scholarly journals Differing Life-History Strategies of Two Mycoheterotrophic Orchid Species Associated with Leaf Litter- and Wood-Decaying Fungi

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 161
Author(s):  
Yuki Ogura-Tsujita ◽  
Kenshi Tetsuka ◽  
Shuichiro Tagane ◽  
Miho Kubota ◽  
Shuichiro Anan ◽  
...  
Keyword(s):  
Life History ◽  
Leaf Litter ◽  
Mycorrhizal Fungi ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Small Scale ◽  
Nutrient Depletion ◽  
Saprotrophic Fungi ◽  
Orchid Species ◽  
Mycoheterotrophic Plants

Mycoheterotrophic orchids depend completely on mycorrhizal fungi for their supply of carbon. The life-history traits of mycoheterotrophic plants (MHPs) can differ according to the characteristics of the associated mycorrhizal fungi. We compared the life-history strategies of two mycoheterotrophic orchids associated with wood- and leaf litter-decaying fungi over a maximum of six years of field monitoring. Seventy percent of the aboveground stems of Erythrorchis altissima, associated with wood-decaying fungi, disappeared from the host wood within two years after tagging, likely due to nutrient depletion. In contrast, Gastrodia confusa, associated with leaf litter-decaying fungi, occurred continuously (18 to 108 fruiting stalks) every year within a small-scale plot (12 × 45 m) for six years through seed and clonal propagation. Our results support the idea that mycoheterotrophic orchids associated with wood-decaying fungi disappear from their habitats due to nutrient depletion after their host wood has mostly decayed, while mycoheterotrophic orchids associated with leaf litter-decaying fungi can survive in small-scale habitats where substantial leaf fall regularly occurs to sustain the associated fungi. Our study provides basic information about a unique life-history strategy in MHPs associated with saprotrophic fungi and an understanding of the variation in life-history strategies among MHPs.

scholarly journals Homo- and Dikaryons of the Arbuscular Mycorrhizal Fungus Rhizophagus irregularis Differ in Life History Strategy

2021 ◽  
Vol 12 ◽  
Author(s):  
Edward Umberto Serghi ◽  
Vasilis Kokkoris ◽  
Calvin Cornell ◽  
Jeremy Dettman ◽  
Franck Stefani ◽  
...  
Keyword(s):  
Life History ◽  
Mycorrhizal Fungi ◽  
Life History Traits ◽  
Mycorrhizal Fungus ◽  
Life History Strategy ◽  
Arbuscular Mycorrhizal ◽  
Rhizophagus Irregularis ◽  
Life History Strategies ◽  
Organ Cultures ◽  
Symbiotic Functioning

Arbuscular mycorrhizal fungi (AMF) are obligate plant symbionts that have the potential to improve crop yield. These multinucleate organisms are either “homokaryotic” or “dikaryotic”. In AMF dikaryons, thousands of nuclei originating from two parental strains coexist in the same cytoplasm. In other fungi, homokaryotic and dikaryotic strains show distinct life history traits (LHTs), such as variation in growth rates and fitness. However, how such traits compare between dikaryons and homokaryons of AMF is unknown. To address this, we measured 20 LHT of four dikaryons and five homokaryons of the model fungus Rhizophagus irregularis across root organ cultures of three host plants (carrot, chicory, and tobacco). Our analyses show that dikaryons have clearly distinct life history strategies (LHSs) compared to homokaryons. In particular, spores of homokaryons germinate faster and to a higher proportion than dikaryons, whereas dikaryons grow significantly faster and create a more complex hyphal network irrespective of host plant species. Our study links AMF nuclear status with key LHT with possible implications for mycorrhizal symbiotic functioning.

scholarly journals Evolutionary histories and mycorrhizal associations of mycoheterotrophic plants dependent on saprotrophic fungi

2021 ◽  
Author(s):  
Yuki Ogura-Tsujita ◽  
Tomohisa Yukawa ◽  
Akihiko Kinoshita
Keyword(s):  
Leaf Litter ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Fungal Species ◽  
Mycorrhizal Symbiosis ◽  
Free Living ◽  
Saprotrophic Fungi ◽  
Culture Systems ◽  
Ecm Fungi ◽  
Mycoheterotrophic Plants

