The complex ecology of genitalia: Gonopodium length and allometry in the Trinidadian guppy

AbstractIn many animal species, individuals with certain morphological, physiological, or behavioural traits may have a disproportionately large role in determining group behaviour. While most empirical studies of leadership have focused on behaviour of individuals exploring new environments or foraging, little is known about leading behaviour in other ecological contexts. Here, we use a selective breeding design in the Trinidadian guppy (Poecilia reticulata) to quantify the heritability of leadership in a cooperative context, and determine the behavioural traits associated with it. Firstly we found that phenotypic selection for high and low leadership (HL and LL, respectively) over three filial generations resulted in pronounced differences in leadership tendency with a moderate degree of heritability. In our assay of other social traits, LL males were more aggressive and sampled their social environment less than HL males, but HL and LL females did not differ in either aggressiveness or sociability. Traits such as boldness and exploratory tendency did not diverge between the two lines. Leading behaviour was thus associated with social traits in males, but not females; suggesting that there may be sex-specific mechanisms driving the emergence of leadership in this context. We discuss our findings in the context of the evolution of cooperation.

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Experimental Evidence for Density-Dependent Regulation and Selection on Trinidadian Guppy Life Histories

The American Naturalist ◽

10.1086/668590 ◽

2013 ◽

Vol 181 (1) ◽

pp. 25-38 ◽

Cited By ~ 66

Author(s):

Ronald D. Bassar ◽

Andres Lopez-Sepulcre ◽

David N. Reznick ◽

Joseph Travis

Keyword(s):

Experimental Evidence ◽

Life Histories ◽

Density Dependent ◽

Trinidadian Guppy ◽

Density Dependent Regulation

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Metabolism, personality and pace of life in the Trinidadian guppy, Poecilia reticulata

Behaviour ◽

10.1163/1568539x-00003375 ◽

2016 ◽

Vol 153 (13-14) ◽

pp. 1517-1543 ◽

Cited By ~ 27

Author(s):

S.J. White ◽

T.J. Kells ◽

A.J. Wilson

Keyword(s):

Individual Variation ◽

Repeated Measures ◽

Life Histories ◽

Poecilia Reticulata ◽

High Growth ◽

Early Maturation ◽

Metabolic Traits ◽

Personality Differences ◽

Pace Of Life ◽

Trinidadian Guppy

While among-individual variation in behaviour, or personality, is common across taxa, its mechanistic underpinnings are poorly understood. The Pace of Life syndrome (POLS) provides one possible explanation for maintenance of personality differences. POLS predicts that metabolic differences will covary with behavioural variation, with high metabolism associated with risk prone behaviour and ‘faster’ life histories (e.g., high growth, early maturation). We used a repeated measures approach, assaying metabolic traits (rate and scope), behaviour and growth to test these predictions in the Trinidadian guppy, Poecilia reticulata. We found that while individuals varied significantly in their behaviour and growth rate, more risk prone individuals did not grow significantly faster. Furthermore, after accounting for body size there was no support for among-individual variation in metabolic traits. Thus, while personality differences are clearly present in this population, they do not covary with metabolism and the POLS framework is not supported.

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