bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal adaptation as a factor affecting colonizing success of introduced Sturnidae (Aves) in North America
Authors: Johnson Stephen R. , Cowan Ian McTaggart
Published: August 2008

Two species of starlings (Sturnidae) have established themselves in southwestern British Columbia: the crested myna (Sturnus cristatellus), by escape from captivity about 5897, and the common starling (Sturnus vulgaris), by natural invasion during the 1950's. The crested myna has shown little capacity to expand its range or its population. The common starling is in an active phase of increasing density and distribution. These sympatric populations have been studied over a period of 3 years. This paper reports comparative aspects of reproduction, and resource use by the two species.We have found that the nesting season for starlings was synchronized into definite peaks of nest building, egg laying, hatching and fledging, which was not the case for crested mynas.Clutch and brood sizes were higher in starlings than mynas. Starlings successfully reared more second broods than mynas (38% vs. 9%). Per 100 pairs/annum, starlings contributed significantly more offspring (547 compared to 238) to the sturnid population.Although development of plumage and endothermy were similar in myna and starling chicks, feeding rates, quality of foods, and subsequent growth rates of chicks were significantly different.Egg transplant and heater nest box experiments suggested that poor nest attentiveness and low incubation temperatures maintained by crested mynas resulted in the low hatching and consequent low fledging success.
Adaptive significance of the caeca in Japanese quail and spruce grouse (Galliformes)
Authors: Fenna L. , Boag D. A.
Published: August 2008

A study of the gross and microscopic anatomy of the caeca of Japanese quail (Coturnix coturnix) and spruce grouse (Canachites canadensis) revealed paired organs that, in combined length, were, respectively, about 35 and 76% of the length of the small intestine, internally, the caeca showed a zonation that reflected differences in lumen size, length of villi, and degree of development of internal folds. The columnar epithelium, lining the caeca, possessed both an absorptive capacity through the presence of microvilli and a secretory capacity through the presence of epithelial glands.Changes in lengths of the caeca in Japanese quail were related to changes in rates of food consumption and not to food quality. Larger volumes of food eaten per day, under colder ambient temperatures, produced significant increases in caecal lengths.We discuss the adaptive significance of the caeca and propose that their major function is to permit a sorting of the intestinal contents: bulky, largely indigestible cellulose material is readily discarded from the intestine and the nutrient-rich residue is retained in the caeca for longer periods of time, where further digestion and absorption probably occur.
Comparative demography of increasing and stable populations of blue grouse (Dendragapus obscurus)
Authors: Redfield J. A.
Published: August 2008

The demographic characteristics of an increasing population of blue grouse were studied from 1968 to 1971. Increasing populations of grouse had high reproductive rates and slightly higher than average mortality rates among females as compared to stable populations.
A biometrical analysis of 22 stocks of four syngens of Paramecium aurelia
Authors: Powelson Elizabeth E. , Gates Michael A. , Berger Jacques
Published: August 2008

Univariate analyses of 22 stocks of four syngens of Paramecium aurelia were conducted to examine the nature and extent of variation in this organism. The problem of syngenic ascertainment by morphology alone has been solved for syngens 1, 2, 4, and 6 by means of multivariate analyses of 20 easily obtained attributes.
Identification of iodoamino acids in the plasma and bile of brook trout, Salvelinus fontinalis (Mitchill)
Authors: Chan Hooi Har , Eales J. G.
Published: August 2008

Thyroxine was the main labelled iodocompound consistently detected by thin-layer chromatography in plasma and bile of starved TSH (thyroid-stimulating hormone) - treated brook trout previously injected with radioiodide. Failure to detect 3,5,3′-triiodo-L-thyronine and iodotyrosines contrasts with results of the few previous studies on circulating iodocompounds in teleosts.No labelled iodoamino acids were detected in plasma of trout held under a variety of conditions but not treated with TSH.
An immunological study of the embryonic stages of the zebra fish, Brachydanio rerio. I. Prehatching-stage antigenic patterns
Authors: Laale Hans , Law Peter Yin-Hong
Published: August 2008

Seven developmental stages of the zebra fish, Brachydanio rerio, namely, ovary, cleavage, high blastula, midgastrula, embryonic shield (11–12 h), optic cup, and hatching stages were analyzed by immunodiffusion and immunoelectrophoresis with unabsorbed and absorbed rabbit antisera to five prehatching developmental stages. The precipitin bands are discussed.
Factors contributing to high levels of plasma iodide in brook trout, Salvelinus fontinalis (Mitchill)
Authors: Gregory Linda A. , Eales J. G.
Published: August 2008

The influences of dietary iodine, ambient iodide, tissue storage of iodide, and iodide binding to plasma proteins have been related to the high plasma iodide in laboratory brook trout.Plasma iodide exceeded 1800 μg/100 ml (μg%) for trout acclimated at 13 °C and fed an Ewos commercial diet. This was largely due to (i) efficient iodide absorption from the gut, and (ii) an iodine concentration in Ewos food (31–35 μg I/g dry wt.) that was 20–78 times greater than that of four other artificial foods or that of several natural food items.Ambient iodide ranged seasonally from 1.26 to2.21 μg I/liter. This source probably contributed little to the high plasma iodide, but helped to maintain plasma levels during starvation or use of low-iodide diets.No major extrathyroidal iodide storage site was found in 15 organs or tissues examined.Iodide binds to brook trout plasma proteins, but the concentration of binding sites is less than that reported for other species. This binding aids maintenance of plasma iodide, particularly when iodide intake is low. Variation in plasma iodide between individual fish was not clearly related to variations in iodide–protein interactions nor to variations in plasma protein levels.
Concerning the mechanics of blastula formation in echinoderms
Authors: Prothero John W.
Published: August 2008

