bluuebunny/crossref_metadata_2025 huggingface dataset:
Alterations in energy metabolism associated with the transition from water to air breathing in fish
Authors: Driedzic William R. , Phleger Charles F. , Fields Jeremy H. A. , French Christopher
Published: August 2008

Hoplias malaharicus and Hoplerythrinus unitaeniatus are two closely related species which live in poorly oxygenated water. The former is an obligate water breather, whereas the latter has the additional capacity to respire atmospheric oxygen through a highly vascularized swim bladder. Hoplerythrinus has greater lipid stores than Hoplias and probably places a greater dependence upon this metabolic fuel as an energy source than Hoplias. In contrast with this, Hoplias has greater heart and liver glycogen reserves than Hoplerythrinus. Hoplias hearts perfused in vitro with buffer containing cyanide continued to beat eight times longer than Hoplerythrinus hearts. The performance of both types of hearts was markedly increased when glucose was added to the perfusate; however, the Hoplias hearts still continued to function better than the Hoplerythrinus hearts. It is concluded that the Hoplias heart is better adapted to function anaerobically than the Hoplerythrinus heart.
Metabolic biochemistry of water- vs. air-breathing fishes: muscle enzymes and ultrastructure
Authors: Hochachka P. W. , Guppy M. , Guderley H. E. , Storey K. B. , Hulbert W. C.
Published: August 2008

To delineate what modifications in muscle metabolic biochemistry correlate with transition to air breathing in fishes, the myotomal muscles of aruana, an obligate water breather, and Arapaima, a related obligate air breather, were compared using electron microscopy and enzyme methods. White muscle in both species maintained a rather similar ultrastructure, characterized by large-diameter fibers, very few mitochondria, and few capillaries. However, aruana white muscle displayed nearly fivefold higher levels of pyruvate kinase, threefold higher levels of muscle-type lactate dehydrogenase, and a fourfold higher ratio of fructose diphosphatase –phosphofructokinase activity; at the same time, enzymes in aerobic metabolism occurred at about one-half the levels in Arapaima. Red muscle was never found in the myotomal mass of aruana, but in Arapaima, red muscle was present and seemed fueled by glycogen, lipid droplets never being observed. From these and other data, it was concluded that in myotomal muscle two processes correlate with the transition to air breathing in Amazon osteoglossids: firstly, an emphasis in oxidative metabolism, and secondly, a retention of red muscle. However, compared with more active water-breathing species, Arapaima sustains an overall dampening of enzyme activities in its myotomal muscle, which because of the large myotome mass explains why its overall metabolic rate is relatively low. By keeping the oxidative capacity of its myotomal muscle low, Arapaima automatically conserves O2 either for a longer time or for other more O2-requiring organs in the body, a perfectly understandable strategy for an air-breathing, diving fish, comparable with that observed in other diving vertebrates. A similar comparison was also made of two erythrinid fishes, one that skimmed the O2-rich surface layers of water and one that obtained three quarters of its O2 from water, one quarter from air. Ultrastructural and enzyme data led to the unexpected conclusion that the surface skimmer sustained a higher oxidative capacity in its myotomal muscles than did the facultative air breather.
The characterization of ATPases from the gill of the osteoglossid Osteoglossum bicirrhosum (aruaná)
Authors: Moon Thomas W.
Published: August 2008

Gill ATPases of the osteoglossid Osteoglossum bicirrhosum (aruaná) were isolated from the microsomal fraction (Nal pellet) and assayed in the presence of various cations and anions. The presence of Ca2+, Mg2+ (Mn2+), Na+ + K+ (with Mg2+) activated ATP hydrolyses; activation by Ca2+ and Mg2+ was similar and both were inhibited by thiocyanate, but the monovalent ions showed much lower activities. Activities in the presence of these ions were in the range reported for temperate teleosts such as the eel, goldfish, or trout. No HCO3− or NH4+ activation was detected. Apparent Km values for divalent cation activation were well above their respective environmental concentrations, but within the range reported for analogous enzymes of temperate teleosts. There is a specific interaction between Ca2+ and Mg2+ binding to the enzyme, but the results cannot distinguish between the existence of one enzyme with multiple binding sites, or a numberof ion-specific ATPases. These results suggest that the enzyme s assayed in this investigation are only indirectly, if at all, associated with gill ion transport in aruaná.
The osteoglossid gill: correlations of structure, function, and metabolism with transition to air breathing
Authors: Hulbert W. C. , Moon T. W. , Hochachka P. W.
Published: August 2008

The gills of aruana and Arapiama, closely related water- and air-breathing osteoglossids commonly found living in similar environments in the Amazon, were compared in terms of cell composition, structure, and metabolic organization. Enzymes selected to represent different metabolic functions, including glycolysis, pentose shunt, gluconeogenesis, the Krebs cycle, hydrogen shuttling, and ammonia release, were found in the gills of both species. However, the aruana gill had higher activities of key glycolytic enzymes, such as pyruvate kinase and phosphofructokinase, but lower potential for gluconeogenesis (lower fructose diphosphatase: phosphofructokinase ratios), and lower activities of enzymes in oxidative metabolism (citrate synthase, malate dehydrogenase, aspartate aminotransferase, and glutamate dehydrogenase) and in the pentose shunt (glucose-6-phosphate dehydrogenase). Gill lactate dehydrogenase activities were quite high in both species, while hexokinase activities were low; coupled with other studies, these data were taken to mean that lactate is a major source of carbon and energy for the gill. In Arapaima adjustments in cell composition, ultrastructure, and structural organization develop the potential for close control of the regional distribution of cardiac output flowing through the gill. It was speculated that use of this potential control of blood flow would have a major effect (a) on the uptake of blood metabolites such as lactate, (b) on CO2 release, and (c) on ion regulation by the abundant chloride cell population of the Arapaima gill.
Respiratory properties of the blood of Amazon fishes
Authors: Johansen K. , Mangum C. P. , Lykkeboe G.
Published: August 2008

