bluuebunny/crossref_metadata_2025 huggingface dataset:
An analysis of morphological variation in limpets of the genus Collisella
Authors: Dehnel Paul A.
Published: August 2008

Shell morphology, radular length, and wet weight of soft parts were compared between three species (Collisella pelta, Collisella persona, and Collisella scutum) from one geographic locality. Shell length vs. shell height, wet weight of soft parts vs. radular length, and shell length vs. radular length are statistically significant relationships to separate the three species. Shell weight vs. wet weight of soft parts, wet weight of soft parts vs. extravisceral space, and shell volume vs. wet weight of soft parts are statistically significant relationships to separate C. scutum from either C. pelta or C. persona. These comparisons do not separate C. pelta from C. persona. Shell length vs. shell width, shell length vs. shell volume, and shell length vs. shell weight were found not to be statistically significant relationships to separate the three species. The importance of using shell length and wet weight of soft parts as a measure of animal growth is discussed.
Lactate dehydrogenase isozymes from heart and white muscle of water-breathing and air-breathing fish from the Amazon
Authors: French C. J. , Hochachka P. W.
Published: August 2008

Lactate dehydrogenase (LDH, EC 1.1.1.27) isozymes were studied from the white muscle and hearts of four species of Amazon fish, Osteoglossum bicirrhosum, an obligate water breather, and the closely related air breather, Arapaima gigas; Hoplias malabaricus, an obligate water breather, and Hoplerythrinus unitaeniatus, a facultative air breather. The LDH pattern was similar in closely related species but could not be correlated with changes in respiratory habits. All the isozymes from both heart and white muscle showed low substrate inhibition by pyruvate. The LDH from Osteoglossum skeletal white muscle showed sigmoidal kinetics with respect to pyruvate, rendered hyperbolic by the addition of 20 mM phosphocreatine. The kinetic properties appear to facilitate a dual function for white muscle in the absence of red muscle in the myotome. Phosphocreatine inhibition of LDH was observed in all the tissues studied and is suggested to be a more general phenomenon than has been previously supposed.
Glycogen 'seas,' glycogen bodies, and glycogen granules in heart and skeletal muscle of two air-breathing, burrowing fishes
Authors: Hochachka P. W. , Hulbert W. C.
Published: August 2008

Studies of the ultrastructures of heart, white muscle, and red muscle of two air-breathing, burrowing Amazon fishes, Lepidosiren paradoxa and Synbranchus marmarotus, indicated an overwhelming dependence upon glycogen as a storage carbon and energy source. In lungfish white muscle, unusually high quantities of glycogen were packaged as large-diameter rosettes or α-particles, typical of organs such as the liver in other species. In lungfish red muscle, glycogen was stored as the usual smaller β-particles, either randomly dispersed or organized into membrane–glycogen complexes called glycogen bodies. The hearts of both species also displayed numerous glycogen bodies, the membrane–glycogen complexes apparently being formed from specialized regions of the interfibrillar sarcoplasmic reticulum. These immense glycogen depots could be mobilized to support either oxidative or fermentative metabolism. However, neither mitochondrial abundance nor the levels of enzymes in oxidative metabolism were abnormally high compared with other fishes. Heart lactate dehydrogenase, on the other hand, occurred at higher levels than thus far found in any vertebrate heart, suggesting that heart glycogen bodies in these species serve primarily as a carbon reservoir for emergency use under conditions of O2 lack.
The osteoglossid kidney: correlations of structure, function, and metabolism with transition to air breathing
Authors: Hochachka P. W. , Moon T. W. , Bailey J. , Hulbert W. C.
Published: August 2008

The cell composition, ultrastructure, ion-activated ATPase content, and metabolic enzyme activities of the kidneys in water- and air-breathing osteoglossids were compared. In both, the nephron consisted of three main segments. The first segment contained a well-developed brush border, numerous lysosomes, numerous mitochondria localized primarily in the basal two-thirds of the cell, and many apical tubules. The most striking feature of the second segment was a highly infolded basilar membrane, laying in close laminar association with large, elongate mitochondria, localized to the basal two-thirds of the cell. Particularly in Arapaima, cells of the third segment formed the longest homogeneous region of the nephron. In both species, the ultrastructure of the third segment was remarkably similar to that of the teleost chloride cell. The kidney in Osteoglossum, a water breather, was divided into head and trunk regions with nephrons only in the latter; in the air breather, the kidney was three- to four-fold larger than in aruana, and it was not divided into head and trunk regions, nephrons being found throughout its length. Total Ca2+-activated ATPase and Na+/K+-ATPase activities were, respectively, some 3- and 15-fold higher in Arapaima kidney than in aruana kidney, implying a much larger fraction of the ion transport work has been taken over by the kidney in the air breather. Glutamate dehydrogenase was found to be the primary ammonia-releasing reaction in both species. It occurred at about sevenfold higher activities in Arapaima kidney than in aruana. The increased potential for ammoniagenesis in Arapaima kidney appeared to correlate with an increased gluconeogenic capacity without which, it is postulated, the acid–base balancing function of ammonia production would be lost.
Control of ammoniagenesis in the kidney of water- and air-breathing osteoglossids: characterization of glutamate dehydrogenase
Authors: Storey K. B. , Guderley H. E. , Guppy M. , Hochachka P. W.
Published: August 2008

