Growing up in a new world: trait divergence between rural, urban, and invasive populations of an amphibian urban invader

Cities are focal points of introduction for invasive species. Urban evolution might facilitate the success of invasive species in recipient urban habitats. Here we test this hypothesis by rearing tadpoles of a successful amphibian urban coloniser and invader in a common garden environment. We compared growth rate, morphological traits, swimming performance, and developmental rate of guttural toad tadpoles (Sclerophrys gutturalis) from native rural, native urban, and non-native urban habitats. By measuring these traits across ontogeny, we were also able to compare divergence across different origins as the tadpoles develop. The tadpoles of non-native urban origin showed significantly slower developmental rate (e.g., the proportion of tadpoles reaching Gosner stage 31 or higher was lower at age 40 days) than tadpoles of native urban origin. Yet, tadpoles did not differ in growth rate or any morphological or performance trait examined, and none of these traits showed divergent ontogenetic changes between tadpoles of different origin. These findings suggest that prior adaptation to urban habitats in larval traits likely does not play an important role in facilitating the invasion success of guttural toads into other urban habitats. Instead, we suggest that evolutionary changes in larval traits after colonization (e.g., developmental rate), together with decoupling of other traits and phenotypic plasticity might explain how this species succeeded in colonising extra-limital urban habitats.

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Relations between morphology, buoyancy and energetics of requiem sharks

Royal Society Open Science ◽

10.1098/rsos.160406 ◽

2016 ◽

Vol 3 (10) ◽

pp. 160406 ◽

Cited By ~ 18

Author(s):

Gil Iosilevskii ◽

Yannis P. Papastamatiou

Keyword(s):

Body Temperature ◽

Negative Selection ◽

Swimming Performance ◽

Ontogenetic Changes ◽

Cost Of Transport ◽

Pectoral Fins ◽

Confined Spaces ◽

Reef Sharks ◽

The Cost ◽

Derivatives Of

Sharks have a distinctive shape that remained practically unchanged through hundreds of millions of years of evolution. Nonetheless, there are variations of this shape that vary between and within species. We attempt to explain these variations by examining the partial derivatives of the cost of transport of a generic shark with respect to buoyancy, span and chord of its pectoral fins, length, girth and body temperature. Our analysis predicts an intricate relation between these parameters, suggesting that ectothermic species residing in cooler temperatures must either have longer pectoral fins and/or be more buoyant in order to maintain swimming performance. It also suggests that, in general, the buoyancy must increase with size, and therefore, there must be ontogenetic changes within a species, with individuals getting more buoyant as they grow. Pelagic species seem to have near optimally sized fins (which minimize the cost of transport), but the majority of reef sharks could have reduced the cost of transport by increasing the size of their fins. The fact that they do not implies negative selection, probably owing to decreased manoeuvrability in confined spaces (e.g. foraging on a reef).

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Social context alters retreat- and nest-site selection in a globally invasive gecko, Hemidactylus frenatus

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blz188 ◽

2019 ◽

Vol 129 (2) ◽

pp. 388-397

Author(s):

Benjamin J Muller ◽

Robin M Andrews ◽

Lin Schwarzkopf ◽

David A Pike

Keyword(s):

Invasive Species ◽

Site Selection ◽

Nest Site ◽

Gravid Female ◽

Nest Site Selection ◽

Invasion Success ◽

Ceramic Tiles ◽

Nest Sites ◽

Gravid Females ◽

Hemidactylus Frenatus

Abstract Microhabitat orientation and structure and the presence of conspecifics may strongly influence the choice of habitat. We studied how these variables influence retreat- and nest-site selection in gravid females of a globally successful invasive species, the Asian house gecko (Hemidactylus frenatus). When provided with various substrates (vertical and horizontal ceramic tiles, vertical and horizontal plywood tiles, horizontal bark over leaf litter, vertical bark over a log, and sand) gravid female geckos preferred to retreat to, and nest in, materials with crevices commonly found in urban habitats. When housed alone, gravid females most frequently retreated to vertical ceramic tile or wooden crevices, and 66.7% nested in vertical ceramic tiles. When housed with two other conspecifics, gravid females most frequently retreated to vertical ceramic tiles, but selected a wider range of nest sites. Overall, gravid geckos housed alone typically nested in the same substrates that they used as diurnal retreats; when housed in groups, however, females oviposited in locations different from those they selected as retreats. Thus, H. frenatus females use a wider range of substrates when conspecifics are present. Invasion success in this species might be driven, in part, by preferences for retreat and nest substrates that are common in human-dominated habitats.

