Uncovering deep mysteries: the underwater life of an amphibious louse

M.S. LEONARDI; C. LAZZARI

Salt Lake City

Conferencia; Internacional Conference on Phthiraptera; 2014

Echinophthiriids lice are among the few insects that successfully colonized the marine realm. This particular adaptation is the result of a long co-evolutionary process that began with the terrestrial ancestor of the present amphibious species. One of the key issues related with this process is to understand how lice adjust their life style to fit the diving behavior of their hosts. The aim of this presentation is to discuss current knowledge and to present new results from physiological experiments that shed light on the underwater life of echinophthiriids. We experimentally analyzed the underwater survival of Antarctophthirus microchir obtained from South America sea lions (Otaria flavescens). The experiments show that A. microchir can survive long periods of time submerged in sea water. Also, these lice survive better in oxygenated than in hypoxic water. Our work indicates that underwater respiration is not essential for louse survival, but lice do better when more oxygen is available. Our study provides evidence of a quiescence state in submerged A. microchir. Further work is necessary to understand how A. microchir absorbs oxygen dissolved in sea water.