Relationship between larval and juvenile growth rates in two marine gastropods, Crepidula plana and C. fornicata

1996 ◽  
Vol 125 (1) ◽  
pp. 119-127 ◽  
Author(s):  
J. A. Pechenik ◽  
T. J. Hilbish ◽  
L. S. Eyster ◽  
D. Marshall
Keyword(s):  
Growth Rates ◽  
Juvenile Growth ◽  
Marine Gastropods

Factors influencing growth of juvenile spruce grouse

1981 ◽  
Vol 59 (9) ◽  
pp. 1790-1795 ◽  
Author(s):  
Norman W. S. Quinn ◽  
Daniel M. Keppie
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
New Brunswick ◽  
Growth Rates ◽  
Egg Laying ◽  
Maternal Influence ◽  
Juvenile Growth ◽  
Factors Influencing ◽  
Differential Timing

The influences of date of hatch, and age and prelaying body weight of brood female on the growth rate of juvenile spruce grouse (Canachites canadensis) were studied in central New Brunswick in 1977 and 1978. Because of differential timing of hatch of broods of adult and yearling females, it was not clear whether a difference in juvenile growth rates during 5–14 days of age in 1977 was related to date of hatch, age of brood female, or both. Differences in juvenile growth rates within and between years apparently were not influenced by body weight of brood females prior to egg laying. Results suggest that posthatch factors are more important in determining growth rate than a prehatch or "maternal" influence.

scholarly journals Environmental and Life-history Factors Influencing  Juvenile Demography of a Temperate Reef Fish

2021 ◽  
Author(s):  
◽  
Anna Clare Smith
Keyword(s):  
Growth Rate ◽  
Reef Fish ◽  
Growth Rates ◽  
Juvenile Growth ◽  
Growth And Survival ◽  
Temperate Reef ◽  
Habitat Composition ◽  
Temperate Reef Fish ◽  
Rates Of Growth ◽  
Larval Traits

<p>Realistic population models and effective conservation strategies require a thorough understanding of the processes that drive variation in individual growth and survival, particularly within life stages that are subject to high mortality. For fragmented marine populations it is also important to consider how processes driving variation performance may vary through space and time. In this study I assess the interaction of two primary factors driving juvenile demography: benthic habitat composition and larval history traits, in a temperate reef fish, Forsterygion lapillum (the common triplefin). It is well understood that juveniles of many marine organisms are closely associated with structured nearshore habitats as they provide resources (refuge and food sources) that are critical for juvenile growth and/or survival. Nursery habitats are often assessed using measures of fitness of juveniles inhabiting them (e.g. rates of growth). However individual fitness measures may not only be indicative of conditions experienced in the benthic phase, but also an individual's prior history. Recent evidence suggests that variation in larval traits at settlement (e.g., size and age at settlement, larval growth rate) can impact on subsequent ecological performance (e.g., feeding ability and/or predator avoidance) and therefore influence subsequent fitness (i.e. rates of growth and/or probabilities of survival). I used otolith microstructure to assess separate and joint effects of habitat composition and larval traits on the growth of young F. lapillum. Both macroalgal composition of habitat patches and larval traits affected juvenile growth rates, and results suggested that habitat composition may have the potential to mediate fitness-related advantages that may accrue to certain individuals as a result of paternal effects and/or larval dispersal history. Quantifying spatio-temporal variability in the post-settlement fitness of Individuals with that differ in larval traits is essential for effective spatial management of marine populations. I further explore the joint effects of macroalgal composition and larval traits, within the context of additional spatial and temporal environmental variation. Results provide direct evidence that habitat can mediate the strength of carryover effects, but that the impact of habitat was variable between local populations and settlement events through time. In chapter 4 of my thesis, I focus on how small-scale variation in macroalgal composition within a nursery habitat (while controlling for individual variation) can affect the strength of density dependent growth and survival rates of F. lapillum. Density-dependent survival is evident during the first 30 days after settlement, and the strength of density dependence varied as a function of macroalgal composition. Resulting variation in estimates of nursery value (i.e., the number of late-stage juveniles produced per area unit of habitat) highlight the importance of incorporating local scale variation in juvenile demography into assessments of nursery habitat. Lastly, I assess a potential strategy of fishes to persist in a wide range of benthic environments. The ability to adjust traits (i.e., phenotypic plasticity) may allow organisms that encounter a range of unpredictable environmental conditions to maximise fitness within a single generation. In chapter 5 I explore patterns of variation in morphology of juvenile F. lapillum from two different subpopulations and from different macroalgal habitats. I evaluate possible evidence for constraints on morphological variation arising from variation in growth rate prior to and following settlement. Results suggest that for organisms with complex life cycles, variation in growth rates experienced during dispersal may constrain plasticity in later stages.</p>

scholarly journals Recent warming reduces the reproductive advantage of large size and contributes to evolutionary downsizing in nature

