Comparative review of Pacific salmon survival rates

1995 ◽  
Vol 52 (6) ◽  
pp. 1327-1338 ◽  
Author(s):  
Michael J. Bradford
Keyword(s):  
Life History ◽  
Survival Data ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Survival Rates ◽  
Adult Survival ◽  
Life History Stages ◽  
Comparative Review ◽  
History Of ◽  
The Mean

I collated estimates of survival from the literature for naturally reproducing populations of the five major commercially harvested species of Pacific salmon (Oncorhynchus spp.) and compared the mean and variability of survival across species and life-history stages. The conclusion that survival rates can be described with a lognormal distribution was extended to include both the marine and freshwater stages. Average egg–fry survival of pink (O. gorbuscha), chum (O. keta), and sockeye (O. nerka) salmon was similar (average 7%) but was significantly lower than that of coho salmon (O. kisutch, 19%). The egg–smolt survival of chinook (O. tshawytscha) was much higher than coho or sockeye that also rear in freshwater for similar periods (7 compared with 1–2%). No direct estimates exist for the marine survival rate of naturally spawning chinook stocks; however, from fecundity and freshwater survival data a species average of 1–2% was derived. Across all species freshwater contributes slightly more to total variation in egg–adult survival than does the ocean, and the schedule of mortality during the egg–adult interval depends on the natural history of each species.

Inbreeding depression and floral type fitness differences in Viola canadensis (Violaceae), a species with chasmogamous and cleistogamous flowers

2000 ◽  
Vol 78 (11) ◽  
pp. 1420-1429 ◽  
Author(s):  
Theresa M Culley
Keyword(s):  
Inbreeding Depression ◽  
Survival Rates ◽  
Early Life History ◽  
Flower Number ◽  
Life History Stages ◽  
The North ◽  
History Of ◽  
Vegetative Biomass ◽  
Similar Survival ◽  
Cross Type

Few studies of inbreeding depression have focused on species producing both showy, chasmogamous (CH) flowers and self-pollinated, cleistogamous (CL) flowers. The goals of this investigation were to measure the level of inbreeding depression in the North American violet, Viola canadensis L., and to determine if any fitness differences were linked to floral type (CH versus CL) rather than to cross type (self versus outcross). Hand pollinations were carried out to produce self- and outcross-pollinated CH progeny, and CL seeds were also collected. In a greenhouse, selfed and outcrossed CH flowers produced similar numbers of seeds, and both types of progeny had similar survival rates and comparable numbers of CH flowers, although outcrossed CH progeny had 14% greater vegetative biomass than selfed CH progeny. The level of inbreeding depression in V. canadensis was low, indicating that there may be few drawbacks to selfing in this species. A comparison of CL and self-pollinated CH progeny showed that, although there were differences in CH flower number, overall fitness differences were minimal. The similar performance of selfed (CL and CH) and outcrossed progeny in early life-history stages of V. canadensis suggests a history of inbreeding in the population.Key words: cleistogamy, inbreeding depression, outcrossing, selfing, Viola canadensis.

LIFE HISTORY STUDIES OF THE TOBACCO FLEA BEETLE, EPITRIX HIRTIPENNIS (MELSHEIMER) (COLEOPTERA: CHRYSOMELIDAE)

1987 ◽  
Vol 22 (3) ◽  
pp. 237-244 ◽  
Author(s):  
W. Davis Martin ◽  
G. A. Herzog
Keyword(s):  
Life History ◽  
Larval Stage ◽  
Flea Beetle ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Adult Longevity ◽  
Male And Female ◽  
Controlled Conditions ◽  
History Of ◽  
The Mean

The life history of the tobacco flea beetle, Epitrix hirtipennis (Melsheimer) (= Epitrix parvula Fab.) was studied under the controlled conditions of 27 ± 2.8°C, 80 ± 6% and a 14L:10D photophase. Eggs matured in ca. 4 days, the larval stage, including 3 instars, developed in 13 days, prepupal development took 3 days and the pupal stage lasted approximately 5 days. There was a 24 day interval between oviposition and adult emergence. Females laid 3.1 eggs/day with a 13 day period between adult emergence and first oviposition. The mean number of total eggs/female was 138.6 ± 14.7. Female oviposition continued until a few days before death and adult longevity was approximately 70 days. A visual means of distinguishing between male and female beetles was also developed.