AbstractMycoheterotrophic plants (MHPs) are leafless, achlorophyllous, and completely dependent on mycorrhizal fungi for their carbon supply. Mycorrhizal symbiosis is a mutualistic association with fungi that is undertaken by the majority of land plants, but mycoheterotrophy represents a breakdown of this mutualism in that plants parasitize fungi. Most MHPs are associated with fungi that are mycorrhizal with autotrophic plants, such as arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. Although these MHPs gain carbon via the common mycorrhizal network that links the surrounding autotrophic plants, some mycoheterotrophic lineages are associated with saprotrophic (SAP) fungi, which are free-living and decompose leaf litter and wood materials. Such MHPs are dependent on the forest carbon cycle, which involves the decomposition of wood debris and leaf litter, and have a unique biology and evolutionary history. MHPs associated with SAP fungi (SAP-MHPs) have to date been found only in the Orchidaceae and likely evolved independently at least nine times within that family. Phylogenetically divergent SAP Basidiomycota, mostly Agaricales but also Hymenochaetales, Polyporales, and others, are involved in mycoheterotrophy. The fungal specificity of SAP-MHPs varies from a highly specific association with a single fungal species to a broad range of interactions with multiple fungal orders. Establishment of symbiotic culture systems is indispensable for understanding the mechanisms underlying plant–fungus interactions and the conservation of MHPs. Symbiotic culture systems have been established for many SAP-MHP species as a pure culture of free-living SAP fungi is easier than that of biotrophic AM or ECM fungi. Culturable SAP-MHPs are useful research materials and will contribute to the advancement of plant science.

Effect of time of day, time of year, and life history strategy on time budgeting in juvenile Atlantic salmon, Salmo salar

1999 ◽  
Vol 56 (12) ◽  
pp. 2397-2403 ◽  
Author(s):  
Sveinn K Valdimarsson ◽  
Neil B Metcalfe
Keyword(s):  
Life History ◽  
Atlantic Salmon ◽  
Salmo Salar ◽  
Life History Strategy ◽  
Time Of Day ◽  
Life History Strategies ◽  
Foraging Efficiency ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Time Of Year

Traditionally, behavioural studies on juvenile Atlantic salmon, Salmo salar, have been conducted during the day in summer. It is known that Atlantic salmon become nocturnal in winter, but very little is known about their behaviour at that time. Therefore, observations in a seminatural stream were carried out during the day and night, from February to June, comparing diel and seasonal differences in behaviour between fish adopting alternative life history strategies. The results showed a general trend for more activity in spring than in winter, and the fish were found to be foraging at surprisingly low light levels. There were differences in relative feeding rate between the life history strategies; the early migrant fish foraged mostly during the day whereas the delayed migrant fish did more foraging at night. There is some evidence that the early migrant fish made fewer feeding attempts over the winter, which is surprising, since they grow faster over that period. This suggests differences in foraging efficiency, which could contribute to the separation into these two life history strategies.

Life History Strategies

2018 ◽  
pp. 95-126
Author(s):  
Marco Del Giudice
Keyword(s):  
Life History ◽  
Individual Differences ◽  
Life History Theory ◽  
Human Life ◽  
Life History Strategy ◽  
Current Theory ◽  
Life History Strategies ◽  
Extended Model ◽  
Life History Variation ◽  
Basic Model

The chapter introduces the basics of life history theory, the concept of life history strategy, and the fast–slow continuum of variation. After reviewing applications to animal behavior and physiology, the chapter reviews current theory and evidence on individual differences in humans as manifestations of alternative life history strategies. The chapter first presents a “basic model” of human life history–related traits, then advances an “extended model” that identifies multiple cognitive-behavioral profiles within fast and slow strategies. Specifically, it is proposed that slow strategies comprise prosocial/caregiving and skilled/provisioning profiles, whereas fast strategies comprise antisocial/exploitative and seductive/creative profiles. The chapter also reviews potential neurobiological markers of life history variation and considers key methodological issues in this area.