The various postulated mechanisms of blastula inflation are briefly reviewed. The mechanical model of Wolpert and Gustafson is discussed in some detail. Two sets of equations are derived embodying various aspects of their model. One set, which appears to represent the most straightforward interpretation of their statements, is not in agreement with their data. The second set, which is in agreement with their data, is not readily compatible with their statements.
Activity of the pituitary gland in embryo and larval stages of coho salmon, Oncorhynchus kisutch
Authors: Leatherland John F. , Lin L.
Published: August 2008

Embryos of coho salmon appear to regulate their internal osmotic environment actively before hatching (Weisbart 1968). However, at the time of hatching the pituitary contains only small numbers of differentiated cell types and it is only within the 1st week after hatching that a rudimentary follicular rostral pars distalis containing active eta (prolactin) acidophils becomes apparent. This suggests that prolactin, which in adult salmonids appears to be involved in freshwater osmo(iono)regulation, may not be involved in the same way in the early larval stages.Late-stage coho alevins can withstand ambient salinities up to 65% seawater for a period of 3 to 4 days. Under these conditions the prolactin cells become less active than in similar fish acclimated to distilled water or well water. The data indicate that the endocrine regulation of freshwater osmo(iono)regulation in late alevins and early fry stages may be similar to that found in adults. The evidence for the involvement of other pituitary factors in the hydromineral regulation of coho fry in hypoosmotic or hyperosmotic environs is inconclusive.Morphological studies of the chorion of the egg and of the yolk sac of the embryo and alevin suggest that these organs are not actively involved in hydromineral regulation.
A note on the caudal neurosecretory system and seasonal changes observed in the urophysis of Rita rita (Bleeker)
Authors: Sharma Sureshwar , Sharma Ashok
Published: August 2008

The general histomorphology of the caudal neurosecretory system of Rita rita has been studied in samples taken each month of the year. During the breeding months (August and September) the stored material disappears from a considerable number of Herring bodies, leaving lacunae in their place. Simultaneously blood capillaries increase in volume. In the light of these findings, a correlation has been established between this system and reproduction.
Factors influencing activity patterns of ungulates at mineral licks
Authors: Carbyn L. N.
Published: August 2008

Seasonal and daily visits to mineral licks by Cervus canadensis (elk or wapiti) and Odocoileus hemionus (mule deer) fluctuated during May to August in 1971 and 1972.The emphasis in this study was on the diurnal activity patterns of these ungulates. Results of their presence at lick sites were analyzed in relation to time of day, temperature, and humidity. A stepwise, multiple regression analysis was applied to identify the important dependent factors.There was a high negative correlation between humidity and the number of "lick visits." Temperature was not as important an environmental factor as humidity. Large carnivores, particularly Canis lupus (wolves) were common in the area; however, there was no evidence that predation pressures influenced the activity patterns of the ungulates.
Ultrastructural studies of the epidermis and gastrodermis of Syndesmis franciscana (Turbellaria: Rhabdocoela)
Authors: Holt Portia A. , Mettrick D. F.
Published: August 2008

Ultrastructural studies of the umagillid Syndesmis franciscana have revealed that it shares morphological characteristics with free-living turbellarians. The epidermis consists of a single layer of ciliated, columnar cells resting on a basal lamina. Organellar stratification is observed within these cells. Nuclei, mitochondria, and Golgi bodies are situated in the basal regions. Ciliary rootlets, microfilaments, and microtubules are associated with a terminal web-like zone in the apical areas. Neither epidermal nor subepidermal gland cells were observed in somatic regions. Rhabdites and pigment granules are lacking.The gastrodermis consists of a single layer of nonciliated columnar cells resting on a basement layer. The intestinal lumen is temporarily open. When food passes into the intestine, opposing luminal surfaces meet, causing local occlusions.The pharyngeal cavity, enclosed within the barrel-shaped pharynx, is lined by esophageal gland cell processes. Ciliates, identified as the sole food element, were found to be species of Entorhipidium. They are ingested and pass intact through the pharynx to the anterior intestinal lumen. In the intestine they were found in all stages of degradation within luminal, extraluminal, and intracellular vacuoles. Lipid droplets were frequently found in extraluminal vacuoles and in the ciliates present in such vacuoles. A mechanism for uptake of digested material is suggested by the occurrence of micropinocytotic vesicles associated with the extraluminal vacuoles.
Prevalence and histopathology of Echinocephalus sinensis (Nematoda: Gnathostomatidae) in natural and experimental hosts
Authors: Ko Ronald C. , Morton Brian , Wong P. S.
Published: August 2008