Among 17 species of Amazon fishes, the respiratory properties of the blood are clearly correlated with the gas exchange medium. A comparison between species shows that bimodal and obligatory air breathers have, in general, a higher blood oxygen carrying capacity, higher levels of intracellular modulators of oxygen binding, lower blood oxygen affinity, and a larger Bohr shift than water breathers. Within a facultative air-breathing species (Synbranchus marmoratus) removal from water and acute exposure to air (13–44 h) resulted in similar changes in blood respiratory properties. The significance of the respiratory adaptations of the blood, however, is clear only when physiological variables such as blood pH and [Formula: see text] are considered.
Renal function and acid–base regulation in two Amazonian erythrinid fishes: Hoplias malabaricus, a water breather, and Hoplerythrinus unitaeniatus, a facultative air breather
Authors: Cameron James N. , Wood Chris M.
Published: August 2008

The function of the kidney in ion, water, and acid excretion was investigated in two erythrinid fishes, the water-breathing Hoplias malabaricus and the facultative air-breathing Hoplerythrinus unitaeniatus. Chronic catheterization of the urinary papilla and the dorsal aorta provided information on the urinary parameters and blood acid–base status. By monitoring total flow of urine, pH, and concentrations of Na+, Cl−, ammonia, titratable acidity, and lactate, the total renal flux of water, various ions, and total acid was computed. The kidneys of both species were found capable of acidifying urine, creating gradients of up to 620:1 for H+ ion, and contributing substantially to steady-state acid excretion. There was no significant increase in lactate or total acid efflux from urine during postoperative (metabolic) acidosis. Respiratory (hypercapnic) acidosis caused a compensatory increase in blood HCO3−, and an increase in branchial Na+ uptake (presumably by Na–H exchange), but no change in ammonia excretion. There was no renal response in one Hoplias to hypercapnia, but an increased acid excretion in one Hoplerythrinus. The behavior of the urinary excretion system appears in various respects similar to the higher vertebrates. There was no obvious correlation between renal parameters and air breathing in these two species.
Ventilation of the respiratory gas bladder in Hoplerythrinus unitaeniatus (Pisces, Characoidei, Erythrinidae)
Authors: Kramer Donald L.
Published: August 2008

Cinematographic analysis of the air-gulping behavior used by Hoplerythrinus to ventilate its respiratory gas bladder showed that this action requires about 0.8 s and that inspiration precedes expiration. Expired breaths contain 15–35 ml gas per kilogram body weight, while the gas bladder contains 30–80 ml/kg. Tidal volume may range from 19 to 130% of the gas bladder volume with a mean of 50%. Newly inspired air is mixed with the gas expired in the same breath. However, there is partial separation of inspired and expired gas. Tying off various parts of the gas bladder showed that the nonrespiratory anterior chamber plays an important role in this separation. X-ray cinematography confirmed these conclusions and demonstrated that the anterior chamber expands greatly to accommodate the newly inspired air.
The partitioning of oxygen uptake from air and from water by erythrinids
Authors: Stevens E. Don , Holeton George F.
Published: August 2008

Oxygen uptake from air and from water was measured during routine activity at 29 °C in two facultative air-breathing teleosts, Hoplerythrinus unitaeniatus and Erythrinus erythrinus. These fish breathe air in hypoxic water, taking a breath every 1 to 2 min. Gill ventilation increases in hypoxic water if air breathing is prevented, but decreases if air breathing is permitted. Average oxygen uptake from water is 105 mg∙h−1∙kg−1 and 69 mg∙h−1 kg−1 from air for Hyplerythrinus; 65 mg∙h−1∙kg−1 from water and 51 mg∙h−1∙kg−1 from air for Erythrinus. In normoxic water Hoplerythrinus obtain from 0 to 56% of oxygen uptake (mean 31%) from air. Two Hoplerythrinus survived in air for 24 h and did not have an elevated oxygen uptake when put back into water.
Difference in diet as an epiphenomenon: space regulates salamanders
Authors: Maiorana Virginia C.
Published: August 2008

Observations on prey size and spatial dispersion of two plethodontid salamanders widely sympatric in California suggest that food resources do not regulate the densities of the salamanders and hence are not the critical resource for their coexistence. Competition may still occur for limited food resources but such competition may influence only relative size or fecundities of the species and not their densities. Observations are consistent with the hypothesis that spatial resources regulate salamander densities. These observations include the following (1) when large prey is scarce the larger Aneides lugubris can consume smaller prey efficiently (as a consequence, its diet overlaps almost completely that of the smaller Batrachoseps attenuatus); (2) size groups that overlap most in diet also overlap most in space; (3) individuals of Batrachoseps seem to be distributed with respect to spatial rather than food resources since large differences in fatness and stomach size among individuals occur within small areas of continuous habitat; and (4) the abundance of Aneides relative to Batrachoseps is greatest in habitats with the greatest abundance of large cavities that adult Aneides can use for protection. The above observations are relevant to the general problem of competition for size-dependent resources between microsympatric vertebrate insectivores.
Spirocercid stomach worms (Nematoda: Spirocercidae) from wild felids in North America
Authors: Pence Danny B. , Samoil Howard P. , Stone Jeanne E.
Published: August 2008