scholarly journals RETRACTED ARTICLE: Novel life history strategy in a deep sea fish challenges assumptions about reproduction in extreme environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Randal A. Singer ◽  
Jon A. Moore ◽  
Edward L. Stanley
Keyword(s):  
Life History ◽  
Deep Sea ◽  
Extreme Environments ◽  
Life History Strategy ◽  
Deep Ocean ◽  
Homogeneous System ◽  
Life History Strategies ◽  
Life History Trait ◽  
Retracted Article ◽  
Sea Fish

Abstract The deep ocean is frequently assumed to be a homogeneous system lacking the same diverse life history strategies found in shallower waters. However, as our methods for exploring the deep ocean improve, common assumptions about dispersal, reproduction and behavior are constantly being challenged. Fishes exhibit the most diverse reproductive strategies among vertebrates. Understanding life history strategies in deep-sea environments is lacking for many species of fishes. Here, we report a novel reproductive strategy where a fish (Parazen pacificus) provides parental care via mouth brooding. This behavior is observed from a specimen collected with eggs present in the buccal cavity, along with other specimens exhibiting pre-brooding morphologies. This is the first description of this unique life history trait in a deep-sea fish and fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.

scholarly journals Reproductive strategy of common dentex Dentex dentex: management implications

2016 ◽  
Vol 17 (2) ◽  
pp. 552 ◽  
Author(s):  
A. GRAU ◽  
F. SABORIDO-REY ◽  
E. PASTOR ◽  
M. PALMER ◽  
E. MASSUTÍ-PASCUAL ◽  
...  
Keyword(s):  
Sex Differences ◽  
Life History ◽  
Reproductive Strategy ◽  
Egg Production ◽  
Gonadosomatic Index ◽  
Life History Strategy ◽  
Minimum Size ◽  
Small Scale ◽  
Female Size ◽  
Dentex Dentex

Common dentex Dentex dentex is an iconic endangered species in the Mediterranean where is a sought after target species for small-scale, recreational and spearfishing fisheries. The reproductive biology of D. dentex in the natural environment is poorly known; therefore the reproductive strategy of the species was assessed by combining reproductive traits with the growth characteristics (estimated from length-at-age data), the size/age of sexual maturity and the energetic dynamics. A total of 358 wild fish were sampled on Mallorca Island (W Mediterranean) from March 1996 to June 1999 with a 19 to 84.7 cm total length (LT) range. The sex ratio was skewed towards females (1.361) albeit the length composition was not different between sexes (p = 0.551). Three young immature individuals (< 28 cm LT, 0.8% individuals) were rudimentary hermaphrodites supporting the late gonochoristic species classification. The age composition determined from sagitta otolith interpretation ranged from 0 to 26 years (yr). Concerning growth, between sex differences in von Bertalanffy parameters were not relevant, even after accounting for potential between-year differences. The most noticeable difference was found for L∞ (64.7 cm for females versus 61.6 for males) but even in this case, the bayesian credibility interval of between-sex differences included zero.  Maturity ogives at size and age showed that females achieved 50% maturity at 34.9 cm LT and 3.3 years, while males did at 33.8 cm LT and 2.5 years. The onset of gonad developing phase took place in December, while it progresses until April. The spawning peak was in April and May for both sexes. A generalized linear model showed that female size didn’t affect significantly the spawning season, whilst there was a strong seasonality in the spawning. Most of the evidences showed that fecundity is likely determinate, with an asynchronous oocyte development before spawning and a clear ovarian bimodal organization after the onset of spawning. Female weight explained 84% of the observed variance for fecundity. The gonadosomatic, hepatosomatic and condition indexes varied significantly with the reproductive season for females and only the gonadosomatic index for males. Storage in muscle seemed to be the primary source of energy for reproduction, although liver appeared to play a short-term role in egg production, suggesting a combination of capital and income breeding. The results indicate that the life history strategy of common dentex possess consist on maturing well before reaching maximum size, investing in growth after maturation, and therefore the reproductive effort is distributed through a longer lifespan and related with the size attained after maturation. At present no management measures are directed to D. dentex; given its life history strategy we suggest that a slot limit should be implemented, i.e. a minimum and a maximum landing size, with a minimum size of 35 cm. The upper threshold, to protect the higher reproductive potential of older and larger fish, should still be defined.

