Differential response of distinct copepod life history types to spring environmental forcing in Rivers Inlet, British Columbia, Canada

The temporal dynamics of five copepod species common to coastal waters of the Pacific Northwest were examined in relation to variability in spring temperature and phytoplankton dynamics in 2008, 2009, and 2010 in Rivers Inlet, British Columbia, Canada. The five species were differentiated by life history strategies. Acartia longiremis, Metridia pacifica, and Paraeuchaeta elongata remained active over most of the year. By contrast, the reproductive effort of Eucalanus bungii and Calanus marshallae was concentrated over the spring period and they spent most of the year in diapause as C5 copepodites. A delay in the timing of the spring bloom was associated with a shift in the phenology of all species. However, following the delay in spring bloom timing, recruitment to the G1 cohort was reduced only for E. bungii and C. marshallae. Recruitment successes of E. bungii and C. marshallae was also drastically reduced in 2010, an El Niño year, when spring temperatures were highest. Reasons for the observed differential response to spring environmental forcing, and its effect on upper trophic levels, are discussed.

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Using nitrogen stable isotopes to detect long-distance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f09-020 ◽

2009 ◽

Vol 66 (4) ◽

pp. 672-682 ◽

Cited By ~ 13

Author(s):

Adam J. Sepulveda ◽

Warren T. Colyer ◽

Winsor H. Lowe ◽

Mark R. Vinson

Keyword(s):

Water Quality ◽

Stable Isotopes ◽

Life History ◽

Headwater Streams ◽

Cutthroat Trout ◽

Trophic Levels ◽

Life History Strategies ◽

Nitrogen Stable Isotopes ◽

Long Distance ◽

Oncorhynchus Clarkii

Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a population is critical to these efforts. We tested the application of nitrogen stable isotopes to discern fluvial from resident Bonneville cutthroat trout (BCT; Oncorhynchus clarkii utah ) in a headwater stream. Fluvial BCT migrate from headwater streams with good water quality to mainstem habitats with impaired water quality. Resident BCT remain in headwater streams. We tested two predictions: (i) fluvial BCT have a higher δ15N than residents, and (ii) fluvial BCT δ15N reflects diet and δ15N enrichment characteristics of mainstem habitats. We found that fluvial δ15N was greater than resident δ15N and that δ15N was a better predictor of life history than fish size. Our data also showed that fluvial and resident BCT had high diet overlap in headwater sites and that δ15N of lower trophic levels was greater in mainstem sites than in headwater sites. We conclude that the high δ15N values of fluvial BCT were acquired in mainstem sites.

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Environmental forcing on life history strategies: Evidence for multi-trophic level responses at ocean basin scales

Progress In Oceanography ◽

10.1016/j.pocean.2009.04.012 ◽

2009 ◽

Vol 81 (1-4) ◽

pp. 214-222 ◽

Cited By ~ 28

Author(s):

Robert M. Suryan ◽

Vincent S. Saba ◽

Bryan P. Wallace ◽

Scott A. Hatch ◽

Morten Frederiksen ◽

...

Keyword(s):

Life History ◽

Trophic Level ◽

Ocean Basin ◽

Life History Strategies ◽

Environmental Forcing

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Differential response to a competitor by Atlantic salmon adopting alternative life-history strategies

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1989.0010 ◽

1989 ◽

Vol 236 (1282) ◽

pp. 21-27 ◽

Cited By ~ 23

Keyword(s):

Life History ◽

Life Cycle ◽

Atlantic Salmon ◽

Feeding Behaviour ◽

Laboratory Experiments ◽

Fold Increase ◽

Differential Response ◽

Life History Strategies ◽

Juvenile Salmon ◽

Growing Conditions

The life cycle of the Atlantic salmon is extremely variable. In good growing conditions, juvenile salmon either metamorphose into the migratory phase by their second spring, or delay this for at least another year. The strategy appears to be decided in their first summer. This study compared competitive responses of fish adopting the two strategies. Laboratory experiments showed that the two types of fish had similar foraging efficiencies in isolation. However, although a simulated competitor had little effect on the feeding behaviour of fast-developing fish, it caused an 18-fold increase in the incidence of failed feeding attempts by fish delaying development. The probability of an attack failing was dependent on how close the competitor came.

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Experiments on Oral Secretion of the Rocky Mountain Wood Tick, Dermacentor andersoni Stiles (Acarina: Ixodidae)

The Canadian Entomologist ◽

10.4039/ent891-1 ◽

1957 ◽

Vol 89 (1) ◽

pp. 1-5 ◽

Cited By ~ 20

Author(s):

J. D. Gregson

Keyword(s):

British Columbia ◽

Pacific Northwest ◽

Rocky Mountain ◽

Dermacentor Variabilis ◽

Oral Secretion ◽

Amblyomma Maculatum ◽

Dermacentor Andersoni ◽

The Pacific ◽

Tick Paralysis ◽

Rocky Mountain Wood Tick

Tick paralysis continues to be one of the most baffling and fascinating tickborne diseases in Canada. It was first reported in this country by Todd in 1912. Since then about 250 human cases, including 28 deaths, have been recorded from British Columbia. Outbreaks in cattle have affected up to 400 animals at a time, with losses in a herd as high as 65 head. Although the disease is most common in the Pacific northwest, where it is caused by the Rocky Mountain wood tick, Dermacentor andersoni Stiles, it has lately been reported as far south as Florida and has been produced by Dermacentor variabilis Say, Amblyomma maculatum Koch, and A. americanum (L.) (Gregson, 1953). The symptoms include a gradual ascending symmetrical flaccid paralysis. Apparently only man, sheep, cattle, dogs, and buffalo (one known instance) are susceptible, but even these may not necessarily be paralysed.

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Exposure to glucocorticoids alters life history strategies in a facultatively paedomorphic salamander

Journal of Experimental Zoology Part A Ecological and Integrative Physiology ◽

10.1002/jez.2445 ◽

2021 ◽

Author(s):

Jason R. Bohenek ◽

Christopher J. Leary ◽

William J. Resetarits

Keyword(s):

Life History ◽

Life History Strategies

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Natural variation in plant telomere length is associated with flowering time

The Plant Cell ◽

10.1093/plcell/koab022 ◽

2021 ◽

Author(s):

Jae Young Choi ◽

Liliia R Abdulkina ◽

Jun Yin ◽

Inna B Chastukhina ◽

John T Lovell ◽

...

Keyword(s):

Life History ◽

Telomere Length ◽

Flowering Time ◽

Dna Sequences ◽

Genome Wide Association Study ◽

Genomic Analysis ◽

Life History Strategies ◽

Length Variation ◽

Chromosomal Structure ◽

Chromosome Integrity

Abstract Telomeres are highly repetitive DNA sequences found at the ends of chromosomes that protect the chromosomes from deterioration during cell division. Here, using whole genome re-sequencing and terminal restriction fragment assays, we found substantial natural intraspecific variation in telomere length in Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays). Genome-wide association study (GWAS) mapping in A. thaliana identified 13 regions with GWAS-significant associations underlying telomere length variation, including a region that harbors the telomerase reverse transcriptase (TERT) gene. Population genomic analysis provided evidence for a selective sweep at the TERT region associated with longer telomeres. We found that telomere length is negatively correlated with flowering time variation not only in A. thaliana, but also in maize and rice, indicating a link between life history traits and chromosome integrity. Our results point to several possible reasons for this correlation, including the possibility that longer telomeres may be more adaptive in plants that have faster developmental rates (and therefore flower earlier). Our work suggests that chromosomal structure itself might be an adaptive trait associated with plant life history strategies.

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