Sound production and associated behaviours in the New Zealand spiny rock lobster, Jasus edwardsii

Abstract

There is extensive knowledge of sound production and their associated behaviours among semi-terrestrial and terrestrial crustaceans. However, there is a lack of research into sound production in aquatic crustaceans. Previously, it was believed that the New Zealand spiny rock lobster (Jasus edwardsii) was a silent species, yet recent anecdotal evidence suggests that this species is in fact capable of producing sound. The aim of this study was to identify sounds produced and determine behaviours associated with sound production of J. edwardsii. Using tank-based experiments equipped with acoustic and video recorders, sound production and behaviour was monitored under different trial conditions (individual, group, feeding, and rasp playback). Jasus edwardsii produced a mutli-pulsed broadband sound signal called the rasp. Rasps were produced both individually and in group settings and were not influenced by size of individuals. In feeding trials, rasp characteristics differed from non-feeding scenario rasps (i.e. normal rasp) and rasp production rate increased. During feeding trials, J. edwardsii displayed guarding behaviours, where larger individuals would not allow smaller individuals near the food source. When “feeding rasps” were played back through an underwater speaker, individuals exhibited searching behaviour and travelled further distances in the tank. In conclusion, this study shows that J. edwardsii is capable of producing sound and identifies behaviours associated with sound production. The rasp may act as an intraspecific communication signal in J. edwardsii, especially in the feeding behaviour of this species.