The influence of hypo‐osmotic stress on the regenerative capacity of the invasive polychaete Marenzelleria viridis from its native range

Abstract

The euryhaline polychaete Marenzelleria viridis is a notorious invader of the Baltic region and while many studies have focused on the effects of osmotic stress on larval development of the species, few have assessed its effect on adult specimens. This study investigated the effects of low salinity on the physiology of M. viridis by using its regenerative capacity as a proxy for physiologic performance. Specimens were collected in spring 2015 on sandy flats in Hempstead Bay (Long Island, New York), a site that falls within its native range. Worms were ablated between the 14th and 20th chaetigers and cultured at five different salinity treatments (24psu, 15psu, 10psu, 5psu and 0psu) that reflected the broad salinity regimes of its distributional range. Data for anterior regeneration were analysed and presented. Morphogenesis during anterior regeneration was characterized by the formation of a blastema from which the major anatomic structures emerged. All specimens cultured at 5-24psu successfully completed regeneration whereas 75% of specimens cultured at 0psu died and the survivors were unable to proceed beyond the blastema stage. Salinity did not have an effect on regeneration time (14.5-15.1 days) but did have an effect on the percentage of chaetigers regenerated (lowest -77% at 5psu, highest -97.5% at 15&). The post-regeneration phase was characterized by variability in pigmentation patterns in the regenerated anterior structures, which appear to be independent of salinity treatments. In conclusion, adult M. viridis appears to exhibit high tolerance to low salinity environments, which may have been inherited from its larval stages. In addition, the different pigmentation patterns observed in regenerated structures may allude to the variability of this feature in spionids.

Anterior regeneration in the polychaeteMarenzelleria viridis(Annelida: Spionidae)

“…). Recently, David & Williams () examined the impacts of salinity on regeneration and survival of M. viridis . However, the present study is the first to provide a detailed description of morphogenesis with scanning electron microscopy following ablation in the laboratory.…”

“…Researchers have indicated that its invasion success is, at least in part, due to its ability to reach high densities even under multiple environmental stressors such as pollution, hypoxia, and low salinity conditions (Bochert & Bick ; Bochert et al. ; Bastrop and Blank ; David & Williams ). In addition, its strong capabilities in regeneration could also play a role in its invasion success, and future studies should examine this possibility through field research and manipulative experiments.…”

Polychaete assemblages in a tropical hypersaline coastal lagoon of the southeastern Gulf of Mexico during the rainy season

“…Polychaetes are largely represented and abundant in estuarine environments (e.g. Glasby & Tarmo, 2008;Hernández-Alcántara, Cortés-Solano, & Solís-Weiss, 2011;Carvalho et al, 2011) and a variety of species are adapted to variable salinity ranges (David & Williams, 2016), including hypersaline conditions (Por, 1972;Lardicci et al, 1993;Lamptey & Armah, 2008;Can et al, 2009;Marzano et al, 2010;Joydas et al, 2011Joydas et al, , 2015. The few available studies of macrobenthic communities in natural hypersaline lagoons with salinity values above 50 psu report the presence of low abundant species tolerant to high salinity at values higher than ca.…”