Combined Effects of Temperature and Salinity on Polyps and Ephyrae of Aurelia solida (Cnidaria: Scyphozoa)

Abstract

Jellyfish outbreaks are conspicuous natural events in marine ecosystems that have a substantial impact on the structure and dynamics of marine ecosystems and different economic sectors of human activities. Understanding the life cycle strategies of jellyfish species is therefore critical to mitigate the impacts these organisms may have. In this context, the present study investigated the effect of different temperature and salinity regimes on the rearing success of the jellyfish Aurelia solida in microcosm experiments on two different life stages: polyps and ephyrae. Polyps showed high survival rates across the different conditions (except at 28 °C/20 psu) and reproduced asexually in all combinations, with the highest budding activity at 20 °C and 30 psu. Strobilation occurred mainly at 16 °C and 35 psu. Although ephyra survival was highest at low salinities (20 psu) and lower temperatures (10 and 15 °C), the highest growth rates were reached at intermediate temperatures (20 °C). The comparison to other Aurelia species underlines the differences between even closely related species. Given the high tolerance capacity that A. solida presented in the experiments, the species has the potential to cope well under current climate change scenarios and possibly adapt successfully to other regions and ecosystems.

Jellyfish diversity, trends and patterns in Southwestern Mediterranean Sea: a citizen science and field monitoring alliance

“…However, A. solida is native to the Red Sea, one of the most saline water bodies in the world's ocean (Ngugi et al, 2012) and where temperature varies from 15 • C to 33 • C during A. solida occurrence (El-Serehy and Al-Rasheid, 2011). Moreover, under laboratory conditions, A. solida polyps and ephyrae, originated from the Adriatic Sea, displayed optimum conditions in survival, asexual reproduction and somatic growth in estuaries-like salinities (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35) and for temperatures varying between 10 • C and 20 • C (Schäfer et al, 2021). Therefore, the probable existence of metapopulations with different ecological characteristics might explain the virtual absence of A. solida in the TP ecoregion.…”

Successful Culture of Pelagia noctiluca (Cnidaria: Scyphozoa) Over Time: A Continuous Supply of the Holoplanktonic Jellyfish for Research and Industrial Applications

“…Exponential somatic growth during the first weeks of development is a typical trend for jellyfish species (Widmer, 2005;Lilley et al, 2014;Ramondenc et al, 2019;Schäfer et al, 2021). Instantaneous growth rates were fastest during early stages and gradually slowed thereafter, when jellyfish invested more energy in the formation and maturation of gonads and egg production than in growth (Figure 6).…”

Microbial community changes correlate with impaired host fitness ofAurelia auritaafter environmental challenge

“…Environmental factors such as temperature, salinity, or food supply influence both the asexual reproduction of the polyps and medusa ecology, such as somatic growth and sexual maturation (Pitt & Kingsford 2000; Xing et al . 2020; Schäfer et al . 2021).…”

“…Temperature plays a crucial role in the reproduction of polyps (e.g., (Willcox, Moltschaniwskyj & Crawford 2007; Purcell et al . 2012; Loveridge, Lucas & Pitt 2021; Schäfer et al . 2021).…”

“…2021). At higher temperatures, polyps tend to reproduce daughter polyps by budding, while below a certain threshold, strobilation is triggered to reproduce planktonic ephyrae (Schäfer et al . 2021).…”