bluuebunny/crossref_metadata_2025 huggingface dataset:
SMALL CHAMBER TESTS OF ETHYLENE DIBROMIDE AND ETHYLENE DICHLORIDE ON ADULT GRAIN-INFESTING COLEOPTERA
Authors: Ellis C. R. , Morrison F. O.
Published: August 2008

Six strains of adult Silophilus granurius and one each of Tribolium confusum and Oryzaephilus surinamensis were fumigated with ethylene dibromide and ethylene dichloride to evaluate a small chamber fumigation technique as a means of establishing susceptibility levels. The influence of external factors, including the effect of insect diet before and after fumigation, on the comparative mortalities was also investigated. The suitability of this technique for detecting and comparing susceptibility differences was indicated.The LD50 values of a strain fumigated on different days varied as much as 40%, whereas the ratios of a standard and test strain fumigated on the same day varied less than 6% on different days.The natural mortality of S. granarius fed 10% sugar solution was less than that of those fed wheat grains. Sugar solution fed before exposure made the weevils more susceptible but when it was fed during the postexposure period it increased the observed LD50 by 60%.
A NEW RECORD FOR THE AFRICAN MOLOSSID BAT TADARIDA ALOYSIISABAUDIAE
Authors: Peterson Randolph L.
Published: August 2008

A specimen of Tadarida aloysiisabaudiae from Western Uganda, Africa, appears to represent the third known example of this species since its original discovery in 1907 and the first specimen to be collected since 1913. External and cranial measurements agree closely with the type specimen. It is compared with Tadarida bivittata and confirmed as a distinctively different species. The lateral view of the lower jaw and anterior aspect of the upper and lower canines and incisors are illustrated for the first time.
COMPARISON OF A DEER YARD AND A MOOSE YARD IN NOVA SCOTIA
Authors: Telfer Edmund S.
Published: August 2008

A winter concentration area or "yard" of moose (Alces alces) was compared with a nearby deer (Odocoileus virginianus) winter concentration area. Although both were on the middle of southwest facing slopes, the deer yard was steeper and drier. The deer yard was 500 ft lower in elevation and had a more continuous cover of heavy softwood, a thinner snow cover, and a smaller browse supply than the moose yard.
THE DISTRIBUTION OF DERMACENTOR TICKS IN CANADA IN RELATION TO BIOCLIMATIC ZONES
Authors: Wilkinson P. R.
Published: August 2008

Dermacentor andersoni has been collected north of Jasper, Alberta, close to 54° N. and near 53° N. in British Columbia. Spread to the north and northwest is probably limited by low summer soil temperatures, which would act principally by slowing egg development, thus disrupting the seasonal cycle of the tick. To the southwest, mild winters may fail to release diapause at the correct time of year. Aspect and slope are important factors. Altitude spread of records is from 1000–7000 ft. The most generally applicable description of its distribution is the ecotone between western grassland and moister regions, including clearings and rocky outcrops m the montane and Columbia forests, and shrubby areas of the prairies. In British Columbia, a series of randomly selected transects indicated a strong association between the tick's presence and several species of shrubs growing without tree shade.Each bioclimatic zone tends to have a characteristic group of rodents as main hosts of the immature stages. The prairie and montane regions differ in the indigenous hosts available to the adult tick.East of 105° D. andersoni is replaced by D. variabilis, which is adapted to the more humid summers of the eastern deciduous forest zones, and differs considerably from D. andersoni in its phenology. There are no reliable records of indigenous D. variabilis north of 52° latitude.D. albipictus occurs from the east to the west coast. Because of the winter activity of its larvae, allowing the whole summer for egg development, it is able to penetrate much farther north than the other two species. There are two records close to 60° latitude.
ASPECTS OF THE INTERACTION BETWEEN A CHALCID PARASITE AND ITS ALEURODID HOST
Authors: Burnett T.
Published: August 2008

Three populations of the greenhouse whitefly, Trialeurodes vaporariorum, and its chalcid parasite Encarsia formosa were propagated each year for three consecutive years on tomato plants in the greenhouse. The abundance of the host and parasite species fluctuated either with peaks of increasing amplitude, with peaks of decreasing amplitude, or with irregular peaks. The dominant process in the interaction was the occurrence of two qualitatively different types of host larval mortality: (a) parasitization, and (b) almost immediate killing after attack by adult parasites. Fluctuations in host and parasite abundance resulted from the almost immediate killing of small host larvae and the death of the short-lived adult parasites. The parasite population tended to destroy similar percentages of host populations of different densities but host mortality was also related to the age structure of the host population. Variation in host reproduction, caused by differences in rearing temperature and by seasonal variation in the physical environment, influenced host and parasite densities.
ULTRASTRUCTURAL FEATURES OF CRAYFISH PHASIC AND TONIC MUSCLE FIBERS
Authors: Jahromi S. S. , Atwood H. L.
Published: August 2008

Phasic and tonic muscle fibers from the abdominal extensor muscles of the crayfish, Procambarus clarki and Orconectes virilis, were examined for differences in fine structure with the electron microscope. The myofibrils of the two types of fiber were similar in size as seen in transverse section, unlike those in vertebrate twitch and tonus fibers. The ratio of thin to thick filaments was about 5:1 in tonic fibers and 3:1 in phasic fibers. Neuromuscular synapses in tonic fibers were enclosed by arms of noncontractile sarcoplasm, whereas the synapses seen in phasic fibers lacked this feature.
EXCRETION OF DDT BY MIGRATORY BIRDS
Authors: Harvey John Michael
Published: August 2008