Glutamate dehydrogenases (EC 1.4.1.2) from the kidney of Osteoglossum bicirrhosum (called aruana) and Arapaima gigas were kinetically characterized. The two enzymes exhibited several common characteristics including Vmax activity ratio, pH optimum, affinity for cofactors, a marked preference for NAD(H) over NADP(H), and a very low affinity for NH4+. A variety of regulatory metabolites affected both enzymes. GTP and GDP were inhibitory while ADP, ATP, AMP, and leucine activated the enzymes. Both enzymes displayed potent product inhibition which was partially reversed by low levels of ADP. Arapaima kidney glutamate dehydrogenase was tightly regulated by the adenylate and guanylate nucleotides, inhibition by GTP and GDP and deinhibition by ADP and AMP being much stronger for this enzyme than for the aruana enzyme. Aruana glutamate dehydrogenase, however, was more responsive to NAD–NADH control. The enzyme was more sensitive to NAD(H) product inhibition and this inhibition was poorly reversed by ADP. From these data, it was concluded that both fish kidney glutamate dehydrogenases could function in glutamate oxidation in vivo. However, the Arapaima enzyme appeared most clearly adapted to a catabolic role, activity being more tightly linked to the energy status of the mitochondrion. Conversely, the aruana enzyme displayed regulatory properties allowing it the potential to function in NADH oxidation during periods of hypoxic stress.
Water-soluble phosphates of fish red cells
Authors: Bartlett Grant R.
Published: August 2008

The nature and significance of water-soluble (small molecule) phosphates in vertebrate red blood cells are reviewed and new data presented for several fish including: three salmon (Oncorhynchus gorbuscha, Oncorhynchus kisutch and Oncorhynchus nerka), a mackerel (Scomber japonicus), a dogfish (Squalus acanthias), the ratfish (Hydrolagus colliei), and two air-breathing fish (Synbranchus marmoratus and Pterygoblichthys) studied on the research vessel Alpha Helix on the Amazon River. Of special interest was the wide variation in the ratio of guanosine triphosphate (GTP) to adenosine triphosphate (ATP); this ratio was much higher in some species of fish than had been reported for red cells of other vertebrates or, for that matter, for any other kind of tissue. The GTP may function in some fish as a regulator of haemoglobin–oxygen affinity.
Phosphates in red cells of two South American osteoglossids: Arapaima gigas and Osteoglossum bicirrhosum
Authors: Bartlett Grant R.
Published: August 2008

Water-soluble phosphates of red blood cells of the South American osteoglossid fish Arapaima gigas were measured by ion-exchange column chromatography. Major phosphate components were ATP and GTP with the former predominant. Of special interest was the presence of a large pool of inositol pentaphosphate, hitherto seen only in red cells of birds and turtles. A close relative of Arapaima, another South American osteoglossid, Osteoglossum bicirrhosum, had no inositol polyphosphates in its red cells. This study stemmed from work on the research vessel Alpha Helix on the Amazon River.
Phosphates in red cells of two lungfish: the South American, Lepidosiren paradoxa, and the African, Protopterus aethiopicus
Authors: Bartlett Grant R.
Published: August 2008

Measurements were made of water-soluble phosphates in red blood cells of two lungfish, the South American, Lepidosiren paradoxa, and the African, Protopterus aethiopicus. Lepidosiren was studied on the research vessel Alpha Helix on the Amazon River and P. aethiopicus was obtained at Lake Victoria, Kenya. The red cells of both species contained moderate amounts of ATP and GTP, with the former predominant. Also present were higher concentrations of the uridine mononucleotides, UDP and UTP, than had been seen in other kinds of red cells. Of special interest was the discovery in red cells of both fish of a previously unreported inositol diphosphate. No other inositol polyphosphates were found. The red cells of P. aethiopicus had two phosphate compounds (one an adenine nucleotide), which are still unidentified
Reduced blood O2 affinity associated with air breathing in osteoglossid fishes
Authors: Johansen K. , Mangum C. P. , Weber R. E.
Published: August 2008

Respiratory properties of blood in two closely related species of tropical freshwater teleosts, the osteoglossids Arapaima gigas, an obligatory air breather, and Osteoglossum bieirrhosum, an exclusive water breather, have been compared. Additionally, the O2 uptake rates (VO2) and breathing responses to hypoxic water were compared.The two species had similar values of hematocrit, hemoglobin (Hb) concentration, and O2, capacity, these being 28%, 7.5 g/100 ml, and 11.0 ml/100 ml for Osteoglossum and 30.8%, 7.5 g/100 ml, and 10.4 ml/100 ml for Arapaima. Red cell ATP and GTP levels were also similar in both species.A striking difference existed in the O2 affinity of red cell suspensions with a P50 value of 6.1 mmHg (1 mmHg = 133.322 Pa) at pH 7.4 (28 °C) for Osteoglossum against 21.0 mmHg for Arapaima. The difference persisted after purification and stripping of the hemoglobins of their red cell cofactors. We conclude that the O2-binding properties of the hemoglobin molecules in the two species are intrinsically different. The low O2 affinity in the air-breathing Arapaima permits O2 unloading at relatively high [Formula: see text]'s thus supporting a high [Formula: see text]. The high O2 affinity in Osteoglossum is necessary for Hb to function in O2 transport from a very hypoxic medium.
Swim-bladder surfactants of Amazon air-breathing fishes
Authors: Phleger C. F. , Saunders B. S.
Published: August 2008

