bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspects of lipid synthesis, hydrolysis, and transport studied in selected Amazon fish
Authors: Patton John S. , Haswell Monty S. , Moon Thomas W.
Published: August 2008

Comparative lipogenic activities offish tissue, lipolytic activity of mesenteric fat and mode of intestinal lipid release into blood were investigated in a variety of Amazon fish. Small catfish were injected intramuscularly with [1-l4C]acetate, killed at intervals, and the lipid radioactivity of 11 separate tissues determined. In 6- and 18-h fish, the heart, eyes, dark muscle, and white muscle synthesized negligible lipid relative to the other tissues. Acetone powders of Triportheus sp, mesenteric fat contained high amounts of triglyceride lipase activity (120 nmol fatty acid release-d/min per milligram protein). The activity exhibited a pH optimum of 8.0 and was not activated by albumin, bile salts, or divalent salts nor inhibited by 1 M NaCl. Characteristics of the observed activity are identical with those of mammalian pancreatic lipase. Hoplias malabaricus were fed [1-14C]oleic acid and a chronic indwelling catheter was placed in the dorsal aorta for blood sampling. Based on the distribution of radioactivity among blood lipid classes, it is suggested that dietary lipid enters fish circulatory systems both as free fatty acid and as lipoproteins.
The membrane permeability of nonelectrolytes and carbohydrate metabolism of Amazon fish red cells
Authors: Kim Hyun Dju , Isaacks R. E.
Published: August 2008

The membrane permeability to nonelectrolytes and carbohydrate metabolism were examined in red cells obtained from the Amazon fishes including the electric eel (Electrophorus electrocus), the arawana (Osteoglossum bicirrhosum), the pirarucu (Arapaima gigas), the lungfish (Lepidosireti paradoxa), and the armored catfish (Pterygoplichthys). Glucose permeability was fastest in the electric eel, followed by the lungfish. The red cells of the arawana were only slightly permeable to glucose. Both the armored catfish and the pirarucu red cells were found to be totally impermeable to glucose. There was no evidence for the presence of the facilitated diffusion mechanism for glucose transport in any of these fish red cells. In sharp contrast with glucose, red cells of all five species were quite permeable to ribose and urea. Urea permeability of red cells decreased in order of magnitude with the lungfish > the electric eel > the arawana > the armored catfish [Formula: see text] the pirarucu. The urea permeability of the lungfish was inhibited in the presence of phloretin.Of the two metabolic substrates, glucose but not ribose was metabolized to lactate with a concomitant contribution to ATP maintenance by the lungfish red cells. Even though the glucose-impervious pirarucu cells could not utilize glucose, ribose was readily metabolized by the pirarucu cells.
Swimming energetics of an Amazonian characin in 'black' and 'white' water
Authors: Holeton George F. , Stevens E. Don
Published: August 2008

Measurements were made of the swimming and metabolic performance of the Amazonian characin Triportheus angulatus in waters from the Rio Negro and the Rio Solimoẽs. When allowances for temperature and size of fish were made there was very little difference among groups of fish tested in either type of water. The most impressive performance was by a group of fish tested in Rio Negro water at 29 °C. These fish, averaging 15.9 g, had a standard metabolic rate of 231 mg∙kg−1∙h−1, an active metabolism of 631 mg∙kg−1∙h−1, and a critical swimming speed of 4.9 body lengths∙s−1 or 52 cm∙s−1.Although these fish live in waters which are often exceedingly dilute and acidic, there appears to be no reduction in their swimming or metabolic performance compared with fish from other parts of the world. This shows that the gills of T. angulatus do not have greatly reduced oxygen permeability, a situation which might be expected to accompany an adaptive reduction in branchial osmotic and ionic permeability.
Comparative biology of four species of glyphocrangonid and crangonid shrimp from the continental slope of the middle Atlantic Bight
Authors: Wenner Elizabeth Lewis
Published: August 2008

Distribution, reproduction, food, and parasites of glyphocrangonid (Glyphocrangon sculpta and Glyphocrangon longirostris) and crangonid (Sabinea hystrix and Metacrangon jacqueti agassizi) shrimp were studied from otter trawl collections on the continental slope of the middle Atlantic Bight. Glyphocrangon sculpta and G. longirostris were found at depths of 2068–2679 m and 1111–2427 m respectively; S. hystrix was found from 452 to 2100 m and M. j. agassizi occurred from 616 to 1430 m. Among all four species, ovigerous females were significantly larger and more numerous than males. Sex ratio patterns expressed as percent male for depth and size are discussed for these species. Reproduction of all species was asynchronous and year-round; ovigerous females were captured during every month. Ovarian growth was continuous, enabling multiple spawnings of small numbers of large eggs. Stomach contents consisted almost entirely of benthic organisms and sediment, but the majority of stomachs were empty. Epibranchial bopyrid isopods were found on G. sculpta, G. longirostris, and M. j. agassizi. Parasite incidence among the species was low but, when present, retarded gonad development in female hosts.
The Lund University Expedition freshwater Ostracoda from Sri Lanka (Ceylon)
Authors: Neale John W. , Victor Reginald
Published: August 2008

Material from six samples from four localities collected by the Lund University Expedition to Ceylon in 1962 contained freshwater ostracods. Seven species were present including Darwinula lundi sp.nov., which is described.
On the involvement of mucous secretion in teleost osmoregulation
Authors: Marshall William S.
Published: August 2008

