Influence of Freshwater Migration on the Reproductive Patterns of Anadromous Populations of Cisco (Coregonus artedii) and Lake Whitefish (C. clupeaformis)

1990 ◽  
Vol 47 (2) ◽  
pp. 335-345 ◽  
Author(s):  
Yvan Lambert ◽  
Julian J. Dodson
Keyword(s):  
Adult Mortality ◽  
Lake Whitefish ◽  
Age At Maturity ◽  
Predominant Role ◽  
Reproductive Patterns ◽  
Interspecific Differences ◽  
Survival And Reproduction ◽  
Coregonus Artedii ◽  
The Difference ◽  
Species Specific

We tested the hypothesis that differences in the cost of freshwater migration are responsible for the different reproductive patterns exhibited by the Eastmain River (James Bay) populations of anadromous cisco and lake whitefish, as predicted by species-specific migration costs that result in interspecific differences in energy allocation to growth, survival, and reproduction. In the Eastmain River, cisco spawn at a younger age and a smaller size, have a shorter life span and show a higher fecundity and a higher mortality than lake whitefish. Assuming that the two populations are stable (being only lightly exploited), the two species spawn at an age that maximizes their lifetime fecundity. Either juvenile (between three and age at maturity) and/or adult mortality is of major importance in moulding the observed age at maturity but adult mortality may play a predominant role. Adult mortality is associated with migration, an obligatory cost representing a major proportion of the energy loss experienced by reproductive individuals. The difference in the energy cost of migration between the two species suggests that migration may play a predominant role in producing the different reproductive patterns of cisco and lake whitefish in the Eastmain River and that within the physiological and size constraints of each species, these patterns represent optimal adaptations maximizing fitness.

BIOSYSTEMATICS OF THE GENUS EUXOA (LEPIDOPTERA: NOCTUIDAE). XVIH. COMPARATIVE BIOLOGY AND EXPERIMENTAL TAXONOMY OF THE SIBLING SPECIES EUXOA RIDMGSIANA (GRT.) AND EUXOA MAIMES (SM.)

1985 ◽  
Vol 117 (4) ◽  
pp. 481-493 ◽  
Author(s):  
J.R. Byers ◽  
D.L. Struble ◽  
J.D. Lafontaine
Keyword(s):  
Life Cycle ◽  
Reproductive Isolation ◽  
Sibling Species ◽  
Mate Recognition ◽  
Recognition System ◽  
Flight Period ◽  
Interspecific Differences ◽  
Mate Recognition System ◽  
The Difference ◽  
Species Specific

AbstractThe species previously recognized as Euxoa ridingsiana (Grt.) is shown to be composed of a sympatric pair of sibling species, Euxoa ridingsiana (Grt.) and Euxoa maimes (Sm.), which in the laboratory will produce viable F1 hybrids but no F2. Results of F1 sib and backcrosses show that the F1 males are fertile and the F1 females are infertile. In mating-bias tests conducted in laboratory cages, 74% of matings were conspecific and 26% interspecific. Differences in the diel periodicities of mating, which are about 2 h out of phase, may account for the mating bias. The duration of development of E. ridingsiana in the laboratory and its seasonal flight period in the field are about 2 weeks in advance of that of E. maimes. However, there is considerable overlap of the flight periods and, with the tendency of females of both species to mate several times, it is unlikely that the difference in seasonal emergence is enough to effect reproductive isolation. It is evident that, under natural conditions, reproductive isolation can be maintained entirely by species-specific sex pheromones. This mechanism of reproductive isolation is, however, apparently ineffective when moths are confined in cages in the laboratory.Biogeographic considerations suggest that the differences in life-cycle timing and mating periodicities might have been adaptations to adjust development and reproduction to prevailing ancestral environments. If the initial differentiation of the 2 species occurred in isolation and included at least an incipient shift in the pheromonal mate-recognition system, it is possible that upon reestablishment of contact between ancestral populations the differences in life-cycle timing and mating periodicities acting in concert could have effected substantial, albeit incomplete, reproductive isolation. Subsequent selection to reinforce assortative mating to preserve coadapted gene complexes could then have resulted in differentiation of discrete pheromonal systems and attainment of species status.