Starlings fed 4.75 mg radioactive DDT per day for 5 days absorbed less than 25% of the insecticide. Concentrations remained high in the body and liver for 1 week after the feeding period, but decreased more quickly in the brain. After 10 days, less than 10% of the ingested DDT remained in the birds.
A REEXAMINATION OF SOME SPECIES OF AMPELISCA (CRUSTACEA: AMPHIPODA) FROM THE EAST COAST OF NORTH AMERICA
Authors: Mills Eric L.
Published: August 2008

Ampelisca verrilli n. sp. occurs from the intertidal to 50 m from southern Cape Cod to at least North Carolina. Individuals from North Carolina are small and slightly divergent in morphology from those from Massachusetts. A. macrocephala Liljeborg, with which A. verrilli has been confused for many years in New England, is figured. It occurs from just south of Cape Cod north, and from Nova Scotia north overlaps the range of A. eschrichti Krøyer. A. agassizi (Judd) (formerly known as A. compressa) is redescribed. Its range in the east is from Nova Scotia to the Caribbean at shallow inshore depths to 450 m. Eastern populations are closely similar to those from the eastern Pacific. A. declivitatis n. sp., which has been confused with A. spinimana Chevreux, is known from west of Greenland to the middle Atlantic States at lower continental shelf to bathyal depths, overlapping the range of A. agassizi on the continental shelf and the ranges of deep-sea species well down the continental slope. Parasitic worms, probably neorhabdocoele Turbellaria, occur in A. declivitatis. The incidence of intersexuality is high, but it does not appear to be related to parasitism by Turbellaria and may result from a polygenic-hormonal sex determination mechanism. A key is provided to the 24 species of Ampelisca known or suspected from eastern North America.
THE DEVELOPMENT OF RETUSA OBTUSA (MONTAGU) (GASTROPODA, OPISTHOBRANCHIA)
Authors: Smith S. Tyrell
Published: August 2008

The development of Retusa obtusa (Montagu 1803) from uncleaved egg to hatching is described. Cleavage is spiral and holoblastic, and results in the formation of a stereoblastula. Gastrulation occurs partly by epiboly and partly by invagination. The veliger form is assumed within the egg membrane: the velar lobes and cilia are comparatively less well developed than those of planktonic veligers.The foregut is ectodermal in origin, whereas the hindgut is almost entirely endodermal. The larval midgut diverticula give rise directly to the adult digestive glands. The left diverticulum is larger than the right from the first. A coelom, of the type described by Saunders and Poole (1910) for Aplysia, is not present at any stage in the development of Retusa. Hatching occurs approximately 28 days (at 12 °C) after oviposition. Development is direct.The alimentary canal and nervous system show some evidence of torsion; but this asymmetry is present from the first appearance of these organ systems, and no torsional process per se is detectable in. development. No jaws or radula are present in Retusa. At hatching, the heart and adult kidney are well developed. The embryonic kidney degenerates. The larval musculature degenerates and plays no part in the formation of the adult musculature. The mantle cavity spreads posteriorly, so that the heart and kidney come to tie within the suprapallium.The conclusion reached is that the trend toward loss of genetic torsion in the opisthobranchia has advanced further in Retusa than in Aplysia (Saunders and Poole 1910). Hyperstrophy of the embryonic shell is attributed to deformation of the visceral mass by the enlarged left midgut diverticulum, before evagination of the shell gland has taken place. There has been no previous record of direct development for a shelled opisthobranch. Comparisons are made with R. truncatula, which has an obligatory planktonic phase in its life history. It is concluded that the acquisition of direct development by R. obtusa is connected with the small size of the adult animal and with its northerly range.
CYTOGENETIC COMPARISON OF SOME PINNIPEDS (MAMMALIA: EUTHERIA)
Authors: Fay F. H. , Rausch V. R. , Feltz E. T.
Published: August 2008

Karyotypes of the harbor seal, Phoca vitulina (2N = 32), the bearded seal, Erignathus barbatus (2N = 34), the Weddell seal, Leptonychotes weddelli (2N = 34), the walrus, Odobenus rosmarus (2N = 32), the Steller sea lion, Eumetopias jubata (2N = 36), and the northern fur seal, Callorhinus ursinus (2N = 36), are described and compared with those of the ringed seal, Pusa hispida, and California sea lion, Zalophus californianus, reported by other workers. These are discussed with reference to current theories of pinniped phylogeny and systematics. The number and morphology of chromosomes in these eight species, representing each family and subfamily of pinnipeds, were found to be remarkably similar. This is interpreted as evidence of close interrelationship, commensurate with the theory of monophyletic origin. Karyograms of the harbor seal and ringed seal are virtually identical, as are those of the bearded and Weddell seals and those of the Steller and California sea lions. The karyotype of the fur seal is similar to the sea lions', while that of the walrus resembles the phocids' in some ways and the otariids' in others. A need for thorough comparative studies and reappraisal of pinniped systematics at the subfamilial and generic levels is indicated.
LA CROISSANCE EN LONGUEUR ET EN POIDS DES AMIA CALVA L. DE LA RÉGION DE MONTRÉAL
Authors: Cartier Denis , Magnin Étienne
Published: August 2008

