Chemical sensing and avoidance of PaV1-infected conspecifics by pueruli post-larvae of the reef-dwelling Caribbean spiny lobster Panulirus argus Latreille, 1804 (Decapoda: Achelata: Palinuridae)

Abstract

Abstract Little is known about chemical sensing during settlement by pueruli of the Caribbean spiny lobster Panulirus argus Latreille, 1804 and the effect that Panulirus argus virus 1 (PaV1), the first pathogenic virus to infect any spiny lobster, has on settling pueruli. Considering that the avoidance of PaV1-infected lobsters by early-benthic juveniles is well documented and the previously reported costs of close proximity to PaV1-infected early-benthic juveniles (increased mortality risk), pueruli of P. argus should avoid infected conspecifics during settlement. We experimentally tested if pueruli show aversion to PaV1-infected conspecifics. We also re-tested the previously reported effect of red algae (Laurencia spp.) and healthy conspecifics on pueruli settlement decisions. Considering the known benefits of inhabiting red algae and costs of close proximity to conspecific juveniles, pueruli were predicted to be attracted to metabolites produced by red algae and repulsed by metabolites produced by conspecifics. We also predicted that attraction to red algae would decrease or cease if this cue was presented together with cues produced by PaV1-infected conspecifics. Our experiments indicate that pueruli do not avoid metabolites produced by benthic juveniles and are not attracted to metabolites produced by red algae. Importantly, pueruli are attracted to a combination of metabolites produced by red algae and conspecific juveniles but this attraction ceases if conspecifics are PaV1-infected. Our results indicate that PaV1 disrupts habitat selection by settling pueruli and suggest that assumptions about cost and benefits experienced by settling pueruli need to be revisited. Research to improve the understanding of the relationship between recruitment, disease avoidance, and fishery stock in this heavily exploited spiny lobster is needed.