Life-history traits and intra-cohort divergence of clearhead icefish (Protosalanx chinensis), indicating cannibalism increased fitness

Cannibalism is considered one of the causes of intra-cohort size divergence in fish and is usually believed to result in increased fitness in terms of survival and reproduction, but direct evidence of this is lacking. Population demographics of the clearhead icefish (Protosalanx chinensis) from Lake Xingkai (Khanka) were investigated for one year. Size-frequencies exhibited a bimodal distribution from July through January, where the population diverged into an upper and a lower modal group based on size. Stomach content analysis confirmed the occurrence of cannibalism, where fish belonging to the larger, upper modal group preyed upon those of the smaller, lower modal group. We found P. chinensis does not spawn until all of the oocytes have reached maturity and then a single spawning event occurs although the oocytes may develope asynchronously in the ovary. Upper modal group females matured slightly earlier than those of the lower modal group, and reproductive investment was considerably greater in the upper modal group than the lower modal group. The lower modal males made up the majority of the population after the spawning period, which meant they may have few opportunities to participate in reproduction. Therefore, piscivory and cannibalism of P. chinensis appears to have increased fitness of the fish belonging to the upper modal group and greatly reduced the fitness of those belonging to the lower modal group.

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Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

Marine Ecology Progress Series ◽

10.3354/meps13300 ◽

2020 ◽

Vol 650 ◽

pp. 7-18 ◽

Cited By ~ 1

Author(s):

HW Fennie ◽

S Sponaugle ◽

EA Daly ◽

RD Brodeur

Keyword(s):

Life History ◽

Early Life ◽

Life History Traits ◽

Direct Evidence ◽

Coho Salmon ◽

Larval Fish ◽

Early Life History ◽

In The Wild ◽

Otolith Microstructure Analysis ◽

Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

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FEEDING HABITS AND HELMINTH PARASITES OF SARDINE (S. PILCHARDUS) AND ANCHOVY (E. ENCRASICOLUS) IN THE ADRIATIC SEA

Mediterranean Marine Science ◽

10.12681/mms.1467 ◽

2015 ◽

Vol 17 (1) ◽

pp. 216 ◽

Cited By ~ 3

Author(s):

B. ZORICA ◽

V. ČIKES KEČ ◽

O. VIDJAK ◽

I. MLADINEO ◽

D. EZGETA BALIČ

Keyword(s):

Diet Composition ◽

Feeding Habits ◽

Stomach Contents ◽

Stomach Content Analysis ◽

Helminth Parasites ◽

Significant Difference ◽

Prey Composition ◽

One Year ◽

Paratenic Hosts ◽

Hysterothylacium Aduncum

We examined the stomach contents of two of the most economically and ecologically important small pelagic fish species, the sardine, Sardina pilchardus and the anchovy, Engraulis encrasicolus, obtained monthly from commercial purse-seine catches operating on Croatian fishing grounds during a one-year period (January–December, 2011). Both species generally showed a similar diet, with copepod and decapod larvae as dominant prey groups. The composition of anchovy and sardine stomach contents was not size- or sex-related, but throughout the year, a significant difference in diet composition was observed for each species as well as between species. Two gastrointerstinal helminths; the digenean Parahemiurus merus and nematode Hysterothylacium aduncum, were recorded during the stomach content analysis. Differences in population dynamics between the two parasites are congruent with differences in the prey composition of sardine and anchovy, reflecting fine-tuned interactions in the trophic web between parasites and intermediate or paratenic hosts included in the sardine and anchovy diet.