Minimum surface tension and phospholipid composition of fish lung and swim-bladder wash and tissue extract were determined on an obligate water breather, Hoplias malabaricus, two species of facultative air breathers, Hoplerythrinus unitaeniatus and Erythrinus erythrinus, and two species of obligate air breathers, Arapaima gigas and Lepidosiren paradoxa. In addition, lung tissue slices were incubated with [1-14C]acetale and [1-14C]palmitate.All lung and swim-bladder wash lipid extracts showed a minimum surface tension of 20–25 dyn/cm (1 dyn = 10 μN). The principle phospholipid of all species is phosphatidylcholine; no phosphatidylglycerol was detected in any sample.The two obligate air breathers had higher rates of incorporation of isotope in tissue slices than facultative air breathers and nonair breathers. This observation correlates well with the greater vascular supply to their lungs.The phospholipid patterns of these fishes are significantly different from those of mammals. We speculate that these lipids recovered from saline wash may not be important in the maintenance of lung stability. Perhaps their function is keeping water from leaking into the lung and swim bladder.
Cardiovascular events associated with air breathing in two teleosts, Hoplerythrinus unitaeniatus and Arapaima gigas
Authors: Farrell A. P.
Published: August 2008

Cardiovascular events associated with air breathing were investigated in two teleosts, Hoplerythrinus unitaeniatus and Arapaima gigas, in which the air-breathing organs are modified swim bladders. These fish are bimodal breathers whilst in water; they maintain gill ventilation and take periodic air breaths. Cardiac output, blood flow to the air bladder, dorsal aortic blood pressure, and air bladder gas pressure were measured directly in A. unitaeniatus. Dorsal aortic blood pressure and air bladder gas pressure were measured in A. gigas. Both fish were subject to air exposure by draining water from the holding tank. Hoplerythrinus unitaeniatus increased air bladder perfusion following an air breath by redistributing blood flow. There was also a tachycardia after an air breath, but cardiac output did not change significantly at or between air breaths. Preferential perfusion of gill arches 3 and 4 and increased general systemic resistance both probably contribute to produce blood redistribution. During air exposure, H. unitaeniatus demonstrated hyperventilation and heart rate was elevated. In A. gigas in water the mean dorsal aortic blood pressure and heart rate remained constant, which is atypical in comparison with other air-breathing fish.
Selective control of branchial arch perfusion in an air-breathing Amazonian fish Hoplerythrinus unitaeniatus
Authors: Smith D. G. , Gannon B. J.
Published: August 2008

Vascular responses to adrenergic and cholinergic agonists were investigated in the air-breathing teleost Hoplerythrinus unitaeniatus during in situ saline perfusion of the ventral aorta.The vasculature resembled that of other teleosts in having inhibitory β-adrenergic receptors and excitatory muscarinic receptors, probably located in the gills. The gas bladder vessels were apparently devoid of adrenergic and cholinergic receptors.The dorsal aorta was specialized between gill arches 2 and 3 in such a way that the dorsal aorta probably received most of its blood supply from arches 1 and 2. Arches 3 and 4 supplied the large coeliac artery whose major branch was to the gas bladder. Acetylcholine reduced the number of perfused gill arches so that most of the ventral aortic flow was directed towards the gas bladder through arches 3 and 4. This was seen as a possible solution to the problem of transbranchial oxygen loss that could arise if blood oxygenated at the gas bladder was exposed to hypoxic water at the gills.
The effect of Amazon water type on acetate metabolism by species of Salvinia and Limnobium
Authors: Patton John S. , Moon Thomas W. , Haswell Monty S.
Published: August 2008

The uptake and incorporation of [1-14C]acetate was studied in two species of free-floating aquatic plants incubated in three different Amazon water types. Waters from the Rio Negro, the Rio Solimoes, and a local lake were used. The plants, species of Salvinia and Limnobium, were collected from the local lake. The results demonstrate that in September, the water of the Rio Negro and Rio Solimoes have similar effects on acetate metabolism by the lake plants and markedly different effects from those of the plants' home waters. Although the Rio Negro and Rio Solimoes are considered to be totally different water types, this study indicates they may cause similar biochemical responses in aquatic plants.
Morphological peculiarities in the neck-bending Amazonian characoid fish Rhaphiodon vulpinus
Authors: Lesiuk T. P. , Lindsey C. C.
Published: August 2008

Manipulation of fresh specimens of Rhaphiodon shows that the head can he bent upwards about 45°, rotating about a well-developed hinge between the fourth and fifth vertebrae. Tendons anchored to the pterotics of the skull are pulled by massive epaxial muscle bands which slide within sheaths and are reinforced by long intermuscular bones. The pectoral girdle swings forward when the head is raised, and the falcate pectoral tins can evidently provide powerful downward thrusts. It is hypothesized that Rhaphiodon attacks from beneath, perhaps pulling down prey that is planing above the surface. The function of an extraordinary series of lateral projections from the gas bladder which penetrate the body wall may be sensory but is as yet unknown.
Respiration and circulation in an apodan amphibian
Authors: Toews Dan , Macintyre Doug
Published: August 2008

Respiration and circulation were studied in the aquatic apodan amphibian Typhlonectes compressicauda (order Oymnophiona). The animals tolerate the often hypoxic and hypercapnic nature of their habitat by means of large blood volumes (25% body weight), high haemoglobin levels (11.28 g/100 ml blood), and a low P50 (22.2 mmHg (1 mmHg = 133.322 Pa)). The Bohr effect is negligible and the effects of haemoglobin concentration on the CO2 dissociation curve are discussed. Partial pH compensation in induced hypercapnic situations was accomplished. Good separation of oxygenated and deoxygenated blood within the ventricle was shown by serial sampling from both pulmonary and systemic arches.
Development and transmission of Oswaldocruzia pipiens Walton, 1929 (Nematoda: Trichostrongylidae) in amphibians
Authors: Baker M. R.
Published: August 2008

