bluuebunny/crossref_metadata_2025 huggingface dataset:
Insemination in the migratory grasshopper, Melanoplus sanguinipes (Fabr.)
Authors: Pickford R. , Gillott C.
Published: August 2008

Insemination in Melanoplus sanguinipes takes place by means of a small, relatively simple, tubular spermatophore which begins to form in the ejaculatory duct almost immediately after a pair is securely coupled. It takes about 5 min to complete the process of forming the spermatophore in the ejaculatory duct, extruding it into the spermathecal duct and ejecting it from the spermathecal duct and aedeagus following sperm transfer. During extrusion the tube penetrates only a short distance into the wide bend of the spermathecal duct at which point the seminal fluid is discharged. The entire spermatophore is then withdrawn and becomes lodged between the valvulae of the female. As many as 14 spermatophores are produced consecutively during a single copulation. The situation in M. sanguinipes is discussed in relation to the information available on other acridids.
The structure, formation, histochemistry, fate, and functions of the spermatophore of Lytta nuttalli Say (Coleoptera: Meloidae)
Authors: Gerber G. H. , Church N. S. , Rempel J. G.
Published: August 2008

The spermatophore of Lytta nuttalli consists of a unique tubular structure and a mass of jelly-like material (JLM). The spermatozoa are located in the JLM at its junction with the tube. The tube wall is composed of three layers of "histochemically" different substances produced by the first pair of male accessory glands. The JLM is secreted by the vasa deferentia. During copulation, usually of 8 to 10 h duration, the tube is molded and hardened in the vagina and posterior part of the spermatophoral receptacle duct and the JLM in the anterior part of the duct. The tube of the spermatophore serves as an intromittent "organ" in the absence of an internal penial sac. The sequence of events in spermatophore formation and the roles of the materials from the second and third pairs of male accessory glands are described. After copulation, usually within 2 h, the tube is ejected by the female. Within 24 h after copulation, most of the spermatozoa are transferred to the spermatheca. The secretion of the female accessory gland apparently is involved in this process. The JLM and third male accessory gland materials are retained in the spermatophoral receptacle and apparently are absorbed. The histochemical composition of the male and female secretions and the components of the spermatophore and the cytology and secretory cycles of the glands are described. The spermatophore of L. nuttalli is compared with those of other insects and the probable form of the spermatophore in other Meloidae is considered.
Observations on jet propulsion in banjo catfishes
Authors: Gradwell Norman
Published: August 2008

In the three species of banjo catfishes investigated, spontaneous enhancement of gill irrigation appears to propel the fishes by the rhythmic posteroventral expulsion of jets of water from the opercular cavities. Progression is by forward lunges during opercular expiration and is independent of propulsive undulations of the fins and body. Some momentum is lost during the inspiration phase of irrigation, when the opercular valves are closed. The thrust velocity is sometimes increased by the superimposition of tail undulations on jet propulsion.
Germinal differentiation of the stem cell in Hydra fusca: a model system
Authors: Schincariol A. L. , Habowsky J. E. J.
Published: August 2008

The consecutive stages in the differentiation of the stem cell to the spermatozoon were characterized based on time of appearance, cytology, volumes, and spatial distribution. In the first few days the stem cells (128 μ3) enlarged and entered a phase of intense mitosis. In these cells or primary spermatogonia (220–1140 μ3), the cytoplasm was intensely basophilic, the DNA dispersed as a fine meshwork, and a large nucleolus was present. In secondary spermatogonia (123 μ3), noted after 14 days, the DNA was organized in small granules and the nucleolus reduced in size. The primary spermatocyte (122 μ3) was seen by 16 days; its cytoplasm was weakly basophilic, the nuclear DNA appeared granular, and a nucleolus was absent. After meiosis I, the secondary spermatocyte (60 μ3) immediately entered meiosis II. The spermatids (31 μ3), noted by 18 days, lacked a nucleolus and had dense irregular masses of DNA scattered throughout the nucleus. Spermatozoa, seen after 20 days, consisted of a cone-shaped head, a middle piece containing four large mitochondria, and a long flagellum. All these cell types were distributed sequentially within the testis according to their chronological order of appearance. The use of spermatogenesis as a model system to study cell differentiation and control requires further methodological developments and biochemical information.
Further notes on Tadarida aloysiisabaudiae and Tadarida russata (Chiroptera: Molossidae—Africa)
Authors: Fenton M. B. , Peterson R. L.
Published: August 2008

Eleven additional specimens of Tadarida aloysiisabaudiae and one of T. russata extend the known range of both species westward to Ghana. Their allopatric ranges appear to be restricted to a narrow zone extending at least 3300 km (2100 mi) just north of the equator. Tadarida russata has been taken only in or adjacent to the "invasive Guinea woodland," whereas all T. aloysiisabaudiae have been collected peripheral to it. Recent specimens taken in association with T. russata were T. (Xiphonycteris) spurrelli and T. thersites. Measurements of the T. russata from Ghana are compared with those from previously recorded specimens, and a statistical summary for the measurements of T. aloysiisabaudiae is given. In addition, other morphological comparisons including the first illustrations of the palatal ridges of both species are provided.
A new species of platyctenean ctenophore, Lyrocteis flavopallidus sp. nov., from McMurdo Sound, Antarctica
Authors: Robilliard Gordon A. , Dayton Paul K.
Published: August 2008