The age of 80 bowfins (Amia calva L.) from the Montreal area has been read from the scales, the gular plate, and the otoliths. Both sexes have the same growth rate. The growth in length of all specimens collected can be summarized in one logarithmic equation: log L = 2.35137 + 0.54922 log A, where L is the total length (in mm) and A the age group. All the age groups can then be described by a particular measured mean length and also by a back-calculated mean length. The ponderal growth is obtained first from the mean weight of different classes, and then from the length–weight relation: log P = −4.961 + 2.992 log L, in which P is the weight (in g) and L the mean length (in mm) determined by back calculation. Maximum length and weight recorded were 870 mm and 6800 g respectively; a 12-year life span seems to be rarely exceeded. The results are compared with those available in the literature.
THE RESPONSE TO MOLLUSCAN SHELLS OF THE SWIMMING SEA ANEMONES STOMPHIA COCCINEA AND ACTINOSTOLA NEW SPECIES
Authors: Ross D. M. , Sutton L.
Published: August 2008

Behavior patterns in the sea anemones Stomphia coccinea and Actinostala new species are described by which these animals settled preferentially on shells of Modiolus modiolus (commensal of S. coccinea) after they have been made to swim in response to the appropriate stimuli (the starfishes Dermasterias or Hippasteria, the nudibranch Aeolidia papillosa, etc.). Tentacular and oral contact without adhesion, followed by great distension of the pedal disc and some flexion of the column towards the shell, were the main components of these behavior patterns. Anemones which had been allowed to settle on other surfaces not more than 6 h previously migrated to shells which were brought into contact with the tentacles. Shells which were boiled in alkali to remove organic matter lost their capacity to elicit the response. This behavior pattern is compared with that of Calliactis parasitica, a commensal of hermit crabs which shows a preference for settling on shells of large gastropods.
THE MONONCHIDAE: A FAMILY OF PREDACEOUS NEMATODES: VII. GENUS PRIONCHULUS (NEMATODA:MONONCHIDAE)
Authors: Mulvey R. H.
Published: August 2008

Males and females of Prionchulus muscorum and of P. longus collected from various localities in the United States and Canada are considered and compared. Females of P. punctatus, including two specimens exhibiting bivulvarity, are described and illustrated. Taxonomic keys are provided for the males and females of this genus.
MATURATION OF GAMETES AND SPAWNING IN MACOMA BALTHICA (L.)
Authors: Caddy J. F.
Published: August 2008

Gametogenesis and spawning are described for a population of Macoma balthica (L.) from the Thames Estuary. The primary gonad passes through a male phase, maturation being achieved in the 2nd year of life. Gametogenesis is associated with a system of follicle cells which break down as the gametes approach maturity. The arrangement of follicle cells is characteristic of the sex. In the female, gametocytes are peripheral to the follicle cells; in the male they are interstitial. Spermatogenesis proceeds most rapidly in the center of the follicle, resulting in a gradient of spermatogenic stages of increasing maturity from the periphery to the center.Spawning takes place principally in spring, and to a lesser extent in autumn, during neap tides. Several spawnings were identified in a season, but repeated cycles of gametogenesis were absent.
MEGAKARYOCYTES IN THE RAT SPLEEN
Authors: McFadden Kenneth D.
Published: August 2008

Spleens from rats, fetal to 3 years of age, were studied histologically with particular attention being directed toward the megakaryocytes. The number of megakaryocytes per unit area studied increased from the fetal stages to the 7th postnatal week and then decreased gradually until only a very few were found in year-old animals. Animals older than 2 years generally showed a slight increase in the number of megakaryocytes.These changes in splenic megakaryocytopoiesis indicate that this organ plays a diminishing role in thrombocyte production. During late fetal and early postnatal life the spleen is active in megakaryocytopoiesis. This function is diminished as thrombocyte production is shifted from the spleen to some other organ, probably the bone marrow.A few mitotic megakaryocytes were observed but these are relatively rare. Mitosis was confined to the most immature type of megakaryocyte.Nuclear pleomorphism was in evidence throughout the various age levels but was more noticeable in the early postnatal animals.Phagocytosis by these giant cells could not be confirmed. Some of these cells seemed to contain foreign material but it was not possible to determine if this was from actual phagocytic activity or material impinging upon the cytoplasm.
THE WINTER BIOENERGETICS OF A BEAVER POPULATION IN NORTHERN LATITUDES
Authors: Novakowski N. S.
Published: August 2008

The winter bioenergetics of a beaver population were studied in au area of Wood Buffalo National Park; which is located partly in Alberta and partly in the Northwest Territories. In these latitudes the beaver (Castor canadensis canadensis) are confined to subnivean existence for approximately 150 days each year. Although there is an unlimited supply of deciduous trees, which are cached by the colonies for this period, the caches were not sufficient for the energy requirements of the colonies, as calculated from the number and weight of animals in each colony. This indicates that energy deficits are a product of the winter behavior of the animals and that methods of energy conservation, such as reduced activity, periods of dormancy, huddling, insulation from ambient temperatures by lodge construction, and an increase in fur insulation and fat deposition provide the necessary mechanisms for survival. Based on a comparison of autumn and winter weights of beaver, the younger animals (kits and yearlings) increased their weight during the winter while the older animals, who presumably use fat reserves for survival, did not.
TRICHODORUS ACUTUS N. SP. (NEMATODEA: DIPHTHEROPHOROIDEA) AND A DISCUSSION OF ALLOMETRY
Authors: Bird G. W.
Published: August 2008