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Patterns of benzodiazepine use in a Canadian population sample

Epidemiologia e Psichiatria Sociale ◽

10.1017/s1121189x00000531 ◽

2009 ◽

Vol 18 (3) ◽

pp. 248-254 ◽

Cited By ~ 14

Author(s):

Eleonora Esposito ◽

Corrado Barbui ◽

Scott B. Patten

Keyword(s):

Survey Methods ◽

Population Sample ◽

Population Level ◽

Diagnostic Interview ◽

Computer Assisted ◽

Population Demographics ◽

Canadian Population ◽

Benzodiazepine Use ◽

One Year ◽

Reasons For Use

SUMMARYAim – The objective of this study was to identify clinical and demographic factors that may be associated with benzodiazepine treatment, to describe the reported reasons for use of these medications and to appraise the pattern of use in relation to standard guidelines in a general population sample. Methods – Telephone survey methods were employed to select a sample of 3345 people between the ages of 18 and 64. A computer assisted telephone interview, including the Mini Neuropsychiatric Diagnostic Interview (MINI), was administered. Estimates were weighted for design features and population demographics. Results – The overall prevalence of benzodiazepines use was 3.3% (95% confidence interval [CI] 2.6 to 4.1%). There was a higher frequency of medication use in women than men, among respondents who were widowed, separated or divorced, and those with lower levels of education. In relation to MINI diagnosis, diagnoses of Panic Disorder and Major Depression increased the probability of taking benzodiazepines. The reported main reason for use was “Sleep disorders” (68.9%), “Anxiety” (35.8%), “Depression” (27.8%) and “Pain management” (21.2%). More than 80% of subjects were taking benzodiazepines for more than one year. Conclusions – When compared to previous estimates, the lower frequency of benzodiazepines use suggests that there has been improvement in their evidence-based use at a population level. However our results once more confirm the difficulty stopping the use of these medications once they have been started. Further randomized control studies may help clinicians in having a better practical approach to rational benzodiazepine use.Declaration of Interest: None.

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Habitat use and population structure of the invasive red swamp crayfish Procambarus clarkii (Girard, 1852) in a protected area in northern Italy

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2018002 ◽

2018 ◽

pp. 12 ◽

Cited By ~ 3

Author(s):

Roberta Donato ◽

Marta Rollandin ◽

Livio Favaro ◽

Alessio Ferrarese ◽

Daniela Pessani ◽

...

Keyword(s):

Riparian Vegetation ◽

Life History Traits ◽

Invasive Alien Species ◽

Procambarus Clarkii ◽

Condition Index ◽

Sampling Effort ◽

Red Swamp Crayfish ◽

Crayfish Population ◽

One Year ◽

First Time

The red swamp crayfish Procambarus clarkii is one of the most invasive alien species in Europe and included in the list of invasive species of Union concern. We describe for the first time some life-history traits of a red swamp crayfish population in the Nature Reserve of the Lago di Candia (Italy). We investigated (1) preferences of this species for specific environmental features on the banks of the lake, and (2) differences in size, sex ratio, and condition index between individuals caught in lake and marsh. Moreover, we compared sampling effort and the features of individuals caught in the lake, for two sampling seasons in 2014 and 2015. Findings indicated that the population was well established, and the marsh seemed to have better conditions for growth of individuals than the lake. Accordingly, continuity of riparian vegetation, opportunity to dig burrows, and trophic resource availability seems to facilitate the proliferation of the crayfish in the lake. Our study demonstrated that massive removal efforts over the whole active period of the species and more than one year of trapping are necessary to increase the controlling activities' success. This study could have important implications for further population management projects directed at biodiversity conservation in the area.

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The Life History and Post Embryonic Development of the Copepods, Calanus tonsus Brady and Euchaeta japonica Marukawa

Journal of the Biological Board of Canada ◽

10.1139/f34-001 ◽

1934 ◽

Vol 1 (1) ◽

pp. 1-65 ◽

Cited By ~ 22

Author(s):

Mildred H. Campbell

Keyword(s):