Lyrocteis flavopallidus sp. nov., a large (up to 110 mm tall) platyctenean ctenophore from the Antarctic, is described on the basis of the external morphology. The pale straw-yellow color, lack of ridges and frills on the body and arms, presence of small papillae on the body, and geographical location are considered sufficient to distinguish L. flavopallidus from L. imperatoris Komai, 1941, the only other species in the genus. The systematic placement of L. flavopallidus is somewhat uncertain because neither the anatomy of the reproductive system nor the larval development is known; the species may represent a new genus and possibly a new family.Lyrocteis flavopallidus is sedentary and usually found atop sponges or other elevated surfaces. However, it is able to move at least 1 to 2 m per day possibly to attain a more advantageous feeding position. Food items are captured by the sticky tentacles and transferred to the mouth.
Occurrence and function of lip hypertrophy in the Anisomyaria (Mollusca, Bivalvia)
Authors: Bernard F. R.
Published: August 2008

Examination of the labial structures of 36 species in 24 genera of the Anisomyaria demonstrates that true hypertrophy occurs only in the Pectinidae s.1., Spondylidae, and Limidae. The Propeamussidae lack enlarged lips, evidence supporting their removal from the Pectinidae. Observation of living materials has suggested that rather than serving as a food-retentive hood, the enlarged lips perform a screening function.
Ultrastructure of protein and lipid inclusions in frozen-etched blackfly oöcytes (Simuliidae, Diptera)
Authors: Liu T. P. , Davies D. M.
Published: August 2008

In frozen-etched oöcytes of 1-day-old female blackflies, Simulium vittatum Zett., lipid yolk granules have a structure of concentric lamellae. The protein yolk spheres possess a highly ordered arrangement which commonly appears as a banded or seemingly hexagonal pattern. The hexagonally arranged subunits are approximately 140 Å in diameter, whereas subunits in the banded pattern are 130 Å wide and 150 Å long. The regularity of the fractured faces suggested that yolk protein spheres possess hexagonally arranged microfilaments, i.e., rod-like, repeat subunits. Both lipid granules and protein spheres in the oöplasm possess a single limiting membrane. The significance of these observations is discussed.
The energy requirements of metamorphosis of the greater wax moth, Galleria mellonella (L.)
Authors: Moon Barbara J. , Carefoot Thomas H.
Published: August 2008

Energy budgets calculated for the period of metamorphosis of 16 female Galleria mellonella showed a range in deviation from the balanced condition of−23% to + 22%. The oxygen consumption of Galleria, measured as one component of the energy budget, was 2.9 μl O2/mg per hour for final-instar larvae of 249–275 mg in weight [Formula: see text] and 2.1 μl O2/mg per hour for adults of 67–136 mg in weight [Formula: see text]. The calorific content increased from 6446 cal/g dry weight in the final-instar larva to 6711 cal/g dry weight in the adult. The "rejecta" of metamorphosis, including cocoon (combined with larval faeces, shed adult scales, and adult excreta), pupal case, and larval remnants (shed larval skin), had comparatively low calorific values (4462, 4847, and 4933 cal/dry g, respectively), and constituted only 12% of the total energy accounted for during metamorphosis.
The fine structure of coelomocytes of the sea urchin, Strongylocentrotus dröbachiensis (Müllier O.F.)
Authors: Vethamany V. G. , Fung M.
Published: August 2008

The fine structure of six different types of coelomocytes from Strongylocentrotus dröbachiensis (Müller), a sea urchin, is described. (1) Phagocytic leukocytes have either phagosomes of different sizes or large bladder-like, as well as veils of, cytoplasmic extensions. Syncytia are not observed under normal physiological conditions, although cell aggregation occurs without fusing of the plasma membranes. (2) Vibra-tile cells have a conventional flagellum and numerous mucopolysaccharide granules fill their cytoplasm. (3) The amoeboid red spherule cells contain typical echinochrome granules showing three structural components. (4) Colorless spherule cells contain numerous vacuole-like structures. (5) Small spherical cells are probably stem cells. (6) The granulocytes are few in number.
Comparison of the breeding habits of two subspecies of longnose dace, Rhinichthys cataractae
Authors: Bartnik V. G.
Published: August 2008

Reproductive behavior of the longnose dace, Rhinichthys cataractae dulcis, from Alouette River, British Columbia, is described and compared with the eastern subspecies, Rhinichthys cataractae cataractae. Color differences between breeding males of the two subspecies are striking. Rhinichthys c. cataractae males display bright crimson patches on the ventral surface but these are lacking in R. c. dulcis males. The former breeds during daylight while the latter breeds at night. Although breeding behavior patterns of the two subspecies are almost identical, slight differences do exist and are correlated with diurnal versus nocturnal breeding.
Seasonal changes in total body water, extracellular fluid, and blood volume in grazing reindeer
Authors: Cameron R. D. , Luick J. R.
Published: August 2008

