The fear of invasive 'killer shrimps' can intimidate native organisms to search for a degree that they are incapable of performing their vital role in river systems, a new study suggests.
Acta Oecologica Scientists focus on the invasive Dikerogammarus villosus which has been steadily replacing resident Gammarus species in river across Europe over the past three decades.
This is having major localized effects
The new study shows for the first time that the mere presence of the predator-a so-called non- consumptive effect (NCE) ̵
It leads to expending more energy in simply avoiding the predator in a bid for self-preservation, rather than focussing on core
The research was conducted by independent consultant dr. Calum MacNeil and Mark Briffa, Professor of Animal Behavior at the University of Plymouth.
Gammarus species (commonly found in European rivers) were placed inside a tank.
The behavior of the Gammarus were then evaluated over the space of several days, with researchers measuring the length of shredded leaves as they would be
The Gammarus specimen showed lower shredding efficiency in the presence of the caged 'killer shrimp' compared to the treatments where it was absent.
Dr. MacNeil, who has spent more than 20 years studying the species in this study, said, "This study demonstrates an unappreciated and indirect impact of a biological invasion by a pre-existing predator However, the Gammarus in our experiment had no prior exposure to its predatory rival
Professor Briffa, whose research has previously been included in the Assessments of Fighting within Species as well as crabs and sea anemones, added: "Our results indicate that the effect of NCEs on functionally important Species may have ramifications, for example, impacting the recovery of stream communities following perturbation A better understanding of the role of NCEs during biologi cal invasions could enhance their ability to predict their progress and, in some cases, the ecosystem level ramifications. "
Predators vs. alien: European shrimp win predatory battles with american invader
Calum MacNeil et al, Fear alone reduces energy processing by resident 'keystone' prey threatened by an invader; a non-consumptive effect of 'killer shrimp' invasion of freshwater ecosystems is revealed, Acta Oecologica (2019). DOI: 10.1016 / j.actao.2019.05.001
Fear of 'killer shrimps' could pose major threat to European rivers (2019, June 4)
retrieved 4 June 2019
This document is copyrighted. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is for information purposes only.