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Abstract

Survival of nematode species depends on how successfully they disperse in their habitat and in finding a new host. Under harsh environmental conditions many free-living nematodes stop development after the second larval (J2) stage and enter into a stage called the dauer larva. For dispersal, dauer larvae of multiple nematodes have evolved a specific behaviour called nictation or waving: worms stand on their tails and wave the body allowing for attachment to larger animal vectors. Nictation of individuals and attachment to insects under laboratory conditions is also described in the nematode Pristionchus pacificus. This behavior is crucial for Pristionchus since, under natural conditions, these nematodes rely on a tight association with scarab beetles, called necromenic. The dauer larvae invade the host, wait for its natural death, and then resume development by feeding on microorganisms that grow on the host carcass. Herein we report that Pristionchus pacificus nematodes synthesize a dauer stage-specific, extremely long-chain polyunsaturated wax ester that we name nematoil. Dauer larvae secrete nematoil to their body surface as an adhesive lipid that promotes the congregation of multiple individuals into large tower-like structures called dauer towers. The formation of the dauer towers is part of a novel host finding strategy, collective nictation, a process in which the whole dauer towers wave, presumably to maximize the chance of attaching to a new host organism.