The effects of climatic and nutritional changes on body fluid compartmentalization and turnover were investigated in grazing female reindeer. Total body water volume and turnover, extracellular fluid volume, and blood volume were estimated using tritiated water, sodium sulfate-35S, and sodium chromate-51Cr, respectively. During winter and spring, body weights were either maintained or reduced while total body water (percentage of body weight) increased, resulting in appreciable losses of total body solids. In summer, large gains in body weight were accompanied by reduced total body water volumes resulting in substantial increases in body solids. An apparent fluid shift from the intravascular to the extracellular compartment during late spring suggested the occurrence of a starvation edema. Mean water flux rates (ml/day per kilogram body weight) were higher in late spring than during other seasons; lowest values were recorded in early winter. Seasonal variations in nutritional status as reflected by body composition and fluid compartmentalization, and changes in water turnover are discussed in relation to climate and the quality and availability of forage. The complicating influences of pregnancy and lactation are also considered.
Swimming in northern terrestrial mammals
Authors: Dagg A. I. , Windsor D. E.
Published: August 2008

Swimming mammals floated at a variety of angles correlated with hair and body fat present, and used a variety of gaits. In general small mammals with long tails used their hind legs alternately while large mammals and those with short tails paddled with four feet alternately as in the trot. The species that used their legs synchronously were either semiaquatic or had a phylogenetic background of hopping. During their development, mice and rats possessed six swimming gaits, including several asymmetrical gaits used by neonates, the early use of the front legs, the subsequent use of four legs, and the final use of hind legs, which was the adult gait. The developmental swimming patterns of guinea pigs, rabbits, hamsters, gerbils, and lemmings were less complex and concluded with the use of four legs, the adult gait. The ability to swim in a straight line was often a function of maturity, occurring sometimes before the eyes opened. The ability to hold the nose out of the water always preceded the opening of the eyes.
Uric acid excretion by midgut epithelium in Gilpinia hercyniae (Htg.)
Authors: Fogal W. H. , Kwain M.-J.
Published: August 2008

Experimental and histological evidence suggest that uric acid is excreted by the midgut epithelium in the diprionid sawfly, Gilpinia hercyniae (Htg.), and that this function resides in specialized accessory structures, the gastric crypts.
Cytoplasmic organelles present during spermatogenesis in the free-living nematode Panagrellus silusiae
Authors: Pasternak J. , Samoiloff M. R.
Published: August 2008

By electron microscopy it was found that two kinds of cytoplasmic organelles occur during spermatogenesis in the free-living nematode Panagrellus silusiae. One type of organelle is called a vesicular body (v-body) and lines the complete internal cell surface of the spherical and aflagellate sperm. V-bodies (about 0.35 μm × 0.6 μm) are formed in the primary spermatocytes and after meiosis they migrate to the surface of the spermatid. In the primary spermatocytes, before the appearance of v-bodies, many double membrane - bound, ovoid crystalline bodies (c-bodies) are formed. These bodies (about 0.5 μm × 0.7 μm) subsequently degenerate and no trace of their fibrillar material is observed in the spermatozoon.The mature sperm is devoid of microtubules, centrioles, Golgi material, and acrosomal-like structures; however, numerous mitochondria lie beneath the surface vesicles and in the central region of the mature sperm the chromatin occurs as discrete condensed clumps.
Ration size and digestion in largemouth bass, Micropterus salmoides Lacépède
Authors: Beamish F. W. H.
Published: August 2008

Organic dry weight, protein N, lipid, and energy of contents in the stomach of largemouth bass decreased curvilinearly with time after a meal of lake emerald shiners, Notropis atherinoides. Time to evacuate the stomach increased with ration size. The proportionate change in time for a given percentage of gastric emptiness was independent of ration size. Proportionately more protein N than lipid was absorbed in the stomach. The pyloric caeca is an area of absorption particularly for protein N. In the intestine absorption of lipid was proportionately greater than that for protein N.Absorption efficiency of protein N, lipid, or energy did not differ significantly among the rations followed nor between the two size classes of bass. The overall geometric mean absorption efficiency for protein N was 95.7%, for lipid, 95.5%, and for energy, 89.6%. Initially the rate of absorption of protein N was highest for fish fed large rations. Differences in rate of absorption of lipid were not observed among the rations followed.
Basic protein composition of anuran sperm: a cytochemical study
Authors: Bols N. C. , Kasinsky H. E.
Published: August 2008

A cytochemical study of the basic protein composition in the sperm of seven species of anurans has revealed that their sperm histones fall into only two classes of the five proposed by Bloch (1969); (1) the Rana type, which is similar to the histones found in the somatic cells; and (2) the Mytilus type, which appears to contain more arginine than that in Rana but less arginine than the arginine-rich histones of mouse and grasshopper sperm. Basic proteins free of DNA were not observed in the sperm.
Accumulation of strontium-90 in pronghorn antelope (Antilocapra americana americana) females in Alberta
Authors: Mitchell George J. , Hontzeas Sotirios , Cameron Wendy
Published: August 2008

Radiochemical procedures were used to determine strontium-90 distribution and concentrations in dentary bone samples taken from three positions on the mandibles of female pronghorn antelopes (Antilocapra americana americana) collected in October 1964 in the Newell study area, Alberta. No significant differences in pCi of 90Sr per gram of calcium were found between mandible position means, and females in the same age-classes showed no individual variations in 90Sr burdens. The differences in mean 90Sr concentrations between age-classes were highly significant, with the youngest and oldest animals showing the largest and smallest 90Sr burdens, respectively.
Variation in the serum proteins of the red-backed mice Clethrionomys rutilus and C. gapperi and its taxonomic significance
Authors: Canham Raymond P. , Cameron David G.
Published: August 2008