Examination of 240 oysters (Crassostrea gigas Thunberg) cultured in Hong Kong showed that 31% of the animals were infected with the larvae of Echinocephalus sinensis Ko, 1975. The worms were located in the genital ducts or Leydig tissue. The prevalence of infection appeared to increase with age. Fibroplasia, and infiltration of amoebocytes were commonly observed at the infected sites.Eleven of 15 eagle rays (Aetabatus flagellum) were found to be infected with adult E. sinensis. Worms were located in the intestine, either in nodules or attached directly to the intestinal wall. Infiltration of leucocytes and fibrinous exudation were commonly seen at the infected sites.Worms were found partially embedded in the stomach and the small and large intestine of a cat and a rhesus monkey experimentally infected with larval E. sinensis from oysters and examined 19 and 17 h post infection. Some worms had penetrated as far as the muscularis externa. Intensive cellular infiltrations were seen at the infected sites.
The structure and development of the pigmented retinal clone
Authors: Crawford Bruce J.
Published: August 2008

Cytological changes during growth and differentiation of chick pigmented epithelial cells in clonal culture are described at the light microscope level. Initially the cells are squamous and unpigmented. By 3 weeks, cells in the center of the colonies are highly differentiated, i.e. they are polygonal in shape and densely pigmented. During differentiation, cells in the center of the colony pass through a series of morphological stages comparable to those seen from the edge to the center of a 3-week-old clone. Cells in the inner two zones of a differentiated colony resemble stages found during differentiation in vivo. Those in the outer two zones appear to have no morphological counterparts in the intact animal.Extracellular materials are abundant in the stratified zone of the colony. These exhibit staining properties similar to those of acid mucopolysaccharides found in the developing retina. Vacuoles containing a flocculent material appear within the differentiated cells of colonies older than 2.5 weeks. Later, some of these vacuoles disappear and flocculent material is found between the cells and the plate. The possible significance of these observations is discussed.
Bacteria as food for temperate-water marine sponges
Authors: Reiswig Henry M.
Published: August 2008

Samples of ambient aquarium water (inhalant) and oscular stream (exhalant) of the sponges Haliclona permollis (Bowerbank) and Suberites ficus (Johnston) were analyzed for bacteria by three methods. Bacterial removal efficiencies were 70.3 and 77% from plate cultures, 44 and 68% from surface fouling, and 77% from direct filter counting in a single transit of the sponge filter. Bacteria alone can satisfy the entire food requirements for these sponges. Bactericidal activity is not expressed in exhalant water samples. If bacterial toxins are produced by these sponges, their activity must be restricted to local sites within the confines of the organisms.
Synthesis and turnover of haemolymph proteins during the reproductive cycle of Glossina austeni
Authors: Tobe S. S. , Davey K. G.
Published: August 2008

The synthesis of haemolymph proteins during the first two pregnancy cycles of the tsetse fly, Glossina austeni, has been investigated by observing the incorporation of 14C-tyrosine and 3H-leucine into the TCA-precipitable fraction. In general, there is a rapid synthesis of haemolymph proteins, with a preferential utilization of 3H-leucine, in newly emerged flies. By the time of the first ovulation, the level of synthesis has dropped, and after this time, there is an apparent preferential incorporation of l4C-tyrosine into haemolymph protein. However, at the first larviposition (L1), there is a rise in incorporation of both amino acids. Haemolymph protein rich in tyrosine has a lower rate of turnover than leucine-rich protein.The percentage incorporation of both 3H-leucine and 14C-tyrosine into haemolymph protein was also determined. At most times during the first-two pregnancy cycles, there is about 2% incorporation. However, in newly emerged flies, the incorporation of 3H-leucine reaches 7%, whereas at L1, about 7% of the 14C-tyrosine is incorporated into haemolymph protein.TCA-soluble label remaining in the haemolymph has been observed during the pregnancy cycles. Whereas 3H-leucine is apparently continuously removed from the haemolymph, 14C-tyrosine, at least at certain stages, may be released into the haemolymph. The significance of these results is discussed in terms of nutrient transfer in Glossina.
Avian Haemoproteidae. 5. The haemoproteids of the family Threskiornithidae
Authors: Bennett Gordon F. , Greiner Ellis C. , Campbell A. G.
Published: August 2008

The haemoproteids of the avian family Threskiornithidae (ibises and spoonbills) are reviewed. Two species, Haemoproteus pelouroi Tendeiro, 1947 and H. plataleae de Mello, 1935 are considered to be valid; these two species are redescribed, illustrated, and compared with similar species in the Gruidae (cranes). Records of Haemoproteus in the ibises and spoonbills are summarized. Haemoproteus galatheae Laird and Laird, 1959 is rejected as a synonym of H. plataleae.
On the prey-catching pedicellariae of a starfish, Stylasterias forreri (de Loriol)
Authors: Chia Fu-Shiang , Amerongen Helen
Published: August 2008

The structure and arrangement of the 35 teeth on each jaw and the positioning of one set of adductor muscles of the crossed pedicellariae in the starfish Stylasterias forreri are excellently adapted for capturing and retaining active prey species, such as fishes.
Thermal regulation of spring mating behavior in the red-sided garter snake (Thamnophis sirtalis parietalis)
Authors: Hawley Alexander W. L. , Aleksiuk Michael
Published: August 2008