Leadership in dangerous times: Life-history strategy and environmental condition affect preferences for dominant and prestigious leaders

2020 ◽  
Author(s):  
Nan Zhu ◽  
Binbin Chen ◽  
Lei Chang
Keyword(s):  
Life History ◽  
Implicit Association Test ◽  
Life History Strategy ◽  
Relative Strength ◽  
Life History Strategies ◽  
Implicit Association ◽  
Leadership Qualities ◽  
Social Hierarchies ◽  
Strategy Study ◽  
Leadership Preferences

Dominance and prestige, as two distinct status-attaining qualities, are present in modern-day leaders at various levels of social hierarchies to various degrees. From an evolutionary perspective, we speculate that such leadership qualities are implicitly linked to the leadership preferences of followers in the environments where they are more effective or necessary. Moreover, individuals’ life-history strategy might moderate the effect of some contextual factors, such as environmental danger, on leadership preferences of dominant versus prestigious leaders. Three studies tested these hypotheses. In two implicit association test (IAT) experiments, we found that (1) participants implicitly associated danger with dominance, and safety with prestige (Study 1a, N = 32); (2) the relative strength of the implicit association between positive evaluation and prestige is positively correlated with participants’ slow life-history strategy (Study 1b, N = 67). In a third experiment (Study 2, N = 95), self-reported life-history strategy also moderated the effects of experimentally manipulated danger on leadership preferences. The association between dangerous environments and dominant leadership preference was stronger for participants with fast life-history strategies than those with slow life-history strategies.

Physiological Characterization of Hatchery-Origin Juvenile Steelhead Oncorhynchus mykiss Adopting Divergent Life-History Strategies

2011 ◽  
Vol 2 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Kyle C. Hanson ◽  
William L. Gale ◽  
William G. Simpson ◽  
Benjamen M. Kennedy ◽  
Kenneth G. Ostrand
Keyword(s):  
Life History ◽  
Fresh Water ◽  
Gonadosomatic Index ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Migratory Fish ◽  
Physiological Characterization ◽  
Subunit Expression ◽  
Mature Fish

Abstract Smoltification by juvenile Pacific salmonids has been described as a developmental conflict whereby individuals face several life-history decisions. Smoltification occurs as a result of interactions between organismal condition and environmental cues, although some fish may forgo ocean migration and remain in freshwater streams for some time (residualize). We compared the physiological profiles of steelhead that were actively migrating to the ocean (migratory fish) and those that remained in fresh water (residuals) for at least a period of between 2 wk and 3 mo after release from a hatchery facility. In addition, we investigated the physiological characterization of residuals that further differentiated into precocial freshwater residents or parr that will either precocially mature in fresh water or migrate to the ocean in the future. Residuals had higher condition factors and gonadosomatic index than migratory fish and were characterized as less prepared for saltwater due to low levels of gill Na+,K+-ATPase activity and Na+,K+-ATPase α1b-subunit expression. Residuals tended to be males with the highest condition factors. Sex-specific differences are probably reflective of male fish adopting an alternative life-history strategy foregoing outmigration as a result of condition at the time of release. Collection of residuals throughout the fall suggested that residual hatchery fish further diversify into precocially mature fish that will presumably attempt to spawn without ever migrating to the ocean or into parr that will precocially mature or migrate in a future year.

Trait-Based Approach to Fish Ecology

2019 ◽  
pp. 150-160
Author(s):  
Ken H. Andersen
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Life History Strategy ◽  
Somatic Growth ◽  
Population Level ◽  
Historical Background ◽  
Life History Strategies ◽  
Asymptotic Size ◽  
Current State ◽  
Investment In Reproduction

This chapter proposes a shortlist of fish “master” traits and connects these traits to classic life-history strategy thinking. First, it sets the historical background for the current state-of-the-art thinking about fish life history strategies. From there, the chapter explains that the main axes of variation between fish species can be captured by three traits: the asymptotic size; the growth rate coefficient; and the adult–offspring mass ratio strategy. Together, these three traits determine the central demographic parameters: somatic growth rate, investment in reproduction, age at maturation, survival to maturation, mortality, and so on, and from there follows population-level quantities like population growth rate, population structure, fitness, and selection responses. The chapter concludes with a reflection on the trait-based approach and compares it to other methods of assessment.

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