Diffusion coefficients of 22Na or 36Cl through fish mucus (1.0–2.4 mg protein/ml) are similar (±15%) to those through control saline solutions. The ion-exchange capacity of the mucus was 70–80 μequiv./g mucus, as measured by titration with added salts. These results suggest that dilute mucous solutions could not impede the passive movement of ions sufficient to explain the sodium-retaining effect of prolactin. Other mechanisms by which mucus may act in teleost osmoregulation are discussed.
A thiol-activated digestive proteinase from adults of Rhodnius prolixus Stål (Hemiptera: Reduviidae)
Authors: Houseman Jon
Published: August 2008

Complete activation of proteinase(s) from the digestive midgut of adult Rhodnius prolixus occurs in the presence of thiol activator and EDTA. In the assay procedure developed and reported upon, gut homogenate is added to 1.5 ml 0.1 M potassium phosphate buffer, pH 5.5, containing 1.5 mM dithiothreitol (DTT) and 3 mM EDTA, and is allowed to incubate at 30 °C for 5 min. Fifty microlitres of N-benzoyl- DL-arginine naphthylamine (BANA), 40 mg/ml in dimethyl sulfoxide, is added, and the reaction is stopped after incubation at 30 °C by the addition of 2 ml fast garnet GBC salt colour reagent. Greatest activation occurs with dithiothreitol, followed by cysteine, glutathione, and mercaptoethanol in descending order of activation ability. Complete activation of BANA hydrolysis occurs with 0.4 mM DTT and 1.5 mM EDTA. With the assay, 0.2 gut provides ΔA 520 nm of 0.15 in 30 min. The conditions of the assay suggest that a cathepsin B1-like proteinase is present. The proteinase occurs in the midgut lumen and maximal activity occurs 5–10 days after ingestion of the blood meal.
The effect of streptomycin and penicillin on the growth and differentiation in vitro of Hymenolepis microstoma
Authors: Evans William S.
Published: August 2008

The degree of growth and differentiation that occurred during 7 days in vitro in cultures of Hymenolepis microstoma metacestodes decreased as the concentrations of both streptomycin sulfate and sodium penicillin G in the medium were increased from 60 to 250, 500, 1000, 2000, or 5000 μg and units, respectively per millilitre.
Helicotylenchus urobelus n.sp. (Nematoda: Hoplolaimidae) from New Brunswick, Canada
Authors: Anderson R. V.
Published: August 2008

A new bisexual spiral nematode, Helicotylenchus urobelus, is described and illustrated. It is differentiated from its closest relative, Helicotylenchus erythrinae, by the more prominent ventral tail projection and narrow annules on the tail end of the female. The male is readily identified by the size and shape of the spicules, the rounded, nonmucronate tail terminus, and peloderan bursa.
Spatial distribution of gill parasites of Lepomis gibbosus (L.) and Ambloplites rupestris (Raf.)
Authors: Hanek George , Fernando C. H.
Published: August 2008

Precise positions with regard to gill arches, sides of gill hemibranchs (anterior or posterior), and their sections (dorsal, medial, ventral) were recorded on 25 specimens monthly to determine spatial distribution of gill parasites of Lepomis gibbosus (L.) and Ambloplites rupestris (Raf.). Data were collected on three groups of parasites, Monogenea, Copepoda, and glochidia. The data, treated synecologically, were analysed for spatial distribution using a two-factor ANOVA and Duncan's multiple range test.A significant preference for anterior sides of hemibranchs was noted for Monogenea and glochidia of L. gibbosus (P < 0.001). A definite affinity for anterior medial and posterior medial sections of hemibranchs was noted for Monogenea and glochidia of L. gibbosus (P < 0.001), while Copepoda of the same host were found most often on either anterior or posterior sections of hemibranchs (P < 0.001).A well-defined preference for gill arches, in descending order, two, three, one, and four was noted for Monogenea and glochidia of L. gibbosus (P < 0.001), while no such preference was found for Copepoda of the same host (P < 0.001). The spatial distribution patterns exhibited by the three groups of parasites of Ambloplites rupestris followed generally the same patterns as those exhibited by the gill parasites of L. gibbosus, the only exception being the preference for anterior sides of hemibranchs exhibited by Copepoda (P < 0.001).
The role of season, habitat, host age, and sex on gill parasites of Lepomis gibbosus (L.)
Authors: Hanek George , Fernando C. H.
Published: August 2008

One thousand and forty pumpkinseeds (Lepomis gibbosus (L.)) were collected from May 1970 through October 1972 from the Bay of Quinte, Ontario. Also, 1018 specimens of the same host were collected during the same sampling period from West Lake, Prince Edward County, Ontario.Data were collected on three groups of gill parasites, Monogenea (seven species), Copepoda (three species), and glochidia (one species). The data, treated synecologically, were analysed using a two-factor ANOVA and Duncan's multiple range test. The roles of season, habitat, host age, and sex on parasite load were analysed. Host sex was found to have no effect on the three groups of parasites. The abundance of parasites increased with host age (P < 0.001). A marked seasonal effect was noted for all three groups of parasites (P < 0.001), all three being most abundant during the summer period. A eutrophic habitat, West Lake, was found significantly more favourable (P < 0.001) for all three parasitic groups.
Comparative studies of Giardia spp. in small mammals in southern Ontario. I. Prevalence and identity of the parasites with a taxonomic discussion of the genus
Authors: Grant David R. , Woo Patrick T. K.
Published: August 2008