Exposure of Thamnophis sirtalis parietalis to elevated temperatures immediately after emergence from hibernation induced intense mating behavior. The thermal threshold for courtship varied widely among individuals, and ranged from below 5 °C to between 20° and 25 °C. The lowest temperature at which copulation occurred was 10 °C. Both courtship and copulation increased with increasing temperature, and reached maximal levels at 25° and 30 °C respectively. The existence of low thermal thresholds for mating behavior and the marked stimulating effect of temperature on mating behavior explain the rapid onset of courtship and copulation after emergence from hibernation. A possible mechanism for thermal induction of mating behavior is discussed.
Reproductive performance and growth in captive collared lemmings (Dicrostonyx groenlandicus)
Authors: Hasler J. F. , Banks E. M.
Published: August 2008

Various aspects of reproduction and growth were studied in a laboratory colony of collared lemmings (Dicrostonyx groenlandicus). Males and females were maintained successfully as breeding pairs, and as many as 17 successive litters were produced by one pair. Litter size increased with parity through the third litter and decreased after the eighth. Gestation, which was 19.5 to 21.5 days in non-lactating females, was extended to a maximum of 23 days in lactating females. Postpartum estrus continued throughout the duration of lactation in some females. Males made up less than 38% of the total number of lemmings produced in the colony, regardless of litter size or age at sexing. There was a significant amount of heterogeneity in the sex ratios produced by different pairs of lemmings. Rabbit chow increased reproductive performance compared with a fresh produce diet. Reproductive performance was increased by long photoperiod compared with short photoperiod. Birth weight was independent of litter size but weaning weight was negatively correlated with size of the litter.
Courtship behavior of phycitid moths. II. Behavioral and pheromonal isolation of Plodia interpunctella and Cadra cautella in the laboratory
Authors: Grant G. G. , Smithwick E. B. , Brady U. E.
Published: August 2008

Interspecific courtship was observed between the Indian meal moth, Plodia interpunctella, and the almond moth, Cadra cautella. Successful cross-mating did not occur, however, because of the following isolation mechanisms: (1) incompatible courtship behavior, (2) male sex pheromone as a species recognition signal, (3) inhibition of males to female sex pheromone stimulation, and (4) mechanical or physiological barriers to insemination.Male Indian meal moths were strongly excited by calling almond moth females and courted them vigorously. However, because the courtship behavior of this combination was incompatible, copulation did not occur. Occasionally courtship continued to a later stage in the sequence but then the female rejected the male apparently because he releases an inappropriate aphrodisiac from his scent scales.In the reciprocal cross, fully two-thirds of the almond moth males failed to be sufficiently excited by Indian meal moth females to court them. Most of these males were inhibited, as indicated by their subsequent lack of response to pheromone extracts from their own female. Those males which were excited by Indian meal moth females courted them successfully and copulated, but insemination apparently did not occur. In a few cases the females rejected the males, as in the reverse cross.
Histochemistry and the structure of the skin of a murrel, Channa striata (Bloch, 1797) (Channiformes, Channidae). I. Epidermis
Authors: Mittal A. K. , Banerjee T. K.
Published: August 2008

The functional organization and cytochemistry of the epidermis of an air-breathing fish, Channa striata, is described. In the basal cells a dense population of mitochondria, strong alkaline phosphatase, and succinic dehydrogenase activity indicates high metabolic activity. In the outermost layer, polygonal cells showed strong succinic dehydrogenase activity and elaborated sulfated acid mucopolysaccharides and lipids. Mucous cells were also numerous. A new term, 'sacciform granulated cells,' is proposed for the 'sacciform cells' or 'granular cells.' The contents of these cells are basic proteins. A thick coat of slime containing mucopolysaccharides, lipids, and basic proteins is probably important in keeping the skin moist for cutaneous respiration, retarding the rate of water loss by evaporation, facilitating burrowing in the mud and swimming movement in water, and protecting the skin from bacterial and fungal attacks. A relatively thin epidermis (32 μm on the general surface, 18 μm at the posterior free margins, and 6 μm below the scales) in conjunction with vascularization of the stratum laxum probably assists cutaneous respiration.
High-arctic lemmings, Dicrostonyx groenlandicus. II. Demography
Authors: Fuller W. A. , Martell A. M. , Smith R. F. C. , Speller S. W.
Published: August 2008

Captures of Dicrostonyx groenlandicus on northeastern Devon Island peaked in 1969 and 1973, were higher than expected in 1971, and were minimal (< 5 per 1000 trap-nights) in 1970 and 1972. Captures declined from July to August in at least five of seven summers and may have declined in a 6th year (1973). No change was detected in 1972. Body size was maximal in 1973 for mature and immature males and females and for all pelage (=age?) classes. Sexual maturity was delayed, at least in males, in 1973. Wintering females conceive under the snow in May and the litter is weaned at the normal time of snowmelt. Two other summer cohorts are produced by surviving old females and early maturing females of the first litters. None of the late summer cohort matures before the onset of winter. No female examined bore more than two summer litters. Mean summer litter size was 5.7 with no significant variation between years. Mean sex ratio was 50.3% male. It is suggested that density-related effects ought to occur in winter, rather than summer, but evidence on this point is equivocal. Arctic adaptations of D. groenlandicus are discussed.
Biology of tree-hole mosquitoes: photoperiodic control of development in northern Toxorhynchites rutilus (Coq.)
Authors: Bradshaw William E. , Holzapfel Christina M.
Published: August 2008