Aspects of the post-larval life history of Limnadia stanleyana King (Crustacea : Conchostraca)

1968 ◽  
Vol 16 (5) ◽  
pp. 885 ◽  
Author(s):  
JA Bishop
Keyword(s):  
Life History ◽  
Maximum Size ◽  
Isolated Populations ◽  
Growth Rings ◽  
Initial Stage ◽  
History Of ◽  
The Mean ◽  
Genetically Determined ◽  
Larval Life History ◽  
Moulting Cycle

L. stanleyana occurs in some rainwater pools near Sydney, N.S.W.. A study of the life history permits description of some aspects of the growth and morphological variation of the species. No growth rings are formed on the carapace during the initial stage of post-larval development. After this a ring is formed at each moult. Animals moult at regular intervals during the period of rapid growth which continues until after maturity. Moulting then occurs less frequently and eventually ceases in aged animals. The increment in size during each moulting cycle varies. It is greater in immature than is adult animals so although the increase in number of growth rings is linear the increase in size at this time is near exponential. The maximum size attained varies from generation to generation even in the same pool. There are sexual differences in the proportions of the carapace and damage due to injury increases markedly in aged animals. At 7.5�C third- and fourth-stage nauplii did not mature and scarcely grew during incubation for 336 hr. At 16, 20, and 25�C similar larvae grew to maturity in about 349, 161, and 109 hr respectively. The mean number of spines on telsons of animals from one pool is different from that of those from other pools. This situation merits further examination since the biological characteristics of the species facilitate the study of this quantitative, probably genetically determined, character in reproductively isolated populations.

scholarly journals Corticosterone, testosterone and life-history strategies of birds

2010 ◽  
Vol 277 (1697) ◽  
pp. 3203-3212 ◽  
Author(s):  
Michaela Hau ◽  
Robert E. Ricklefs ◽  
Martin Wikelski ◽  
Kelly A. Lee ◽  
Jeffrey D. Brawn
Keyword(s):  
Life History ◽  
Body Mass ◽  
Breeding Season ◽  
Life History Traits ◽  
Survival Rates ◽  
Life History Strategies ◽  
Adult Survival ◽  
Tropical Species ◽  
Published Data ◽  
Season Length

Steroid hormones have similar functions across vertebrates, but circulating concentrations can vary dramatically among species. We examined the hypothesis that variation in titres of corticosterone (Cort) and testosterone (T) is related to life-history traits of avian species. We predicted that Cort would reach higher levels under stress in species with higher annual adult survival rates since Cort is thought to promote physiological and behavioural responses that reduce risk to the individual. Conversely, we predicted that peak T during the breeding season would be higher in short-lived species with high mating effort as this hormone is known to promote male fecundity traits. We quantified circulating hormone concentrations and key life-history traits (annual adult survival rate, breeding season length, body mass) in males of free-living bird species during the breeding season at a temperate site (northern USA) and a tropical site (central Panama). We analysed our original data by themselves, and also combined with published data on passerine birds to enhance sample size. In both approaches, variation in baseline Cort (Cort0) among species was inversely related to breeding season length and body mass. Stress-induced corticosterone (MaxCort) also varied inversely with body mass and, as predicted, also varied positively with annual adult survival rates. Furthermore, species from drier and colder environments exhibited lower MaxCort than mesic and tropical species; T was lowest in species from tropical environments. These findings suggest that Cort0, MaxCort and T modulate key vertebrate life-history responses to the environment, with Cort0 supporting energetically demanding processes, MaxCort promoting survival and T being related to mating success.

Survival and life history characteristics among wild and hatchery coho salmon (Oncorhynchus kisutch) returns: how do unfed fry differ from smolt releases?

2010 ◽  
Vol 67 (3) ◽  
pp. 486-497 ◽  
Author(s):  
Véronique Thériault ◽  
Gregory R. Moyer ◽  
Michael A. Banks
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Molecular Analysis ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Adult Survival ◽  
Life History Characteristics ◽  
Hatchery Program ◽  
Release Strategy ◽  
Integrated Hatchery Program