Life History Variations of Anadromous Cisco (Coregonus artedii), Lake Whitefish (C. clupeaformis), and Round Whitefish (Prosopium cylindraceum) Populations of Eastern James–Hudson Bay

1982 ◽  
Vol 39 (7) ◽  
pp. 958-967 ◽  
Author(s):  
Roderick Morin ◽  
Julian J. Dodson ◽  
Geoffrey Power
Keyword(s):  
Life History ◽  
North American ◽  
Life History Theory ◽  
Life History Traits ◽  
Reproductive Effort ◽  
Hudson Bay ◽  
Lake Whitefish ◽  
The North ◽  
Interspecific Differences ◽  
Coregonus Artedii

Differences in life history among three species of anadromous coregonines from La Grande River, James Bay, were significant with lake whitefish (Coregonus clupeaformis) and round whitefish (Prosopium cylindraceum) displaying reproductive patterns more typical of harsh northern environments and characteristic of "K-selection," relative to cisco (Coregonus artedii). Interspecific differences at La Grande River were more apparent than intraspecific differences in life history traits of cisco and lake whitefish over the James–Hudson Bay range. Although cisco exhibit decreasing reproductive effort independent of growth over the North American range, thus conforming to life history theory, both growth and reproductive effort are reduced northwards over their James–Hudson Bay range. The observations suggest that physiological constraints related to the shorter growing season at the northern limit of cisco's coastal Hudson Bay range may overwhelm expected coadapted life history traits. Lake whitefish exhibit reduced reproductive effort independent of variations in growth northwards over their North American and James–Hudson Bay coastal range; this suggests coadaptation of life history traits that permit survival at northern sites.Key words: reproduction, growth, life history theory, anadromous coregonines, James–Hudson Bay

scholarly journals Bark traits, decomposition and flammability of Australian forest trees

2017 ◽  
Vol 65 (4) ◽  
pp. 327 ◽  
Author(s):  
Saskia Grootemaat ◽  
Ian J. Wright ◽  
Peter M. van Bodegom ◽  
Johannes H. C. Cornelissen ◽  
Veronica Shaw
Keyword(s):  
Forest Tree ◽  
Remarkable Feature ◽  
Interspecific Differences ◽  
Eucalypt Plantations ◽  
Physical Traits ◽  
Key Driver ◽  
Multiple Species ◽  
Species Specific ◽  
First Time ◽  
Different Tissues

Bark shedding is a remarkable feature of Australian trees, yet relatively little is known about interspecific differences in bark decomposability and flammability, or what chemical or physical traits drive variation in these properties. We measured the decomposition rate and flammability (ignitibility, sustainability and combustibility) of bark from 10 common forest tree species, and quantified correlations with potentially important traits. We compared our findings to those for leaf litter, asking whether the same traits drive flammability and decomposition in different tissues, and whether process rates are correlated across tissue types. Considerable variation in bark decomposability and flammability was found both within and across species. Bark decomposed more slowly than leaves, but in both tissues lignin concentration was a key driver. Bark took longer to ignite than leaves, and had longer mass-specific flame durations. Variation in flammability parameters was driven by different traits in the different tissues. Decomposability and flammability were each unrelated, when comparing between the different tissue types. For example, species with fast-decomposing leaves did not necessarily have fast-decomposing bark. For the first time, we show how patterns of variation in decomposability and flammability of bark diverge across multiple species. By taking species-specific bark traits into consideration there is potential to make better estimates of wildfire risks and carbon loss dynamics. This can lead to better informed management decisions for Australian forests, and eucalypt plantations, worldwide.

scholarly journals Environmental correlates and energetics of winter flight by bats in southern Alberta, Canada

2016 ◽  
Vol 94 (12) ◽  
pp. 829-836 ◽  
Author(s):  
B.J. Klüg-Baerwald ◽  
L.E. Gower ◽  
C.L. Lausen ◽  
R.M. Brigham
Keyword(s):  
Heat Loss ◽  
Barometric Pressure ◽  
Myotis Lucifugus ◽  
Energetic Cost ◽  
Cold Temperatures ◽  
Bat Activity ◽  
Environmental Correlates ◽  
Interspecific Differences ◽  
Winter Activity ◽  
Species Specific