Carnivorous larvae of the tree-hole mosquito, Toxorhynchites rutilus, were collected from the northern portion of their range. Long days were found to promote rapid growth and metamorphosis from egg to adult; short days retard development during the second and third instars and evoke diapause in the fourth. All larvae exposed continuously to long days from embryos to the third or fourth instar developed without entering diapause. Diapause-averting long days experienced earlier in development could be reversed in at least some individuals by subsequent short days. Among laboratory-reared larvae or those caught early in the fall, the critical photoperiod for the maintenance of diapause is around 13 h of light per day. Among larvae caught in midwinter, diapause is not maintained in all larvae at any photoperiod and in 50% or less of the larvae at photophases shorter than 12.5 h. Winter conditions in the northern part of the range of T. rutilus appear to play a prominent role in the maintenance and termination of diapause.
Indolealkylamines in the coordination of nematode behavioral activities
Authors: Croll Neil A.
Published: August 2008

Nematode movements result from spontaneous myogenic depolarizations, neuromuscular coordination, and localized hydrostatic changes. These components are integrated into activities which are mutually exclusive or interdependent. Nervous connection is not known between all the organ systems, and the pharynx and female tract are somewhat autonomous. This problem is discussed, as is the limitation of a theory involving only cholinergic transmission. Serotonin, 5-hydroxytryptophan (5HTP), and epinephrine were all found to induce rapid and prolonged contractions in the female vagina/vulva of Caenorhabditis elegans, Aphelenchus avenae, Panagrellus redivivus, and Oswaldocruzia filiformis. It also caused spicule extension in males of P. redivivus. The responses are fully described together with dose-response data and the effect of adult age. The potential significance of indolealkylamines in nematode behavioral coordination is discussed, together with the relevance of anthelmintic formulation and the basis of immunological rejection.
Studies on monogenetic trematodes. XLVI. A redescription of Tetraonchus alaskensis Price, 1937 and a review of the family Tetraonchidae Bychowsky, 1937
Authors: Mizelle John D. , Crane John W.
Published: August 2008

Tetraonchus alaskensis Price, 1937 is redescribed with several differences from, and additions to, the original description. A review of the genus Tetraonchus is given from its original description to the present status of the family Tetraonchidae Bychowsky, 1937. The genus Salmonchus Spassky and Roytman, 1948 and the subgenera Tetraonchus and Salmonchus Strelkov, 1963 are rejected on a comprehensive basis. A host–parasite list, and a parasite–host list are presented. Presently there are 17 species belonging to the single genus Tetraonchus in the family Tetraonchidae.
Avian Haemoproteidae. 6. Description of Haemoproteus caprimulgi sp. nov., and a review of the haemoproteids of the family Caprimulgidae
Authors: Williams Norman A. , Bennett Gordon F. , Mahrt J. L.
Published: August 2008

Haemoproteus caprimulgi sp. nov. is described from the common nighthawk, Chordeiles minor (Forster), from Vancouver Island, British Columbia. This represents the first specific taxonomic designation of a haemoproteid from the family Caprimulgidae. The haemoproteids of the Caprimulgids are reviewed, and hosts and geographic distributions are summarized.
Phallodrilus hallae, a new tubificid oligochaete from the St. Lawrence Great Lakes
Authors: Cook David G. , Hiltunen Jarl K.
Published: August 2008

The predominantly marine tubificid genus Phallodrilus is defined, a key to its nine species constructed, and an illustrated description of Phallodrilus hallae n. sp. from the St. Lawrence Great Lakes presented. The species is distinguished from other members of the genus by its well-developed atrial musculature, extensions of which ensheath the posterior prostatic ducts.Phallodrilus hallae n. sp. is a small worm which is widely distributed in the sublittoral and profundal benthos of Lake Superior; lakewide it occurred in mean densities of 50 individuals per square metre. Available records indicate a more restricted distribution in Lake Huron and Georgian Bay. We suggest that P. hallae n. sp. is either a glaciomarine relict species, or that it entered the Great Lakes system at the time of the marine transgression of the St. Lawrence valley. The apparent restriction of P. hallae n. sp. to waters of high quality suggests that it may be a sensitive oligotrophic indicator species.
Winter coexistence of voles in spruce forest: relevance of seasonal changes in aggression
Authors: Turner Brian N. , Perrin Michael R. , Iverson Stuart L.
Published: August 2008

Beginning in November 1973, numerous meadow voles (Microtus pennsylvanicus) moved onto a spruce forest grid occupied by red-backed voles (Clethrionomys gapperi). A resident meadow vole population resulted, the two species coexisting until April 1974, when most meadow voles disappeared from the grid during a relatively short period. Interspecific aggression levels, as determined from voles temporarily removed from the populations and tested in paired encounters in a laboratory arena, were low during the winter, but increased when males of both species entered reproductive condition in the spring. Microtus was generally dominant in early breeding period encounters, but this dominance declined concurrently with the meadow voles' disappearance from the forest. It is argued that meadow voles did not leave the forest to breed, or because the snow cover melted, since this species will live and reproduce in forest in the absence of Clethrionomys. The results are interpreted as support for an earlier hypothesis that competitive habitat exclusion varies seasonally with reproduction-related aggression. Thus, these species apparently may coexist in either of their preferred habitats when interspecific aggression is low (the nonbreeding season), but this relationship terminates when interspecific aggression levels increase with the resumption of breeding in the spring.
Seasonal changes in louse populations on white-tailed deer (Odocoileus virginianus)
Authors: Watson Thomas G. , Anderson Roy C.
Published: August 2008