Giardia microti Kofoid and Christiansen, 1915 was identified in 98.8% (322 of 326) of meadow voles (Microtus pennsylvanicus) and G. peromysci Filice, 1952 emend, in 98% (48 of 49) of deer mice (Peromyscus maniculatus) that were livetrapped at six locations in southern Ontario. One feral brown rat (Rattus norvegicus) was infected with Giardia simoni Lavier, 1924 and Giardia muris Grassi, 1881. Laboratory rats (Wistar strain) harboured only G. simoni and laboratory mice (C3H strain) were infected with G. muris. Golden hampsters (Mesocricetus auratus) were infected with Giardia mesocricetus Filice, 1952 emend.Giardia spp. were separated into two morphologically distinct groups. Trophozoites of G. muris and G. mesocricetus were almost as wide as long and had round or oval centrally situated median bodies. Trophozoites of G. microti, Giardia peromysci, and G. simoni were elongate with long curved median bodies lying perpendicular to the long axis of the trophozoite.Further differentiation of species was not possible by comparing trophozoite morphology but was accomplished by comparing the average lengths and widths of trophozoites.
Changes in thyroid activity of Ambystoma gracile (Baird) during different larval, transforming, and postmetamorphic phases
Authors: Eagleson G. W. , McKeown B. A.
Published: August 2008

Thyroid activity for two populations of Ambystoma gracile acclimated to laboratory conditions was assessed by thyroid radioiodide (125I) uptake and serum thyroxine level determined by radioimmunoassay. Both populations exhibited a gradual rise in thyroid activity preceding the mean size for metamorphosis. Larval and transformed salamanders also exhibited a decline in thyroid activity following attainment of this mean size, and this decline was observed for both transformed and neotenous animals. Thyroid activity and serum thyroxine levels were greatest during metamorphic climax. Neoteny was attributed to the generally lower thyroid activity preceding the mean size for metamorphosis which was observed for the high altitude population (having greater neotenic tendencies).
Aggressive distance in juvenile coho salmon (Oncorhynchus kisutch)
Authors: Dill Lawrence M.
Published: August 2008

The distances from which resident coho salmon approached, charged, or gave lateral displays to intruders were recorded, as were the approach and charge velocities. Each of five residents was tested while under three feeding regimes, and in response to three sizes of intruder 120 mm smaller, 10 mm smaller, and of the same size as the resident). Larger intruders were approached and displayed to from greater distances, and charge distance also tended to increase with intruder size. Feeding regime had no effects on aggressive distance. Neither approach nor charge velocity was influenced by intruder size, but charge velocity was highest in the least well fed fish. These results are discussed with reference to the economic defendabilily theory of territoriality.
Characteristics of Nothocriconema sphagni (Nematoda: Criconematidae) from Canada
Authors: Ebsary B. A.
Published: August 2008

Nothocriconema sphagni is redescribed from Canadian populations, extending the distributional range and giving new characters for the male. The juvenile male has a shorter prorhabdion than is previously known and the adult has shorter spicules (31–35 μm vs. 40–42 μm) and is characterized by a mucronated, rather than attenuated, terminus of two to three annules.
An alternative interpretation of the fine structure of the basal zone of the cuticle of the dauerlarva of the nematode Caenorhabditis elegans (Nematoda)
Authors: Popham J. D. , Webster J. M.
Published: August 2008

The fine structure of the basal zone of the cuticle of the dauerlarva of Caenorhabditis elegans was examined in order to help resolve controversies regarding its structure. The results show that the striated layer in the basal zone consists of two sets of laminae oriented at right angles to each other. One set of laminae consists of longitudinally oriented, alternately thick and thin, osmiophilic strips with the distance between similar strips measuring 19 nm. The other set of laminae consists only of thick strips spaced about 14.5 nm apart which are oriented circumferentially about the larva. It is speculated that the striated layer of the basal zone of the cuticle consists of blocks of protein separated by this apparent network of interconnecting osmiophilic laminae.
Feeding habits and diet overlap of three species of garter snakes (Thamnophis) on Vancouver Island
Authors: Gregory Patrick T.
Published: August 2008

Closely related, sympatrtc species of organisms often show resource partitioning. In this study, diet partitioning is examined in three sympalric species of garter snakes (Thamnophis) on Vancouver Island. Thamnophis sirtalis feeds mainly on amphibians and earthworms, Thamnophis ordinoides on earthworms and slugs, and Thamnophis elegans on slugs, fish, and small mammals. Thamnophis sirtalis and T. ordinoides, which are mote widely distributed on Vancouver Island than is T. elegans, have not been shown to modify their diets in the absence of T. elegans, but it is suggested that this lack of niche shift may be due to variations in prey availability. Neither innate differences in food preferences among the species nor interspecific competition for food have been shown to explain the observed differences in diet among the three species. Certain types of prey appear more likely than others to turn up in large numbers in stomach samples and it is suggested that this may be due to variations in ease of capture and (or) abundance. Possible explanations of the observed diets are discussed.
Statistical analysis of geographic variation in the skull of the arctic hare (Lepus arcticus)
Authors: Baker Allan J. , Peterson R. L. , Eger Judith L. , Manning T. H.
Published: August 2008