Cylicospirura felineus (Chandler 1925) Sandground 1933 is redescribed from the bobcat (Felis rufus (Schreber)) and Canada lynx (Felis canadensis (Kerr)) in Texas and Alberta, respectively. This species produces large granulomas in the pyloric stomach. Histologically, these are characterized by a cavernous center containing necrotic debris, adult nematodes, eggs, and inflammatory cells. Peripherally there is a disruptive granuloma with layers of collagen surrounding islets of eosinophils, plasma cells, histiocytes, fibroblasts, and lymphocytes. These lesions are principally confined to the submucosa, but communicate to the mucosal surface via a small orifice. A second species, Cyathospirura chevreuxi (Seurat 1913) Baylis 1934, is redescribed from the bobcat in Texas. Although primarily a lumen parasite, this species frequently occurs in the nodular lesions formed by C. felineus. A new host record is established for Didelphonema longispiculata (Hill 1939) Wolfgang 1953 from the bobcat in Texas. The taxonomy, host–parasite relationships, and pathology of these and related species are discussed.
Rapports de la morphologie et de l'histologie dentaires d'Anarhichas lupus L. (Poisson Téléostéen Perciforme) avec son mode d'alimentation: apport de la microradiographie et du marquage par la tetracycline
Authors: Cabellec Marie-Thérèse Le , Daculsi Guy , Geistdoerfer Patrick
Published: August 2008

The dental system and teeth morphology of Anarhichas lupus L. are perfectly suited to its mode of feeding. The anterior teeth are used for grasping preys. The molariform lateral and posterior teeth, palatine and vomer, are used for crushing ingested organisms with hard shells such as gasteropods and lamellibranchs. Microradiography gives evidence of the high degree of mineralization of enameloid and osteodentine trabecules. The supporting bone is constituted of two parts: a basal bone, with a low degree of mineralization, and a proper bone, highly mineralized, with large medullar canals. The structure of the basal bone, closely connected with the proper bone, accounts for the resilience of the whole system.
The littoral Chironomidae (Diptera) of saline lakes in central British Columbia
Authors: Cannings R. A. , Scudder G. G. E.
Published: August 2008

Collections of chironomid larvae, pupae, and adults were taken from the 1-m depth zone of 15 lakes of varying salinities in central British Columbia. Thirty-four species were identified.The littoral chironomid fauna of the lake series is divided into predominant associations whose existence seems to depend on salinity and productivity levels. A Cricotopus abanus – Procladius bellus association prevails in the lowest salinities (40 to 80 μmho/cm (1 mho = 1 S) conductivity) while in conductivities between 400 and 2800 μmho/cm a Glyptotendipes barbipes – Einfeldia pagana association predominates. In the most saline lakes (conductivity 4100 to 12 000 μmho/cm) a Tanytarsus gracilentus – Cryptotendipes ariel association is characteristic.Using these three chironomid associations it is possible to divide the 15 lakes into three groups. Waters with conductivities from 40 to 80 μmho/cm have chemical characteristics and a chironomid fauna distinct from those of higher salinities. The 10 lakes showing increasing conductivity (400 to 2800 μmho/cm) have physical, chemical, and biotic characters related to high productivity. In the particular case of this saline lake series, lakes with salinities about 3‰ (conductivity above 4000 μmho/cm) have a reduced productivity and a chironomid fauna characteristic of high salinities.
Detection of substrate vibrations by salamanders: inner ear sense organ activity
Authors: Ross R. J. , Smith J. J. B.
Published: August 2008

Microphonic potentials were recorded from the inner ear of anesthetized adult and juvenile Notophthalmus viridescens, adult Plethodon cinereus, and larval Ambystoma maculatum lying prostrate in air on a horizontally vibrating platform. At temperatures of 15–17 °C, responses were obtained from all groups over the frequency range 20 Hz to 500–650 Hz. At 20–22 °C, adult N. viridescens responded to 1100 Hz. Microphonics were produced over a maximum vibration amplitude range of 0.011–35 μm peak-to-peak displacement, but the range limits varied at individual frequencies. A lower range limit, or higher sensitivity, was found for adult N. viridescens at 20–22 °C than at 15–I7 °C. The amplitude of the response increases nonlinearly with increasing vibration amplitude and does not adapt to a steady-state vibration. Microphonics were double the frequency of the stimulus, indicating that the receptors have hair cells of opposite polarization. Inner ear sense organ activity can occur in salamander ears in response to gross substrate vibration. The variety of response characteristics found indicates a versatile sensory system.
Pairing and nest site selection in solitary and yellow-throated vireos with a description of a ritualized nest building display
Authors: James Ross D.
Published: August 2008

Solitary (Vireo solitarius) and yellow-throated (Vireo flavifrons) vireos were studied in May and June, in Ontario between 1969 and 1975, and in British Columbia in 1976. Most unmated males search for nest sites and begin to build nests prior to the arrival of females in their territories. Upon the female's arrival, the first displays by the male are precopulatory. Displays involving chasing are seldom seen. Nests started by males, and other suitable nest sites serve as display areas during pair formation. The presence of more than one display site indicates that nests started by males are more important in pairing than as sites for final nests. A nest building display occurs most often and vigorously in the early building period when the male is actively assisting in nest construction. The frequency and duration of the display then wanes along with the male's building activity. The nest building display is not part of the precopulatory display, but has become important in pair formation. The males appear to choose the site for a final nest.
The population biology of Cyprinotus carolinensis and Herpetocypris reptans (Crustacea, Ostracoda)
Authors: McLay C. L.
Published: August 2008