The morphological description of the genus Trichodorus Cobb, 1913, as described by Allen (1957), was emended to include specimens with tail shapes other than bluntly rounded. Trichodorus acutus n. sp. collected from soil about the roots of gloxinia was described and figured. Anteriorly its tail shape was convex-conoid, then conoid to an acute or slightly rounded terminus. The allometry of T. acutus was discussed with special reference to ratios commonly used for taxonomic purposes.
POLAR BEAR MILK: III. GEL-ELECTROPHORETIC STUDIES OF PROTEIN FRACTIONS ISOLATED FROM POLAR BEAR MILK AND HUMAN MILK
Authors: Baker B. E. , Hatcher V. B. , Harington C. R.
Published: August 2008

Polar bear milk was stored in the frozen state for 2 months. It was then thawed and subjected to low-speed centrifugation. The material (D) which deposited at the bottom of the centrifuge tube and also the casein and whey proteins isolated from the supernate were analyzed by polyacrylamide-gel (without urea) electrophoresis. The precipitate (D) and the casein gave closely similar electrophoretic patterns. However, the precipitate (D) contained less than 20% of the carbohydrate (hexose, hexosamine, sialic acid) content of the casein. Polar bear casein and bovine casein gave similar electropherograms when subjected to polyacrylamide-gel (7 M urea) electrophoretic analysis. Human casein gave eight distinct bands, four of which had higher mobilities than did bovine αs-casein. Starch-gel (2-mercaptoethanol added) electrophoretic analysis indicated that polar bear casein and human casein produced 8 and 13 electrophoretic components respectively.
A MORPHOLOGICAL COMPARISON OF ANTIPODEAN TELEOGRYLLUS SPECIES (ORTHOPTERA: GRYLLIDAE)
Authors: Chen G.-T. , Vickery V. R. , Kevan D. K. McE.
Published: August 2008

The common "black" field crickets of the germs Teleogryllus from different regions of Australia and New Zealand were studied morphometrically in order to elucidate their taxonomy.Results show that these crickets, formerly regarded as comprising a single species, T. commodus (Walker), are actually two distinct species: T. oceanicus (Le Guillou) from northern Queensland and T. commodus from Western Australia, with other very closely related populations from southeastern Australia and from North Island, New Zealand. A population from Kaikoura, South Island, New Zealand, although a member of the T. commodus group, may represent a different subspecies.
THE MONOGENEAN PARASITES OF CANADIAN FRESHWATER FISHES
Authors: Price Charles E. , Arai Hisao P.
Published: August 2008

A brief history of work performed on the Monogenea of Canadian freshwater fishes is recounted; a list indicating the host – monogenean parasite relationships of Canadian freshwater fishes is included. Dactylogyrus albertensis sp. nov., recovered from the gills of the flathead chub, Hyhopsis gracilis (Richardson), is described. Two additional known parasite species are recorded for Canada: (1) Pseudomurraytrema muelleri Price, 1967, recovered from Catostomus commersoni (Lacépède) and (2) Dactylogyrus banghami Mizelle and Donahue, 1944, recovered from Rhinichthys cataractae (Valenciennes). Hosts were collected from the Milk River in Alberta.
FIELD KEY AND METHODS OF COLLECTING FRESHWATER OSTRACODES IN CANADA
Authors: Delorme L. D.
Published: August 2008

A 6-inch Ekman dredge can be used successfully to collect ostracodes from ponds, lakes, and streams. Standard 20- and 60-mesh sieves are used to wash and separate the bulk of sediment and plant debris from the ostracodes. Acetone is then used to float and thus concentrate the ostracode carapaces. In preparing a key for use in the identification of 77 Canadian species, morphological parameters such as size, shape, and carapace outline have been found to be very useful for preliminary identifications.
A PROPOSED SYSTEM OF ANATOMY FOR FRESHWATER MONOGENEA
Authors: Price Charles E. , Arai Hisao P.
Published: August 2008

A lack of standardized anatomical terms for use in morphological descriptions of monogenetic trematodes has resulted in excessive confusion and needless synonymy. The present proposed systems of terminology will hopefully contribute toward more meaningful descriptions in future studies. The desired result of using a standardized system of anatomy is the eventual establishment of an improved system of monogenean taxonomy.
The influence of temperature on histological and radiochemical measurements of thyroid activity in the eastern brook trout, Salvelinus fontinalis Mitchell
Authors: Drury D. E. , Eales J. G.
Published: August 2008

Histological and radiochemical techniques for assessing thyroid activity were compared on yearling brook trout acclimated at 5, 12, and 15 °C.The mean thyroid follicle epithelial cell height was 7.4 μ (range 6.0–8.6 μ) at 5 °C; 3.5 μ (range 2.9–3.9 μ) at 12 °C, and 2.3 μ (range 1.9–2.9 μ) at 15 °C. Assuming that a taller epithelial cell height indicates greater thyroid activity, then an inverse relationship between thyroid activity and acclimation temperature exists.Both the uptake of radioiodide by the thyroid (T/S) and the clearance of radioiodide from the serum were greater at higher temperatures. Serum PB125I production was negligible within 8 days after radioiodide injection and the conversion ratio could not be applied as an index of thyroid function, Assuming, however, that the thyroid radioiodide uptake is an index of thyroid activity, then there is a direct relationship between thyroid activity and acclimation temperature.In view of the marked discrepancy between these histological and radiochemical techniques, fractional rates of turnover of serum thyroxine were compared by determining the biological half-life (t½) for serum PB125I after L-thyroxine-125I intraperitoneal injection at different temperatures. The serum PB125I clearance curves were complex and tentative t½ values of 18.0 days (5 °C, 3.2 days (12 °C), and 1.5 days (15 °C) were obtained. These results indicate a more rapid serum PBI turnover at higher temperatures and support the radiochemical measurements.
In vitro cultivation of Choristoneura fumiferana (Clemens) (Lepidoptera:Tortricidae) tissues
Authors: Sohi S. S.
Published: August 2008