Survival and life history characteristics were evaluated for a coho salmon ( Oncorhynchus kisutch ) integrated hatchery program using two stocking strategies. Fish were released as unfed fry or smolts and returned as adults, and then molecular analysis was employed to pedigree the entire population. We showed that mean adult survival of individuals released as unfed fry was less than that of individuals released as smolts (0.03% vs. 2.39%). The relative reproductive success (RRS) of the fry release strategy to wild spawning was significantly greater for one of two cohorts, whereas the smolt release strategy to wild RRS was significantly greater for both cohorts. Fish released as smolts were significantly smaller upon returning as adults than either those released as unfed fry or wild returns. Mean run timing was also significantly biased towards an earlier run time for hatchery-released fish when compared with the wild component. The incidence of jacking (males maturing at age 2) was greater among fish stocked as smolts than for fish stocked as fry. Differences in survival, RRS, and life history appeared to be the result of hatchery practices and indicated that a fry stocking strategy produced fish more similar to the wild component of the population than to that of fish released as smolts.

A multi-year and multi-site population study on the life history of Salamandrina perspicillata (Savi, 1821) (Amphibia, Urodela)

2008 ◽  
Vol 29 (2) ◽  
pp. 161-170 ◽  
Author(s):  
Carlo Utzeri ◽  
Claudio Angelini ◽  
Damiano Antonelli
Keyword(s):  
Life History ◽  
Body Size ◽  
Population Study ◽  
Climatic Conditions ◽  
Life History Variation ◽  
Differential Growth ◽  
History Of ◽  
Natural Pond ◽  
The Mean ◽  
Site Population

Abstract We studied nine populations of Salamandrina perspicillata for two to nine years and described the life history variation among these population. Despite experiencing similar climatic conditions, populations differed in mean body size: populations using still water bodies for oviposition were larger body-sized than those using brooks. One semi-natural pond was used by particularly small individuals and was probably recently colonised. The mean body size of ovipositing females varied from year to year. Measurements of individuals in successive years showed that the tail grew more than the trunk and this differential growth increased with age. Females did not oviposit every year and, within a given population, the number of ovipositing females varied widely from year to year.

The life history of Diastylis sculpta Sars, 1871 (Crustacea: Cumacea) in Passamaquoddy Bay, New Brunswick

1976 ◽  
Vol 54 (5) ◽  
pp. 615-619 ◽  
Author(s):  
Susan Corey
Keyword(s):  
Life History ◽  
New Brunswick ◽  
Life Span ◽  
Shallow Water ◽  
Maximum Life Span ◽  
Summer Generation ◽  
Passamaquoddy Bay ◽  
History Of ◽  
The Mean ◽  
Gravid Females

Diastylis sculpta was collected from shallow water (1–15 m) in Passamaquoddy Bay over a 26-month period. D. sculpta produces a rapidly growing and developing summer generation between two successive winter generations. The overwintering generation releases young in mid-July and late August. The summer generation releases young in November. The mean fecundity of the summer-gravid females (78.4) is much greater than the mean fecundity (20.0) of the fall-gravid females. The maximum life-span is 5 months and 12 months for members of the summer and winter generations respectively.

Natural history of neuromodulation devices and therapies: a patient-centered survival analysis

2020 ◽  
Vol 132 (5) ◽  
pp. 1385-1391
Author(s):  
Zoe E. Teton ◽  
Daniel Blatt ◽  
Amr AlBakry ◽  
James Obayashi ◽  
Gulsah Ozturk ◽  
...  
Keyword(s):  
Survival Analysis ◽  
Survival Data ◽  
Rapid Development ◽  
Survival Rates ◽  
Therapeutic Benefit ◽  
Patient Centered ◽  
Kaplan Meier ◽  
History Of ◽  
Hardware Failures ◽  
First Time

OBJECTIVEDespite rapid development and expansion of neuromodulation technologies, knowledge about device and/or therapy durability remains limited. The aim of this study was to evaluate the long-term rate of hardware and therapeutic failure of implanted devices for several neuromodulation therapies.METHODSThe authors performed a retrospective analysis of patients’ device and therapy survival data (Kaplan-Meier survival analysis) for deep brain stimulation (DBS), vagus nerve stimulation (VNS), and spinal cord stimulation (SCS) at a single institution (years 1994–2015).RESULTSDuring the study period, 450 patients underwent DBS, 383 VNS, and 128 SCS. For DBS, the 5- and 10-year initial device survival was 87% and 73%, respectively, and therapy survival was 96% and 91%, respectively. For VNS, the 5- and 10-year initial device survival was 90% and 70%, respectively, and therapy survival was 99% and 97%, respectively. For SCS, the 5- and 10-year initial device survival was 50% and 34%, respectively, and therapy survival was 74% and 56%, respectively. The average initial device survival for DBS, VNS, and SCS was 14 years, 14 years, and 8 years while mean therapy survival was 18 years, 18 years, and 12.5 years, respectively.CONCLUSIONSThe authors report, for the first time, comparative device and therapy survival rates out to 15 years for large cohorts of DBS, VNS, and SCS patients. Their results demonstrate higher device and therapy survival rates for DBS and VNS than for SCS. Hardware failures were more common among SCS patients, which may have played a role in the discontinuation of therapy. Higher therapy survival than device survival across all modalities indicates continued therapeutic benefit beyond initial device failures, which is important to emphasize when counseling patients.

