and Glu accounted for 100% of the increase in the FAA pool after 5 h of acclimation. A sudden drop in the medium osmolality from 240 to 40 mosmol/kg water resulted in a "leveling" reduction of the FAA pool, with decreases in Ala, γ-aminobutyric acid, and Pro accounting for 71% of the sixfold change observed after 5 h. The preferential use of FAA and particularly of Pro as osmoregulatory solutes can be explained in terms of energetic considerations and of compatibility with enzyme function.
Measurement of hydrostatic pressure in salmonid eggs
Authors: Alderdice D. F. , Jensen J. O. T. , Velsen F. P. J.
Published: December 2009

A method is described, based on applanation tonometry of the human eye, for measurement of hydrostatic (internal, turgor) pressure in salmonid eggs. The area of an egg flattened by an external applanating force is related to the volume of the egg displaced by applanation. The hydrostatic pressure in steelhead trout eggs (Salmo gairdneri) (1248 h postfertilization, 5 °C) was 53 (−7, +8) mmHg (1 mmHg = 133.322 Pa). Unfertilized, flaccid eggs of the species, with an assumed zero internal pressure, had a measured pressure of 1.1 (−0.6, +1.1) mmHg, taken as equivalent to the force required to bend the relatively thick capsule (zona radiata) wall. Hence, the corrected internal pressure is estimated as 51.9 mmHg. Internal pressure in fertilized eggs of three species of Pacific salmon (Oncorhynchus nerka (sockeye), O. gorbuscha (pink), and O. tshawytscha (chinook)) increased during incubation at 10 °C. Between 2 and 8 h after fertilization, hydrostatic pressure was approximately 15 mmHg for sockeye, 25 mmHg for pink, and 40 mmHg for chinook. After 1000 h of incubation, the pressures (millimetres Hg) were approximately 76 for sockeye, 47 for pink, and 51 for chinook. Possible relations between hydrostatic and osmotic pressures are discussed with reference to effective filtration pressure, as well as the potential influence of the latter on oxygen transport across the capsule.
Experiments on colony foundation in the slave-making ant Harpagoxenus canadensis M. R. Smith (Hymenoptera; Formicidae)
Authors: Stuart Robin J.
Published: December 2009

Queens of obligatory socially parasitic ants are unable to found colonies independently and typically initiate new colonies by invading host-species nests and usurping the role of reproductive. In some cases, fission ("budding") of parasite colonies also occurs. This study is the first to investigate colony foundation in the obligatory slave-making ant Harpagoxenus canadensis M. R. Smith. Laboratory experiments examined whether colonies could be founded (i) independently by a parasite queen, (ii) jointly by a parasite queen and a host queen, (iii) by budding, and (iv) by usurpation. Parallel experiments using host-species queens (Leptothorax sp.) were conducted for independent colony foundation and joint colony foundation by two conspecific queens. The results indicate that parasite queens found colonies by usurpation. Parasites invaded host nests using either an "active" aggressive strategy or a relatively less aggressive "passive" strategy, obtained host brood, and were occasionally adopted by a large portion of the host colonies' adults. Host-species queens successfully founded colonies both independently and jointly.
Predator–prey size relationships in North American dabbling ducks
Authors: Nudds Thomas D. , Bowlby James N.
Published: December 2009

Diets of dabbling ducks (Anas: Anatidae) usually have been recorded only with respect to taxonomic composition and not prey size. Interspecific diet overlap thus has been termed large. However, using published taxonomic diet lists for seven species of ducks, measurements of bill morphology from museum specimens, and "handbook" data on the sizes and caloric density of invertebrates, prey size distributions were found to differ among species (P < 0.001). Also, the sizes of prey in each species' diet differed from that found in the environment. The number of lamellae per centimetre of bill negatively correlated with mean prey size (P < 0.001); body size and bill length did not. Based on the similarity of environmental and dietary prey size distributions, species were classified as specialist or generalist foragers. This classification corresponded well with one generated from analyses of foraging behaviour alone. An explanation for the diminuitive sizes of ducks on islands was advanced: if interspecific competition for food selects for niche divergence among coexisting dabbling ducks along a prey size niche dimension, then in the absence of competition from small species on islands, large solitary species have evolved to a smaller size which may be optimal for the distribution of energy among prey size classes in the environment.
Sexual size dimorphism in relation to resource partitioning in North American dabbling ducks
Authors: Nudds Thomas D. , Kaminski Richard M.
Published: December 2009

