Diversification of the pectoral fin shape in damselfishes (Perciformes, Pomacentridae) of the Eastern Pacific. ZOOMORPHOLOGY 132 (2): 197-213.
Fin shape strongly influences performance of locomotion across all swimming styles. In this study, we focused on the diversity of the pectoral fin morphology in damselfishes of the Eastern Pacific. Underwater
observations and a review of literature allowed the characterization of ten behavioral groups. Territorial and
non-territorial species were discriminated easily with traditional morphometrics. Five ecomorphological
groups were recognized by geometric morphometric analyses. Geometric data segregated the outgroup from
the damselfishes and allowed the distinction of mean morphologies from extreme ones within territorial and
non-territorial species. Additionally, geometric morphometric data split Abudefduf into two groups: (1) A.
troschelii is similar to C. atrilobata and (2) A. concolor and A. declivifrons are close to Stegastes. Solitary
territorial species (e.g., Stegastes) show rounded and high fins when non-territorial species living in groups
(e.g., Chromis) present long and curved pectoral fins. In the range of morphological variation, the
morphologies of Microspathodon (elongate with highly curved hydrodynamic trailing edge) and Azurina
(long, slender and angular) represent the extreme morphologies within territorial and non-territorial species,
respectively. Our study revealed a strong relationship between the pectoral fin shape and the behavioral
diversification in damselfishes.
Keywords: Ecomorphology - Geometric morphometrics - Locomotion - Reef fishes - Swimming - Territorial behavior.