Life-history variation in Neomysis mercedis Holmes (Crustacea, Mysidacea) in the Fraser River estuary, British Columbia

1989 ◽  
Vol 67 (2) ◽  
pp. 363-372 ◽  
Author(s):  
N. T. Johnston ◽  
T. G. Northcote
Keyword(s):  
Life History ◽  
Body Size ◽  
River Estuary ◽  
Mortality Rates ◽  
Tidal Marshes ◽  
Adult Size ◽  
Fraser River ◽  
Life History Variation ◽  
Adult Body Size ◽  
Adult Body

The brackish-water mysid Neomysis mercedis in tidal marshes of the Fraser River produced overwintering and summer generations that differed in life-history traits. Summer generation females matured at a smaller size and produced fewer and larger eggs than the overwintering generation. Size-adjusted clutch weights were identical for summer and overwintering females. Reproductive effort was slightly lower for the overwintering females. Both generations were iteroparous, but the average frequency of breeding was higher for the overwintering generation. Seasonal variations in reproductive traits were strongly linked to fluctuations in the relative mortality rates of neonates and adults. Overwintering adults that bred in late spring had lower mortality rates than neonates, while mortality rates for summer adults were higher than those for neonates. Rearing suggested that changes in adult body size were a phenotypic response to temperature. Food availability had little additional effect on adult body size. A positive correlation between ambient water temperatures and the increase in mortality with increasing adult size provided a possible mechanism through which temperature-dependent phenotypic variation in adult body size could be selected.

Geographical variations in adult body size and reproductive life history traits in an invasive anuran, Discoglossus pictus

Zoology ◽  
2016 ◽  
Vol 119 (3) ◽  
pp. 216-223 ◽  
Author(s):  
Neus Oromi ◽  
Eudald Pujol-Buxó ◽  
Olatz San Sebastián ◽  
Gustavo A. Llorente ◽  
Mohamed Aït Hammou ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Traits ◽  
Adult Body Size ◽  
Discoglossus Pictus ◽  
Geographical Variations ◽  
Adult Body ◽  
Reproductive Life ◽  
Reproductive Life History

Decrease in litter size in the shrew Crocidura suaveolens (Mammalia, Insectivora) from Corsica (France): Evolutionary response to insularity?

1997 ◽  
Vol 75 (6) ◽  
pp. 954-958 ◽  
Author(s):  
Roger Fons ◽  
Françoise Poitevin ◽  
Josette Catalan ◽  
Henri Croset
Keyword(s):  
Life History ◽  
Body Size ◽  
Litter Size ◽  
Life History Traits ◽  
Breeding Experiment ◽  
Adult Body Size ◽  
Three Generations ◽  
Evolutionary Response ◽  
Adult Body ◽  
Genetically Determined

Populations of the lesser white-toothed shrew, Crocidura suaveolens (Pallas, 1811), from Corsica show an increase in adult body size associated with a decrease in litter size. The average number of embryos in wild Corsican females is smaller (mean 2.6, n = 62) than in mainland females (mean 4.6, n = 173). A breeding experiment was run for 4 years, yielding three generations. Under standard breeding conditions, the differences between island and mainland populations were maintained and were significant (median litter size was 2 for Corsica and 5 for the mainland). These differences in life-history traits were therefore proved experimentally to be genetically determined. Hypotheses concerning the mechanisms responsible for these differences are discussed.

scholarly journals Geographical variation in larval host-plant use by Heliconius erato (Lepidoptera: Nymphalidae) and consequences for adult life history

2002 ◽  
Vol 62 (2) ◽  
pp. 321-332 ◽  
Author(s):  
D. RODRIGUES ◽  
G. R. P. MOREIRA
Keyword(s):  
Life History ◽  
Body Size ◽  
Larval Stage ◽  
Egg Size ◽  
Geographical Variation ◽  
Size Range ◽  
Adult Size ◽  
Experimental Station ◽  
Female Body Size ◽  
Adult Body

Adult body size, one of the most important life-history components, varies strongly within and between Heliconius erato phyllis (Lepidoptera: Nymphalidae) populations. This study determines if this variation is caused by geographical changes in host-plant used by the larval stage, whose reproductive parameters are influenced by female body size, with estimates of the corresponding heritability. The variation in adult body size was determined together with a survey of passion vine species (Passifloraceae) used by the larvae in seven localities in Rio Grande do Sul State: three located in the urban area of Porto Alegre and Triunfo Counties, two within Eucalyptus plantations (Barba Negra Forest, Barra do Ribeiro County, and Águas Belas Experimental Station -- Viamão County), one in a Myrtaceae Forest (Itapuã State Park -- Itapuã County) and one in the Atlantic Rain Forest (Maquiné Experimental Station -- Maquiné County). Effects of female body size on fecundity, egg size and egg viability were determined in an outdoor insectary. Size heritability was estimated by rearing in the laboratory offspring of individuals maintained in an insectary. The data showed that adults from populations where larvae feed only upon Passiflora suberosa are smaller than those that feed on Passiflora misera. The larvae prefer P. misera even when the dominant passion vine in a given place is P. suberosa. Fecundity increases linearly with the increase in size of females, but there is no size effect on egg size or viability. Size heritability is null for the adult size range occurring in the field. Thus, the geographical variation of H. erato phyllis adult size is primarily determined by the type, corresponding availability and quality of host-plants used by the larval stage. Within the natural size range of H. erato phyllis, the variation related to this caracter is not genetically based, thus being part of H. erato phyllis phenotypic plasticity.

