Feeding ecology of pipefish species inhabiting Mediterranean seagrasses

Abstract

Pipefish are a vulnerable and diverse group of ichthyofauna tightly associated to seagrass meadows, key habitats in shallow marine areas. Despite of their charismatic role, main ecological features, habitat and diet of this group remain largely unknown. This study focuses on assessing pipefish habitat and feeding preferences including different hosting seagrasses such as Posidonia oceanica and Cymodocea nodosa from the Balearic Islands, western Mediterranean. Four species (Syngnathus typhle, S. abaster, Nerophis ophidion and N. maculatus) were found associated to different seagrasses. S. typhle and N. maculatus were more frequent in P. oceanica meadows, while S. abaster and N. ophidion in C. nodosa. Individuals of all species captured in P. oceanica were larger than those living in C. nodosa, suggesting a size-dependent habitat preference. Feeding preferences, however, were driven by prey availability and fish features, e.g head/snout morphology. For the first time in the western Mediterranean, a thorough description of the diet and potential preys of this group was carried out. Epifaunal assemblages (potential prey) were dominated in both habitats by harpacticoid copepods and gammarid amphipods, and they were also the primary preys according to stomach contents of all species. These results can contribute to future pipefish conservation and management actions, such as targeting crucial habitat identification and designing culture and reintroduction protocols.

Structure and Trophic Niches in Mobile Epifauna Assemblages Associated With Seaweeds and Habitats of Syngnathid Fishes in Cíes Archipelago (Atlantic Islands Marine National Park, North West Iberia)

“…The Family Syngnathidae includes small and cryptic fishes (e.g., seahorses, pipefishes, and seadragons), generally associated with marine flora or other complex benthic habitats (Kuiter, 2009;Ahnesjö and Craig, 2011). In Europe, seahorses (Hippocampus) and pipefishes (e.g., Syngnathus, Nerophis, Entelurus) are members of the ichthyofauna inhabiting temperate sheltered and semi-sheltered coastal habitats dominated by seaweeds and seagrasses (Franzoi et al, 1993;Curtis and Vincent, 2005;Gristina et al, 2014;Correia et al, 2018;Scapin et al, 2018;Ape et al, 2019;Castro-Fernández et al, 2020;Planas et al, 2021a). Unlike many pipefishes, most seahorse species are characterized by limited home ranges and reduced mobility (Foster and Vincent, 2004) due to their morphology and body characteristics.…”

“…Copepods are also an important dietary source in euryhaline pipefishes (e.g., S. abaster) inhabiting invaded freshwater habitats (Didenko et al, 2018). Speciesspecific studies of pipefish species (i.e., S. acus, S. typhle, S. abaster, N. ophidion, and N. maculatus) inhabiting diverse coastal areas in southern Europe revealed the importance of harpacticoid copepods, gammarids, carideans, isopods, and mysidaceans in their diet (Franzoi et al, 1993;Vizzini and Mazzola, 2004;Oliveira et al, 2007;Gürkan and Taskavak, 2019;Castro-Fernández et al, 2020;Planas et al, 2020a). However, habitat type and seasonal fluctuations in the composition and availability of food sources may govern variations in the dietary composition (Roelke and Sogard, 1993;Nenciu et al, 2018;Ape et al, 2019;Manning et al, 2019;Planas et al, 2021a).…”

Fish morphological and parasitological traits as ecological indicators of habitat quality in a Mediterranean coastal lagoon

“…In fact, an explosive increase in copepods from the Mar Menor was detected by Gilabert (2001) mainly for one species (Oithona nana). Syngnathids can display a strong prey selection (see Castro-Fernández et al, 2020 for a study on four syngnathid species, including S. abaster) and this may be the reason, along with a potential decrease in copepod diversity, why the observed effect on the examined pipefish species was negative in this study (i.e. lower body condition in the Littoral sites).…”