Development of Oswaldocruzia pipiens was similar to that of other trichostrongyles which have been studied. First-stage larvae have a valved, rhabditiform oesophagus. Infective larvae are ensheathed and have a strongyliform oesophagus. Development to the infective stage occurred in faeces and transmission was by skin penetration. In frogs, early development occurred on the mucosa of the stomach: worms then migrated to the anterior portion of the intestine. The prepatent period was 14–18 days at 14–18 °C. Patent infections developed in experimentally infected tadpoles of Rana sylvatica. However, there was no evidence of natural infections in tadpoles. There were no significant fluctuations of prevalence and intensity between April and October, 1976 and 1977, in transformed R. sylvatica from a single marsh near Guelph, Ontario. Transmission apparently took place during spring and throughout the summer. Young frogs acquired infections rapidly.
A comparison between two populations of the Johnny darter, Etheostoma nigrum nigrum (Percidae), from Ontario, with notes on other populations
Authors: Kott Edward , Humphreys Gregory
Published: August 2008

Johnny darters, Etheostoma nigrum nigrum, collected from Lake Superior were compared with individuals of the same subspecies collected in the Nith River (Lake Erie drainage). Nith River specimens, on an average, had 4.5 fewer lateral line scales, and more scales on the nape. The Lake Superior individuals had a snout which exhibited a subconical profile, whereas the individuals from the Nith River possessed a blunt profile.Examination of other populations of this subspecies indicates that lateral line scale count exhibits a northwest to southeast cline from Saskatchewan and Manitoba to North Carolina. All the supplementary populations were predominantly of one morph with regards to snout profile, the northwesterly populations being similar to the Lake Superior population, and the southeasterly ones being similar to the Nith River population. The taxonomic significance of snout profile is discussed.
Variation in the density of ringed seal (Phoca hispida) birth lairs in the Amundsen Gulf, Northwest Territories
Authors: Smith Thomas G. , Stirling Ian
Published: August 2008

Identical helicopter-supported surveys indicated a large decrease in the density of ringed seal birth lairs in Amundsen Gulf, N.W.T., between 1974 and 1975. A similar decrease was shown by ground surveys in the Prince Albert Sound area south of Holman. The factors stimulating the change in productivity in the area are not clear but the responses of the seals appear to have included lowered reproductive rates and movement of a significant portion of the population out of the area.
Snowshoe hare populations in woodlot habitat
Authors: Windberg Lamar A. , Keith Lloyd B.
Published: August 2008

Snowshoe hare (Lepus americanus) population dynamics were monitored on six woodlots totaling 33 ha in an agricultural area near Westlock, Alberta, from May 1970 to May 1974. Numerical trends in woodlot and nearby forest hare populations at Rochester were similar, but densities were consistently lower in woodlot habitat until the final stages of a general population decline. Annual reproductive rates were greater in woodlot populations in 1971 (11.2 vs. 9.1 young per adult female) and 1973(11.1 vs. 7.4); and similar to forest populations in 1970 and 1972. Consistently low rates of 1st-year survival (4 to 7%) in woodlot hare populations resulted in lower annual population growth rates and hence lower population densities. Browsing-intensity surveys indicated that both forest and woodlot hare populations encountered overwinter food shortages. In addition, woodlot hare populations may have suffered higher rates of predation.
Phénologie de Tanypodinae de ruisseaux des Laurentides (Diptera; Chironomidae)
Authors: Cloutier Louise , Harper P. P.
Published: August 2008

Emergence of Tanypodinae (Diptera; Chironomidae) was monitored in 1972 and 1973 in several streams in the Laurentides. Only summer species occurred. All species appeared to be univoltine, except perhaps Paramerina fragilis which may be bivoltine. Two types of emergence pattern were observed: four species had a short and synchronous emergence period; eight others emerged over many weeks. Arctopelopia flavifrons and Arctopelopia americana have different emergence patterns when they coexist in the same section and when they occur alone. Considerable variations in emergence patterns between stations were often observed for the same species. Weather conditions most affected the emergence of species with extended emergence periods.
The descriptive and comparative postcranial osteology of marten (Martes americana Turton) and fisher (Martes pennanti Erxleben): the axial skeleton
Authors: Leach D. H. , Kleer V. S. De
Published: August 2008

The postcranial axial skeletons of 23 fisher (Martes pennanti) and 25 marten (Martes americana) are described to determine those characteristics that could be used to distinguish between species and sexes. Measurements and illustrations were used to supplement the description of most bones. The axial skeletons of marten and fisher are similar in structure but it is possible to distinguish interspecific differences in each postcranial skeletal element of these mustelids using morphometric data. Distinction can also be made between certain elements of males and females within each species using bone measurements. The morphological basis of function is described for the spinous processes of the vertebrae.
Lack of caching of direct-seeded Douglas fir seeds by deer mice
Authors: Sullivan Thomas P.
Published: August 2008

Seed caching by deer mice was investigated by radiotagging seeds in forest and clear-cut areas in coastal British Columbia. Deer mice tend to cache very few Douglas fir seeds in the fall when the seed is uniformly distributed and is at densities comparable with those used in direct-seeding programs.
Oxyspirura turcottei n.sp. (Nematoda: Thelaziidae) from the eastern wild turkey (Meleagris gallopavo silvestris)
Authors: Addison Edward M. , Prestwood Annie K.
Published: August 2008