Morphometric variation in 21 characters of 470 skulls of Lepus arcticus from Canada and Greenland was analysed statistically. Geographic trends in variation were assessed separately in Canada and Greenland using composite samples derived from groupings of geographically contiguous localities. For most characters, univariate analyses revealed clines of decreasing size from the polar regions southwards, though jugal maxillary ridge width exhibited a reverse cline and maxilla orbital process width varied irregularly among samples. Discriminant analysis synthesized these trends such that the phenetic positions of the samples in discriminant space were approximately congruent with their geographic positions. The smoothness of the cline is interrupted between the Queen Elizabeth Islands and the islands of the lower Arctic Archipelago and is not paralleled by similar sharp environmental transitions. Gene flow across the water gap therefore seems to be very restricted. Discontinuities among the Greenland samples can be attributed partly to sampling or distributional hiatuses, but infraspecific differentiation appears to be occurring on either side of the Melville Bay glacial barrier. Statistically significant multiple regressions of factor scores of climatic variables on factor scores of skull morphology suggest thermoregulatory adaptation as a result of selection for increased skull size in colder climates, as is subsumed by Bergmann's rule.
Helminth and arthropod parasites of black bear, Ursus americanus, in central Ontario
Authors: Addison E. M. , Pybus M. J. , Rietveld H. J.
Published: August 2008

One hundred and forty-eight black bears (Ursus americanus) from central Ontario, Canada, were examined for parasites between 1975and 1977. Nine species of helminths and two species of ectoparasites were recovered: Taenia krabbei Moniez, 1879 in 2 of 83 bears; Alaria americana Hall and Wigdor, 1918 in 1 of 83; Baylisascaris transfuga (Rudolphi 1819) in 20 of 83; Crenosoma spp. (C. petrowi Morozov, 1939, C. potos Buckley, 1930, and C. vulpis (Dujardin 1844)) in 21 of 64; Dirofilaria ursi Yamaguti, 1941 in 140 of 148; Physaloptera rara Hall and Wigdor, 1918 in 1 of 83; Trichinella sp. in 1 of 59; Oropsylla arctomys (Baker) on 1 of 5; and Trichodectes pinguis euarctidos Hopkins on 1 of 5 bears. The data are discussed in relation to previous records of parasites within central Ontario and previous reports of parasites of bears. Alaria americana is considered a new host record for North American ursids.
Trehalase activity of serum and whole haemolymph in the American cockroach, Periplaneta americana L.
Authors: Downer R. G. H. , Matthews J. R.
Published: August 2008

The trehalase activity of whole haemolymph of the American cockroach, Periplaneta americana, was compared with that of serum (whole haemolymph from which clotting factors have been removed). The activity of serum trehalase exceeds that of whole haemolymph when insects are in an excited state, but the ratio of serum trehalase to whole-haemolymph trehalase is reversed in rested insects.
Pairing in captive brown-headed cowbirds (Molothrus ater)
Authors: Darley James A.
Published: August 2008

Twenty-five male and 15 female brown-headed cowbirds were captured in the fall of 1966. In mid-December of 1966 they were subjected to extended photoperiod to bring them into breeding condition. Various combinations of yearling and adult males and females were observed in eight trials to determine the effect of age and dominance of males on pairing with females. Both yearling and adult males paired with females. Only dominant males paired with females. Subordinate males remained unpaired if sufficient females were unavailable. These observations confirm impressions formed in field studies on the role of dominance and age in pairing in cowbirds.
Winter bioenergetics of Rocky Mountain bighorn sheep
Authors: Chappel R. W. , Hudson R. J.
Published: August 2008

Changes in voluntary dry matter intake, body weight, and resting metabolic rates at 10 and −10 °C were measured in four adult Rocky Mountain bighorn sheep from October until May. Voluntary intake in mid-February decreased to 0.55 of that in mid-October. Body weights increased until January after which stasis or slight declines occurred. Resting metabolic rate at 10 °C fluctuated without a consistent pattern over winter. Resting metabolic rates at −10 °C were lowest in February and highest in May. The lower critical temperatures of fed animals in winter pelage were below −20 °C. As temperatures were lowered from −20 to −30 °C, metabolic rates increased 1.37- to 1.39-fold. Wind speeds from 4 to 8 m/s increased metabolic rates only at temperatures below −20 °C.
Territoriality and dominance in male Columbian ground squirrels (Spermophilus columbianus)
Authors: Murie J. O. , Harris M. A.
Published: August 2008

We describe the spacing system and associated aggressive behavior of male Columbian ground squirrels in southwestern Alberta for the 2 months following emergence from hibernation. Adult males (> 2 years old) were classified as dominant if they chased other males more than they were chased by them within their core areas and subordinate if the reverse was true. For dominant males, the proportion of interactions in which they were chased was much less within their core areas than outside them, and defended boundaries between some pairs of adjacent males were apparent from locations of chases and chase reversals. We consider these males to maintain spatiotemporal territories. For subordinate males, the proportion of interactions in which they were chased was similar inside and outside their core areas; they were subordinate in most interactions with any territorial male. Status (dominant–territorial or subordinate) was related to age. Most 2- and 3-year-old males were subordinate; all males of 4 years or older were territorial. Among different groups of male Columbian ground squirrels, variation in expression of the spacing system may depend on habitat features that affect visual contact among squirrels and age and length of residence of the males in the area.
Growth and adaptation to sea water in 'underyearling' sockeye (Oncorhynchus nerka) and coho (O. kisutch) salmon subjected to regimes of constant or changing temperature and day length
Authors: Clarke W. C. , Shelbourn J. E. , Brett J. R.
Published: August 2008