The population mechanics of two species of ostracod in a temporary freshwater puddle are considered in relation to their competitive interaction in a variable environment. Both species survive dry periods as eggs. When the puddle refills eggs hatch over a long period of time but in two main groups. Cyprinotus spreads hatching more evenly between the two groups, recruits more slowly, but requires less time to mature than Herpetocypris. Unhatched eggs decay at lower rates for Cyprinotus, which inhabits the shortest lived part of the puddle.Cyprinotus mortality is more affected by density than is Herpetocypris. In mixed culture, Cyprinotus mortality increases disproportionately with density while Herpetocypris mortality is simply related to joint density. This difference may be attributed to a lower resistance to food shortage by Cyprinotus which also becomes more crowded at high density. Increased density increases time required to mature. Both species lay eggs at similar rates which decline with increasing density and decreasing temperature.Natural selection has favoured competitive prowess and rapid recruitment in Herpetocypris, which is suited to a permanent environment. In Cyprinotus, which is suited to a temporary, variable environment, selection has favoured the production of durable eggs and conservative recruitment.
Présence de fibres striées transversalement et d'agrégats tubulaires intrasarcoplasmiques dans le prostomium de Magelona papillicornis (Annélide Polychète)
Authors: Boilly Bénoni , Wissocq Jean-Claude
Published: August 2008

The prostomium of the polychaetous annelid Magelona papillicornis contains a very well developed musculature formed of narrow, transversely striated fibers. These fibers are characterized by irregular A bands, discontinuous and winding Z lines, absence of a T system, and sarcoplasmic reticulum (SR) with longitudinal tubules anastomosing in the I bands. In some fibers the SR also develops aggregates of tubules in the non-contractile sarcoplasm. The occurrence and characteristics of these fibers, and specially the presence of aggregates of tubules are discussed in relation to the role of the prostomium in burrowing.
The influence of density and behavioural type on the active entry of two mayfly species (Ephemeroptera) into the water column
Authors: Corkum Lynda D.
Published: August 2008

Laboratory experiments were conducted in still water and under lighted conditions to induce maximal departure rates of two mayfly species from a substrate. A larger proportion of Baetis vagans McDunnough nymphs left the substrate than of Paraleptophlebia mollis (Eaton) at densities of up to 750 nymphs per 330 cm2. Differences in the tendency of nymphs of each species to leave the substrate were related to behavioural traits rather than density. Overt aggression between interacting P. mollis nymphs served as a spacing mechanism on substrate surfaces. Interactions among B. vagans nymphs were never observed. Rather than developing a spacing mechanism on the substrate, these nymphs are adapted to swim into the water column. A comparison of drift–density relationships for mayflies used in this and other studies revealed a gradation among behavioural groups within the Ephemeroptera in their tendency to leave the substrate and enter the water column.
Seasonal dynamics and spatial distribution of Urocleidus ferox Mueller 1934, a gill parasite of Lepomis gibbosus (L.)
Authors: Hanek George , Fernando C. H.
Published: August 2008

Seasonal dynamics and spatial distribution were determined for Urocleidus ferox Mueller 1934, a gill parasite of Lepomis gibbosus (L.). Twenty-five specimens of L. gibbosus from eutrophic (West Lake) and 25 specimens from oligotrophic (Glenora) habitats were examined monthly between November 1971 and October 1972.The data were analysed using a two-factor ANOVA and Duncan's multiple range test.High abundance levels of U. ferox were recorded in both localities throughout the sampling period. The peak was reached in July 1972 and the lowest levels recorded in November 1971 in both localities. The eutrophic habitat, West Lake, was significantly (P < 0.001) more favourable for U. ferox than the oligotrophic one, viz. Glenora.The anterior side of hemibranchs and their medial sections were preferred sites of infection (P < 0.001); gill arches two and three were found to be preferred sites of infection (P < 0.001) for U. ferox.
Oxygen receptors in the rainbow trout, Salmo gairdneri
Authors: Daxboeck C. , Holeton G. F.
Published: August 2008

A new technique for the detection in situ of oxygen-sensitive chemoreceptors in fish is described. By studying the hypoxic responses of the rainbow trout, Salmo gairdneri, at least two loci of respiratory control were found to be operating. One component initiated the hypoxic bradycardia and its rapid release, a second was responsible for ventilatory responses. The anterodorsal region of the first branchial arches has been established as a peripheral oxygen-sensitive chemoreceptor site, mediating bradycardia, without affecting either the amplitude or frequency of breathing. The study does not preclude the existence of oxygen receptors in other areas of the fish.
Localization of receptors causing hypoxic bradycardia in trout (Salmo gairdneri)
Authors: Smith Frank M. , Jones David R.
Published: August 2008