Migration distance is a fundamental axis of the slow-fast continuum of life history in boreal birds

The Auk ◽  
2021 ◽  
Author(s):  
Benjamin M Winger ◽  
Teresa M Pegan
Keyword(s):  
Life History ◽  
Survival Rates ◽  
Reproductive Investment ◽  
Seasonal Migration ◽  
Adult Survival ◽  
Vital Rates ◽  
Long Distance ◽  
Migration Distance ◽  
Breeding Grounds ◽  
Survival And Reproduction

Abstract Seasonal migration is intrinsically connected to the balance of survival and reproduction, but whether migratory behavior influences species’ position on the slow-fast continuum of life history is poorly understood. We found that boreal-breeding birds that migrate long distances exhibit higher annual adult survival and lower annual reproductive investment relative to co-distributed boreal species that migrate shorter distances to winter closer to their breeding grounds. Our study uses “vital rates” data on reproductive output and survivorship compiled from the literature for a species assemblage of 45 species of mostly passerine birds. These species breed sympatrically in North American boreal forests but migrate to a diversity of environments for the northern winter. After controlling for body size and phylogeny, migration distance and apparent annual adult survival are positively related across species. Both migration distance and survival are positively correlated with wintering in environments that are warmer, wetter, and greener. At the same time, longer migrations are associated with reduced time spent on the breeding grounds, lower clutch sizes, and lower fecundity (clutch size × maximum number of broods per year). Although seasonal migration is often associated with high mortality, our results suggest that long-distance migration imposes selection pressures that both confer and demand high adult survival rates. That is, owing to the reproductive cost of long-distance migration, this strategy can only persist if balanced by high adult survival. Our study supports the idea that migration evolves to promote survival of species breeding in seasonal environments. In boreal birds, the evolution of the longest migrations yields the highest survival, but at an inherent cost to annual fecundity. Our results therefore reveal migratory distance as a fundamental axis of the slow-fast continuum that predicts, and is inextricable from, the balance of survival and reproduction.

Nutrients in Salmonid Ecosystems: Sustaining Production and Biodiversity

2003 ◽  
Keyword(s):  
Life History ◽  
North America ◽  
Ecosystem Function ◽  
Pacific Salmon ◽  
Life History Stage ◽  
High Productivity ◽  
Life History Stages ◽  
Ecosystem Effects ◽  
Precipitous Decline ◽  
Northwestern North America

<em>Abstract.</em>—Pacific salmon <em>Oncorhynchus </em>spp. are important components of numerous food webs throughout their life history, yet we know very little about the historic and current abundance of these life history stages. We used past cannery records, recent harvest and hatchery records, and salmon life history information drawn from the literature to construct a simple bioregional model of historic and recent salmon abundance at egg, fry, smolt, ocean adult, and spawning stages for five species of Pacific salmon from Alaska to California. We found a historic-to-recent bioregional decline in salmon biomass in all life history stages. Recent salmon egg, fry, smolt, ocean-going adult, and escapement biomass estimates for northwestern North America are 74%, 55%, 59%, 86%, and 35%, respectively, of historic levels. Recent high productivity in Alaskan waters, however, masks a precipitous decline south of Alaska, where recent egg, fry, smolt, ocean-going adult, and escapement biomass levels are 34%, 23%, 50%, 40%, and 15% that of historic levels. Adult production and harvest levels are no longer sufficient measures of salmon management success. Researchers need to quantify and elucidate the ecosystem effects of historic biomass changes in life history stages of Pacific salmon on a watershed basis. Fisheries managers must set and meet specific targets for salmon life history stage abundance—from egg to spawning adult—to restore and maintain ecosystem function.

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