Growth and hypoosmoregulatory ability of 'underyearling' sockeye and coho were studied in relation to the influence of constant as well as changing temperature and day length. Both environmental factors influenced growth and osmoregulatory performance. Temperature controlled the rate of response to photoperiod so that changes in growth rate caused by photoperiod treatments were apparent sooner at higher temperatures than at lower ones. Changing temperatures did not alter the final length or weight achieved in comparison with a constant temperature of the same mean.The sensitivity of the fry to photoperiod varied seasonally. The characteristics of photoperiod which formed the most important cues were direction of change and rate of change of day length.It is concluded that artificial photoperiod treatments are not required to produce 'underyearling' sockeye smolts in spring, provided that water temperatures are sufficient to allow growth to a weight of 3–4 g. However, coho smoltify at a larger size and thus would require a substantially greater thermal input to produce 'underyearling' smolts in spring.
A quantitative comparison of morphological characters common to both sexes in the family Phytoseiidae (Acarina: Mesostigmata)
Authors: Rowell H. J. , Chant D. A.
Published: August 2008

Morphological characteristics common to both sexes in 46 species, including exemplars from six genera and four tribes, of the family Phytoseiidae were compared interspecifically, intergenerically, and intertribally. The relationships between the sexes were quantified in terms of correlation coefficients and model II linear regression analyses, comparing the same set of morphological characters in both sexes. It is shown that there is a high degree of association between the males and females of a species despite their obvious morphological differences and that these relationships vary among some systematic groupings. The quantified differences shown between some taxa permit speculation on the phylogenetic relationships between the species studied. The quantitative relationships between the sexes in most cases are shown to be unique for males and females of the same species, offering a numerical method of identifying unknown male specimens. Many morphological characteristics are shown to be consistently shared by both sexes.
Cycle de développement de Leucon nasica (Crustacea, Cumacea) dans la nappe glaciale circalittorale de la baie des Chaleurs, golfe du Saint-Laurent, en 1968 et 1969
Authors: Granger Daniel , Brunel Pierre , Messier Danielle
Published: August 2008

Macer–GIROQ suprabenthic sled tows have brought 166quantitative samples taken bimonthly from June to October 1968–1969 at two monitoring stations (depths 110–119 m) on homogeneous muddy bottoms inconstantly cold (0.1–1.5 °C) water. The population is dominated by immatures and subadults having a rather stable density of about 0.5–1.0 individuals/m3. Mature male densities, marked in July–August by a strong peak mostly at dusk and at night, indicate nuptial swarmings. Females bear an average of 30–60 eggs, 0.40–0.44 mm in size. Fertilization and release of mancas occur mostly in July–August, apparently synchronized with probable food inputs to the bottom from the spring (May) bloom of surface primary production. There are eight postmarsupial instars in both sexes, and sometimes one postadult in females. Maturity is reached after 3 years at 11.3–11.4 mm in length. Mature males die after fertilization. Growth in length is about 24–25% per molt, but lacking at the maturation molt, and flexible in the late immature male.
Time patterns and metabolic rates of natural torpor in the Richardson's ground squirrel
Authors: Wang Lawrence C. H.
Published: August 2008

Using radiotelemetry for body-temperature sensing in field animals, torpor season in the Richardson's ground squirrel (Spermophilus richardsonii) was found to commence from mid-July in adults and mid-September in juveniles and to terminate for both groups in mid-March. The duration of torpor averaged 3 and 4.3 days in July and August and gradually lengthened to 19.1 days in January, after which it shortened to 14.2 and 6.0 days in February and March. The duration of intertorpor homeothermy ranged from 300 to 1500 min. The metabolic costs associated with entry into torpor, during torpor, arousal from torpor, and intertorpor were quantified in the laboratory at ambient temperatures comparable with those observed in burrow. Applying these metabolic data to the time budget for torpor in field animals, the estimated seasonal energetic costs for entry into torpor averaged 12.8% of total, deep torpor 16.6%, arousal from torpor 19.0%, and intertorpor 51.6%. The monthly energy savings by utilization of torpor ranged from 38.8% in July and 51.2% in March to between 81.6 and 96.0% between August and February. For the whole torpor season, which extended 8 months, the energy savings amounted to 87.8%.
Fatty acid composition of blubber from the four species of Bering Sea phocid seals
Authors: West George C. , Burns John J. , Modafferi Marilyn
Published: August 2008

The fatty acid composition of blubber lipid was analyzed from one example of both sexes of the four species of phocid seals inhabiting the Bering Sea: spotted seal (Phoca vitulina largha), ringed seal (P. hispida), ribbon seal (P. fasciata), and bearded seal (Erignathus barbatus). All specimens had similar fatty acid complements (10 fatty acids predominated, ranging from chain lengths of 14 to 22 carbons with zero lo six double bonds) although there were specific differences among species and between sexes. The greatest interspecific differences in blubber fatty acid composition occurred in the ringed seal and may have been due to diet.Double-bond indices (indicating degree of unsaturation) were high in all samples and higher than those calculated for Atlantic or southern hemisphere seals. Melting points of the blubber lipid ranged from −2 to −8 °C for some components; all components melted below 15 °C correlating with expected peripheral blubber temperatures of seals in cold water of the Bering Sea.
Nutrient reserve dynamics of lesser snow geese staging at James Bay, Ontario
Authors: Wypkema Ronald C. P. , Ankney C. Davison
Published: August 2008