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200608 ◽  
Author(s):  
David C. Fryxell ◽  
Alexander N. Hoover ◽  
Daniel A. Alvarez ◽  
Finn J. Arnesen ◽  
Javiera N. Benavente ◽  
...  
Keyword(s):  
Body Size ◽  
Growth Rates ◽  
Rapid Evolution ◽  
Functional Trait ◽  
Common Source ◽  
Juvenile Growth ◽  
Thermal Environments ◽  
Large Size ◽  
Source Populations ◽  
Warming World

Body size is a key functional trait that is predicted to decline under warming. Warming is known to cause size declines via phenotypic plasticity, but evolutionary responses of body size to warming are poorly understood. To test for warming-induced evolutionary responses of body size and growth rates, we used populations of mosquitofish ( Gambusia affinis ) recently established (less than 100 years) from a common source across a strong thermal gradient (19–33°C) created by geothermal springs. Each spring is remarkably stable in temperature and is virtually closed to gene flow from other thermal environments. Field surveys show that with increasing site temperature, body size distributions become smaller and the reproductive advantage of larger body size decreases. After common rearing to reveal recently evolved trait differences, warmer-source populations expressed slowed juvenile growth rates and increased reproductive effort at small sizes. These results are consistent with an adaptive basis of the plastic temperature–size rule, and they suggest that temperature itself can drive the evolution of countergradient variation in growth rates. The rapid evolution of reduced juvenile growth rates and greater reproduction at a small size should contribute to substantial body downsizing in populations, with implications for population dynamics and for ecosystems in a warming world.

Tropical tree rings reveal preferential survival of fast-growing juveniles and increased juvenile growth rates over time

2009 ◽  
Vol 185 (3) ◽  
pp. 759-769 ◽  
Author(s):  
Danaë M. A. Rozendaal ◽  
Roel J. W. Brienen ◽  
Claudia C. Soliz-Gamboa ◽  
Pieter A. Zuidema
Keyword(s):  
Tree Rings ◽  
Growth Rates ◽  
Tropical Tree ◽  
Juvenile Growth ◽  
Fast Growing ◽  
Over Time

scholarly journals Environmental and Life-history Factors Influencing  Juvenile Demography of a Temperate Reef Fish

2021 ◽  
Author(s):  
◽  
Anna Clare Smith
Keyword(s):  
Growth Rate ◽  
Reef Fish ◽  
Growth Rates ◽  
Juvenile Growth ◽  
Growth And Survival ◽  
Temperate Reef ◽  
Habitat Composition ◽  
Temperate Reef Fish ◽  
Rates Of Growth ◽  
Larval Traits

<p>Realistic population models and effective conservation strategies require a thorough understanding of the processes that drive variation in individual growth and survival, particularly within life stages that are subject to high mortality. For fragmented marine populations it is also important to consider how processes driving variation performance may vary through space and time. In this study I assess the interaction of two primary factors driving juvenile demography: benthic habitat composition and larval history traits, in a temperate reef fish, Forsterygion lapillum (the common triplefin). It is well understood that juveniles of many marine organisms are closely associated with structured nearshore habitats as they provide resources (refuge and food sources) that are critical for juvenile growth and/or survival. Nursery habitats are often assessed using measures of fitness of juveniles inhabiting them (e.g. rates of growth). However individual fitness measures may not only be indicative of conditions experienced in the benthic phase, but also an individual's prior history. Recent evidence suggests that variation in larval traits at settlement (e.g., size and age at settlement, larval growth rate) can impact on subsequent ecological performance (e.g., feeding ability and/or predator avoidance) and therefore influence subsequent fitness (i.e. rates of growth and/or probabilities of survival). I used otolith microstructure to assess separate and joint effects of habitat composition and larval traits on the growth of young F. lapillum. Both macroalgal composition of habitat patches and larval traits affected juvenile growth rates, and results suggested that habitat composition may have the potential to mediate fitness-related advantages that may accrue to certain individuals as a result of paternal effects and/or larval dispersal history. Quantifying spatio-temporal variability in the post-settlement fitness of Individuals with that differ in larval traits is essential for effective spatial management of marine populations. I further explore the joint effects of macroalgal composition and larval traits, within the context of additional spatial and temporal environmental variation. Results provide direct evidence that habitat can mediate the strength of carryover effects, but that the impact of habitat was variable between local populations and settlement events through time. In chapter 4 of my thesis, I focus on how small-scale variation in macroalgal composition within a nursery habitat (while controlling for individual variation) can affect the strength of density dependent growth and survival rates of F. lapillum. Density-dependent survival is evident during the first 30 days after settlement, and the strength of density dependence varied as a function of macroalgal composition. Resulting variation in estimates of nursery value (i.e., the number of late-stage juveniles produced per area unit of habitat) highlight the importance of incorporating local scale variation in juvenile demography into assessments of nursery habitat. Lastly, I assess a potential strategy of fishes to persist in a wide range of benthic environments. The ability to adjust traits (i.e., phenotypic plasticity) may allow organisms that encounter a range of unpredictable environmental conditions to maximise fitness within a single generation. In chapter 5 I explore patterns of variation in morphology of juvenile F. lapillum from two different subpopulations and from different macroalgal habitats. I evaluate possible evidence for constraints on morphological variation arising from variation in growth rate prior to and following settlement. Results suggest that for organisms with complex life cycles, variation in growth rates experienced during dispersal may constrain plasticity in later stages.</p>

