Phylogenetic perspectives on reef fish functional traits

Abstract

Functional traits have been fundamental to the evolution and diversification of entire fish lineages on coral reefs. Yet their relationship with the processes promoting speciation, extinction and the filtering of local species pools remains unclear. We review the current literature exploring the evolution of diet, body size, water column use and geographic range size in reef-associated fishes. Using published and new data, we mapped functional traits on to published phylogenetic trees to uncover evolutionary patterns that have led to the current functional diversity of fishes on coral reefs. When examining reconstructed patterns for diet and feeding mode, we found examples of independent transitions to planktivory across different reef fish families. Such transitions and associated morphological alterations may represent cases in which ecological opportunity for the exploitation of different resources drives speciation and adaptation. In terms of body size, reconstructions showed that both large and small sizes appear multiple times within clades of mid-sized fishes and that extreme body sizes have arisen mostly in the last 10 million years (Myr). The reconstruction of range size revealed many cases of disparate range sizes among sister species. Such range size disparity highlights potential vicariant processes through isolation in peripheral locations. When accounting for peripheral speciation processes in sister pairs, we found a significant relationship between labrid range size and lineage age. The diversity and evolution of traits within lineages is influenced by trait-environment interactions as well as by species and trait-trait interactions, where the presence of a given trait may trigger the development of related traits or behaviours. Our effort to assess the evolution of functional diversity across reef fish clades adds to the burgeoning research focusing on the evolutionary and ecological roles of functional traits. We argue that the combination of a phylogenetic and a functional approach will improve the understanding of the mechanisms of species assembly in extraordinarily rich coral reef communities.

Diversification and functional evolution of reef fish feeding guilds

“…We compiled dietary data for 315 wrasses and 200 damselfishes at their adult stage mainly from Floeter et al . (), Baliga & Law () and Frédérich et al . () (Table ).…”

“…(), and a recent update of this work was provided by Floeter et al . (). Four major feeding categories were used for Labridae: benthic feeders (i.e.…”

Determinants of reef fish assemblages in tropical Oceanic islands

“…We obtained data on fish assemblages from 1527 Underwater Visual Censuses (UVCs), performed at 96 sites at 18 oceanic islands (from five marine provinces) between 2006 and (Supplementary material Appendix 1 Table A1). The sampling consisted of visually identifying, counting and estimating the size (total length in cm) of all actinopterygian fish species observed both in the water column and on the bottom of belt transects (Brooks 1954).…”

“…Multiple dimensions of diversity must be assessed and tested against proposed predictions to evaluate the robustness of macroecological and biogeographical hypotheses (Whittaker et al 2008). However, hypotheses typically focus on a single biodiversity metric, usually species richness, and uncommonly make use of multiple parameters such as biomass, density of individuals or parameters linked to ecological function, which are key to fully understanding the mechanisms driving global distributions of reef fish assemblages (Kulbicki et al 2013, Mouillot et al 2014, Floeter et al 2018. For instance, knowing the drivers of functional dispersion at the global scale may help predict species responses to environmental change because traits dictate their resource and habitat requirements (Laliberté and Legendre 2010).…”

The meaning of the term ‘function’ in ecology: A coral reef perspective

“…The fossil record and phylogenetic reconstructions show how taxa have changed over time (Bellwood, Goatley, & Bellwood, ; Floeter et al, ). These insights help us to understand global patterns of biodiversity, biogeography and evolutionary processes.…”