Starch gel electrophoresis revealed the existence of four transferrins, five albumins, and 17 α-globulins in the serum of red-backed mice from nine locations in western Canada. Two of the transferrins and one of the albumins occurred in populations of both Clethrionomys rutilus and C. gapperi, but every population sampled contained at least one of the remainder of these proteins at a moderately high frequency. Populations of the two species near the boundary between their ranges of distribution could also be distinguished by the frequencies of the shared transferrins and albumins. Eight of the α-globulins were found only in C. gapperi, and two only in C. rutilus. Populations of the two species could not invariably be distinguished by means of these proteins: the same seven α-globulins were present in both species near their common boundary in the Northwest Territories, although only one was shared by populations on either side of the boundary in the Rocky Mountains of British Columbia. Several α-globulins were found only in samples of C. gapperi from southern Alberta. Differences between populations with respect to the α-globulins present, as well as to the frequencies of certain transferrins and α-globulins, were probably the result of differences in the environmental conditions to which the populations were subject.
Determination of age, age structure, and mortality of the pika, Ochotona princeps (Richardson)
Authors: Millar John S. , Zwickel Fred C.
Published: August 2008

Determination of age of pikas (Ochotona princeps Richardson) by counting adhesion lines in periosteal bone of the lower jaw is described. Pikas attain a maximum age of at least 7 years in Alberta and Colorado. Estimated yearly losses of adults did not differ significantly between sexes, years of the study, or among collecting areas, and averaged 46%. Age-specific rates of mortality were greatest in the 0–1 and 5–7 year age groups and the general mortality pattern was similar to those reported for other mammals.
Hematology of the brown bear (Ursus arctos) from southwestern Yukon Territory, Canada
Authors: Pearson A. M. , Halloran D. W.
Published: August 2008

Blood samples from 22 brown bears (Ursus arctos) and 5 black bears (Ursus americanus) were examined for erythrocyte count, erythrocyte morphology, erythrocyte diameter, hematocrit, hemoglobin, erythrocyte indices, serum iron, total iron-binding capacity, leucocyte count, and leucocyte differential count.A statistically significant decrease in erythrocyte count and hematocrit and increase in erythrocyte indices was found in brown bears from spring to summer. Limited evidence suggests that the spring to summer change may be reversed in the fall.No differences were apparent between sexes at any season but it was indicated that young bears had lower red blood cell concentration, lower hematocrit, and lower hemoglobin concentration than other animals.Leucocyte differential counts in the study were similar to those reported for other bears. Anisocytosis with numerous spherocytes and burr cells characterized the erythrocytes.Serum iron and total iron-binding capacity varied but did not suggest iron-deficiency anemia.Hematology results for the black bears were similar to those of brown bears but our small sample did not allow an investigation of seasonal changes in the species.
The structure of aerial-feeding bat faunas as indicated by ears and wing elements
Authors: Fenton M. Brock
Published: August 2008

Structure in the aerial-feeding bat faunas of southeastern Ontario, southern British Columbia, Cameroun, Guyana, and the Philippines is demonstrated on the basis of wing shape and relative ear size. The former is derived from the ratio of the length of the third digit metacarpal to the length of the fifth digit metacarpal (III/V) and the latter from the ratio of the length of the ear to the length of the forearm (E/FA). It is assumed that these characters affect flight pattern and echolocatory characteristics and thus prey selection in the aerial-feeding, echolocating bat. On the basis of these characteristics some Emballonurinae and the Mormoopidae are thought to replace the Vespertilionidae in the neotropics, and some Phyllostomatinae may be neotropical counterparts of the Rhinolophidae, Nycteridae, and Megadermatidae. The Diclidurinae seem to parallel the old world Taphozous in wing shape and ear size.
Songs of song sparrows (Melospiza melodia): individual variation and dialects
Authors: Harris Margaret A. , Lemon Robert E.
Published: August 2008

Male song sparrows from two areas in Quebec had repertoires of several song patterns, each one of which was generally made up of two repeated units, or syllables, plus unrepeated note complexes. Variability between individuals was large, but there was also some similarity: while most syllable types were sung by one individual only, some were shared with others in the population. The relative occurrence of the different syllable types was similar in two sites at Pare Cote Ste. Catherine but between Pare Cote Ste. Catherine and Mont St. Hilaire (separated by 23 mi) there was almost complete lack of similarity, which was taken as evidence that dialects existed. Birds from the less densely populated area at Mont St. Hilaire had slightly smaller repertoires of syllables and song patterns.
The muscular system of Pachycerianthus fimbriatus
Authors: Arai Mary Needler
Published: August 2008

The movement of Pachycerianthus fimbriatus in response to food, and electrical and mechanical stimuli is described. Animals were examined in their tubes, in glass dishes, in glass tubes, on a beaker of sand, or using preparations of different portions of the column. The observed movement was correlated with anatomical data obtained principally from histological sections. Possible conducting pathways controlling the movement are discussed.
The fine structure of the esophagus of some trichuroid nematodes. I. The stichosome of Capillaria hepatica, Trichuris myocastoris, and Trichuris vulpis
Authors: Wright K. A.
Published: August 2008