Hadrosaurid and lambeosaurid bone beds from the Upper Cretaceous Two Medicine Formation of Montana: taphonomic and biologic implications

1993 ◽  
Vol 30 (5) ◽  
pp. 997-1006 ◽  
Author(s):  
David J. Varricchio ◽  
John R. Horner
Keyword(s):  
Growth Rates ◽  
Upper Cretaceous ◽  
Mass Mortality ◽  
Common Mechanism ◽  
Adult Size ◽  
Juvenile Growth ◽  
Total Length ◽  
Size Frequency ◽  
Related Mortality ◽  
Bone Beds

Numerous dinosaur bone beds have been found in the Upper Cretaceous Two Medicine Formation. Taphonomy and size-frequency profiles for the most common skeletal elements of six predominantly hadrosaurid and (or) lambeosaurid assemblages were compared. All six localities are single, highly concentrated bone horizons within silty mudstones. Most are monospecific with some degree of skeletal association, parautochthonous, and likely the result of mass mortality. Four are associated with small lacustrine or waterhole environments and may be the result of drought-related mortality. Within the Two Medicine Formation drought was apparently a common mechanism for generating fossil assemblages.Both hadrosaurids and lambeosaurids appear to have been gregarious. Lack of association between small (total length < 3 m) and larger individuals suggests either that juvenile growth rates were as rapid as large ungulates or less likely, that juveniles had a period of noninteraction with adults, perhaps dwelling in strictly juvenile groups. In Maiasaura peeblesorum, reproduction appears to have been synchronous among herd members and seasonal. Additionally, mortality was high for juveniles and dropped off rapidly as animals approached adult size.

scholarly journals Enamel formation and growth in non-mammalian cynodonts

2018 ◽  
Vol 5 (5) ◽  
pp. 172293 ◽  
Author(s):  
Rachel N. O'Meara ◽  
Wendy Dirks ◽  
Agustín G. Martinelli
Keyword(s):  
Growth Rates ◽  
Polarized Light ◽  
Growth Patterns ◽  
Juvenile Growth ◽  
Tooth Replacement ◽  
Replacement Rate ◽  
Adult Growth ◽  
Evolution Of Mammals ◽  
Additional Explanation ◽  
Incremental Lines

The early evolution of mammals is associated with the linked evolutionary origin of diphyodont tooth replacement, rapid juvenile growth and determinate adult growth. However, specific relationships among these characters during non-mammalian cynodont evolution require further exploration. Here, polarized light microscopy revealed incremental lines, resembling daily laminations of extant mammals, in histological sections of enamel in eight non-mammalian cynodont species. In the more basal non-probainognathian group, enamel extends extremely rapidly from cusp to cervix. By contrast, the enamel of mammaliamorphs is gradually accreted, with slow rates of crown extension, more typical of the majority of non-hypsodont crown mammals. These results are consistent with the reduction in dental replacement rate across the non-mammalian cynodont lineage, with greater rates of crown extension required in most non-probainognathians, and slower crown extension rates permitted in mammaliamorphs, which have reduced patterns of dental replacement in comparison with many non-probainognathians. The evolution of mammal-like growth patterns, with faster juvenile growth and more abruptly terminating adult growth, is linked with this reduction in dental replacement rates and may provide an additional explanation for the observed pattern in enamel growth rates. It is possible that the reduction in enamel extension rates in mammaliamorphs reflects an underlying reduction in skeletal growth rates at the time of postcanine formation, due to a more abruptly terminating pattern of adult growth in these more mammal-like, crownward species.

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