title: Parabolic variation in sexual selection intensity across the range of a cold-water pipefish: implications for susceptibility to climate change.
abstract: While an understanding of evolutionary processes in shifting environments is vital in the context of rapid ecological change, one of the most potent selective forces, sexual selection, remains curiously unexplored. Variation in sexual selection across a species range, especially across a gradient of temperature regimes, has the potential to provide a window into the possible impacts of climate change on the evolution of mating patterns. Here, we investigated some of the links between temperature and indicators of sexual selection, using a cold-water pipefish as model. We found that populations differed with respect to body size, length of the breeding season, fecundity, and sexual dimorphism across a wide latitudinal gradient. We encountered two types of latitudinal patterns, either linear, when related to body size, or parabolic in shape when considering variables related to sexual selection intensity, such as sexual dimorphism and reproductive investment. Our results suggest that sexual selection intensity increases toward both edges of the distribution and that the large differences in temperature likely play a significant role. Shorter breeding seasons in the north and reduced periods for gamete production in the south certainly have the potential to alter mating systems, breeding synchrony, and mate monopolization rates. As latitude and water temperature are tightly coupled across the European coasts, the observed patterns in traits related to sexual selection can lead to predictions regarding how sexual selection should change in response to climate change. Based on data from extant populations, we can predict that as the worm pipefish moves northward, a wave of decreasing selection intensity will likely replace the strong sexual selection at the northern range margin. In contrast, the southern populations will be followed by heightened sexual selection, which may exacerbate the problem of local extinction at this retreating boundary.
authors.affiliation: CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, rua Padre Armando Quintas, Vairão, 4485-661, Portugal.|CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, rua Carlos da Maia 296, Porto, 4200-150, Portugal.
authors.forename: Nuno
authors.identifier: 0000-0001-6994-4673
authors.initials: N
authors.lastname: Monteiro
authors.affiliation: CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, rua Padre Armando Quintas, Vairão, 4485-661, Portugal.|Faculdade de Ciências, Universidade do Porto, rua do Campo Alegre, Porto, 4169-007, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Cunha
authors.affiliation: CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, rua Padre Armando Quintas, Vairão, 4485-661, Portugal.
authors.forename: Lídia
authors.initials: L
authors.lastname: Ferreira
authors.affiliation: Faculdade de Ciências, Universidade do Porto, rua do Campo Alegre, Porto, 4169-007, Portugal.|CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, Porto, 4050-123, Portugal.
authors.forename: Natividade
authors.initials: N
authors.lastname: Vieira
authors.affiliation: Faculdade de Ciências, Universidade do Porto, rua do Campo Alegre, Porto, 4169-007, Portugal.|CIIMAR/CIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas, 289, Porto, 4050-123, Portugal.
authors.forename: Agostinho
authors.initials: A
authors.lastname: Antunes
authors.affiliation: National Parks & Wildlife Service, Custom House, Druid Lane, Flood Street, Galway, Ireland.
authors.forename: David
authors.initials: D
authors.lastname: Lyons
authors.affiliation: Department of Biology, Texas A&M University, 3258 TAMU, College Station, TX, 77843, USA.
authors.forename: Adam G
authors.initials: AG
authors.lastname: Jones
mesh_terms: D000818:Animals; D049628:Body Size; D057231:Climate Change; D003080:Cold Temperature; D005399:Fishes; D012098:Reproduction; D012641:Selection, Genetic; D012727:Sex Characteristics; D014867:Water
chemical_list: D014867:Water
keywords: 
  Nerophis lumbriciformis
  ; 
  Syngnathidae
  ; Bergmann's rule; Rensch's rule; coloration; dimorphism; distribution; expansion; investment; secondary sexual characters