The posterior glandular esophagus (stichosome) of the trichuroids Capillaria hepatica, Trichuris myocastoris, and T. vulpis has been found to include three components: the large gland cells or stichocytes, the lumenal epithelium with its cuticular lining, and an external muscle reticulum surrounding the entire stichosome. A pore, composed in C. hepatica of a local thickening of the lumenal cuticle, connects the lumen to a branching system of intracellular collecting ducts in the stichocytes that receive the secretory products (granules and vesicles) formed in the cell. A system of filament bundles within the stichocyte cytoplasm probably suspends the collecting duct system within the cell. Opening and closing of the esophageal lumen appears to occur through contraction of the external muscle reticulum, as the lumenal epithelium either lacks myofilaments entirely (C. hepatica), or retains only vestigial clumps of them (T. vulpis).
Effects of cyclohexamide and hydroxyurea on mating behavior and its development in the free-living nematode Panagrellus silusiae (de Man 1913) Goodey, 1945
Authors: Cheng Ronald , Samoiloff M. R.
Published: August 2008

Females of the free-living dioecious nematode Panagrellus silusiae that have undergone postembryonic development in hydroxyurea do not attract males, and treated males do not respond to normal females. Nematodes placed in hydroxyurea as adults have normal gonads and retain the sexual attraction system. Hydroxyurea has no effect upon copulatory behavior of adult animals. Treatment of adult females with actidione stops production of attractant, although production resumes within 24 h after removal of the females from actidione. Actidione treatment of males has no effect upon the response to attractant by males or on copulation. It is proposed that sexual attraction depends on complete development of the reproductive system, but that copulation does not.
Skrjabingylus lutrae n. sp. (Nematoda: Metastrongyloidea) from otter (Lutra canadensis)
Authors: Lankester Murray W. , Crichton Vincent J.
Published: August 2008

Skrjabingylus lutrae n. sp. from otter in Ontario is distinguished from other members of the genus by its short spicules (239–275 μ long) with globe-shaped tips, and a small buccal capsule. It is the only sinus worm known from otter (Lutrinae). First-stage larvae from the uteri of female worms and third-stage larvae from experimentally infected gastropods (Mesodon roemori) are described.
Histochemical and radiographic investigations of Malathion-induced malformations in embryonic chick limbs
Authors: Gill G. R. , LaHam Q. N.
Published: August 2008

The organophosphate Malathion produces malformations in the limbs of chick embryos. Staining with buffered toluidine blue reveals abnormal areas in the cartilage characterized by hypertrophy of the chondroblasts, lack of ground substance, and weak (gamma) γ metachromasia. Radioautography with S35 shows little incorporation into the chondroitin sulfates of the cartilage ground substance.
Studies on the heterophyid trematode Apophallus brevis, the "sand-grain grub" of yellow perch (Perca flavescens) I. Redescription and resolution of synonymic conflict with Apophallus imperator Lyster, 1940 and other designations
Authors: Sinclair Norman R.
Published: August 2008

Apophallus brevis Ransom, 1920, collected from the intestine of a ringbilled gull (Larus delawarensis), has been identified as the definitive stage of metacercariae found encysted in flesh of yellow perch (Perca flavescens). These metacercariae and (or) cysts have been described under various names: Distomum sp. larv. of Cooper, 1915; "sand-grain grub," Tetracotyle sp. of Hunter, 1942; and Apophallus itascensis Warren, 1953. In addition, an aberrant postmetacercarial form was described as Apophallus americanus by Van Cleave and Mueller (1932). Known definitive hosts are ringbilled and herring gulls (L. argentatus), the latter constituting a new host record for this worm species.Apophallus imperator Lyster, 1940, the etiological agent of "black-spot disease" in brook trout (Salvelinus fontinalis), synonymized by Miller (1941) with Apophallus brevis, is here recognized as a distinct species. Except for shape and length of pharynx, adult flukes of these two species are difficult to differentiate unless extremes of characters are present in observed specimens as ranges of measurements of morphological features have considerable overlap. Though these organisms are nearly identical morphologically during the adult stage, they have the following major distinctions: host specificity, sexual development, location and type of cyst and body size as metacercariae, and maturation time and longevity in definitive hosts.
Estrone and estradiol concentrations in peripheral plasma of laying hens as determined by radioimmunoassay
Authors: Peterson A. J. , Common R. H.
Published: August 2008

An application of radioimmunoassay to measurement of concentrations of estradiol and estrone in peripheral plasma of hens is described. Evidence is presented that the estradiol measured by the procedure was essentially estradiol-17β.For 13 ovulatory cycles the average concentration of estradiol was 123 pg/ml with a range from 36 pg/ml to 284 pg/ml. The corresponding average concentration for estrone was 64 pg/ml with a range from 14 pg/ml to 138 pg/ml. For 12 days of no ovulation the average concentration of estradiol was 142 pg/ml with a range from 42 pg/ml to 364 pg/ml. The corresponding average value for estrone was 91 pg/ml with a range from 18 pg/ml to 242 pg/ml.The results are interpreted as demonstrating the existence of peak levels of plasma estradiol at 22–18 h and again at 6–2 h before ovulation, and a minimal level at 14–10 h before ovulation. The corresponding plasma estrone concentrations displayed a similar cycle but the earlier peak and the minimum occurred 2–4 h later than the corresponding values for estradiol. Such peak values were not demonstrable on days when ovulation did not occur.The results are discussed briefly in relation to variation in the levels of blood progesterone during the ovulatory cycle.
Amino acid pools of Syndesmis franciscana (Turbellaria: Platyhelminthes) and of host coelomic fluid
Authors: Mettrick D. F. , Boddington M. J.
Published: August 2008