We compared mean body weights, nutrient reserves (fat and protein), and an index of feeding of lesser snow geese arriving at and leaving southern James Bay in spring and fall 1976. Feeding increased in spring and decreased in fall. Body weight and protein of adults increased in spring, and fat reserves were maintained. The protein increase of adult females was equivalent to the protein in one egg. Ovarian follicular development in adult females appeared to proceed as reserves became available. Juvenile males had completed body growth by the end of the fall staging period but juvenile females had not. Fat and protein reserves of adults arriving on James Bay in the fall were significantly larger than those of adults after wing molt on the breeding grounds. Fat reserves of adults and juveniles increased significantly during the fall; body weight of juvenile females increased also. The fat gain greatly increases the theoretical maximum flight range of the geese and we suggest it is an important determinant of normal fall migration.
Optimal combination of temperature, humidity, and period for healthy growth of Dermatophagoides farinae (Acarina: Pyroglyphidae)
Authors: Maurya Kashi Ram , Jamil Zafar , Srivastava R. P.
Published: August 2008

The best combination of temperature, humidity, and time for rearing colonies of Dermatophagoides farinae (Acarina: Pyroglyphidae) was found to be 26 °C, 13%, and 13 weeks respectively.
Effects of the food supply on the life history of Simuliidae (Diptera)
Authors: Colbo M. H. , Porter G. N.
Published: August 2008

Data are presented from laboratory experiments to show the effect on the life history of Simulium vittatum and the S. verecundum complex of reducing available food supply. These experiments showed that development time was extended, survival declined, size decreased, and fecundity markedly reduced when food supply was reduced beyond a certain level. Differences between the two species may have an ecological basis. It is argued that such effects occur in natural populations of simuliids and that they have implications for studies of vectors and their control.
The anatomy of the eye of the Adélie penguin with special reference to optical structure and intraocular musculature
Authors: Sivak J. G. , Vrablic O. E.
Published: August 2008

Optical studies have indicated that the penguin cornea is abnormally flattened and it is suggested that this adaptation minimizes the loss of refractive power which accompanies submergence in water. Study of the gross anatomy of the eye of the Adélie penguin supports the optical results; the cornea is small in diameter and it has an abnormally large radius of curvature. Histological study of the intraocular muscles indicates that an accommodative mechanism can compensate for refractive losses in water. The ciliary muscle as well as the iris muscles are striated. Direct action by the ciliary muscle on the crystalline lens is facilitated by the presence of scleral ossicles and an annular pad around the lens. The massive size of the sphincter muscle of the iris as well as its striated appearance agrees with a suggested role for the iris sphincter in accommodation in aquatic birds.
Wing-beat pattern in Rhodnius prolixus Stål (Heteroptera: Reduviidae) during exhaustive flight
Authors: Gringorten J. L. , Friend W. G.
Published: August 2008

Stationary, tethered Rhodnius prolixus males were stimulated to beat their wings for periods averaging 2–3 h. Wing-beat frequency averaged 70 Hz and was quite variable. Wing-beat amplitude declined as the insects approached exhaustion, but no consistent change was observed in beat frequency. Male R. prolixus assumes a characteristic flight posture and exhibits the typical reflexes and anatomical adaptations observed in other flying insects. The long periods of wing beating under laboratory conditions suggest they may be capable of flights of considerable duration in the wild.
Quantifying interspecific variation in foraging behavior of syntopic Anas (Anatidae)
Authors: Eadie John McAllister , Nudds Thomas D. , Ankney C. Davison
Published: August 2008

Foraging behavior of six Anas species was studied during autumn at Long Point Bay. southwestern Ontario. Data were collected using Cody's technique, but statistical analyses identified significant differences among species that could not be discerned from qualitative examination of foraging-behavior curves alone. A relationship between similarity in body size and dissimilarity of foraging behavior was observed.
Factors affecting basking in a northern population of the common snapping turtle, Chelydra serpentina
Authors: Obbard Martyn E. , Brooks Ronald J.
Published: August 2008

Busking behavior was studied in an Ontario population of the common snapping turtle. Atmospheric basking was more common than previously reported in this species. The number of atmospheric-basking turtles was positively correlated with total daily solar radiation and with maximum air temperature and was negatively correlated with total daily amount of precipitation. Maximum water temperature had little influence on the number of atmospheric-basking turtles. Turtles usually basked alone on offshore logs. Mean (27.6 °C) and maximum (34.0 °C) cloacal temperatures of atmospheric-basking turtles were significantly above ambient air temperatures.
The origin and homology of the chondrostean vertebral centrum
Authors: Laerm Joshua
Published: August 2008

The development of vertebral centra in living chondrostean fishes and their structure in fossil forms are reviewed. Vertebral centra or centrum elements form in three ways in chondrosteans: (1) chordal centra occur as calcifications in the notochordal sheath (Australosomus); and perichordal centra occur as either (2) holospondylous ossifications (Polypterus, Pygopterus) or as (3) intercalated chondrifications or ossifications (Australosomus, Birgeria, Haplolepis, Pteronisculus, and Turseodus). The Gadovian view that a primitive chondrostean vertebral pattern exists is unlikely. The differences in developmental patterns of centrum formation suggests chondrosteans lack a common morphogenetic plan for centrum formation. The homology of intercalated elements in different chondrosteans is equivocal and an alternative theory based on their independent origin as space-filling compression members is presented. It is unlikely chondrosteans share a common plan for centrum formation with crossopterygians or dipnoans.
Spermiogenesis in the shrimp, Crangon septemspinosa, Say
Authors: Arsenault A. L. , Clattenburg R. E. , Odense P. H.
Published: August 2008