Receptors causing the cardiac response to environmental hypoxia have been located in rainbow trout (Salmo gairdneri). Intact, unrestrained trout, acclimated to7or 16 °C. showed a marked increase in ventilation and bradycardia when exposed to hypoxia at their acclimation temperature, In experiments designed to locate the site of receptors causing hypoxic bradycardia, the buccal cavity of a fish was divided into two chambers by a tongue depressor, allowing oxygen tension of water flowing over each set of gills lo be varied independently. Irrigating one set of gills with hypoxic water [Formula: see text] while flowing hyperoxic water [Formula: see text] over the other caused heart rate to fall from 42.2 ± 0.6 (± SEM) to 26.4 ± 0.5 (± SEM) beats/min after 1 min of hypoxic water flow. Dorsal aortic [Formula: see text] was always above that recorded when both sets of gills were flushed with normoxic water [Formula: see text]. Bilateral ligation of the efferent pseudobranch artery and the pseudobranch nerve (cranial nerve IX) had no effect on the cardiac response to irrigation of one set of gills by hypoxic water. Physical removal of, or section of the nerve supply (cranial nerves IX and X) to, the first gill arch eliminated hypoxic bradycardia. The biological advantage of hypoxic bradycardia is discussed and it is suggested that gill arch receptors may function to monitor and maintain oxygen tension of blood leaving the gills.
A study of the family Phytoseiidae (Acarina: Mesostigmata) using the methods of numerical taxonomy
Authors: Chant D. A. , Hansell R. I. C. , Rowell H. J. , Shaul E. Yoshida
Published: August 2008

The taxonomic history of the family Phytoseiidae is briefly reviewed. The taxonomic structure of the family is analysed using the methods of numerical taxonomy, with 221 morphological characters in 93 species covering the major taxonomic groups that have been proposed within the family. Both weighted and unweighted character analyses are used. It is shown that definite gaps separate groups of species within this family. At the level of major hierarchical separations both the unweighted and weighted character analyses are similar. A classification based on these major hierarchical separations is proposed. It is demonstrated that neither the classical system, based mainly on dorsal chaetotaxy, nor the numerical system alone provides a completely acceptable classification of the family, but that numerical taxonomic analyses are useful as a tool in helping to determine the hierarchical organization of the group.
Comparative studies of Giardia spp. in small mammals in southern Ontario. II. Host specificity and infectivity of stored cysts
Authors: Grant David R. , Woo Patrick T. K.
Published: August 2008

Carefully controlled cross transmission experiments showed that some species of Giardia (Giardia simoni from laboratory rats, Giardia muris from laboratory mice, and Giardia peromysci from deer mice) are highly host specific while others are not. Although Giardia microti infected hamsters, and Giardia mesocricetus infected laboratory rats, these species are morphologically dissimilar from the Giardia spp. which are normally found in these animals. This study also shows that there are two varieties or subspecies of G. muris. Giardia muris from laboratory mice and from a feral brown rat were identical in morphology and dimensions, but differed in host specificity.Infectivity of cysts of G. simoni in faecal suspensions stored at three temperatures was tested using the eosin dye test and by administering portions of suspensions to Giardia-free rats at regular intervals. An exponential decrease in the proportion of cysts that resisted penetration by eosin was observed. The rate of decline was temperature dependent. Rats could not be infected when less than approximately 50% of cysts in suspension were eosin negative.Metronidazole (Flagyl) and quinacrine hydrochloride (Atabrine) did not have a prophylactic effect in rats treated for 7 days. Infections were established in animals inoculated with cysts of G. simoni 24 h after cessation of treatment.
Description and evaluation of a photoelectric system for monitoring the locomotor activity of a pelagic fish
Authors: Godin Jean-Guy J. , Groot Cornelis , Armstrong M. Connor
Published: August 2008

A photoelectric system, designed to monitor continuously the 'spontaneous' locomotor activity of individual, juvenile pink salmon in the laboratory, is described and evaluated quantitatively. Data on the swimming behaviour of individual fish in the circular channel indicate that the design permitted salmon to swim freely in circuits without physical obstructions impeding or water currents directing their movements. Swimming speeds of individual fish were not influenced by infrared light beams emitted across the activity channel. The photoelectric monitoring system was found to be reliable, equally sensitive in detecting the locomotor movements of small (4.3–5.8 cm) and of large (13.0–19.0 cm) fish, and provided data which closely approximated (on average to within 94.0–102.6%) the total momentary locomotor activity of individual pink salmon.
A possible defensive function for calls given by bats (Myotis lucifugus) arousing from torpor
Authors: Martin K. A. , Fenton M. B.
Published: August 2008

Presentation of stimuli in a Y maze showed that Peromyscus maniculatus which inhabit hibernacula used by bats may use auditory stimuli to locate bats which have fallen from their hibernation perches. However, the intense calls (95 dB sound pressure level, linear at 10 cm) given by bats (mainly Myotis lucifugus) as they arouse from torpor may serve a defensive function by repelling the mice.
Adrenal response in a wild Microtus population: seasonal aspects
Authors: Seabloom Robert W. , Iverson Stuart L. , Turner Brian N.
Published: August 2008

Adrenal response was determined during a 13-month period in a population of southern Manitoba meadow voles (Microtus pennsylvanicus) as a preliminary part of a study to determine the effects of chronic ionizing radiation on free-living mammals. Livetrapped voles were subjected to behavioral tests, killed, and their isolated adrenals superfused and stimulated with ACTH. Superfusates were assayed fluorometrically for corticosterone. Peaks of adrenal response occurred during spring in both adult males and females, followed by a significant decline into early summer. Subadult males exhibited a peak response in early summer. Corticosterone levels of adults were generally higher than those of juveniles in the same season. Levels of nonpregnant adult females were higher than those of pregnant voles. Observed differences over the annual cycle were attributed to the behavioral and hormonal states of various age and sexual components of the population.
The genus Travassosius Khalil, 1922 (Nematoda, Trichostrongyloidea) in beaver, Castor spp.: a review and suggestion for speciation
Authors: Bush Albert O. , Samuel W. M.
Published: August 2008