The hides of 47 white-tailed deer (Odocoileus virginianus) shot at Long Point, Ontario, between September 1972 and August 1973 were examined for lice. Adult Tricholipeurus lipeuroides were most abundant from January to April and T. parallelus from May to August. The distributions of biting lice changed over the study period, possibly influenced by environmental factors such as solar radiation, temperature, rainfall, and changes in pelage. Solenopotes ferrisi was found throughout the study period. There was no significant change in abundance of the various louse stages throughout the study, although all stages were slightly more numerous during winter. Adults primarily infested the head and neck, while immature stages infested upper body regions. Changes in distribution of lice may be the result of environmental and host pelage changes.
Improved techniques for rapid removal of mandibular glands from worker honeybees
Authors: Liu Ying-Shin , Jay S. C.
Published: August 2008

A dissecting apparatus was designed for removing the mandibular glands from large numbers of worker honeybees within a short period of time. The mortalities of the worker bees after gland removal, although low, were significantly higher than the non-treated control bees.
Utaperla gaspesiana sp. nov., le premier Plécoptère Paraperliné de l'Est canadien
Authors: Harper P. P. , Roy D.
Published: August 2008

The adult male of Utaperla gaspesiana, a new species of stonefly from the Gaspé Peninsula (Quebec), is described and illustrated. This is the first record of a member of the Paraperlinae (Chloroperlidae) from Eastern Canada. The relations of this new species with the other two known species of the genus, the western nearctic U. sopladora and the eastern palaearctic U. orientalis are briefly discussed.
Ornithophilic vectors of avian hematozoa in insular Newfoundland
Authors: Bennett Gordon F. , Coombs Richard F.
Published: August 2008

Ornithophilic vectors of avian hematozoa on the Avalon Peninsula, Newfoundland, were determined to be Simulium latipes and S. aureum for Leucocytozoon, Culicoides stilobezzioides for Haemoproteus, and possibly, on circumstantial evidence, Aedes punctor for Plasmodium. Simuliids and ceratopogonids were captured following attraction to bird bait most frequently at heights of 3–4 m in the forest canopy, in the evening, during July and August. Vector density was extremely low when compared to elsewhere in North America, but the highly efficient host–vector–parasite relationship maintained a high prevalence of blood parasites in the bird population.
Plasma cells in the avian Harderian gland and the morphology of the gland in the rook
Authors: Burns R. B.
Published: August 2008

Plasma cells occur in the Harderian glands of 32 species of birds investigated. They are found in the interstitium of the gland among the primary and secondary tubules. In the fowl, quail, and turkey and to a much lesser extent in the duck, their numbers increase with age. Other cells of the lymphoid series were only rarely seen. Foci of lymphocytes were encountered in few Harderian glands. Mott cells (Russell-body-containing plasma cells) occur among the plasma cells of all avian Harderian glands. Their numbers follow the pattern of plasma cell numbers.The rook Harderian gland has been studied and compared with other avian Harderian glands of similar morphology. Macroscopically it is a uniform structure but histologically it is composed of two lobule types. Type I lobules are compound tubuloacinar structures with a large plasma cell population in the interstitium. Type II lobules are compound tubular and have no plasma cells. The rook Harderian gland forms the "type specimen" for a third category of avian Harderian glands. The other two kinds may be compared with that of the fowl (type I) and with that of the duck (type II).
Chemical variability in plumage of wild lesser snow geese
Authors: Kelsall John P. , Pannekoek W. J. , Burton Roland
Published: August 2008

This experiment was designed to show whether there were chemical differences within a population of wild lesser snow geese between the plumage of young of the year and older birds, males and females, left and right wings, and among primary flight feathers 2 to 7, inclusive. The chemical elements Na, Ca, K, Cu, Fe, Mg, Mn, Zn, and Si were used as variables. Many points of statistically significant difference were found, some reflecting physiological and metabolic differences associated with sex and growth.Tests for analytical error, due to technique or equipment, showed it to be large. That result emphasizes the need to randomize the order in which samples are run in this sort of work, and the need for adequate numbers of samples.
Factors influencing ovary development of worker honeybees of European and African origin
Authors: Jay S. C.
Published: August 2008

The effect of the presence of a queen, pollen feeding, and the presence of worker comb on ovary development of worker bees of European and African origin were assessed after they had been caged for 10 days. There was no significant difference in ovary development of workers of European and African origin. The presence of worker comb appeared to stimulate ovary development in workers in cages without queens when pollen was present, or absent, in the diet. No eggs were found in any of the cages.
Photobehavioral differentiation within and between the sexes of Drosophila pseudoobscura
Authors: Rockwell Robert F. , Harmsen Rudolf , Cooke Fred , Grossfield Joseph
Published: August 2008