The molar ratios and concentrations of the free amino acid pools of Syndesmis franciscana and of the coelomic fluid of the host urchin, Strongylocentrotus purpuratus, were significantly different.The amino acid pool of Syndesmis franciscana was similar in array and in concentration to those of other parasitic members of the Platyhelminthes. It was also similar in array but differed in concentration from those of marine invertebrates (including turbellarians), and differed in both array and concentration from those of freshwater turbellarians.
The transmission of Ackertia marmotae Webster, 1967 (Nematoda: Onchocercidae) of groundhogs (Marmota monax) by Ixodes cookei
Authors: Ko Ronald C.
Published: August 2008

Adults of Ackertia marmotae of groundhogs (Marmota monax) were located in lymphatics. Few microfilariae were recovered from blood but large numbers were in the reticular layer of the dermis, especially in skin of the ears. Microfilariae tended to accumulate in dermal tissue at feeding sites of Ixodes cookei.In laboratory-reared I. cookei maintained at 30C, microfilariae developed to the infective stage in about 1 month. First- and second-stage larvae were usually recovered from fat cells but some were also in epidermal cells. Infective larvae were found in the haemocoel and in ducts of salivary glands. Morphological changes of larvae during development are described; there is no "sausage-stage."One unfertilized female and one adult male A. marmotae were recovered from two groundhogs inoculated with infective larvae from laboratory-reared ticks. The prepatent period is estimated to be at least 1 year.Twenty-eight percent of 426 adult groundhogs examined in southern Ontario had adult worms. Microfilariae and adult worms were not found in 76 young of the year and 59 yearling animals.
Ultrastructural morphology of the body wall, stoma, and stomatostyle of the nematode, Tylenchorhynchus dubius (Bütschli, 1873) Filipjev, 1936
Authors: Byers J. R. , Anderson R. V.
Published: August 2008

The fine structure of the body wall, stoma, and stomatostyle of the plant parasitic nematode, Tylenchorhynchus dubius, is described. The body wall consists of a six-layered cuticle, about 1 μ thick, and a thin interchordal hypodermis. Some details of the labial framework and the cuticular lining of the stoma are described. The shaft of the stomatostyle is composed of five distinct layers. The attachment between the shaft and the stomatal cuticle is characterized by several specializations. One of these is an extensive attachment complex formed at the lateral junction between the stomatal and stylet epithelia. The protractor musculature consists of three main units which are each subdivided anteriorly into smaller elements. Also present are four secondary muscle elements which extend posteriorly beyond the base of the stylet and attach to the cuticular lining of the esophagus above the dorsal duct orifice.The ultrastructural morphology described for T. dubius is compared with that known for other plant parasitic nematodes. Some likely relationships between structure and function are also discussed.
Probabilistic phototactic behavior in a bark beetle: comment
Authors: Thomas Hollis A. , Swindel Benee F. , Hafley William L. , Monroe Robert J.
Published: August 2008

An alternative analysis of a study on the phototactic behavior of a bark beetle leads to two conclusions that differ from those of the original author. We find (1) that the beetles behaved in a normal manner and (2) that they could be selected for their positive response to uv. light.
Ducks nesting in association with gulls—an ecological trap?
Authors: Dwernychuk L. W. , Boag D. A.
Published: August 2008

The reproductive success of ducks nesting in association with gulls on islands in Miquelon Lake, Alberta, was studied over a period of 3 years. Gulls protected nesting ducks by preventing other egg-eating birds from foraging on the islands. Pilfering of duck eggs by gulls was correlated with the point in incubation when ducks were trapped and handled. Without trapping, we estimated hatching success would exceed 90%. However, duckling mortality, concentrated in the 1st week posthatching, was positively correlated with the numbers of associated gulls. The survival of ducklings declined to zero when the number of nesting gulls approached 500 pairs. The origin and maintenance of this ecologically unstable relationship is discussed.
The harp seal, Pagophilus groenlandicus (Erxleben, 1777). III. The underwater audiogram
Authors: Terhune J. M. , Ronald K.
Published: August 2008

A free-field underwater audiogram from 0.76 to 100 kHz was obtained for Pagophilus groenlandicus. Areas of increased sensitivity occurred at 2 and 22.9 kHz. The lowest threshold was −32.9 db/μbar at 15.0 kHz. Above 64 kHz the threshold increases at a rate of 40 db/octave. The audiogram was similar to that of the Phoca vitulina. The effects of ambient noise on the audiogram are discussed.
Fine structure of pegs on the palps of female culicine mosquitoes
Authors: McIver Susan B.
Published: August 2008