Cameron's (1938. On the morphology and parasitic development of Travassosius rufus Khalil, 1922, a trichostrongyle parasite of the Canadian beaver (Castor canadensis canadensis). Libra Jubilar L. Travassos, Rio de Janeiro, pp. 103–106) synonomy of Travassosius americanus with Travassosius rufus is rejected on the basis of examination of paratype specimens, other specimens from Alberta, British Columbia, and Pennsylvania, and statistical analysis. It is suggested that T. americanus in beaver of North America, Castor canadensis, is the ancestral stock and that T. rufus has evolved following allopatric evolution of the beaver of Eurasia, Castor fiber.
Growth of juvenile arctic ground squirrels (Spermophilus parryii) at McConnell River, N.W.T.
Authors: Kiell David J. , Millar John S.
Published: August 2008

Growth of juvenile arctic ground squirrels was documented and compared with reports on other North American hibernators to determine the effect of reduced homeothermal periods on rates of development. The hypothesis that increased growth rates compensate for short summer seasons was supported. Growth rates were negatively correlated with the duration of the homeothermal period. Arctic ground squirrels at McConnell River, N.W.T., had the fastest growth rate among 12 populations.
La réaction phagocytaire chez Amoeba proteus. II. Phagocytose de particules non-vivantes
Authors: Marsot Pierre , Couillard Pierre
Published: August 2008

Artificial inductors have been developed to study qualitatively and quantitatively the phagocytosis of nonliving particles by Amoeba proteus. The experimental system includes nylon microcapsules, ion-exchange particles, and treated glass beads. Our results show that there are two fundamental mechanisms of phagocytosis in A. proteus. The first mechanism, related to the ingestion of living prey or particles that diffuse chemotactic substances, involves biphasic activity of the chemotactic substances. The second mechanism, in connection with insoluble particle phagocytosis, involves the presence of a positive charge at the surface of the particle.
Characteristics of Nothocriconema petasum (Nematoda: Criconematidae)
Authors: Ebsary B. A.
Published: August 2008

Nothocriconema petasum is redescribed from topotypes and a range of measurements is provided. New characters include two head annules, greater diameter of the stylet knobs, and a more posterior position of the excretory pore. A juvenile female and adult male are described and illustrated for the first time. The most distinctive character of the juvenile is the presence of minute spines on the scale margins. The distinctive characters of the male are a conoid tail of 16 annules and 53 μm with a finely rounded terminus, four incisures, spicules of 37 μm with a well developed manubrium, and a rudimentary bursa.
Biochemical relationships of the Holarctic vole genera (Clethrionomys, Microtus, and Arvicola (Rodentia: Arvicolinae))
Authors: Nadler Charles F. , Zhurkevich N. M. , Hoffmann Robert S. , Kozlovskii A. I. , Deutsch Ljerka , Nadler Jr. Charles F.
Published: August 2008

Transferrin (Tf), hemoglobin (Hgb), leucine aminopeptidase (LAP), 6-phosphogluconate dehydrogenase (6PGH), and glucose-6-phosphate dehydrogenase (G6PD) were examined by starch-gel electrophoresis in Holarctic Microtus oeconomus and Clethrionomys rutilus, Siberian Microtus hyperboreus and Clethrionomys rufocanus, and North American Microtus miurus, Microtus ochrogaster, Microtus pennsylvanicus, Arvicola richardsoni, and Clethrionomys gapperi. Thirty alleles of five to seven loci, the number depending on the presence or absence of one or two minor hemoglobin fractions, were identified in these species. Interspecific comparisons were based on the presence of at least one allele shared in common at the various loci. The closest biochemical resemblances occurred between populations of Holarctic M. oeconomus and C. rutilus. Clethrionomys gapperi and C. rutilus were quite similar but C. rufocanus was divergent. Observed resemblances between M. hyperboreus and M. miurus were not strong and do not support the inclusion of the former in the amphiberingian narrow-skulled vole group. Arvicola richardsoni, though seemingly close to M. pennsylvanicus, was quite divergent from all other species of Microtus at the LAP locus and warrants comparison with Palearctic Arvicola. Microtus ochrogaster and M. pennsylvanicus shared many similarities and served as reference samples.
Morphological differences between nymphal instars and descriptions of the antennal sensory structures of the nymphs and adults of Psylla pyricola Foerster (Homoptera: Psyllidae)
Authors: Singleton-Smith J. , Chang J. F. , Philogène B. J. R.
Published: August 2008

Variations in the external appearance of the nymphs and imago of the pear psylla, Psylla pyricola, are described. The antennal flagellum has five types of sensilla: sensilla chaetica, sensilla trichodea, sensilla campaniformia, sensilla basiconica, and sensilla placodea. The sensilla placodes of the nymphal instars have a 'honeycomb' appearance which is replaced by 'flaps' in the adult. There is an increase in the number of sensilla placodea from one in the first nymphal instar to four in the adult.
Efficiency of filter feeding of black fly larvae (Diptera: Simuliidae)
Authors: Kurtak Daniel C.
Published: August 2008