Data from museum specimens were used to examine patterns of sexual size dimorphism in bill morphology in relation to resource partitioning in seven species of North American dabbling ducks (Anas sp.). All species were dimorphic with respect to bill length. Male and female bill length distributions were skewed in opposite directions in five of seven species (P < 0.01). Four of seven species were dimorphic with respect to lamellar density, but male and female distributions were skewed in opposite directions in only two species. The four dimorphic species were positioned between other species along a prey size dimension; species which were not dimorphic had only one neighbour on the prey size dimension. These results are consistent with the hypothesis that intersexual competition for food promotes niche divergence between sexes and contributes to sexual size dimorphism in ducks.
Habitat, diet, and composition of assemblages of garter snakes (Thamnophis) at eight sites on Vancouver Island
Authors: Gregory Patrick T.
Published: December 2009

This study examines diet, habitat, and diversity relationships of three species of garter snakes (Thamnophis) at eight sites on Vancouver Island. Species diversity varied considerably among sites from a single species only to roughly equal representation of all three species; most sites were dominated by one or two species and were temporally stable in species composition. Relative abundance of each species at a site was generally associated with specific habitat features, but no direct relationship between habitat characteristics and diet was seen. Diet diversity of all species combined was positively correlated with species diversity over all sites. The three species had different diets, and differences within species among sites were attributable mainly to shifts in the proportions of different prey taken. Overall, diets of the three species were more distinct the more nearly equally represented the three were, suggesting a diffuse pattern of interspecific interactions.
Alcataenia longicervica sp. n. from murres, Uria lomvia (Linnaeus) and Uria aalge (Pontoppidan) in the North Pacific basin, with redescriptions of Alcataenia armillaris (Rudolphi, 1810) and Alcataenia meinertzhageni (Baer, 1956) (Cestoda: Dilepididae)
Authors: Hoberg Eric P.
Published: December 2009

Alcataenia longicervica sp. n. (Cestoda: Dilepididae) is described from murres, Uria spp., in Alaska and other localities in the Pacific basin. From Alcataenia armillaris (Rudolphi, 1810), which it most closely resembles, A. longicervica is distinguished by larger size of organs (cirrus sac, vitelline gland, and seminal receptacle), greater number of testes, and extremely long neck. In specimens of A. longicervica there are 22–27 rostellar hooks distributed in two rows. Hooks in the anterior row measure 41–49 μm in length while those in the posterior are 38–48 μm. Two species of Alcataenia, A. armillaris and A. meinertzhageni (Baer, 1956), both characteristic cestodes of birds of the genus Uria Brisson, are redescribed from material from the North Pacific basin and are compared with descriptions of specimens from the North Atlantic region.
Echolocation and foraging behaviour in the Hawaiian hoary bat, Lasiurus cinereus semotus
Authors: Belwood Jacqueline J. , Fullard James H.
Published: December 2009

Free-flying individual Lasiurus cinereus semotus were observed as they foraged near incandescent lights on the island of Kauai, Hawaii. Two types of vocalizations were recorded from the bats: an echolocation–hunting signal with peak frequency of 27.8 kHz and an agonistic social signal, emitted while the bats were in aggressive pursuit of one another, with a peak frequency of 9.6 kHz. The tendency to vocalize agonistically increased with increased numbers of bats in the foraging area and increased as the density of insects available to the hunting bats decreased. Our observations suggest that the bats may gather echolocation information from their social signals. The bats at the site foraged under most weather conditions, including fog, moderate rain, strong winds, and temperatures as low as 13 °C. Groups of up to eight animals were common, although bats hunted in airspaces that were vigorously defended against other individuals. Small flies and small moths (< 10 mm body length) were the most common insects available as prey, but larger moths (16–20 mm) made up the bulk of the bats' diet. Moths larger than 20 mm were available but not fed on by the bats. This unique study site provides a rare opportunity to compare both prey availability to prey consumption in a population of bats. Our results suggest that this bat, at least on a short-term basis, exhibits a high degree of selectivity in its foraging, a behaviour similar to the mainland subspecies.
The response of Western Meadowlarks (Sturnella neglecta) to the playback of undegraded and degraded songs
Authors: McGregor Peter K. , Falls J. Bruce
Published: December 2009