Winter activity of bats is common, yet poorly understood. Other studies suggest a relationship between winter activity and ambient temperature, particularly temperature at sunset. We recorded echolocation calls to determine correlates of hourly bat activity in Dinosaur Provincial Park, Alberta, Canada. We documented bat activity in temperatures as low as −10.4 °C. We observed big brown bats (Eptesicus fuscus (Palisot de Beauvois, 1796)) flying at colder temperatures than species of Myotis bats (genus Myotis Kaup, 1829). We show that temperature and wind are important predictors of winter activity by E. fuscus and Myotis, and that Myotis may also use changes in barometric pressure to cue activity. In the absence of foraging opportunity, we suggest these environmental factors relate to heat loss and thus the energetic cost of flight. To understand the energetic consequences of bat flight in cold temperatures, we estimated energy expenditure during winter flights of E. fuscus and little brown myotis (Myotis lucifugus (Le Conte, 1831)) using species-specific parameters. We estimated that winter flight uses considerable fat stores and that flight thermogenesis could mitigate energetic costs by 20% or more. We also show that temperature-dependent interspecific differences in winter activity likely stem from differences between species in heat loss and potential for activity–thermoregulatory heat substitution.

Changes in fish populations affected by the construction of the La Grande complex (Phase I), James Bay region, Quebec

1995 ◽  
Vol 73 (10) ◽  
pp. 1860-1877 ◽  
Author(s):  
Jean-Claude DesLandes ◽  
Sylvie Guénette ◽  
Yves Prairie ◽  
Réjean Fortin ◽  
Dominique Roy ◽  
...  
Keyword(s):  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Time Intervals ◽  
Complex Phase ◽  
Coregonus Artedii ◽  
Secondary Productivity ◽  
Longnose Sucker ◽  
The Impact

Catches per unit of effort (CPUE) with experimental gill nets, recruitment, growth, and condition were monitored between 1977 and 1992 to evaluate the impact of impoundment on the main fish species of La Grande 2, Opinaca, and Caniapiscau reservoirs and the Boyd–Sakami diversion. CPUE and recruitment of northern pike (Esox lucius) and lake whitefish (Coregonus clupeaformis) increased markedly at most stations after impoundment and decreased at the end of the series. The lake whitefish and cisco (Coregonus artedii) showed their most striking rise in CPUE at two bay stations of La Grande 2 and Opinaca reservoirs. CPUE and recruitment of the longnose sucker (Catostomus catostomus), white sucker (Catostomus commersoni), and lake trout (Salvelinus namaycush) (Caniapiscau) showed a general decrease following impoundment. CPUE for the walleye (Stizostedion vitreum) also decreased at several stations; however, the two most southerly stations in La Grande 2 reservoir and the Boyd–Sakami station showed high CPUE during the series. Concentration–redistribution phenomena explain part of the observed variations in CPUE. Correlation analyses showed that walleyes and white suckers were attracted to the warmer, more turbid stations, and that the high primary and secondary productivity of bay stations attracted the coregonines. Growth and condition of the main species increased during variable time intervals after impoundment and decreased at the end of the series.

scholarly journals Interspecific differences of stridulatory signals in three species of bark beetles from the genus Polygraphus Er. (Coleoptera: Curculionidae, Scolytinae) inhabiting the island of Sakhalin

2019 ◽  
Author(s):  
Ivan Andreevich Kerchev
Keyword(s):  
Host Plant ◽  
Plant Species ◽  
Bark Beetles ◽  
Acoustic Signals ◽  
Interval Number ◽  
Host Plant Species ◽  
Interspecific Differences ◽  
Species Specific ◽  
Conspecific Interactions

