Survival, growth, and recruitment of octocoral species (Coelenterata: Octocorallia) in Coiba National Park, Pacific Panama

Abstract

Octocorals (order Alcyonacea) from the tropical eastern Pacific have been largely ignored in coral reef studies, with the exception of recent taxonomic reviews. This study is the first to examine the population dynamics of 10 shallow water species in six genera (Leptogorgia, Pacifigorgia, Muricea, Psammogorgia, Heterogorgia, and Carijoa) found in rocky coral communities in Coiba National Park, Pacific Panama. For a 17-mo period, we monitored, every 4 mo, 1445 colonies of 15 species in fixed plots at 20 m depth in four coral communities. Size distribution, survivorship, and recruitment rates were calculated. Growth rate was calculated for Leptogorgia alba Duchassaing and Michelotti, 1864, Pacifigorgia Irene Bayer, 1951, Psammogorgia arbuscula Verrill, 1868, and Muricea austera Lamouroux, 1821. Average octocoral density was 38.7 (SD 27.55) colonies m -2 (n = 1394) with a range of 1-103 colonies m -2 and 1-11 species within a study plot. An overall population decline of 25.2% was observed in 1 yr. Leptogorgia alba was the most common species; it was abundant at all sites and exhibited characteristics of an r-selected species. In contrast, M. austera showed traits of a K-selected species, with low mortality and recruitment rates. Studied species were grouped into two distinct clusters based on their distribution, average density, mortality, and recruitment rates. Five species were grouped with L. alba and six species were grouped with M. austera.