The spermatozoa of Crangon septemspinosa are composed of an oblong nucleus, an electron-dense acrosome and a cluster of mitochondria and (or) mitochondrial derivatives near each nuclear pole. All components of each spermatozoa are ensheathed by a membrane. The secondary spermatocytes give rise to extensive syncytia within which the spermatid nuclei become organized into clusters. The acrosome develops from a reticulum derived from vacuoles within the core of syncytial cytoplasm common to each spermatid cluster. As spermiogenesis proceeds, the base of the acrosome spreads over the nuclear envelope, each spermatid becomes enclosed in a membrane, and syncytial cytoplasm diminishes in volume and the original clustering of spermatids is lost. The spermatozoa remain within a portion of the syncytial cytoplasm in which they developed and are stored within the ejaculatory tube. According to the fine structural details the differentiation process of spermiogenesis has been divided into four stages.
Incidence of Marvinmeyeria lucida (Hirudinea: Glossiphoniidae) in the fingernail clam, Sphaerium occidentale
Authors: McKee P. M. , Mackie G. L.
Published: August 2008

Marvinmeyeria lucida (Moore, 1954) is noted for the first lime in Ontario. It has been reported to feed exclusively on freshwater gastropods but the present study shows that it also occurs in natural association with the fingernail clam. Sphaerium occidentale (Prime). This small leech is found in the pericardium of its sphaeriid host and shows a marked preference for larger clams (> 5.0 mm shell length). Infestation rates are highest in winter (11.1–15.5%), lowest in spring and fall (1.1–3.6%), and intermediate (4.1–5.4%) in estivating clams. Rates of infestation are inversely related to dissolved oxygen levels in spring, fall, and early summer and to temperature in the fall. Possible commensal, parasitic, and (or} predatory relationships of M. lucida with S. occidentale are discussed.
North American weasels: resource utilization and distribution
Authors: Simms D. A.
Published: August 2008

A livetrapping program, augmented by enclosure experiments, was undertaken to study resource utilization by ermine (Mustela erminea) and long-tailed weasels (M. frenata) in southern Ontario. Data on food habits, habitat preferences, foraging strategies, and competitive interactions were collected. Based on this information, a theory was formulated to explain the distribution or North American weasels. Ermine fed primarily on meadow voles (Microtus pennsylvanicus) and had body diameters closely approximating those of meadow voles, enabling them to readily exploit these items in subnivean and subterranean environments. Long-tailed weasels were larger and their feeding habits were more general. Dietary overlap between the two species in areas of sympatry was 57.5%. Regarding habitat preferences, ermine selected successional communities, whereas long-tailed weasels showed no preferences. Overlap in areas of sympatry was 76.9%.Long-tailed weasels appear to be limited in their northward distribution by snow cover which restricts the size of foraging spaces, thereby conferring an advantage to the smaller weasels. Conversely, the southward distributions of ermine and least weasels (M. nivalis) appear to be limited by interference interactions with long-tailed weasels. Where ermine and least weasels are sympatric, size differences and general distributions suggest that they hunt different prey in different habitats.
Growth stages of the medusa of Proboscidactyla flavicirrata Brandt, 1835 (Hydrozoa; Limnomedusae)
Authors: Rees John T.
Published: August 2008

The growth stages of laboratory-reared medusae of Proboscidactyla flavicirrata Brandt, 1835 which link the polyp with the adult medusa are described. Eggs of female medusae were visible in the gonads after 9 weeks of development. Variability in development of radial canals and gonads was infrequent and possibly the result of poor culture conditions. Nematocysts tended to increase in size as the medusae grew. Medusae were maintained in the laboratory for 121 days.
Evolution in the introduced New Zealand populations of the common myna, Acridotheres tristis (Aves: Sturnidae)
Authors: Baker Allan J. , Moeed Abdul
Published: August 2008

Common mynas were introduced into New Zealand from Australia in the 1870's. Seventy birds released at Wellington have apparently given rise to populations that now occur almost exclusively north of latitude 40° S. Morphometric variation in 28 characters of 307 adults was assessed statistically, based on eight samples spanning their New Zealand range. Univariate analysis revealed that 17 characters of males and 13 of females varied significantly among localities and that birds tend to be larger in the north. Discriminant analysis confirmed the north–south pattern of differentiation but disclosed that the newly established northern populations are very similar morphometrically. Both sexes have differentiated among localities in size and shape. Size variation is aligned with temperature only in males, and shape differences are associated with variation in precipitation in both sexes and altitude in females, females have differentiated in fewer characters than males, but overall, they show a stronger relationship between interlocality and intralocality character variability. Although the adaptive basis of increased size in warmer climates is unclear, the consistency of character covariation in localities with different climatic conditions argues against an ecophenotypic explanation. It is therefore concluded that the New Zealand populations are in the early stages of adaptive differentiation.
Effects of Eubothrium salvelini (Cestoda: Pseudophyllidea) on the growth and vitality of sockeye salmon, Oncorhynchus nerka
Authors: Boyce N. P.
Published: August 2008

Sockeye salmon (Oncorhynchus nerka) fry infected experimentally with the cestode Eubothrium salvelini, as well as noninfected controls, were studied in the laboratory for approximately 1 year through their development to the smolt stage. Fish were weighed and measured at 10-day intervals and tested for stamina in an active capacity tunnel. Parasitism had a deleterious effect on the growth, survival, and swimming performance of the fish.
Investigatory behaviour of plains garter snakes, Thamnophis radix (Reptilia: Colubridae), in tests of repellant chemicals
Authors: Secoy D. M.
Published: August 2008