scholarly journals Regulation of Body Size and Growth Control

Genetics ◽  
2020 ◽  
Vol 216 (2) ◽  
pp. 269-313 ◽  
Author(s):  
Michael J. Texada ◽  
Takashi Koyama ◽  
Kim Rewitz
Keyword(s):  
Body Size ◽  
Tissue Growth ◽  
Whole Body ◽  
Adult Size ◽  
Juvenile Growth ◽  
Organ Growth ◽  
Regulatory Pathways ◽  
Adult Body Size ◽  
Steroid Signaling ◽  
Adult Body

The control of body and organ growth is essential for the development of adults with proper size and proportions, which is important for survival and reproduction. In animals, adult body size is determined by the rate and duration of juvenile growth, which are influenced by the environment. In nutrient-scarce environments in which more time is needed for growth, the juvenile growth period can be extended by delaying maturation, whereas juvenile development is rapidly completed in nutrient-rich conditions. This flexibility requires the integration of environmental cues with developmental signals that govern internal checkpoints to ensure that maturation does not begin until sufficient tissue growth has occurred to reach a proper adult size. The Target of Rapamycin (TOR) pathway is the primary cell-autonomous nutrient sensor, while circulating hormones such as steroids and insulin-like growth factors are the main systemic regulators of growth and maturation in animals. We discuss recent findings in Drosophila melanogaster showing that cell-autonomous environment and growth-sensing mechanisms, involving TOR and other growth-regulatory pathways, that converge on insulin and steroid relay centers are responsible for adjusting systemic growth, and development, in response to external and internal conditions. In addition to this, proper organ growth is also monitored and coordinated with whole-body growth and the timing of maturation through modulation of steroid signaling. This coordination involves interorgan communication mediated by Drosophila insulin-like peptide 8 in response to tissue growth status. Together, these multiple nutritional and developmental cues feed into neuroendocrine hubs controlling insulin and steroid signaling, serving as checkpoints at which developmental progression toward maturation can be delayed. This review focuses on these mechanisms by which external and internal conditions can modulate developmental growth and ensure proper adult body size, and highlights the conserved architecture of this system, which has made Drosophila a prime model for understanding the coordination of growth and maturation in animals.

Grass-flower thrips of the genus Chirothrips (Thysanoptera: Thripidae), with a key to species from Iran

Zootaxa ◽  
2010 ◽  
Vol 2411 (1) ◽  
pp. 33 ◽  
Author(s):  
KAMBIZ MINAEI ◽  
LAURENCE MOUND
Keyword(s):  
Body Size ◽  
Species Group ◽  
Identification Key ◽  
Key To Species ◽  
Adult Body Size ◽  
Flower Thrips ◽  
New Synonym ◽  
Adult Body ◽  
Structural Differences

Species of the genus Chirothrips Haliday breed and pupate only within grass florets. Each larva is restricted to a single floret, and adult body size is thus presumably related to floret size. Despite this, some Chirothrips species are distinguished only on states that are related to body size. The validity of some commonly recorded members of the C. manicatus species-group, including C. africanus and C. pallidicornis, is therefore considered questionable. Character states that have been used to define the genus Agrostothrips Hood are shown to be variable, and this genus is placed as a new synonym of Chirothrips. An identification key, based on illustrated structural differences, is provided to the Chirothrips known from Iran: C. aculeatus, C. atricorpus, C. kurdistanus, C. manicatus, C. meridionalis and C. molestus.

scholarly journals Childhood retardation resulting in reduction of adult body size due to lesser adolescent skeletal delay

1970 ◽  
Vol 33 (3) ◽  
pp. 325-336 ◽  
Author(s):  
A. Roberto Frisancho ◽  
Stanley M. Garn ◽  
Werner Ascoli
Keyword(s):  
Body Size ◽  
Adult Body Size ◽  
Adult Body

Geographical and latitudinal variation in growth patterns and adult body size of Swedish moose (Alces alces)

Oecologia ◽  
1995 ◽  
Vol 102 (4) ◽  
pp. 433-442 ◽  
Author(s):  
H�kan Sand ◽  
G�ran Cederlund ◽  
Kjell Danell
Keyword(s):  
Body Size ◽  
Alces Alces ◽  
Growth Patterns ◽  
Latitudinal Variation ◽  
Adult Body Size ◽  
Adult Body

Evolutionary Divergence of Adult Body Size and Juvenile Growth in Sympatric Subpopulations of a Top Predator in Aquatic Ecosystems

2015 ◽  
Vol 186 (1) ◽  
pp. 98-110 ◽  
Author(s):  
Petter Tibblin ◽  
Anders Forsman ◽  
Per Koch-Schmidt ◽  
Oscar Nordahl ◽  
Peter Johannessen ◽  
...  
Keyword(s):  
Body Size ◽  
Aquatic Ecosystems ◽  
Evolutionary Divergence ◽  
Juvenile Growth ◽  
Top Predator ◽  
Adult Body Size ◽  
Adult Body
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