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INCREASED PLANT SIZE IN EXOTIC POPULATIONS: A COMMON-GARDEN TEST WITH 14 INVASIVE SPECIES

Ecology ◽

10.1890/06-2115.1 ◽

2007 ◽

Vol 88 (11) ◽

pp. 2758-2765 ◽

Cited By ~ 83

Author(s):

Dana M. Blumenthal ◽

Ruth A. Hufbauer

Keyword(s):

Invasive Species ◽

Common Garden ◽

Plant Size

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Native turncoats and indirect facilitation of species invasions

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.1936 ◽

2018 ◽

Vol 285 (1871) ◽

pp. 20171936 ◽

Cited By ~ 8

Author(s):

Tobin D. Northfield ◽

Susan G. W. Laurance ◽

Margaret M. Mayfield ◽

Dean R. Paini ◽

William E. Snyder ◽

...

Keyword(s):

Invasive Species ◽

Native Species ◽

Potential Role ◽

Indirect Interactions ◽

Invasion Success ◽

Competitive Interactions ◽

Species Invasion ◽

Species Invasions ◽

Indirect Facilitation

At local scales, native species can resist invasion by feeding on and competing with would-be invasive species. However, this relationship tends to break down or reverse at larger scales. Here, we consider the role of native species as indirect facilitators of invasion and their potential role in this diversity-driven ‘invasion paradox’. We coin the term ‘native turncoats’ to describe native facilitators of non-native species and identify eight ways they may indirectly facilitate species invasion. Some are commonly documented, while others, such as indirect interactions within competitive communities, are largely undocumented in an invasion context. Therefore, we use models to evaluate the likelihood that these competitive interactions influence invasions. We find that native turncoat effects increase with the number of resources and native species. Furthermore, our findings suggest the existence, abundance and effectiveness of native turncoats in a community could greatly influence invasion success at large scales.

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Evolution of increased vigour associated with allopolyploidization in the newly formed invasive species Salsola ryanii

AoB Plants ◽

10.1093/aobpla/plz039 ◽

2019 ◽

Author(s):

Shana R Welles ◽

Norman C Ellstrand

Keyword(s):

Invasive Species ◽

Common Garden ◽

Plant Evolution ◽

Seed Number ◽

Testing Hypotheses ◽

Fixed Heterozygosity ◽

Study Support ◽

A Site

Abstract A correlation between allopolyploidization and increased fitness is an explanation for the importance of allopolyploidy throughout evolution, specifically plant evolution. Although many authors have suggested correlation between allopolyploidy and increased fitness, common garden comparisons testing hypotheses about fitness shifts associated with allopolyploidy are lacking. In this study, we test the theory that allopolyploidy is associated with increased fitness in the newly formed allopolyploid weed Salsola ryanii. We conducted a common garden comparison over 2 years to determine how different fitness correlates (plant volume, plant mass and estimated seed number) of the newly formed allopolyploid species S. ryanii compares to its progenitors (S. tragus and S. australis) at a site within the range of all the newly formed allopolyploid and both of its progenitors. We document an increase in above-ground plant mass and above-ground volume in the newly formed allopolyploid compared to its progenitors. Plant mass and volume of the newly formed allopolyploid relative to its progenitors was dependent on year. The results of this study support the hypothesis that allopolyploidization is associated with increased growth, which is consistent with predictions that allopolyploid lineages experience vigour due to fixed heterozygosity.

