Cryptic effects of biological invasions: Reduction of the aggressive behaviour of a native fish under the influence of an “invasive” biomolecule

• Published in: PloS one Vol. 12; no. 9; p. e0185620
• Main Authors: Magliozzi, Laura, Almada, Frederico, Robalo, Joana, Mollo, Ernesto, Polese, Gianluca, Gonçalves, Emanuel J., Felline, Serena, Terlizzi, Antonio, D’Aniello, Biagio
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 29.09.2017; Public Library of Science (PLoS)
• Subjects: Aggression; Aggressive behavior; Aggressiveness; Aggressiveness (Psychology); Algae; Analysis; Animal tissues; Animals; Aquatic plants; Behavior; Behavior, Animal; Bioactive compounds; Biocompatibility; Biodiversity; Biological effects; Biology and Life Sciences; Caulerpa; Chlorophyta; Chromatography; Competitive advantage; Diet; Discriminant analysis; Ecology and Environmental Sciences; Ecosystems; Environmental science; Fish; Fish behavior; Fish populations; Indigenous species; Introduced Species; Invasive species; Medicine and Health Sciences; Metabolism; Metabolites; Native species; Nonnative species; Oncorhynchus mykiss; Perciformes; Physiology; Sea Bream - physiology; Italy
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0185620

The invasive green alga Caulerpa cylindracea has become an important component of the diet of the Mediterranean white seabream Diplodus sargus. As a consequence of this "exotic diet", the algal bisindolic alkaloid caulerpin accumulates in the fish tissues. Although the compound shows structural similarity to endogenous indolamines that modulate animal behaviour, the potential impact of caulerpin on fish behaviour still remains unexplored. In this report, behavioural experiments both on groups and on single fish responding towards a mirror were performed under different doses of dietary caulerpin. Differences between treated and control groups for each behaviour and for the overall aggressive pattern during the different experimental phases showed that the aggressiveness of D. sargus decreased with the administration of caulerpin. These results call the attention to a still unexplored potential ability of bioactive metabolites from marine invasive species, to alter the behaviour on native species, with putative negative effects on patterns of fish growth and population dynamics.