Caribbean spiny lobsters equally avoid dead and clinically PaV1-infected conspecifics

Abstract

Social behaviour in Caribbean spiny lobsters (Panulirus argus) is mediated by conspecific chemical cues. These lobsters can be attracted to shelters emanating chemical cues from conspecifics but tend to avoid shelters emanating chemical cues from injured conspecifics, dead conspecifics, and conspecifics with visible signs of a potentially lethal disease caused by the pathogenic Panulirus argus virus 1 (PaV1). However, previous studies have not controlled for the presence of PaV1 (i.e. subclinical infection) in grossly “healthy” lobsters, although visible signs of disease do not appear until several weeks after infection. We conducted a controlled experiment using a set of 2 m-long Y-mazes to examine and contrast the response of P. argus lobsters to shelters emanating chemical cues from conspecifics in four different conditions: uninfected, subclinically PaV1-infected (i.e. infected but not diseased), clinically PaV1-infected (i.e. infected and diseased), and dead. Using polymerase chain reaction, we tested for PaV1 in all grossly healthy lobsters and used exclusively uninfected lobsters in intermolt as focal lobsters. Focal lobsters similarly avoided shelters emanating chemical cues from clinically infected (80% avoidance) and from dead conspecifics (85% avoidance), but their response to chemical cues from uninfected and from subclinically infected conspecifics did not differ significantly from random. These results indicate that PaV1-diseased lobsters produce chemical cues that are as repellent to conspecifics as are chemicals emanating from dead conspecifics, and that subclinically infected lobsters either do not emit the repellent chemicals or they do so at sub-threshold levels. However, the nature of the repellent chemicals and whether they originate from the pathogen or the host remains to be determined.

White Spot Syndrome Virus and the Caribbean Spiny Lobster, Panulirus argus: Susceptibility and Behavioral Immunity

“…However, when responses of test lobsters to WSSV infected conspecifics were compared to the responses of the healthy control animals, there was a significant increase in avoidance behavior (n = 56, p < 0.0001). Previous work by Behringer et al (2006) and Candia-Zulbarán et al (2015), using similar methods, have reported that lobsters aggregate with PaV1 infected conspecifics in only 20% of all trials [n = 20, p = 0.012; results from Candia-Zulbarán et al (2015)] and are detailed here for comparison (Fig 5) [29, 40]. This represents significant avoidance of PaV1 infected individuals when compared to 50% or random sheltering.…”

“…Panulirus argus also avoids dead conspecifics [40]. Avoidance of dead conspecifics may also occur through necromones, which are associated with decomposing organisms [40, 52, 53]. Avoidance of injured, dead, or diseased conspecifics results in a form of behavioral immunity, protecting against predation and disease via avoidance [11, 31, 52–56].…”

Do ecological characteristics drive the prevalence of Panulirus argus virus 1 (PaV1) in juvenile Caribbean spiny lobsters in a tropical reef lagoon?

“…Although most of the lobsters that we sampled were found in experimental casitas, there is no evidence that the prevalence of PaV1 is any higher in areas where casitas are used [9,14,15,25]. This is probably because healthy lobsters avoid diseased conspecifics [17][18][19][20], and if forced to share a casita with a diseased lobster (e.g., due to the risk of predation), they tend to keep some distance from the diseased lobsters [40].…”

“…Although Caribbean spiny lobsters are gregarious, healthy lobsters tend to avoid heavily PaV1-infected conspecifics, which may help curb prevalence levels [17][18][19][20]. However, infections involve interactions not only between the pathogen and the host, but among networks of species [21].…”

iTRAQ-Based Proteomic Profile Analysis of the Hepatopancreas of Caribbean Spiny Lobsters Infected With Panulirus argus Virus 1: Metabolic and Physiological Implications

“…Due to the semi-open nature of the crustacean circulatory system, the change in the biosynthesis of this neuroactive compound could also affect the behavior and motility capabilities of the host (Giles and Usherwood, 1985;Stentiford et al, 1999). Considering that infected lobsters are avoided by healthy conspecifics (Behringer et al, 2011;Candia-Zulbarán et al, 2015), taurine could be tested as an odorant compound potentially mediating this social interaction (Giles and Usherwood, 1985).…”