Meeting Abstract

97.4  Sunday, Jan. 6  Rapid Burrowing by the Mantis Shrimp Squilla empusa VETTER, K. M.*; BUMP, P.; Denison University; Univ. of Hawaii, Manoa ksmvetter@gmail.com

Mantis shrimp rely on their burrows for shelter, protection from predators, reproduction efforts, and food manipulation. While some species incur great costs during burrow construction and consequently maintain each burrow for a long time, Squilla empusa can create simple burrows very rapidly. We investigated S. empusa burrowing by collecting nine animals and filming their burrowing motions in the laboratory using high speed video and particle image velocimetry. We also released captive animals back into their native habitat and filmed the resulting burrow excavation in situ. In both in the laboratory and in the field, S. empusa employed two methods of moving sediment: pleopod fanning, which directed stirred-up sediment posteriorly, and bulldozing, in which the animals carried sediment forward in a basket made of their maxillipeds. Pleopod fanning occured in short bursts: S. empusa formed depressions deep enough to accommodate their body in about two minutes. After this stage, maxilliped bulldozing became the dominant excavation method. Video analysis suggested that pleopod fanning effectiveness was improved by rotational movements of the pleopods that directed the resultant current medially. Scanning electron micrographs indicated that the extremely setose nature of the pleopods greatly increased their surface area, facilitating current generation. The formation of the maxilliped basket was enhanced by a complex arrangement of setae, especially on maxilliped pairs 3-5, that interlocked to form a robust chamber able to carry substantial amounts of varied substrate. Together, the morphology of the appendages and the dynamics of their movement made it possible for S. empusa to make completely new burrows in less than thirty minutes, and to carry out daily adjustments to already existing burrows.