Embryonic tissue fragments of the spruce budworm, Choristoneura fumiferana (Clemens), survived in vitro for 6–7 weeks. Three- to five-day-old eggs, maintained at 22 °C, were used to obtain embryos which were cut into small pieces and maintained in drop cultures using Grace's medium. Explants contracted rhythmically for 3–4 weeks and stayed in good condition for a further 2–3 weeks. Explanted tissues produced three types of growth: hollow vesicles, continuous cell sheets, and free cells. The size of vesicles in some cases was 4–5 times that of the explant. The free cells increased in number considerably and formed good monolayers. The cultures deteriorated after 6–7 weeks. Ovarian tissue cultures of late sixth-instar larvae of this insect did not produce any growth, and deteriorated in 3–4 days.
Splendidofilaria papillocerca (Lubimov, 1946) and Microfilaria lagopodis (Haaland, 1928) (Filarioidea) from ptarmigan in northwestern North America
Authors: Gibson George G.
Published: August 2008

Splendidofilaria papillocerca (Lubimov, 1946) Anderson and Chabaud, 1959 is redescribed on the basis of specimens from Alaska and the USSR. The Alaskan specimens constitute the first North American record for this species. A preliminary description of the microfilaria of S. papillocerca is presented and quantitative data are provided to supplement existing descriptions of Microfilaria lagopodis (Haaland, 1928) Brinkmann, 1950. The possibility that these two forms are conspecific is discussed and the writer expresses hope that parasitologists with access to more abundant material will resolve this issue. Filaria urogalli Linstow, 1879 is considered a nomen nudum.
The nutrition of the female mink (Mustela vison). III. The water requirement for maintenance
Authors: Farrell D. J. , Wood A. J.
Published: August 2008

The water intake of five female mink has been measured under non-stress conditions over a period of several months. These animals consumed 2.8 g total water/g of dry feed or 0.63 g/kcal of apparent digestible energy intake (A.D.E.). Their water intake, when related to surface area is appreciably higher, but when related to the A.D.E. of the feed it is in reasonable agreement with values reported for other species.
Two effects of photoperiod on wing development in Gryllodes sigillatus (Walk.)
Authors: Mathad S. B. , McFarlane J. E.
Published: August 2008

Larvae and adults of Gryllodes sigillatus (Walk.) were exposed to various photoperiods (10 h–18 h) to determine the influence of photoperiod on wing development. In the larva, a 14-h photoperiod was optimal for wing development and a 10-h photoperiod suppressed wing development completely. Adults exposed to a 14-h photoperiod produced more winged progeny than adults exposed to an 18-h photoperiod. Photoperiod therefore produces its effect on wing development both directly on the larvae and indirectly through their parents.
The annual testicular cycle of the brown-headed cowbird (Molothrus ater)
Authors: Scott D. M. , Middleton A. L. A.
Published: August 2008

An analysis of the spermatogenic condition and of the weights of testes from about 450 brown-headed cowbirds (Molothrus ater) was made to determine the annual cycle of this species at London, Ontario, and to ascertain variation in the cycle due to age. Testes of birds more than 1 year old (adult) reached maximal weights in late April and early May coincident with the beginning of egg-laying, and about 3 weeks before the testes of 1-year-old birds (yearlings) reached their maximal weight. The mean weights of testes of adults were usually greater, often significantly so, than those of yearlings. From about May 23 to June 23 there were no statistically significant differences in the weights of testes from the two age groups. Beginning in late June, the weights of testes declined rapidly in both age groups and reached a minimum in August. Minimal weights of testes persisted in captive birds until February.Large amounts of sperm were present in the testes of adults in mid-April and of yearlings in late April well in advance of maximal testicular weights. Sperm production occurred in most birds until early July but had ceased in most by late July.Testes, apparently undergoing regression, were noted significantly (p <.005) more frequently in adults than in yearlings in May and early June at the height of the breeding season. The significance of this observation and some aspects of testicular regression, previously unrecorded, are discussed. Adult birds are more sedentary than most yearlings in the breeding season and, unlike the latter, habitually associate with the same female. These behavioral differences may be related to the observed differences between the age groups in the testicular cycle.
Ecological significance of respiration and substrate for burrowing Ephemeroptera
Authors: Eriksen C. H.
Published: August 2008

In an attempt to understand the differential distribution of Ephemera simulans and Hexagenia limbata in intergrading substrates, the author extended his studies of the ecological roles of the laboratory-derived comparisons of respiration, morphology, and behavior.Conclusions drawn, mainly from my earlier and present work and also work reported by Lyman in 1943 and Hunt in 1953, seem to be consistent with field distribution. It appears that H. limbata is not found in streams unless prevailing conditions include undisturbed, fine sediments, for Hexagenia does not burrow into coarse substrates. To the contrary, E. simulans can thrive in gravel and pebble stream substrates in which the oxygen content of interstitial water is greater than 1.20 cc/l. In lakes where Ephemera can burrow into substrates of gravel, marly sand, and marl, it is limited in the fine sediments by the relative inefficiency of its small gills at low oxygen concentrations (< 1.20 cc/l). Again, Hexagenia does not occur in coarse substrates. However, in fine sediments such as marl it is found in large numbers and increases in abundance in muds. Most probably its distribution further into lakes is limited by impenetrable peaty substrates or by oxygen stratification (< 0.80 cc/l).
Plagiorchis peterborensis sp. n. (Trematoda:Plagiorchiidae), a parasite of Lymnaea stagnalis appressa, reared in the laboratory mouse, Mus musculus
Authors: Kavelaars Bro. Joseph , Bourns T. K. R.
Published: August 2008