Nineteen adult and 24 young Thamnophis radix, collected at two sites in southern Saskatchewan, were tested for avoidance to 10 common chemicals and commercial repellants. Avoidance was noted only to a repelling fumigant containing pyrethrum. Analysis of tongue flick rate showed that the adults used this part of searching behaviour significantly more than the young.
Digger wasp predatory behavior (Hymenoptera, Sphecidae): fly hunting and capture by Oxybelus uniglumis (Crabroninae: Oxybelini); a case of extremely concentrated stinging pattern and prey nervous system
Authors: Steiner A. L.
Published: August 2008

Several Orthoptera-hunting wasps usually deliver four paralyzing stings to their prey (one for each thoracic segment and one for the ventral side of the neck) in a predictable, although not immutable, order. This also matches the number of thoracic ganglia of the ventral nerve cord and leg pairs plus the subesophageal ganglion that controls the potentially dangerous mandibles. Oxybelus wasps usually deliver only one thoracic sting, behind one foreleg base, and no neck sting. Many flies have only a single mass of fused ganglia in the thorax, no subesophageal ganglion, and no potentially dangerous mouthparts. Furthermore, some Oxybelus wasps use the sting for prey carriage. The number of thoracic stings matches the number of thoracic ganglionic masses (one), rather than the number of leg pairs (three), thoracic segments (three), or pairs of easily punctured soft membranes (three). This case of extremely reduced paralyzing sequence and prey nervous system is discussed from an evolutionary standpoint and compared with cases in which less or no such reduction occurred. Correlative differences in the state of the prey are also considered.
The erythrocyte plasma membrane in murine muscular dystrophy: a scanning electron microscopic and freeze fracture study
Authors: Atkinson Burr G. , Shivers Richard R. , Nixon Bruce , Atkinson Kristine H.
Published: August 2008

The plasma membrane of red blood cells from mice afflicated with congenital muscular dystrophy exhibits a dramatic depletion of intramembrane particles. Examination of protein particles on fracture faces of erythrocyte plasma membranes from dystrophic mice revealed a 33% decrease in the number of intramembrane particles when compared with similarly prepared erythrocytes from nondystrophic animals. This alteration in the internal molecular architecture of these plasma membranes is correlated with the morphological distortion manifested by most red blood cells from mice inflicted with this genetic disorder.
The oncomiracidium of Urocleidus adspectus Mueller, 1936 (Monogenea: Ancyrocephalinae)
Authors: Cone D. K.
Published: August 2008

The oncomiracidium of Urocleidus adspectus Mueller, 1936 (Monogenea: Ancyrocephalinae) is described and compared with others. Its body is fusiform to pyriform in shape and measures approximately 30 by 75 μm. Sixty-one ciliated locomotory cells are arranged into four zones: an anterior zone with 27 cells; two ventrolateral zones, each with 10; and a posterior zone with 14 cells. An undetermined number of small argyrophilic sensilla occur anteroventrally on the head and 46 (34 dorsal and 12 ventral) large argyrophilic sensilla are on the body and haptor. Four pigmented eyes, 10 flame cells, lipid droplets, and a gut are present. Ten to 12 lateral and 2 median gland cells empty on the prohaptor and 4 posterior gland cells empty on the haptor. Fourteen marginal hooks (10 lateral, 2 posterior, 2 ventral) occur in the haptor, and rudiments of the hamuli are not present.
Nocturnal behaviour of ring-billed gulls during the early incubation period
Authors: Fetterolf Peter M.
Published: August 2008

Observations of ring-billed gull behaviour on Mugg's Island, Toronto Harbour, in 1978 demonstrated that behaviour at night was much less aggressive and more sexual than during the day. The differences were probably caused by reduced visual discrimination and increased fear within the gulls at night. The evolutionary causes and consequences of the behavioural differences are discussed with reference to the temporal and spatial patterns of nesting in ring-bills.
The life-cycle of Bythotiara huntsmani (Fraser 1911) (Calycopsidae, Hydrozoa, Cnidaria)
Authors: Brinckmann-Voss Anita
Published: August 2008

The medusa stage of the hydroid Endocrypta huntsmani (Fraser 1911) is described. The species is transferred to the genus Bythotiara. The hydroid forms a colony in the prebranchial zone of ascidians. The medusa has no marginal bulbs; it has four radial canals and four perradial tentacles with a cnidocyst concentration on each tip. The manubrium has four pointed lips with a band of cnidocyst clusters. There are eight adradial gonads with weak and irregular folds. The medusae live 20 to 30 days.
Underwater vocalizations of leopard seals (Hydrurga leptonyx) and crabeater seals (Lobodon carcinophagus) near the South Shetland Islands, Antarctica
Authors: Stirling Ian , Siniff Donald B.
Published: August 2008

Four underwater vocalizations of leopard seals (Hydrurga leptonyx) and one from the crabeater seal (Lobodon carcinophagus), representing most of their vocal repertoires, are described quantitatively and illustrated with sound spectrographs. Most of the underwater vocalizations given by these seals can now be identified, which will facilitate future investigation of possible geographic variation. Coupled with further studies of diurnal and seasonal variations in seal vocalizations, underwater recording may be used to study sub-ice distribution and possibly relative abundance.