Document of bibliographic reference 363085

BibliographicReference record

Type

Bibliographic resource

Type of document

Journal article

BibLvlCode

AS

Title

Functional and sex-specific dynamics of ectoparasite size evolution in marine isopod–fish interactions: Harrison’s rule and increasing variance

Abstract

Harrison’s rule, a pattern predicting that the body size of parasites correlates positively with the size of their hosts, is well-supported. However, its interaction with highly distinct “guilds” of closely related parasites warrants further exploration. The increasing variance hypothesis predicts that the variance in parasite size should also increase with the size of their hosts. Though untested, in parasite taxa with differential sex-dependent pressures on body size, this relationship should also be divergent across sexes due to differential size–fecundity relationships. We compiled global data on sequentially hermaphroditic isopods (Isopoda: Cymothoidae) parasitic on fish from published literature. With a data set comprising of 204 marine cymothoid species and their hosts, we used Bayesian hierarchical models to primarily test (1) Harrison’s rule and its scaling across three functionally distinct guilds (mouth, gill, external); (2) the increasing variance hypothesis and sex-specific patterns. Our results revealed a strong positive association between parasite and host body sizes, but with uniform scaling across guilds. Host size exerted divergent, sex-specific effects on the relative intraspecific variation in parasite size, where this association was positive in males and absent in females. Here, we show that Harrison’s rule is independent of guild, suggesting body size evolution across all cymothoids is equally underpinned by the size of their hosts. The sex-specificity of the increasing variance hypothesis can be explained by female fecundity being tightly bound to body size, whereas the dependency of reproductive success on size is inherently more relaxed in males.

WebOfScience code

https://www.webofscience.com/wos/woscc/full-record/WOS:000899464200001

Bibliographic citation

Ni, S.; de Angeli Dutra, D. (2023). Functional and sex-specific dynamics of ectoparasite size evolution in marine isopod–fish interactions: Harrison’s rule and increasing variance. Oecologia 201: 213-225. https://dx.doi.org/10.1007/s00442-022-05302-9

Topic

Marine

Is peer reviewed

true