Male Western Meadowlarks (Sturnella neglecta) respond more strongly to playback of undegraded songs than degraded songs when both are played at the same amplitude and from the same position in the territory. The difference in response is only found if the song played is of a type that is sung by the test bird. These results support the use of cues from sound degradation to estimate distance; they also support a mechanism of degradation assessment which requires familiarity with the stimulus. We discuss the role of acoustic and visual cues in distance estimation and the significance of our results for a proposed function of song matching.
The pair bond in ptarmigan
Authors: Bergerud A. T. , Mossop D. H.
Published: December 2009

The three North American ptarmigan species are monogamous, whereas the other six North American grouse species are polygynous. In the Arctic there are few nest predators, which means ptarmigan should be prepared to nest nearer each other than polygynous grouse that lose more nests to predators. Hence, ptarmigan females search relatively small prelaying ranges for nest sites. The small space requirements of females allows males to economically defend with territorial behaviour the nesting resource (cover and space) that females will later search and require, and thus the fitness of males is determined by the quality of the nesting resource that he controls which results in selection by females. In the Arctic the open habitat, continuous daylight, and the presence of effective avian predators have resulted in females also selecting conspicuous, vigilant males in a prolonged pair bond. These males deflect predation risk away from females during nest searching and egg laying in all three species and from hens with chicks in willow ptarmigan.
Blood rheology in the pigeon (Columba livia), hen (Gallus gallus domesticus), and black-headed gull (Larus ridibundus)
Authors: Viscor G. , Fuentes J. , Palomeque J.
Published: December 2009

The hemorheological characteristics of three birds with different activity levels were analyzed: the pigeon, a powerful flapping flyer, the black-headed gull, a gliding bird, and the hen, a nonflyer. The apparent viscosity of blood of the hen, owing to its small hematocrit (Hc = 32%), was lower than that of the two others. On the other hand, the pigeon (Hc = 52%) and the gull (Hc = 42%) gave similar values in blood viscosity principally as a consequence of the smaller amount of plasma proteins (particularly fibrinogen) in the pigeon (3.5 g/dL) compared with the gull (5.8 g/dL). Measurements of viscosity at a fixed hematocrit of 40% were performed in normal and hardened erythrocytes suspended in different media. The results showed slight differences in the rheological behavior of the red cells in the three species and a lower deformability in the red cells of the gull. Erythrocyte deformability was also analyzed by the microfiltration technique. The results were in agreement with those obtained with the viscosimetric method. Erythrocyte osmotic fragility, expressed as a NaCl concentration at 50% of hemolysis, was greater in the pigeon (0.43 g/dL) and gull (0.36 g/dL) than in the hen (0.25 g/dL). The results are discussed in relation to red cell morphology.
Potentiation of acetylcholine-induced skeletal muscle contractions in vitro by prostaglandin F2α in the lizard, Crotaphytus collaris
Authors: Guillette Jr. Louis J. , Dickey David A.
Published: December 2009

Acetylcholine-induced in vitro contractions of the puboischiotibialis muscle was potentiated by pretreatment with prostaglandin F2α (1.5 ng/mL). This phenomenon was exhibited by both sexually active male and female Crotaphytus collaris collaris and the degree of response was similar in both sexes. However, females exhibited a greater mean (±SE) percent increase as well as more variation than males (males, 54.6 ± 10.9%; females, 114.7 ± 61.4%). These data suggest that prostaglandin F2α plays a role in the control of striated muscle function in lizards. Moreover, prostaglandin potentiation of muscle contraction may be important during the reptilian reproductive cycle, particularly at the time of oviposition.
Intraspecific competition between different aged larvae of Agromyza frontella (Rondani) (Diptera: Agromyzidae): advantages of an oviposition-deterring pheromone
Authors: Quiring Daniel T. , McNeil Jeremy N.
Published: December 2009

In laboratory studies evaluating the effects of intraspecific competition between Agromyza frontella larvae of different ages, individuals starting 24 or 48 h before other larvae within the same leaflet largely escaped the negative effects of competition. However, larvae starting development later experienced a higher incidence of mortality and reduced pupal weight. Thus an oviposition-deterring pheromone laid down by ovipositing A. frontella females would only have to remain effective for 24 h to confer a competitive advantage to the first individual developing within the leaflet. In two separate field tests this proved to be the case, with active pheromone remaining for > 24 h under both hot and rainy conditions. There has been some doubt concerning the adaptive value of certain oviposition-deterring pheromones under field conditions because of their water-soluble nature. The results of these experiments would suggest that the required active life of an oviposition-deterring pheromone may be considerably shorter than previously thought, and thus their persistence, even for short periods, may be adequate to reduce intraspecific competition in natural populations.