Larvae of nine species of black flies were exposed to synthetic particles in the laboratory. Sizes and concentrations of particles were chosen to simulate natural conditions. Smaller particles (diameter 5–10 μm) were offered at a rate of 50–100/cephalic fan area per second, and larger ones (diameter approximately 150 μm) at 0.3–1.0/cephalic fan area per second. Experiments were conducted at water velocities of 30, 50, and 70 cm/s.In all the laboratory experiments, only a small percentage of the particles passing through an area equal to that of the cephalic fans of a single larva were ingested. Particles larger than the spacing between the fan rays were ingested more efficiently than smaller ones. At 50 cm/s, the mean percentage ingested for all species was 1.6% (0.14–8.3%) of particles 150 μm in diameter and 0.094% (0.0026–0.76%) of particles 5–10 μm in diameter. The percentage of material ingested decreased at higher concentrations and water velocities. There were significant differences among the species.Experiments were done with one of the species in the field with similar results.Based on this work, an individual black fly larva in nature probably ingests 1–10% by weight of the material passing through its cephalic fans.
Distribution of benthos in a stagnant estuarine bay
Authors: Burns Gordon R.
Published: August 2008

In the summers of 1974 and 1975, profiles of temperature, salinity, and dissolved oxygen were made monthly at four stations in Kennebecasis Bay. Samples of the benthic fauna and substrate were also taken.Sediment particle size distribution did not vary between stations. Combustible organic content of sediments was highest at the head of the bay and lowest near the mouth.Surface water was generally of low salinity, high dissolved oxygen, and seasonally variable temperature. Bottom water showed a stable salinity of 18 to 20‰, stable temperature of 4 to 7 °C, and stable oxygen concentrations of 1.5 to 4.5 mg/ℓ.While the parameters just mentioned are thought to be uniform throughout Kennebecasis Bay, the observed distribution pattern of species and individuals in the benthic fauna was not uniform. Samples taken at the mouth of the bay produced greater numbers of taxa and abundance of fauna than samples from the head of the bay. It is proposed that this bay mouth-to-head gradient is related to infrequent saline water inflows reaching only lower parts of Kennebecasis Bay.
Neural regulation of blood pressure in rainbow trout (Salmo gairdneri)
Authors: Smith D. G.
Published: August 2008

Mean dorsal aortic blood pressure (Pda) and heart rate were measured in free-swimming rainbow trout (Salmo gairdneri). The fish were swum in a water tunnel at 0.5 body lengths/s (control) and were exercised at 45-min intervals by a 5-min period of rapid swimming at 2 body lengths/s.Control Pda was 4.0 ± 0.11 kPa and control heart rate was 56 ± 2.1 beats/min. During rapid swimming Pda and heart rate increased by 15 and 13% respectively. α-Receptor blockade with phentolamine (2 mg/kg) or adrenergic transmitter release blockade with bretylium (10 mg/kg) prevented the exercise hypertension and converted it to a decrease of 5% (phentolamine) or 18% (bretylium). Exercise tachycardia was reduced slightly by each compound. Phentolamine decreased the control Pda by 5%. Acute bretylium treatment increased Pda by 39% but Pda in fish treated chronically with bretylium was 30% below control and decreased by a further 6% during rapid swimming. The acute effects of these and other antihypertensive compounds are discussed. It is concluded that systemic blood pressure in trout is controlled by tonically active adrenergic nerves acting on systemic vessels via α-adrenoreceptors. These nerves produce a selective increase in peripheral resistance during rapid swimming.
Instar development rates of Diaptomus minutus (Copepoda: Calanoida) in a small lake in Quebec
Authors: Boers J. J. , Carter J. C. H.
Published: August 2008

A study of the life history of the calanoid copepod Diaptomus minutus Lilljeborg in C-22, a small lake of the Matamek River System, Quebec, demonstrated that instar duration times of the nauplii and younger copepodites in the major generation were considerably shorter than those reported elsewhere. It is hypothesized that these differences may be attributable to the abundance of nannoplankters characteristic of highly oligotrophic waters.
A comparison of limb regeneration in diploid and triploid larvae of Ambystoma (Amphibia, Urodela)
Authors: Scadding Steven R. , Vinette Jean L.
Published: August 2008

This study was carried out to determine if the triploid condition of some Ambystoma species has any influence on the rate, extent, and histology of limb regeneration, when compared with diploid Ambystoma species. Egg clumps of both diploid and triploid Ambystoma were obtained, their ploidy determined, and limb regeneration observed after development had proceeded to the 3- to 4-cm larval stage. The rate, extent, and histology of limb regeneration was the same in both diploids and triploids. In Ambystoma, the triploid condition appears neither to promote nor to inhibit limb regeneration.
Avian Haemoproteidae. 8. The haemoproteids of the bee-eater family (Meropidae)
Authors: Bennett Gordon F.
Published: August 2008

The haemoproteids of the bee-eater family, Meropidae, are reviewed and the hosts and geographic distributions are summarized. Haemoproteus manwelli sp.nov. is described from Merops orientalis from India and Haemoproteus lairdi is described from Melittophagus variegatus from Uganda; the latter parasite occurs in host cells lacking a nucleus. Haemoproteus meropis Tartakovskii, 1913 is declared a nomen nudum and Haemoproteus meropis (Zargar, 1945) emend. Bennett, 1978 is redescribed.
Variations des protéines de l'hémolymphe et de l'hypoderme au cours du cycle de mue chez Carcinus mediterraneus Czerniavsky: analyses électrophorétique et immunochimique
Authors: Herberts Charmaine , Andrieux Nicole , Frescheville Jacques de
Published: August 2008