Photoresponse and changeability of photoresponse were measured separately with males and females of Drosophila pseudoobscura. The measurements indicate no sexual dimorphism in photobehavior, but do show a distinct sexual dimorphism in changeability of photobehavior. Differentiation between isofemale lines of the population was observed from photobehavior and shown to be of equal magnitude in both sexes. However, such isofemale line differentiation in changeability of photobehavior was very low and restricted to females. Previously published work indicating sexual dimorphism in photobehavior may be the result of experimental designs confounding two effects: (1) photobehavior per se, and (2) changeability of photobehavior.This study of photobehavior suggests that two distinct, but not necessarily mutually exclusive, strategies are involved in the development of intrapopulation differentiation: one leading to a high degree of sexual dimorphism, the other leading to intrasexual differentiation. Concerning the former, it is methodologically and conceptually important to separate sexual dimorphism related to sexual selection from that related to ecological selection. This separation may be easier with behavioral traits than with morphological or biochemical traits.
Erratum: The effects of capture, "stress," and storage of whole blood on the red blood cells, plasma proteins, glucose, and electrolytes of the winter flounder (Pseudopleuronectes americanus)
Authors: Fletcher G. L.
Published: August 2008

not available
Solitary play of the red squirrel (Tamiasciurus hudsonicus)
Authors: Ferron Jean
Published: August 2008

A description of the different forms of solitary play behavior in the red squirrel (Tamiasciurus hudsonicus) is presented here. These play activities are subdivided into two main groups: non-directed and object-directed. In the first are included (a) tumbles on the ground; (b) leaps and feats of skill in trees; (c) body shaking while suspended by the feet, and (d) running. In the second the motor patterns can be (a) gnawing, eating and caching food; (b) rubbing against an object; (c) acrobatic use of an object; (d) play-fighting with objects, and (e) chasing and play-fighting with the tail. The comparison of the solitary play behavior of the red squirrel with that of some other sciurids shows that this behavior seems to be almost non-existent in the social species studied so far and is subject to variation with age at the intraspecific level. It is suggested that a certain relation exists between the degree of sociability and the relative proportion of solitary and social play activities.
Cestodes of the genus Hymenolepis Weinland, 1858 (sensu lato) from bats in North America and Hawaii
Authors: Rausch R. L.
Published: August 2008

Hymenolepidid cestodes obtained through the examination of 539 vespertilionid bats representing 15 species and five genera, collected in three regions of North America and on the Island of Hawaii, were studied. Three species of the genus Hymenolepis Weinland, 1858 sensu lato, previously known from nearctic Chiroptera, are redescribed: H. christensoni Macy, 1931, H. roudabushi Macy and Rausch, 1946, and H. gertschi Macy, 1947. A fourth, H. lasionycteridis sp. nov., recorded from bats of eight species in North America and Hawaii, is described and distinguished morphologically from the other species of Hymenolepis s.l. characterized in part by the presence of an armed rostellum and occurring in bats. The presence of this cestode in the Hawaiian hoary bat, Lasiurus cinereus semotus (Allen), indicates that at least some of the progenitors of the population on the Island of Hawaii were migrants of western North American origin. The zoogeography of cestodes in bats is briefly discussed.
Calculated risk-taking by predators as a factor in Batesian mimicry
Authors: Dill Lawrence M.
Published: August 2008

A simulation model is constructed from a set of disc equations (Holling 1959b) incorporating a probability term which represents calculated risk-taking by the predator, and determines the proportion of encountered models and their perfect Batesian mimics which are sampled by the predator. The risk-taking parameter (R) is assumed to be a function of both mode:mimic ratio (the higher the ratio, the lower R) and availability of alternate prey (the greater the availability, the lower R).The model was tested with an artificial predator–prey system in the laboratory, and was able to predict mimic mortality under most conditions. Computer simulation experiments were then conducted to explore a variety of relationships, including the functional response to mimic density, the effect of alternate prey density on mimic mortality, and the effect of proportion of models on the effectiveness of mimicry as an anti-predator strategy. Despite its simplicity the model makes predictions qualitatively similar to those of more complex models, and to the results of various empirical studies of mimicry. The importance of considering the alternate prey to be an integral component of any mimetic system is discussed.
Two species of Myxobilatus (Myxosporida: Myxobilatidae) from freshwater fishes of western Canada, with description of M. yukonensis sp. nov.
Authors: Arthur J. R. , Margolis L.
Published: August 2008

Myxobilatus yukonensis sp. nov. and Myxobilatus gasterostei (Parisi, 1912) sensu S. Shulman, 1953, are described and figured from the kidney tubules and urinary bladder of Cottus cognatus Richardson from Aishihik Lake, Yukon Territory, and Gasterosteus aculeatus Linn. from Vancouver Island, British Columbia, respectively.
The Rhodnius testis: hormones, differentiation of the germ cells, and duration of the molting cycle
Authors: Dumser J. B. , Davey K. G.
Published: August 2008

Allatectomy of third- and fourth-stage Rhodnius larvae results in the production of precocious adults at the succeeding molt. When the allatectomy is performed on fourth-instar larvae, the testes of which contain spermatocysts of approximately 26 cells, spermatozoa are evident in the testis of the resulting precocious adult. If the allatectomy is performed on third-instar larvae, the testes of which contain spermatocysts of approximately 24 cells, the precocious adult never shows germ cell development beyond the early spermatocyte (28) stage, in spite of extensive metamorphosis of mesodermal and ectodermal structures. These results support the view that differentiation of the male germ cells in insects is inflexibly tied to a species-specific division sequence, and thus not directly manipulable by morphogenetic hormones. Evidence is also presented that the presence or absence of juvenile hormone influences the duration of the molt and hence the available time for germ cell division within each instar.
Endocrine activity during caste differentiation in Zootermopsis angusticollis Hagen (Isoptera): a morphometric and autoradiographic study
Authors: Yin Chih-Ming , Gillott Cedric
Published: August 2008