Oxyspirura turcottei n.sp. from beneath the nictitating membrane of Meleagris gallopavo silvestris of West Virginia is distinguished from other species of the subgenus Oxyspirura (undivided buccal capsule) by its size (males 9.8–13.8 mm long; females 9.6–17.7 mm long), the presence and morphology of the gubernaculum, the presence of three pairs of preanal papillae, no adanal papillae and three pairs of postanal papillae in most specimens, and by its long right and left spicules (215–245 μm and 495–615 μm, respectively).
Successful mating, oviposition, and complete generation rearing of the multivoltine black fly Simulium decorum (Diptera: Simuliidae) in the laboratory
Authors: Simmons K. R. , Edman J. D.
Published: August 2008

Adults of the autogenous, multivoltine black fly Simulium decorum Walker were reared from field larvae and induced to mate and oviposit approximately 100 fertile eggs in the laboratory. Two of seven F1 females reared from these eggs mated but neither oviposited. Vision, age, and olfaction appear important for mating in both sexes. Preliminary experience suggests that colonization of this species is feasible.
Evaluation of the potential for using a chinook salmon (Oncorhynchus tshawytscha) pituitary extract versus bovine growth hormone to enhance the growth of coho salmon (Oncorhynchus kisutch)
Authors: Higgs David A. , Donaldson Edward M. , McBride Jack R. , Dye Helen M.
Published: August 2008

Groups of yearling coho salmon, held at 10 °C and on a 12-h photoperiod, were injected intramuscularly once weekly with 10 or 100 μg of a chinook salmon pituitary extract (oncPE)/g body weight, 0.1–10 μg (9.2 × 10−3 IU) of bovine growth hormone (bGH)/g body weight, solvent, or no treatment for 70 days.Both oncPE and bGH treatment stimulated growth in length and weight. The potency of oncPE per unit weight was about one-ninth that of bGH. The lowest effective bGH dosage was 3.2 μg/g body weight, while 10 μg/g body weight induced the maximum growth response. Coho given 100 μg of oncPE/g body weight had the highest growth rates. Condition factors of bGH-treated fish were depressed when the dosage exceeded 1.0 μg/g body weight.It is concluded that use of bGH is more economical than the available pituitary extracts or purified piscine growth hormones for coho salmon culture. Two alternatives to the use of native growth hormones in salmon culture are discussed.
The role of season, habitat, host age, and sex on gill parasites of Ambloplites rupestris (Raf.)
Authors: Hanek George , Fernando C. H.
Published: August 2008

One thousand and forty-five rock bass (Ambloplites rupestis (Raf.)) were collected from May 1970 through October 1972 from the Bay of Quinte, Ontario. During the same sampling period, 1043 specimens of the same host were collected from West Lake, Prince Edward County, Ontario.Data were collected on three groups of gill parasites, Monogenea (four species), Copepoda (three species), and glochidia (one species). The data, treated synecologically, were analysed using a two-factor ANOVA and Duncan's multiple range test. The roles of season, habitat, host age, and sex on parasite load were analysed.Host sex was found to have no effect on the three groups of parasites. The abundance of parasites increased with host age (P < 0.001). A marked seasonal effect was noted for all three groups of parasites (P < 0.001). A eutrophic habitat, West Lake, was found significantly more favourable (P < 0.001) for Monogenea, while an oligotrophic habitat, Glenora, was clearly more favourable (P < 0.001) for Copepoda.
Quelques aspects de la biologie du grand corégone Coregonus clupeaformis des lacs Hélène et Nathalie, territoire de la Baie James
Authors: Dumont Pierre , Fortin Réjean
Published: August 2008

The life history of lake whitefish in lakes Nathalie (53°27′ N; 77°27′ W) and Hélène (53°27′ N; 77°31′W) was studied between June 1974 and November 1975. The age of 840 specimens was determined from the scales. Growth rates are very slow, compared only with those of dwarf whitefish of certain North American lakes. Food varies with the length of the fish and with the season of the year. Main food items are aquatic insects (larvae and adults), mollusks, and small fishes. In 1975, spawning occurred in late October (water temperature: 4 °C), at depths of 2–4 m; substrates utilized were sand, gravel, and boulders. Spawning lasted less than 2 weeks. Males mature at 390 mm (age 8) and females at 400 mm (age 9). Lake Nathalie whitefish (N = 41) show a low relative fecundity (17 980 eggs/kg). In the fall of 1974, the population density of Lake Nathalie whitefish 350 mm and longer was estimated at 839 individuals (0.72 kg/ha).
Variation in spectral reflectance of alpine and arctic Colias (Lepidoptera: Pieridae)
Authors: Roland Jens
Published: August 2008

Arctic and alpine species of the lepidopteran genus Colias (Pieridae) were collected in northern and western Canada and, utilizing reflectance spectrophotometry, the variations in their dorsal and ventral reflectance values were quantified from the infrared through ultraviolet. Variation in ventral colouration seems closely correlated with gradients of both latitude and altitude, possibly indicating selection for thermoregulatory requirements; dorsal colour variation is related to species and sexual differences.
Digestive proteases in four species of Polistes wasps
Authors: Kayes Barry M.
Published: August 2008