Cercariae of Plagiorchis peterborensis sp. n. were obtained from Lymnaea stagnalis appressa, and the life cycle was completed using Aedes aegypti larvae and laboratory mice as experimental hosts. Description of the adult is based upon whole mounts and serial sections of 14-day-old worms. P. peterborensis resembles most closely P. muris, but differs in stylet shape, adult dimensions, and egg size.
Neoechinorhynchus carpiodi n. sp. (Acanthocephala:Neoechinorhynchidae) from quillback of Lake Erie
Authors: Dechtiar Alex O.
Published: August 2008

A new species of acanthocephalan, Neoechinorhynchus carpiodi, from Carpiodes cyprinus (LeSueur) is described. It is the eighth species of the genus Neoechinorhynchus reported from North American fishes in which there is marked diversification of the lemnisci. The new species has the longest trunk length of any acanthocephalan previously known from North American fishes. Twenty-five percent of 48 fish were infected with from two to seven parasites per fish. Inflammation of surrounding tissue was observed together with a prominent connective tissue nodule around the penetrating proboscis.
Mammoth from the Middle Wisconsin of Woodbridge, Ontario
Authors: Churcher C. S.
Published: August 2008

Parts of a tusk and lower molar of a mammoth, Mammuthus primigenius, have been recovered from above the Early Wisconsin Sunnybrook Till at Woodbridge, Ontario. A Mid-Wisconsin (Port Talbot Interstade) age (40 000–50 000 years B.P.) is suggested for these specimens.
A study of the effect of egg separation on hatching time and of the source of clicking sounds in the embryo of the domestic chicken
Authors: McCoshen John A. , Thompson Robert P.
Published: August 2008

The phenomenon of synchronized hatching was studied in a two-part investigation using White Leghorn and Rhode Island Red embryos and chicks. Experiments were conducted to test for the effect of separating eggs on hatching time and to locate the source of clicking sounds emitted by embryos during the final hours of incubation.A total of 25 eggs separated by no less than 4 in. and five clutches, each with 10 eggs in contact, were incubated and their hatching times compared. There was no difference in the mean hatch times of separated versus contact eggs. Separated eggs, however, were more variable in their hatch times than contact eggs, a statistical analysis showing a significant difference at the 0.05 level.Recordings were made of audible activity produced by embryos from their 17th day of incubation, and of hatched chicks up to 2 days after hatching. Clicking sounds from within the embryos were heard from 2 to 7 h after pipping (first puncture of the egg shell) had occurred. The source of the clicking was associated primarily with the right abdominal air sac and possibly with the right posterior thoracic air sac of the respiratory system. Other observations are described.
Relapses in ducks chronically infected with Leucocytozoon simondi and Parahaemoproteus nettionis
Authors: Desser S. S. , Fallis A. M. , Garnham P. C. C.
Published: August 2008

Six Pekin ducks, experimentally infected with L. simondi the previous summer, were observed from September to May. From March to May, a general increase in gametocytaemia occurred, with the appearance of both round and elongate gametocytes. The course of gametocytaemia was observed during the "relapse season" of 33 wild ducks. Seven were found to be infected with L. simondi, seven with Parahaemoproteus nettionis, and six with both species. One wild duck exhibited numerous young forms of both parasites in the blood. It was killed and the organs were examined. "Relapse schizonts" of L. simondi were fairly numerous in the lungs of the duck and a single schizont was seen in the heart. The morphology was characteristic, particularly the elongate parasites, enclosed in a well-marked capsule or cyst wall.
Observations on the ecology and population dynamics of the Blanding's turtle, Emydoidea blandingi
Authors: Gibbons J. Whitfield
Published: August 2008

Ecological studies were made on the Blanding's turtle, Emydoidea blandingi, in southwestern Michigan. Observations were made regarding population size and structure, seasonal activity, and reproductive potential and cycles. Reproductive cycles and periods of terrestrial activity were found to be coincident with those of the painted turtle, Chrysemys picta.
Twinning in American leaf-nosed bats (Chiroptera: Phyllostomatidae)
Authors: Barlow Jon C. , Tamsitt J. R.
Published: August 2008

Twinning is reported for the first time in the bats Glossophaga soricina, Artibeus jamaicensis, and Erophylla bombifrons of the American family Phyllostomatidae. The rarity of twinning in tropical species of this family is explained as a function of the typically tropical reproductive program of prolonged breeding seasons and single young born several times a year.
Observations on the embryogenesis of Trichodorus christiei (Nematodea: Diphtherophoroidea)
Authors: Bird G. W. , Goodman R. M. , Mai W. F.
Published: August 2008

Trichodorus christiei eggs were laid in the single cell stage. The first two cleavages were transverse to the longitudinal axis of the egg, forming four blastomeres of similar size. Metaphase chromosomes were approximately 3 μ in length. First-stage juveniles were recognizable after 96 hours, and emerged from the egg 100–120 hours after it was laid. Stomatal armature was well developed after 96 hours. The esophagus and intestine developed shortly before emergence.
The internal anatomy of the woodlouse, Metoponorthus pruinosus (Brandt), (Porcellionidae, Peracarida)
Authors: Alikhan M. A.
Published: August 2008