Stridulatory signals are involved in conspecific interactions between bark beetles (Coleoptera: Curculionidae, Scolytinae). In this study, we compared the qualitative profiles of acoustic signals in three species from the genus Polygraphus Er. Sympatry can be periodically observed in two of them – P. proximus and P. subopacus. Sporadically they occur on the same plants. P. nigrielytris colonize distinctly different host plant species; however, on the island of Sakhalin it inhabits the same biotopes. The purpose of the study is to identify species-specific parameters and the extent of differences in stridulatory signals of these species. Airborne signals produced during the contact of males of the same species were experimentally recorded. Among tested parameters of stridulatory signals, as the most species-specific were noted: chirp duration, interchirp interval, number of tooth-strikes per chirp, and intertooth-strike interval.

scholarly journals Ba incorporation in benthic foraminifera

2017 ◽  
Author(s):  
Lennart J. de Nooijer ◽  
Anieke Brombacher ◽  
Antje Mewes ◽  
Gerald Langer ◽  
Gernot Nehrke ◽  
...  
Keyword(s):  
Trace Elements ◽  
Benthic Foraminifera ◽  
General Trend ◽  
Seawater Chemistry ◽  
Minor And Trace Elements ◽  
Foraminiferal Species ◽  
Element Partitioning ◽  
The Difference ◽  
Species Specific ◽  
New Applications

Abstract. Barium (Ba) incorporated in the calcite of many foraminiferal species is proportional to the concentration of Ba in seawater. Since the open ocean concentration of Ba closely follows seawater alkalinity, foraminiferal Ba/Ca can be used to reconstruct the latter. Alternatively, Ba/Ca from foraminiferal shells can also be used to reconstruct salinity in coastal settings where seawater Ba concentration corresponds to salinity as rivers contain much more Ba than seawater. Incorporation of a number of minor and trace elements is known to vary (greatly) between foraminiferal species and application of element/Ca ratios thus requires the use of species-specific calibrations. Here we show that calcite Ba/Ca correlates positively and linearly with seawater Ba/Ca in cultured specimens of two species of benthic foraminifera, Heterostegina depressa and Amphistegina lessonii. The slopes of the regression, however, vary 2–3 fold between these two species (0.33 and 0.78, respectively). This difference in Ba-partitioning resembles the difference in partitioning of other elements (Mg, Sr, B, Li and Na) in these foraminiferal taxa. A general trend across element partitioning for different species is described, which may help developing new applications of trace elements in foraminiferal calcite in reconstructing past seawater chemistry.

Interspecific differences in the tolerance of arbuscular mycorrhizal fungi to freezing and drying

2001 ◽  
Vol 79 (10) ◽  
pp. 1161-1166 ◽  
Author(s):  
John N Klironomos ◽  
Miranda M Hart ◽  
Jane E Gurney ◽  
Peter Moutoglis
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Plant Species ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Fungal Species ◽  
Drought Treatment ◽  
Interspecific Differences ◽  
The Difference ◽  
One Year ◽  
Arbuscular Mycorrhizal Fungal

Arbuscular mycorrhizal fungal communities in northern temperate ecosystems must function during extremes in environmental conditions. However, it is not known if arbuscular mycorrhizal fungi that co-exist in soil communities have similar tolerances to stresses such as drought and freezing. The phenology of arbuscular mycorrhizal fungi was determined over one year in a community in southern Ontario, Canada. Five fungal species from the same community were then used to inoculate five plant species, in all possible combinations, and were subjected to either a freezing treatment or a drought treatment after which new seedlings were transplanted into the treated pots. The percent colonization of roots of each plant species was measured as the difference in mean colonization from the control. Freezing reduced percent colonization in almost every case, whereas drought resulted in both increased and decreased percent colonization. Fungal species responded differently to the treatments, and there was a pronounced plant × fungus effect. These results support the hypothesis that distinct functional groups of arbuscular mycorrhizal fungi exist, and these may determine plant community structure.Key words: arbuscular mycorrhizal fungi, freezing, drying, functional diversity.

