Spatio-temporal dynamics of the nudibranch Doris kyolis living on the sponge Halichondria melanadocia

Abstract

Doris kyolis (Ev. Marcus and Er. Marcus, 1967) (Nudibranchia, Dorididae) has been reported in tropical and subtropical locations of the western Atlantic, from Florida, USA, to Rio de Janeiro, Brazil (Belmonte et al., 2015; Caballer- Gutiérrez et al., 2015). Throughout its distribution range, it has been frequently observed in interaction with sponges (Belmonte et al., 2015; Ortea et al., 2017) but there is no data of its density on the sponges from which it feeds. A recent study conducted in a southern Gulf of Mexico estuary (Laguna de Términos, Mexico) revealed that this nudibranch species is part of the associated macrofaunal assemblage with the sponge Halichondria (Halichondria) melanadocia Laubenfels, 1936 in seagrass meadows and red mangrove prop roots habitats (Ávila and Briceño-Vera, 2018). However, although D. kyolis was common in the samples of this sponge, basic aspects of its population dynamics, such as the small-scale spatial and temporal variation in its frequency of occurrence and density, have not been investigated. Therefore, the aim of the present study was to determine whether the frequency of occurrence and density of D. kyolis in association with H. (H.) melanadocia varies (i) between seagrass meadows and mangrove prop root habitats and (ii) throughout the year as a function of the sponge prey size and/or environmental factors, such as water temperature and salinity.