Adults of Polistes exclamons, Polistes metricus, Polistes fuscatus, and Polistes annularis (Hymenoptera: Vespidae) were examined for digestive protease activity. All samples analysed were found to contain chymotrypsin-like, trypsin-like, 'carboxypeptidase-A-like,' and 'carboxypeptidase-B-like' activities. The wasp chymotryptic enzyme has a serine and histidine in its active center and a specificity for aromatic amino acids and in these respects is similar to bovine chymotrypsin. The tryptic enzyme does not react like its bovine homologue, though low concentrations of this enzyme and the limit of sensitivity of the spectrophotometer may account for the differences. Enzyme comparisons are made between these Polistes species and three Vespid species.
Seasonal changes in hemolymph amino acids, proteins, and inorganic ions of a desert millipede Orthoporus ornatus (Girard) (Diplopoda: Spirostreptidae)
Authors: Pugach S. , Crawford C. S.
Published: August 2008

Composition of hemolymph of Orthoporus ornatus (Girard) was examined seasonally. Mean amino acid concentration was highest in early summer at time of molt (June, 61.73 mg%) and lowest in winter (December, 22.53 mg%; January, 32.10 mg%). Protein concentration was lowest in fall (October, 11.63 mg%) and highest in early spring (March, 37.56 mg%). Sodium and Cl− were the main hemolymph ions, accounting for about half of the hemolymph osmolality. Significant seasonal changes occur in concentration of these and other hemolymph ions. Indirect evidence suggests regulation of Na+, K+, Ca2+, and Mg2+. Hemolymph osmolality was higher in winter (December, 295.7 mosmol; January, 321.6 mosmol) than in summer (June, 211.9 mosmol; August, 204.1 mosmol). However, the contribution of measured ions to osmolality was greater in summer than in winter. Fluctuations of some hemolymph parameters suggest association with developmental changes.
Phonotactic preferences of female meadow katydids (Orthoptera: Tettigoniidae: Conocephalus nigropleurum)
Authors: Morris Glenn K. , Kerr Gordon E. , Fullard James H.
Published: August 2008

Sexually receptive females of Conocephalus nigropleurum were tested in an arena at 30 °C for responsiveness to tape-recorded models of male calling song. Exit bearing from the arena relative to speakers was the response criterion. Models were the song of a male recorded at 30 °C, the same recording with tegminal opening sounds deleted, and the same male's song at 25 °C. A fourth model was a recording of two males, 10 cm apart, singing at 30 °C, less than 10 cm equidistant from the microphone. Female choice was established for all model pairings. Preferences could not be ranked on a single scale, indicating that discriminatory criteria change with particular combinations. The model with two males proved most effective.In presenting a choice between 'two males' and 'single male with intact song (30 °C),' when the broadcast amplitude levels of these models were identical for both speakers, four times as many phonotactic exits occurred in the quadrant of the speaker broadcasting dual song than occurred in the single male quadrant. This suggests that males, competing acoustically in the field, could increase their chances of attracting females by (paradoxically) signalling in proximity to other competitors.
The division process of Cryptobia salmositica in experimentally infected rainbow trout (Salmo gairdneri)
Authors: Woo Patrick T. K.
Published: August 2008

Cryptobia salmositica was isolated from its vector, Piscicola salmositica, which was collected from spawning salmon. The organisms were first injected into coho salmon and then maintained in rainbow trout. The process of multiplication is described from Giemsa's stained smears. The first stage of division is the production of two new flagella (one long and one short). This is followed by nuclear division which is not completed until kinetoplast division is completed. Body division commences from the posterior end soon after the long flagellum attaches to the body. Following this, the nucleus, the kinetoplast, and the blepharoplast migrate into the newly divided part of the organism. Final body division is completed after the migration of these organelles. Multiplication of C. salmositica is by unequal longitudinal binary fission.
Embryonic stages: morphology, timing, and variance in the toad Bombina orientalis
Authors: Sussman Paul , Betz T. W.
Published: August 2008

A Staged series (n = 25–476} with time data for Bombina orientalis embryonic development is presented. Stages for Bombina and Rana pipiens seem identical except that approximately 50% of opercular closures are symmetrical in Bombina. Counting numbers of embryos at a stage at regular intervals allowed mathematical interpolation of the average time of stage change. A single systematic curve fit the average time per stage of embryonic development, while the increase with time in variance per stage of development was primarily linear. It is possible that the increasing complexity of morphological interstage changes causes increases in the interstage interval and variance per stage over time. The reported method of arriving al a staged series for a previously undocumented species seems more efficient than time-lapse photography. The unusually easy maintenance and dependability or Bombina, contrasting with some amphibians, suggest its use where others have been less practical.
Seasonal levels of pituitary and plasma gonadotropin in male and female Atlantic salmon parr
Authors: Crim L. W. , Evans D. M.
Published: August 2008

The annual cycle of precocious testes development was studied in the male Atlantic salmon parr. Pituitary and plasma gonadotropin (GtH) levels were related to stages of testicular activity and the precocious male values were compared with those of immature males and also with those of female parr which fail to undergo sexual development during presmolt freshwater residency. Plasma GtH increases during gonad development of precocious males. Whereas immature male and female parr pituitary GtH remains low throughout the year, precocious male values vary more than 100-fold rising quickly with the onset of spermiation. A lengthy period of spermiation matches a prolonged span of elevated GtH levels which begin falling during gonad involution and the stage of spermatogonial proliferation. It is concluded that dramatic changes in synthesis and release of pituitary GtH underlie precocious sexual development of the male Atlantic salmon parr.
Recent evolution of Zosterops lateralis on Norfolk Island, Australia
Authors: Grant P. R.
Published: August 2008