Variations on a segmental theme: muscle receptor organs and extensor neuromusculature in the squat lobster Munida quadrispina (Anomura, Galatheidae)

1995 ◽  
Vol 198 (12) ◽  
pp. 2453-2463 ◽  
Author(s):  
E Wallis ◽  
D Paul ◽  
B Antonsen ◽  
R Hollenberg
Keyword(s):  
Relative Size ◽  
Extracellular Recording ◽  
Blue Staining ◽  
Squat Lobster ◽  
Muscle Receptor ◽  
Axial Muscles ◽  
Extensor Motoneurones ◽  
The Difference ◽  
Segmental Variation ◽  
Species Specific

Extensor neuromusculature and the muscle receptor organs (MROs) associated with them have been conserved during the evolution of malacostracan crustaceans, despite species-specific differences between homologous segments in divergent taxa. Investigations of these differences could provide insight into how sensory and neuromuscular elements are modified to accommodate changing behavioural patterns. The most obvious differences between squat lobsters (galatheid anomurans) and macruran decapods, such as crayfish, are the greater dorso-ventral flattening of the galatheid abdomen and its flexed resting posture. To investigate whether the evolution of this altered posture affected extensor neuromusculature and MRO morphology and physiology, we used Methylene Blue staining, cobalt backfilling and extracellular recording techniques to describe these elements in the caudal thoracic and six abdominal segments of the squat lobster Munida quadrispina and compared our results with published descriptions of homologous elements in macrurans. In M. quadrispina, there is segmental variation both in the orientation of the MROs along the abdomen and in their physiological responses to stretch: apparent sensitivity is higher in caudal than rostral MROs. Homologues of three of the four accessory neurones found in crayfish occur, but AN#1 has a major dendrite not present in crayfish. Intersegmental differences in size and morphology of extensor motoneurones occur in M. quadrispina, as have been reported in crayfish, but are dissimilar in the two: abdominal ganglion 5 extensor motoneurones are the largest in M. quadrispina and the smallest in crayfish; this difference correlates with the difference in relative size of axial muscles along the abdomen reported previously for these species. M. quadrispina also differs from macrurans in having a single tonic, and no phasic, MRO on each side of the last abdominal segment. Together, these observations suggest that galatheids have evolved modified or additional neurobehavioural control(s) for the abdomen and tailfan.

scholarly journals Variable Rates of Simple Satellite Gains across the Drosophila Phylogeny

2018 ◽  
Vol 35 (4) ◽  
pp. 925-941 ◽  
Author(s):  
Kevin H -C Wei ◽  
Sarah E Lower ◽  
Ian V Caldas ◽  
Trevor J S Sless ◽  
Daniel A Barbash ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Rapid Evolution ◽  
Single Mutation ◽  
Closely Related Species ◽  
Interspecific Differences ◽  
Limited Sampling ◽  
Drosophila Phylogeny ◽  
Males And Females ◽  
Species Specific ◽  
Turn Over

Abstract Simple satellites are tandemly repeating short DNA motifs that can span megabases in eukaryotic genomes. Because they can cause genomic instability through nonallelic homologous exchange, they are primarily found in the repressive heterochromatin near centromeres and telomeres where recombination is minimal, and on the Y chromosome, where they accumulate as the chromosome degenerates. Interestingly, the types and abundances of simple satellites often vary dramatically between closely related species, suggesting that they turn over rapidly. However, limited sampling has prevented detailed understanding of their evolutionary dynamics. Here, we characterize simple satellites from whole-genome sequences generated from males and females of nine Drosophila species, spanning 40 Ma of evolution. We show that PCR-free library preparation and postsequencing GC-correction better capture satellite quantities than conventional methods. We find that over half of the 207 simple satellites identified are species-specific, consistent with previous descriptions of their rapid evolution. Based on a maximum parsimony framework, we determined that most interspecific differences are due to lineage-specific gains. Simple satellites gained within a species are typically a single mutation away from abundant existing satellites, suggesting that they likely emerge from existing satellites, especially in the genomes of satellite-rich species. Interestingly, unlike most of the other lineages which experience various degrees of gains, the lineage leading up to the satellite-poor D. pseudoobscura and D. persimilis appears to be recalcitrant to gains, providing a counterpoint to the notion that simple satellites are universally rapidly evolving.

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