The fine structure of the thin-walled pegs known to respond to carbon dioxide was studied in Aedes aegypti (L.), Culex pipiens L., and Culex territans Walker. Each peg is composed of an external cuticular structure with numerous pores which occur in groups, three bipolar neurons, and sheath cells. In A. aegypti two morphologically different types of neurons were found innervating the same sensillum: two electron-dense neurons and one electron-lucid neuron per peg. In addition to distinctive cell bodies and nuclei, the two types of neurons have different organization patterns of their dendritic processes within the lumen. Culex pipiens is shown to have several times more area available for perception of carbon dioxide than A. aegypti.
Studies on the heterophyid trematode Apophallus brevis, the "sand-grain grub" of yellow perch (Perca flavescens). II The metacercaria: position, structure, and composition of the cyst; hosts; geographical distribution and variation
Authors: Sinclair Norman R.
Published: August 2008

The metacercarial cyst of Apophallus brevis, the "sand-grain grub," is composed of fish bone within peripheral blood vessels of yellow perch (Perca flavescens) forming a tire-like structure; two escape canals are maintained opposite each other. In thin section, lines indicating interruption of growth apparently delimit annual incrementation as in scales and other bony structures of fish. Cysts are oriented with their long axes paralleling the long axis of a host's body with escape canals contiguous to walls of enclosing blood vessels. Cysts of A. brevis in situ at times appear partially or entirely pigmented but are actually transparent; pigmentation, when present, is a phenomenon of a cyst's position within certain types of blood vessels and is not an integral part of a cyst's construction. The organism as a metacercaria is almost exclusively a parasite of yellow perch (known deviations are noted) and is apparently confined to North America, having a known broad range from Saskatchewan to Cape Cod. Massachusetts. Distribution is extremely diffuse and appears dependent on patchy distribution of the organism's molluscan host, Amnicola limosa. Geographical variation in cyst site selection and clustering indicates some sort of intraspecies inhibition on the part of metacercariae of A. brevis.
Duality in function in corpora allata of honeybee larvae
Authors: Dixon S. E. , Moser E.
Published: August 2008

Corpora allata of honeybee worker larvae 48 h of age are capable of activating Periplaneta female accessory glands. Corpora allata from queen larvae of the same age are repressive in action. By 72 h of age the worker allata have a considerably reduced activity but queen larvae of the same age have allata of the activating type. Thus, corpora allata show a duality in function during caste development.
The effect of sex and sex hormones on the infection of rats by Trichinella spiralis
Authors: Mankau Sarojam K. , Hamilton Raymond
Published: August 2008

Male hooded rats infected with Trichinella spiralis larvae had three times more larvae in the muscles than females. Gonadectomized males injected with stilbestrol had a lower worm burden than normal males. Gonadectomized females injected with testosterone propionate harbored far more worms than normal females. Stilbestrol administered to normal male rats caused a marked decrease in T. spiralis, while testosterone administered to normal females resulted in a significant increase in the number of parasites.
The effect of salt gland removal on cloacal ion and water excretion in the growing kittiwake, Rissa tridactyla
Authors: Hughes Maryanne Robinson
Published: August 2008

The supraorbital salt glands were surgically removed from five nestling kittiwakes, Rissa tridactyla, which, with four sham-operated birds, were reared in individual cages for 29 days on a diet of weighed fish. The daily cloacal excreta were weighed and analyzed for Na+, K+, Cl−, and water. Salt gland removal did not greatly affect cloacal ion excretion. In both groups cloacal fluid contained 30% of the ingested water and 20–50% of the ingested ions. The cloacal fluid of control birds was always hypotonic to the food, that of glandless birds hypertonic. In all samples the solid excreta (mainly uric acid) comprised 10% of the weight, but contained 25–50% of the cloacally excreted Na+ and Cl− and up to 60% of the K+. Fecal material might account for 10% of the ingested NaCl. Since cloacal excreta contained only one-half of the ingested ion load, extrarenal salt excretion may still have existed in the kittiwakes lacking supraorbital salt glands. These birds did not secrete after acute salt loading, but the plastic cage liners of these birds had nearly as much NaCl on them as did those of control birds, suggesting secretion from the head region. The tears were approximately isotonic to the plasma. Salt gland removal did not affect adrenal, lacrymal, or Hardenian glands, kidney, or body weight, but glandless birds had slightly larger hearts.
Relationships within the genus Myoxocephalus (Pisces: Cottidae) based on morphological and biochemical data using numerical and conventional methods of analyses
Authors: Cowan Garry I. McT.
Published: August 2008

Systematic relationships within the cottid genus Myoxocephalus are derived, based on morphological and biochemical (muscle myogen, lactic and malic dehydrogenase electropherograms) characteristics. The effects of numerical and conventional taxonomic analyses on the relationships derived from both sources of data are investigated.Comparison of numerical clustering of morphological and biochemical data indicates that the relationships are not comparable. However if the data are combined, the relationships obtained are similar to those based solely on morphological information.Conventional analyses of 45 morphological and 35 biochemical characters yielded similar patterns of relationship. The biochemical ones are, however, notably more conservative and simplified. The two treatments of morphological data and the numerical treatment of combined morphological and biochemical data indicate very similar relationships. However the numerical treatment of biochemical data resulted in completely different affinities.It is nevertheless possible to conclude that where evidence is available from a wide variety of systems within the organism, the two analytical techniques yield similar results. Also the inclusion of a limited amount of biochemical data should not be expected to result in greatly improved or altered systematic conclusions.
Comparative morphology of the cottid genus Myoxocephalus based on biochemical characters
Authors: Cowan Garry I. McT.
Published: August 2008

