Substrate choice and settlement preferences of planula larvae of five Scyphozoa (Cnidaria) from German Bight, North Sea

• Published in: Marine biology 2007-05, Vol.151 (3), p.863-871
• Main Authors: HOLST, Sabine, JARMS, Gerhard
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal behavior; Animal, plant and microbial ecology; Aurelia aurita; Biological and medical sciences; Chrysaora hysoscella; Cnidaria; Cnidaria. Ctenaria; Cyanea capillata; Cyanea lamarckii; Developmental stages; Experiments; Fundamental and applied biological sciences. Psychology; Habitats; Invertebrates; Larvae; Marine; Marine biology; Marine debris; Marine pollution; Mollusks; Rhizostoma octopus; Scyphozoa; Sea water ecosystems; Substrates; Synecology
• ISSN: 0025-3162; 1432-1793
• DOI: 10.1007/s00227-006-0530-y

The settlement behaviour of planula larvae and their development to young polyps was investigated in laboratory experiments in five scyphozoan species [Aurelia aurita (L.), Cyanea capillata (L.), Cyanea lamarckii Peron and Leseur, Chrysaora hysoscella (L.), and Rhizostoma octopus (L.)]. The undersides of settling plates were strongly preferred for settlement. Shells, the only natural substrate type offered, were less attractive than artificial substrates (concrete, machined wood, polyethylene, and glass). The advantages of colonization of substrate undersides for survival and reproduction of polyps are discussed. It is supposed that the increase of artificial substrates in our seas, due to marine litter pollution and submarine building activities, enlarge the areas of distribution of scyphozoan polyps, in coastal as well as in off-shore regions. Subsequent increases in ephyra production by polyps are probably one reason for the increase in mass occurrences of jellyfish recognized worldwide during the last few decades. It is suggested that the early developmental stages in the cnidarian life cycle, the planula larvae, and the polyps, play the key role in the development of jellyfish outbursts. [PUBLICATION ABSTRACT]