Life History ◽

Deep Water ◽

Reproductive Period ◽

Spawning Period ◽

Strait Of Georgia ◽

Deep Water Species ◽

One Year ◽

Development Proceeds ◽

Water Species ◽

Reserve Food

Calanus tonsus Brady is an abundant, deep water species in the strait of Georgia. Development is characterized by a distinct metamorphosis and the six nauplius and six copepodid stages are described. The life cycle extends over one year and breeding occurs in the spring at the surface. The nauplii and early copepodid stages are soon replaced by stage V which dominates the plankton from May to December. C. tonsus exists as an adult for approximately two months—January and February. Maturity is accompanied by marked degeneration of the mouth parts in both sexes, death following shortly. The retrograde development appears associated with a change in habits. Stage V stores up reserve food, and the mature females with the disappearance of feeding devices depend upon this accumulated food during the reproductive period. Euchaeta japonica Marukawa occurs in limited numbers in the deep water of the strait of Georgia. It undergoes a similar metamorphosis to C. tonsus and the twelve stages are described. There is no definite spawning period but reproduction occurs throughout the year in deep water where development proceeds. Several broods may be produced by one female but the males are believed to die shortly after copulation. The nauplii differ from those of C. tonsus due to larger size, slight increase in length from stage I to stage VI and retarded development of the appendages. The conspicuous feature of the copepodid development is the extreme degeneration of the male mouth parts.

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Cold shock induces a terminal investment reproductive response in C. elegans

10.1101/2021.09.11.459896 ◽

2021 ◽

Author(s):

Leah Gulyas ◽

Jennifer R. Powell

Keyword(s):

Life History Traits ◽

Cold Shock ◽

Reproductive Investment ◽

Environmental Stressors ◽

Offspring Survival ◽

Future Studies ◽

Terminal Investment ◽

C Elegans ◽

Reproductive Response ◽

Maternal Provisioning

AbstractChallenges from environmental stressors have a profound impact on many life-history traits of an organism, including reproductive strategy. Examples across multiple taxa have demonstrated that maternal reproductive investment resulting from stress can improve offspring survival; a form of matricidal provisioning when death appears imminent is known as terminal investment. Here we report a reproductive response in the nematode Caenorhabditis elegans upon exposure to acute cold shock at 2°C, whereby vitellogenic lipid movement from the soma to the germline appears to be massively upregulated at the expense of parental survival. This response is dependent on functional TAX-2;TAX-4 cGMP-gated channels that are part of canonical thermosensory mechanisms in worms and can be prevented in the presence of activated SKN-1/Nrf2, the master stress regulator. Increased maternal provisioning promotes improved embryonic cold shock survival, which is notably suppressed in animals with impaired vitellogenesis. These findings suggest that cold shock in C. elegans triggers terminal investment to promote progeny fitness at the expense of parental survival and may serve as a tractable model for future studies of stress-induced progeny plasticity.

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Echoes of the hunt? An inter-continental comparison of patterns of growth and determinants of size of brown bears in Canada and Sweden.

10.22541/au.164141260.00031935/v1 ◽

2022 ◽

Author(s):

Andreas Zedrosser ◽

Marc CAttet ◽

Jon Swenson ◽

Gordon Stenhouse

Keyword(s):

Population Density ◽

Body Length ◽

Life Histories ◽

Life History Traits ◽

Reproductive Investment ◽

Negative Effects ◽

Brown Bears ◽

Positive Effects ◽

The Past ◽

The Difference

Comparing life history traits among populations that have been separated genetically for several hundred thousand years, but live in similar habitats on different continents, may help us understand how ecological and anthropomorphic factors shape life histories. We compared patterns of growth in body length and mass, and the influence of population density, habitat quality (NDVI), and reproduction on age-specific length and mass of male and female brown bears between Alberta, Canada, and Sweden. We found that Swedish females were significantly smaller in both length and mass than Alberta females. Swedish females also reached primiparity earlier and at a smaller mass and length. However, there were no continental differences in the patterns of growth in males. We found strong positive effects of NDVI, but only weak negative effects of population density on female mass and length in both areas. Generally, especially mass of Alberta females was more strongly affected by NDVI and density than for Swedish females. Reproduction had stronger negative effects on female mass in Alberta than in Sweden. We found no effects of NDVI and population density on male mass and body length in both areas. The larger variation in female growth and size between the areas, in contrast to males, may be related to differences in female reproductive investment due to differences in population trends, i.e., earlier reproduction in increasing populations or populations below carrying capacity, or to different selection pressures in the past, potentially due to human persecution. Swedish females exhibited characteristics typical of increasing populations, whereas Alberta females exhibited characteristics typical of stable or decreasing populations. The difference in reproduction investment means that Swedish bears can be harvested at higher rates, whereas Alberta bears must be managed more conservatively.