Zosterops lateralis invaded Norfolk Island in 1904. In the next 9 years it hybridized with Zosterops tenuirostris to a small extent. Evolutionary change in lateralis is indicated by a comparison of bill measurements in samples collected in different years. Specimens collected in 1926 had narrower bills than did those collected in 1912–1913 and in 1968–1969. These changes were not produced by hybridization. They may have been caused by selection whose direction was reversed after 1926, but the reasons are obscure.
Time budgets of polar bears (Ursus maritimus) on North Twin Island, James Bay, during summer
Authors: Knudsen Brian
Published: August 2008

During the summers of 1969 and 1970 polar bears (Ursus maritimus) were observed on North Twin Island (53°20′ N; 80°00′ W), James Bay. Almost all of their time (86.8%) was spent resting. They spent only 3.2% of their time feeding, primarily on geese (Branta canadensis) and crowberries (Empetrum nigrum). There was no difference between the time budgets of lone bears and females accompanied by cubs.
Functional anatomy of the coronary system of the harbour porpoise, Phocoena phocoena (L.)
Authors: Halina W. G. , Gaskin D. E.
Published: August 2008

The heart of the harbour porpoise, Phocoena phocoena (L.), is a dorsoventrally flattened, cone-shaped organ which is large relative to the size of the animal. The cardiac fibres also have a large diameter compared with those of terrestrial mammals and may be capable of exerting a greater contractile force. Atrial and ventricular fibroelastosis are present, indicating that the chambers could distend, thereby permitting engorgement during a dive. The gross coronary vascular pattern is similar to that found in terrestrial mammals except that the right coronary artery supplies the larger area of tissue in most specimens. The major coronary arteries and veins are elastic, not muscular, and are therefore distensible. When the diastole of bradycardia is prolonged during a dive, these vessels may be capable of retaining an increased volume of blood, regulating its distribution, and storing the energy necessary for its later distribution. Extensive subepicardial venous plexi, also containing much elastic tissue, can easily receive myocardial blood and pool it, relieving the pressure on the microcirculation and thereby reducing coronary vascular resistance while blood flow is maintained during a dive. These mechanisms could help extend diving time.
A comparative study of the external form and skeleton of the calcareous sponges Clathrina coriacea and Clathrina blanca from Santa Catalina Island, California
Authors: Johnson Marion Fischel
Published: August 2008

The external morphology and skeleton of Clathrina coriacea (Montagu) and Clathrina blanca (Miklucho-Maclay) from Santa Catalina Island, California, were studied to determine whether the differences, taken as a whole, were consistent and justified the separation into two distinct species. Clathrina coriacea is an encrusting sponge, whereas C. blanca is pedunculate in form. The diameter of the uncontracted anastomosing tubes is significantly greater in C. coriacea. The skeleton of the two sponges consists of equiangular triradiate spicules; these are more sagittal in C. blanca. The junction of the spicule rays is more nearly planar in C. coriacea than in C. blanca. The spicule dimensions are significantly greater in C. coriacea. These differences in external morphology and skeleton between the two sponges and the lack of intergrading forms indicate that separate specific names are justified.
Cold hardiness of some adult mosquitoes in central Alberta
Authors: Hudson J. E.
Published: August 2008

Temperatures were recorded continuously in overwintering sites of female Anopheles earlei Vargas, Culex territans Walker, and Culiseta alaskaensis (Ludlow) near George Lake (53°57′N, 114°06′W). Daily mean and absolute minimum temperatures in winter (November–March) 1972–75 were −6 and −31 °C in three rock piles, −6 and −21 °C in a log pile, −2 and −7 °C in a mammal burrow, and −10 and −42 °C in the open air. Live An. earlei and Cx. territans from rock piles in winter had mean supercooling points of −23.6 and −26.1 °C respectively. Freezing to determine supercooling points was fatal to all mosquitoes tested. Culex territans females collected in fall (September–October) had a mean supercooling point of −20.1 °C and an LT50 (median lethal time) of 138 days at −5 °C. Female Cs. inornata (Williston) were not found in winter; those collected in fall had a mean supercooling point of −11.3 °C and LT50 of 20 days at −5 °C. Supercooling points of Cs. inornata females laboratory reared at 20 °C were lowered after 1 or 10 days at 10 °C, but not at 2 °C, and not affected by blood or meconium in the midgut. Laboratory-reared, diapausing Cs. alaskaensis females had a mean supercooling point of −12.9 °C and an LT50 of 30 days at −5 °C. Nondiapausing Cs. inornata females had a mean supercooling point of −14.4 °C but their LT50 was only 9.3 days at −5 °C.
Overwintering of helminths in the garter snake (Thamnophis sirtalis sirtalis)
Authors: Rau M. E. , Gordon D. M.
Published: August 2008

The overwintering of helminths in the garter snake (Thamnophis sirtalis sirtalis) was studied. The hypobiosis of the host was not accompanied by significant changes in the prevalence or the intensity of infection of the trematodes Zeugorchis aequatus and Lechriorchis primus, the mesocercariae of Alaria sp., or the nematode Rhabdias sp. There is evidence to suggest that some species continue their development in the overwintering host.
A new nonparasitic species of Lethenteron Creaser and Hubbs 1922 (Petromyzonidae) from Hokkaido, Japan
Authors: Vladykov Vadim D. , Kott Edward
Published: August 2008