Tbe circulatory system, lying in the mid-dorsal line of the body, consists of an oval heart, the opthalmic artery, and a dorsal abdominal artery.The digestive system comprises a wide, large alimentary tube and two pairs of digestive glands. An oesophagus, a proventriculus, midgut, and a short proctodacum or hindgut form the digestive tube. The digestive glands are very well developed and are beaded in form; each pair lies on either side of the alimentary canal.The reproductive organs are well developed in both sexes: in the male they consist of paired testes and their vas deferentia, and in the female paired bilobed ovaries and oviducts.A cerebral or supraoesophageal ganglion, a suboesophageal ganglion, and seven thoracic ganglia form the nervous system. The supraoesophageal ganglion is united with the suboesophageal ganglion by means of the circumoesophageal commissures, whereas the thoracic ganglia and suboesophageal ganglia are linked with each other by paired connectives.The gills and the tracheae are the organs of respiration. The gills are borne of the bases of the pleopods and are enclosed in the branchial chamber. The tracheae are located on the lateral lobes of the first two pleopods only.
Cytological changes in the developing ovary of the house fly fed milk and other diets
Authors: Goodman Tine , Morrison P. E. , Davies D. M.
Published: August 2008

In the house fly, oogenesis from stages 1 to 4 occupied the last 2 days of the pupal period. The completion of the first ovarian cycle from stages 4 to 14. in the well-fed female at 25 °C, required between [Formula: see text] and 4 days. Growth of the follicle approached a constant exponential rate from stages 1 to 10. The period of vitellogenesis was divided into two phases: an early phase from stages 8 to 10, and a late phase of slower growth from stages 11 to 12 after the vitelline membrane was formed. Reproduction in the adequately fed female showed ovarian synchrony, all oocytes of a cycle developing at the same rate. In females fed only sugar water, oogenesis was arrested at stages 7 to 8, the potential resting phase. After oviposition, subsequent cycles from stages 7 or 8 were completed in about 2 days. As long as a mature egg was retained in the ovariole, the follicle of the next cycle remained at stage 8. The dynamics of the growing oocyte was related to changes in the nurse cells and follicular cells. The nature of the yolk spheres at different stages of development and the formation of the egg membranes was investigated.
The influence of larval crowding on the development time of populations of Drosophila melanogaster on chemically defined medium
Authors: Cohen Barrie
Published: August 2008

Work with Drosophila melanogaster, cultured on chemically defined amino acid medium, showed that at extreme larval densities the average time to pupation and eclosion of the survivors of the insect population is a decreasing function of the initial density. Evidence is presented which illustrates that at extreme densities larval development rate is significantly increased. Possible causes of this phenomenon are cited. It is stressed, however, that a very complex situation exists and more experimentation, particularly biochemical analysis, will be necessary to arrive at the proper causative factors. A new formula is presented for a chemically defined medium for Drosophila melanogaster, and detailed methods of preparation given. The new formula will support an estimated 200 larvae through complete development to adult flies on 5 ml of medium. It is thought that the system utilizing the development of Drosophila melanogaster on chemically defined amino acid medium is a fundamental one for the experimental analysis of developing insect populations.
Growth and reproduction of some Diaptomus spp. in Saskatchewan ponds
Authors: Sawchyn William W. , Hammer U. Theodore
Published: August 2008

Field studies on the life cycles of seven species of Diaptomus were undertaken in some ponds in southern and central Saskatchewan. D. sanguineus, D. arcticus, D. stagnalis, and D. kiseri have one generation per year, beginning early in the spring and disappearing by early summer. D. leptopus, D. forbesi, and D. nudus appear somewhat later, have two or three generations per year, and persist throughout the rest of the ice-free period. Correlations were found between water temperature and egg clutch size of Diaptomus females. Variations in size of individuals of different generations were related to temperature. Attempts to associate changes in chemical conditions of the ponds with growth and reproduction of Diaptomus spp. were unsuccessful.
Coat-color polymorphism in North Plains red fox populations
Authors: Johnson Donald R.
Published: August 2008

As in other regions of North America, the frequencies of genes producing dark-phase phenotypes in red fox populations of the northern Great Plains are much reduced from that of fur-trade times. Despite their lower fitness, the dark phases are maintained primarily by reproduction rather than mutation or immigration. The hypotheses that have been advanced to explain the decrease in frequency of dark-phase foxes in North America during the past century are briefly reviewed.
The simuliid vectors of Splendidofilaria fallisensis of ducks
Authors: Anderson Roy C.
Published: August 2008

Simulium rugglesi and S. anatinum are vectors of Splendidofilaria fallisensis of ducks. Reports of other simuliids serving as vectors of this filarioid are undoubtedly the result of mistakes in identification.
Observations on air shipments and experimental use of the cyprinodont fish Fundulus heteroclitus
Authors: Abbott Frank S. , Schwartz Frank J.
Published: August 2008

The survival of air-shipped Fundulus heteroclitus is greatly improved by chilling the fish before packing them for shipment. Prophylactic treatments on arrival and therapeutic treatments during long-term holding are described.
The digestion and storage of fat by the amphinomid polychaete, Hermodice carunculata
Authors: Marsden Joan Rattenbury
Published: August 2008