An immunochemical analysis of the proteins of the serum and hypodermis of healthy male Carcinus mediterraneus revealed variations during the moult cycle. In the hemolymph two groups of proteins appeared at the end of the physiological resting period, increased at the beginning of stage D0 and became magnified as ecdysis approached. In the hypodermis, proteins corresponding to these two groups increased at the time of elaboration of new cuticular structures, particularly in stages D1 and D2. An additional fraction was found in the hemolymph during intermoult and D0 only. It had disappeared by the time of the appearance of two new hypodermal fractions.
Comparative hunting abilities of polar bear cubs of different ages
Authors: Stirling Ian , Latour Paul B.
Published: August 2008

In most areas of the Canadian Arctic polar bear (Ursus maritimus) cubs apparently remain with their mothers until they are 2.5 years of age. The degree to which cubs of each age-class participate in the hunting of seals while with their mothers is examined in this paper in order to evaluate the degree to which they might be capable of independent hunting, should they be orphaned prior to the completion of the normal weaning period. Cubs of all age-classes did almost no hunting during the spring. The proportions of time spent hunting by yearling and 2-year-old cubs, and the durations of their lying 'still hunts' were not significantly different from each other but they were significantly shorter than their mothers' and than adult males' during the summer. However, the frequency of the lying 'still hunts' of 2-year-old cubs was double that of yearling cubs and the kill rate of 2-year-old cubs was comparable with that of adult age-classes, despite the fact they hunted for a significantly lesser proportion of their time. These results suggest that cubs which remain with their mothers until they are weaned have a higher probability of survival than those that do not and this interpretation lends support lo the management concept of total protection of family groups and the harvesting of independent bears only.
Changes in activity patterns, agonistic behavior, and territoriality of black ducks (Anas rubripes) during the breeding season in a Nova Scotia tidal marsh
Authors: Seymour Norman R. , Titman Rodger D.
Published: August 2008

Observations of marked wild black ducks provided a qualitative and quantitative description of hostile interactions between pairs throughout the breeding season. This study was carried out on a tidal estuary on the St. Lawrence estuary shore of Nova Scotia from 1972 to 1974. Interactions occurred first on the communal part of the marsh and later on territories.Territories corresponded to tidal ponds (0.16–3.8 ha) at the marsh periphery and were established only after pairs were on the marsh 30–40 days. Territories were established approximately 5 days before egg laying began and females were responsible for their location. Females spent approximately 45 days on the territory and males stayed 27–32 days. Males remained almost continuously on territories during the prelaying and laying periods but left both females and territories during midincubation.The activity of males and females of pairs was analysed and compared according to three activities: foraging, loafing, and hostility. Females foraged at a faster rate and for longer durations than their mates in both the preterritorial and territorial periods. Hostility by territorial males toward intruding pairs provided seclusion for resident pairs. Changes in the form and intensity of hostility led to the spatial displacement of pairs. The pursuit flight by males was the main mechanism in the establishment and maintenance of territories.
Variations of the lorica in the genus Parafavella (Protozoa: Tintinnida) in northern Norway waters
Authors: Davis Charles C.
Published: August 2008

Photographs were made of the loricae of 272 specimens of the tintinnid genus Parafavella, encountered in plankton samples taken in the vicinity of Tromsø, northern Norway. From the loricae alone it is impossible to distinguish among P. cylindrica, P. gigantea, P. denticulata, P. dilitata, P. obtusangula, P. parumdentata, and P. elegans. The results are compared with those of other authors working with this difficult genus. It is emphasized that additional methods for the distinction of species must be undertaken beyond simple examination of the loricae if the taxonomic obscurities of the genus are to be unravelled.
Regulation of shell growth in the pulmonate gastropod Helisoma duryi
Authors: Kunigelis S. C. , Saleuddin A. S. M.
Published: August 2008

Photoperiod has a significant effect on linear shell deposition rates; animals maintained in continuous darkness (DD) deposit shell more rapidly than those held in continuous light (LL) or 12L: 12D. Shell deposition is endogenously governed and might be synchronized by photoperiod. Photoperiod also affects the relative proportion of shell occupied by different crystal layers.Injections of brain homogenates from fast-growing animals stimulate shell deposition in slow-growing animals. Supraoesophageal and suboesophageal brain fractions both have a greater effect than whole brain; both fractions may contain factors affecting shell growth. Suboesophageal fractions from shell-repairing donors show a reduced effect. A supraoesophageal factor may be involved in normal shell growth and a suboesophageal factor in shell repair.
The effect of feeding on the cerebral neurosecretory system of the adult male tsetse, Glossina austeni Newst
Authors: Grossman M. , Davey K. G.
Published: August 2008

An analysis of the intensity of staining of the corpus cardiacum and of the neurosecretorty cells of the pars intercerebralis in 3-day-old fed or fasting adult male tsetse has revealed two periods of apparent release of neurosecretion. In fed males, stainable neurosecretion disappears from 14 of the 20 recognizable neurosecretory cells within 10 min of the termination of feeding. There is always less neurosecretory material in the corpora cardiaca of fed males. Secondly, there is an indication of a depletion of material from the cardiaca of both fed and fasted males at about 1700 hours EST.