A new nonparasitic lamprey, Lethenteron matsubarai, from Shokotsu River, northern Hokkaido, Japan, is described and illustrated. The holotype (No. BC 77-71) is deposited in The Ichthyological Collection, University of British Columbia, Vancouver, Canada.This species by its nonfunctional intestinal tract and smaller eye and disc is easily separable from the parasitic Lethenteron japonicum. By its high number of trunk myomeres, 66–70 (mean 68.5), it is distinguishable from the nonparasitic Lethenteron reissneri. The description is based on seven metamorphosed individuals.
Ultrastructural observations on sensory cells and the peripheral nervous system in the mantle edge of Helisoma duryi (Mollusca: Pulmonata)
Authors: Jones Gwyneth M. , Saleuddin A. S. M.
Published: August 2008

The dorsal surface of the mantle edge produces the overlying periostracum and shell; the ventral epithelium is not involved in shell formation. This regionalization is reflected in the distribution of epithelial receptors. Six ultrastructurally distinct receptor types have been identified on the ventral surface, particularly at the tip of the mantle edge, and one on the dorsal surface. Dorsal receptors occur in a single row along the edge of the mantle edge gland and are also scattered over the dorsal epithelium. Each receptor has a ciliated intraepithelial segment (receptor ending), connected to the subepithelial cell body by a narrow process, and an axon. Variation occurs in the general morphology of the receptor ending, the number of cilia, and the shape of the ciliary tuft. In most types the cell body and axon contain electron-dense granules. Ventral and dorsal receptors differ in the complexity of their subepithelial connections. Ventral receptors send their axons to branches of the pallial nerves. Intrinsic neurons are present in the pallial nerves and in connective tissue and may be responsible for neuromuscular innervation in the mantle edge. Dorsal receptors synapse with intrinsic neurons in a discrete, localised subepithelial plexus. Three types of intrinsic cell have been identified in the plexus, and synapses between them are common. Intrinsic cells form neuromuscular synapses near the plexus and may also innervate epithelial cells in regions responsible for periostracum thickening and calcium deposition.
Reproductive cycle of the green sea urchin, Strongylocentrotus droebachiensis
Authors: Himmelman John H.
Published: August 2008

The gonadal index cycle of the echinoid Strongylocentrotus droebachiensis is described from observations on the Atlantic and Pacific coasts of Canada. An annual cycle, with spring spawning, is evident, but the exact timing of spawning and of gonadal growth varies. Consideration is given to controlling factors, using information from the present and previous studies. A number of gonadal events begin abruptly, which suggests they are controlled externally. An increase in energy channeled into gonadal growth in midsummer may be stimulated by an environmental cue. However, advanced gonadal growth will occur when excess food is available, and none will occur if food is not available. Spawning is not closely correlated with temperature, but records from the North Pacific, Arctic, and North Atlantic Oceans show that spawning is synchronized with the spring phytoplankton increase. An experimental study has confirmed that phytoplankton is the spawning cue. Concurrent observations of Strongylocentrotus purpuratus show a prolonged spawning, compared with S. droebachiensis, suggesting a different mechanism initiating spawning.
Niche relationships among species of aphids feeding on fireweed
Authors: Addicott John F.
Published: August 2008

Three species of aphids in the genus Aphis and one in the genus Macrosiphum feed on fireweed in the Rocky Mountains of Colorado, U.S.A. These species differ in their time of colonization of fireweed, time of maximum number of colonies, feeding position on fireweed, relationships to tending ants, life table parameters, and other life history characteristics. Possible reasons for such differences among cooccurring aphids are discussed.
Predaceous nematodes of the family Mononchidae from the Mackenzie and Porcupine river systems and Somerset Island, N.W.T., Canada
Authors: Mulvey R. H.
Published: August 2008

Paramononchus arcticus n.gen., n.sp., Coomansus fletcherensis n.sp., and Mononchus superbus n.sp. from the Mackenzie and Porcupine river systems and Somerset Island are described and illustrated. Paramononchus n.gen. is closest to Mononchus Bastian, differing in having the dorsal tooth opposed by a denticulated rib with two small basal teeth and a transverse rib at the level of the dorsal tooth. Other mononchids from the river and lake samples are described and illustrated including Coomansus gerlachei and Mononchus maduei which are reported for the first time in Canada.A new genus Parahadronchus is defined with Parahadronchus adamanicus (Jairajpuri, 1969) n.comb. as its type species, and generic diagnoses and a key to the 23 recognized genera of Mononchidae are included.
Effects of seasonal availability of sodium and potassium on the adrenal cortical function of a wild population of snowshoe hares, Lepus americanus
Authors: Smith M. C. , Leatherland J. F. , Myers K.
Published: August 2008

Snowshoe hares (Lepus americanus) collected from the Stokes Bay area of the Bruce Peninsula, Ontario appeared to inhabit a markedly Na+-deficient habitat as evidenced by the low Na+ concentrations found in vegetation, precipitation, soil, and water samples taken from that area. The percentage of the area of adrenal gland occupied by zona glomerulosa tissue was significantly larger in hares collected during breeding season (especially in pregnant females) than in hares collected during the winter. Preliminary studies also showed plasma aldosterone levels to be elevated in breeding females. Both observations are suggestive of an increased need for Na+ conservation and (or) K+ excretion. Plasma Na+ was depressed and plasma K+ elevated in hares collected in the summer compared with winter levels, whereas muscle Na+ and K+ did not show any age–sex or seasonally related changes. Analyses of urine and faeces suggested that the hares were maximally conserving Na+ while at the same time excreting excess K+.