Population dynamics of the giant jellyfish Nemopilema nomurai with age structure

Abstract

We propose and study a three-stage life cycle model of Nemopilema nomurai with a distributed delay to explore the roles of podocyst playing in blooms, and the potential strategies for controlling outbreaks of the giant jellyfish. Our new proposed CPM model is more realistic by considering dormant podocyst, the exclusive form of asexual reproduction of N. nomurai. We investigate the effect of the podocyst production rate and the strobilation rate on the population size, and demonstrate the interannual variation of three phases in the Dalian sea. Our study shows that (1) the long-term dormancy would result in the cardinal number of podocysts multiplying but no discernible effects on a long time dynamics; (2) sensitivity analysis confirms that the recurrence of medusae of N. nomurai is most sensitive to the bottom-up supplement and the key process of the life cycle is strobilation; (3) the effective control strategies are to increase the harvest of ephyrae and to reduce the expansion of substrates.