The distribution of neutral lipids and esterases has been studied histologically in the intestinal region of male individuals of the polychaete Hermodice carunculata. It is suggested that the products of lipid digestion in the intestinal lumen are absorbed by the intestinal epithelium where neutral fats are reformed. After animals have fed, lipids accumulate in the peritoneal tissue, an accumulation which becomes depleted during starvation. Possible routes of transport of lipids from intestinal epithelium to peritoneal tissue are discussed.
Gel filtration of insect haemolymph proteins
Authors: Loughton B. G. , West A. S.
Published: August 2008

Haemolymph from 6th instar larvae of Malacosoma americanum and 5th instar nymphs of Locusta migratoria was subjected to gel filtration on Sephadex G-200. Three protein fractions were produced in each case. Each fraction was analyzed for protein content and assayed for esterase and tyrosinase activity. The degree of resolution obtained by gel filtration was tested by Polyacrylamide "disc" electrophoresis. Each fraction displayed a specific type of enzyme activity and protein composition. The similarities between the haemolymph proteins of the two insects are discussed.
Species composition of the genus Streptocara Railliet et al., 1912 and the occurrence of these avian nematodes (Acuariidae) on the Canadian Pacific coast
Authors: Gibson George G.
Published: August 2008

Description and figures are presented for the following species and subspecies, which the writer considers should constitute the genus Streptocara: S. crassicauda crassicauda (Creplin, 1829), S. crassicauda longispiculata n. subsp., S. californica (Gedoelst, 1919), S. formosensis Sugimoto, 1930, S. incognita n. sp., and S. recta (Linstow, 1879). Host-lists and data on prevalence in birds, mainly waterfowl, from British Columbia, Canada, are given for these species and Paracuaria tridentata (Linstow, 1877). Yamaguti's 1961 list of species of Streptocara is examined critically; some of the modifications suggested in the literature since 1961 are accepted, and the following changes proposed: S. cirrohamata (Linstow, 1888) to Ingliseria cirrohamata (Linstow, 1888) new genus, new combination; S. triaenucha (Wright, 1879) to Synhimantus (D.) triaenucha (Wright, 1879) n. comb. (syn. S. (D.) canadensis Mawson, 1956); and S. somateriae Ryzhikov, 1960 to synonymy with S. formosensis Sugimoto, 1930.
Paraplectonema canadianum n. sp. (Nematoda: Leptolaimidae), a freshwater nematode from the Ottawa River
Authors: Hopper B. E.
Published: August 2008

Paraplectonema canadianum n. sp. is distinguished from the type and only other species, P. pedunculatum (Hofmänner, 1913) by its longer tail and the dioecious nature of the population. The tuboid preanal supplements, reduced number of hypodermal gland structures (and their external setose nature), the single male gonad, and the muscular chromadorid esophageal bulb provide the basis for including Paraplectonema under the Leptolaimidae. An emended diagnosis of Paraplectonema and a consideration of the taxonomic position of the remaining genera of the Plectinae are provided.
A new natural definitive host, and morphometry of Soboliphyme baturini Petrow, 1930 in interior Alaska
Authors: Swartz L. G.
Published: August 2008

One marten (Martes americana) and nine mink (Mustela vison) from near Fairbanks, Alaska, were examined; two Soboliphyme baturini Petrow, 1931 were removed from the marten and a total of 98 from eight of the nine mink. These findings extend the known range of the parasite in North America about 800 miles to the northwest of the nearest previous record at Petersburg, Alaska, and, with the mink, add a new natural definitive host. Morphological measurements of these worms are given and compared with those available from other areas.
Inhibition of pituitary gonadotropic activity in the viviparous seaperch Cymatogaster aggregata Gibbons by a dithiocarbamoylhydrazine derivative (I.C.I. 33 828)
Authors: Wiebe John P.
Published: August 2008

A suspension of Methallibure (I.C.I. Compound 33 828) was added regularly for about 6 weeks to aquaria housing males of the teleost Cymatogaster aggregata. The testis atrophied and the gametogenetic processes of maturation were suspended. Histochemically demonstrable 3β-hydroxysteroid dehydrogenase and sudanophilic lipids diminished and the interstitial cells of Leydig regressed. At the end of the experiments the fleshy modifications on the male anal fin (secondary sex structures which develop under the influence of male gonadal hormones) were in a state characteristic of immature fish. Methallibure treatment resulted in these changes, which were characteristic of hypophysectomy, without the marked antithyroid activity histologically evident in thiourea treatment. All thiourea-treated and control animals remained in breeding condition. It is concluded that the addition of Methallibure to the aquarium water will directly block the production and (or) release of pituitary gonadotropins and thus inhibit spermatogenesis and testicular steroidogenesis.
Scavenging by Alloperla (Plecoptera: Chloroperlidae) nymphs on dead pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon embryos
Authors: Nicola Stephen J.
Published: August 2008

The relationship between stonefly nymphs of the genus Alloperla and developing pink and chum salmon embryos was studied in Harris River, Alaska, from August, 1965, to April, 1966. Polyethylene containers with alternating layers of salmon eggs and washed gravel and containers with washed gravel only were buried in sections of an upstream spawning riffle and were removed and examined in three sampling periods. Correlation and linear regression analysis of numbers of missing embryos, dead embryos, and stonefly nymphs in the containers supported the hypothesis that the nymphs were scavengers but failed to support the hypothesis that they were predators.Some of the beneficial effects to living embryos of scavenging by nymphs is discussed, as well as the likelihood of occurrence of predation by stonefly nymphs in general.