Specimens of 11 nominal species of the cottid genus Myoxocephalus were subjected to micro starch-gel electrophoretic analyses. Muscle myogens and isozymes of muscle lactic and malic dehydrogenases were examined.No sexual variations were evident in the electropherograms. Geographic variation in myogen characteristics was investigated for three species, two of which were of a homogeneous nature. In the third, M. scorpius, the specimens from Europe differed from all others.The myogen banding patterns were highly species-specific as were the shapes of their densitometer tracings. Two banding patterns were detected in malic dehydrogenase isozymes. Lactic dehydrogenase isozymes also evinced two distinct patterns, 11 species having one pattern and one (M. scorpioides) exhibiting both.On the basis of myogen data two natural groupings are evident, one composed of the Asiatic species and another of the Arctic and American east coast forms.
The reproductive apparatus of sexual specimens from fissiparous populations of Fonticola morgani (Tricladida, Paludicola)
Authors: Benazzi Mario , Ball Ian R.
Published: August 2008

Abnormal, but spontaneous development of sexual organs in fissiparous specimens of Fonticola morgani is noted and described. The phenomenon is compared with similar abnormalities which have been noted in European populations of Dugesia gonocephala s.1., for which a genetic basis has been established.
Blood parasites of game birds from insular Newfoundland
Authors: Bennett Gordon F. , Inder James G.
Published: August 2008

Blood smears of 209 tetraonids of three species, 184 anatids of nine species and 35 scolopacids of six species from insular Newfoundland were examined for hematozoa. Forty-six percent of the tetraonids harbored Leucocytozoon bonasae and 4% harbored microfilaria; 3% of the anatids harbored blood parasites (Leucocytozoon simondi, Parahaemoproteus nettionis, Plasmodium circumflexum, microfilaria); the scolopacids were parasite-free.
Extreme vertebral variation induced by temperature in a homozygous clone of the self-fertilizing cyprinodontid fish Rivulus marmoratus
Authors: Lindsey C. C. , Harrington Jr. Robert W.
Published: August 2008

Embryos from one clone of Rivulus marmoratus were reared at various constant temperatures ranging from 19.5 to 31.2C, sustained throughout early development, or else were transferred from 26 to 20C after various periods of development. Resultant vertebral counts were progressively lower at higher sustained temperatures (ranging from 34.94 to 32.57). Vertebral differences expressed as a percentage of the total count were greater in this (7.0%) than in previously reported comparable experiments on 14 other fish species (4.1% or less). In most previous experiments meristic variation may have been due, at least in part, to selective mortality acting on a varied gene pool. In R. marmoratus the high degree of genetic uniformity eliminates the likelihood of selective mortality as a cause of vertebral variation, which must therefore have been environmentally induced. Pectoral ray counts also were lower at higher sustained temperatures; other meristic series did not show sharp responses. Temperature transfer experiments showed that vertebral counts are determined within 4 days at 26C (by first appearance of retinal pigmentation). Pectoral ray counts are not fully determined until about 8 days, shortly before hatching. Temperature breaks produced "shock effect" in pectoral rays but not in vertebrae. The bearing of homozygosity on amplitude of temperature-induced vertebral variation is discussed.
La réaction phagocytaire chez Amoeba proteus I. Phagocytose decellules dissociées d'hydre d'eau douce
Authors: Marsot Pierre , Couillard Pierre
Published: August 2008

EDTA-dissociated cells from freshwater hydrae were found to be good, nonmotile inductors of chemotaxis and phagocytosis in Amoeba proteus. Food-cup formation can take place in the absence of contact between the Amoeba and the ingested cell. Aged hydra cells are not phagocytized but induce the formation of twin pseudopodia.Hydra cells, stained vitally with acridine orange, were used to measure quantitatively the rate of phagocytosis. High concentrations of hydra cells proved to be inhibitory.Our results are in accord with the theory which considers pseudopod induction as a chemotactic phenomenon and which attributes food-cup formation to a local inhibition by the same chemotactic substances, which are present in high concentration in the vicinity of the ingested cell.
Histogenesis of the tibiotarsus in Malathion-treated chick embryos
Authors: Ho M. , Gibson M. A.
Published: August 2008

Chick eggs were injected with 0.1 ml of 2% Malathion in corn oil on the 5th day of incubation, and its effect on skeletogenesis, particularly the development of the tibiotarsus, was studied throughout the incubation period. Anatomically, the treated embryos showed a generalized reduction in body size, delayed patterns of mineralization in certain of the endochondral bones, and micromelia. The treated tibiotarsi consistently exhibited a reduced growth rate and an angulation at the junction of the diaphysis and distal epiphysis. The rate of periosteal ossification, cartilage resorption, and marrow cavity formation progressed more rapidly in the tibiotarsi of the treated embryos. The striking feature of the treated tibiotarsi was degenerative necrosis of the cartilage within both proximal and distal epiphyses. This necrotic zone exhibited a reduced matrix and progressive degeneration of the chondrocytes.