The diameters of the median neurosecretory cells (MNC) and their nuclei, and the volumes of the corpora cardiaca (CC) and corpora allata (CA) were measured in termites (Zootermopsis angusticollis) of differing age, sex, and caste. The synthetic activities of the MNC and CA were estimated autoradiographically.No significant differences in the diameters of the MNC and their nuclei were observed between insects of differing age, sex, and caste, with the exception of primary reproductives whose MNC are significantly larger than those of larvae of the same instar. The six types of MNC distinguishable histologically differ in their nuclear diameter : cell diameter ratios and in their rates of [3H]uridine and [3H]cystine incorporation.The volumes and (or) synthetic activities of the CA change markedly during the differentiation of reproductives and soldiers. The CA of recently molted primary and supplementary reproductives are several times larger than those of larvae and nymphs of the previous instar, yet their synthetic activity remains low. In contrast, the CA of presoldiers and soldiers are only slightly larger than those of previous instar larvae, but show high synthetic activity. The data are discussed in terms of the endocrine control of caste differentiation.
Endocrine control of caste differentiation in Zootermopsis angusticollis Hagen (Isoptera)
Authors: Yin Chih-Ming , Gillott Cedric
Published: August 2008

The effect of injection of Röller's juvenile hormone (JH) or farnesyl methyl ether (FME) on differentiation of supplementary reproductives and presoldiers of Zootermopsis angusticollis has been studied. Early in the stadium (that is, during the competence period) Röller's JH and FME inhibit differentiation. When injected after the competence period the substances do not alter the rate of supplementary reproductive differentiation in orphaned colonies but enhance presoldier differentiation in soldierless colonies provided that there is a sufficient number of supplementary reproductives present.A modified version of Lüscher's (1960) hypothesis for the endocrine control of caste differentiation is proposed. It is suggested that all the developmental possibilities that exist in the termite colony can be explained on the basis of a single corpus allatum hormone produced in different quantities and at different times within the stadium.
Observations on the establishment, growth, and development of Hymenolepis hopkinsi Schiller, 1951 (Cestoda) in the mallard
Authors: McLaughlin J. Daniel
Published: August 2008

Most young H. hopkinsi become established in the caeca of 3-week-old mallards 6 h after ingestion. Migration of H. hopkinsi into the caeca is completed within 36 h after infection. Worms increased in size rapidly between 6 h post infection and 7 days post infection, when the worms became gravid. The worms maintained a relatively constant size from day 7 until the termination of the experiment (day 19). Proglottid production begins 12–24 h after infection and the number increases rapidly until day 7. The mean number of proglottids per worm remained relatively constant until the termination of the experiment. Egg packets of H. hopkinsi are passed periodically in the caecal evacuations beginning 7 days after infection. These are infective immediately to the intermediate host Hyalella azteca.
Les Cladocères littoraux de trois lacs des Laurentides à Saint-Hippolyte (Québec)
Authors: Margaritora Fiorenza G. , Magnin Etienne , Pinel-Alloul Bernadette
Published: August 2008

Some littoral species of Cladocera of Quebec were studied in a series of samples collected from March to October 1974, in three lakes at the Biology Station of St. Hippolyte. Forty-three species of Cladocera are listed, bringing to 71 the number of species known in Quebec. Sixteen are described for the first time in this region; 2 of them, known in North America, are new ones for Canada (Alona circumfimbriata Megard and A. rustica americana Flössner and Frey). Also given are some ecological, biological, and systematic details concerning the most important species.
Reproduction et dynamique de population de la barbotte brune Ictalurus nebulosus (Le Sueur) dans la frayère de la rivière aux Pins, fleuve Saint-Laurent, près de Montréal (Québec)
Authors: Harvey Gilles , Fortin Rejean
Published: August 2008

Two trap nets set in Rivière aux Pins, near its confluence with the St. Lawrence River, permitted the capture and subsequent marking or tagging of adult brown bullhead for the study of their reproductive biology and population dynamics. Spawning activity is examined in relation to water temperature and water level which, in 1976 and 1977, was controlled by means of a log weir, in order to enhance northern pike reproductive success. The study of sex ratio, sexual maturity, gonadosomatic ratio, and fecundity served to characterize the Rivière aux Pins bullhead spawning population. The results of the captures, markings, taggings, and recaptures led to the evaluation of total mortality, several aspects of exploitation by sport fishing, movements, population density, biomass, production, and yield.
Fertility, egg weight loss, hatchability, and fledging success in replacement clutches of captive American Kestrels
Authors: Bird David M. , Laguë Paul C.
Published: August 2008

From 1974 to 1977, 78 pairs of captive American Kestrels (Falco sparverius) were induced to lay replacement clutches by removal and artificial incubation of their first clutches. No significant differences existed between first and replacement clutches for fertility, hatchability, and fledging success. Hatchability, as well as fledging success of young, did not differ significantly between artificially and naturally incubated eggs. Both fertility and hatchability declined with eggs laid later in the season.