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Plasticity in life history traits of a cyprinid fish in an intermittent river

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2019015 ◽

2019 ◽

pp. 25 ◽

Cited By ~ 1

Author(s):

Maria Glarou ◽

Aikaterini Vourka ◽

Leonidas Vardakas ◽

Argyro Andriopoulou ◽

Nikolaos Skoulikidis ◽

...

Keyword(s):

Life History Traits ◽

Prey Availability ◽

Reproductive Investment ◽

Liver Weight ◽

Reproductive Period ◽

The Body ◽

Feeding Intensity ◽

Intermittent Rivers ◽

Flooding And Drying ◽

Intermittent River

The extreme seasonal environmental variation of intermittent rivers has a profound effect on freshwater fish communities. Yet, few studies have examined the consequences of the seasonal cycles of flooding and drying to fish condition and reproduction in these ecosystems. In this study, we compared the body condition, reproduction and diet of two chub populations from two adjacent sites (a perennial and an intermittent site) on the main stem of a Mediterranean river (Evrotas River, S. Greece). The study was conducted in spring 2017, three months after flow resumption and before the onset of chub reproductive period. Condition (net weight adjusted for length) of fish did not differ significantly between the two sites, despite lower aquatic macroinvertebrate availability at the intermittent site. Fish at the intermittent site compensated for the lower aquatic prey availability by increasing their feeding intensity and by shifting to higher terrestrial prey consumption. In addition, chub liver weight (adjusted for length) and gonadal weight (adjusted for length) were significantly higher at the intermittent site, indicating higher somatic and reproductive investment. These results highlight the resilience of fish populations inhabiting streams with extreme variation in flow, due to natural and/or anthropogenic drought.

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

The Auk ◽

10.1093/ornithology/ukab043 ◽

2021 ◽

Cited By ~ 1

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.

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A “Population Dynamics” Perspective on the Delayed Life-History Effects of Environmental Contaminations: An Illustration with a Preliminary Study of Cadmium Transgenerational Effects over Three Generations in the Crustacean Gammarus

International Journal of Molecular Sciences ◽

10.3390/ijms21134704 ◽

2020 ◽

Vol 21 (13) ◽

pp. 4704

Author(s):

Pauline Cribiu ◽

Alain Devaux ◽

Laura Garnero ◽

Khédidja Abbaci ◽

Thérèse Bastide ◽

...

Keyword(s):

Life History ◽

Life History Traits ◽

Egg Yolk ◽

Transgenerational Effects ◽

Cascading Effects ◽

Delayed Effects ◽

Parental Exposure ◽

History Effects ◽

Freshwater Crustacean ◽

One Year

We explore the delayed consequences of parental exposure to environmentally relevant cadmium concentrations on the life-history traits throughout generations of the freshwater crustacean Gammarus fossarum. We report the preliminary results obtained during a challenging one-year laboratory experiment in this environmental species and propose the use of population modeling to interpret the changes in offspring life-history traits regarding their potential demographic impacts. The main outcome of this first long-term transgenerational assay is that the exposure of spawners during a single gametogenesis cycle (3 weeks) could result in severe cascading effects on the life-history traits along three unexposed offspring generations (one year). Indeed, we observed a decrease in F1 reproductive success, an early onset of F2 offspring puberty with reduced investment in egg yolk reserves, and finally a decrease in the growth rate of F3 juveniles. However, the analysis of these major transgenerational effects by means of a Lefkovitch matrix population model revealed only weak demographic impacts. Population compensatory processes mitigating the demographic consequences of parental exposure seem to drive the modification of life-history traits in offspring generations. This exploratory study sheds light on the role of population mechanisms involved in the demographic regulation of the delayed effects of environmental toxicity in wild populations.

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