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The relationship between specific growth rate and swimming performance in male fathead minnows (Pimephales promelas)

Canadian Journal of Zoology ◽

10.1139/z95-254 ◽

1995 ◽

Vol 73 (11) ◽

pp. 2165-2167 ◽

Cited By ~ 46

Author(s):

Alan S. Kolok ◽

James T. Oris

Keyword(s):

Growth Rate ◽

Specific Growth Rate ◽

Swimming Speed ◽

Specific Growth ◽

Swimming Performance ◽

Pimephales Promelas ◽

Significant Negative Correlation ◽

Fathead Minnows ◽

Critical Swimming Speed ◽

The Relationship

The objective of this study was to test the hypothesis that the specific growth rate of male fathead minnows (Pimephales promelas) was positively correlated with swimming performance. Subadult fish were allowed to grow into adults over a period of 31 – 55 days, after which the critical swimming speed of each fish was determined. Variation in critical swimming speed was substantial (greater than 50%), and a significant positive correlation was found between number of growing days and critical swimming speed, whereas a significant negative correlation was found between specific growth rate and critical swimming speed. A multiple regression using specific growth rate and number of growing days explained over 47% of the variation in swimming performance. Fathead minnows that grow fast are poor swimmers, suggesting a trade-off between swimming performance and specific growth rate in this species.

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Differences in Swimming Performance Among Strains of Rainbow Trout (Salmo gairdneri)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f77-048 ◽

1977 ◽

Vol 34 (2) ◽

pp. 304-307 ◽

Cited By ~ 16

Author(s):

Allan E. Thomas ◽

Michael J. Donahoo

Keyword(s):

Growth Rate ◽

Rainbow Trout ◽

New Zealand ◽

Swimming Performance ◽

Salmo Gairdneri ◽

Swimming Ability ◽

Fish Swimming ◽

Fish Size ◽

Swimming Time ◽

Performance Profiles

Swimming performance profiles, relating fish size to swimming time, were established for three strains of rainbow trout (Salmo gairdneri). No differences were found in slope of regressions; only in level at each size of fish. Swimming performances of New Zealand and Sand Creek strains did not differ, but were superior to the Manchester strain. In stamina results from 189-day-old fish from individual matings of seven strains and various crosses, similar strains and crosses had closely matching profiles whereas profiles of unrelated groups were variable. Comparison of slowest, average, and fastest growing fish within the New Zealand strain showed that swimming ability was not related to growth rate.

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Individual variation and interrelationships between swimming performance, growth rate, and feeding in juvenile rainbow trout (Oncorhynchus mykiss)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f98-044 ◽

1998 ◽

Vol 55 (7) ◽

pp. 1583-1590 ◽

Cited By ~ 73

Author(s):

T Ryan Gregory ◽

Chris M Wood

Keyword(s):

Growth Rate ◽

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Plasma Cortisol ◽

Positive Relationship ◽

Swimming Performance ◽

Individual Performance ◽

Significant Positive Relationship ◽

Juvenile Rainbow Trout ◽

Rainbow Trout Oncorhynchus Mykiss

Variation among individuals in specific growth rate (SGR), feeding, and two measures of swimming performance and their possible interrelationships were investigated in juvenile rainbow trout (Oncorhynchus mykiss) kept in groups on either satiation or half-satiation rations. Maximum sustainable velocity (Ucrit) was measured as an index of aerobic swimming performance and stamina (fatigue time in a fixed-velocity test at 6 body lengths ·s-1) as an index of anaerobic performance. Individual performance in both of these tests was found to be significantly repeatable. Trout fed on half-satiation ration exhibited significantly lower mean values of SGR and body size and higher levels of aggression-related fin damage, but no significant differences in stamina, relative or absolute Ucrit, glycogen content, or plasma cortisol. However, in these fish, there was a significant negative relationship between SGR and relative Ucrit, a significant positive relationship between SGR and stamina, and a significant positive relationship between SGR and total daily meal. None of these relationships were seen in fish fed to satiation. Plasma cortisol and tissue glycogen stores were not related to SGR. These results indicate that under the intensified competition of restricted ration, there are trade-offs between growth, feeding, and different types of swimming performance.

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