Antarctic Science

Biological Sciences

Skin-digging tanaids: the unusual parasitic behaviour of Exspina typica in Antarctic waters and worldwide deep basins

Maria Chiara Alvaroa1, Magdalena Błażewicz-Paszkowycza2, Niki Daveya3 and Stefano Schiaparellia4 c1

a1 Museo Nazionale dell'Antartide (MNA), Sezione di Genova, Viale Benedetto XV no. 5, Genova I-16132, Italy

a2 University of Łódź, Department of Polar Biology and Oceanobiology, ul. Banacha 12/16, Łódź 90-237, Poland

a3 National Institute of Water and Atmosphere Research Ltd, 217 Akersten Street, PO Box 893, Nelson, New Zealand

a4 Dipartimento per lo Studio del Territorio e delle sue Risorse (Dip.Te.Ris.), Università di Genova, Europa 26, Genova I-16132, Italy


The order Tanaidacea includes over 1000 species which are mainly free-living or tube-dwelling detritivores. Exspina typica Lang, 1968 represents an exception to these common life styles, having being found in the intestine and body cavity of deep sea holothuroids. The 2008 New Zealand ‘IPY-CAML Cruise’ held in the Ross Sea collected several deepwater holothuroids that were observed to carry specimens of E. typica inside their coelomic cavity. A clear interpretation of this association was hence possible. Even if E. typica shows slight adaptations to a parasitic life style, the tanaids were found to actively ‘dig’ into the host's skin, grasping tissue with their claws and producing tunnels in the body wall. It is therefore possible to clearly define this association, which is here reported from the Antarctic for the first time, as parasitism.

(Received September 08 2010)

(Accepted December 09 2010)

(Online publication March 03 2011)


c1 corresponding author: