tanaid Nototanais dimorphus

Nototanais dimorphus is found in Antarctica and the Antarctic Peninsula, Kerguelen Island, Marion and Prince Edward Islands, Macquarie Island, and southern tip of South America, from 4 to 230 meters depth [1,2,4,5,6,7]. N. dimorphus is a dominant species in the McMurdo jetty soft-bottom macrofaunal community and is a foundation species for the ecological community there, regulating species composition and population size (age) structure by preying on small species and small individuals of large species [8]. N. dimorphus lives in a tube and is located in or near its tube [8]. Its gut contents include diatoms, bacteria, and amorphous organic material [8,9]. The predators of N. dimorphus include the anemone Edwardsia meridionalis and the fish Trematomus bernacchii and Trematomus hansoni [8]. N. dimorphus transforms from female to male [1]. In this photo, the male is above the female [3].

The tanaid's upper body (thorax) has seven pairs of walking legs, the first of which has a large pincerlike claw for clasping and the second specialized for burrowing. The tanaid's abdomen has five pairs of swimming limbs and a pair of posterior appendages. Tanaids live on or in soft sediments and feed on organic detritus and plankton. The female carries eggs and developing young in a brood pouch on its underside.

1: Journal of Crustacean Biology 4(2):298-306, 1984; 2: Mitteilungen aus dem Zoologischen Museum in Berlin 56(1):45-71, 1980; 3: Kathleen Conlan, personal communication, 1999; 4: Journal of the Royal Society of New Zealand 13(4):279-294, 1983; 5: South African Journal of Antarctic Research 21(1):3-44, 1991; 6: A Survey of the Marine Fauna in Shallow Coastal Waters of the Vestfold Hills and Rauer Islands, Antarctica. MJ Tucker & HR Burton. ANARE Research Notes 55, 1987; 7: Tethys 6(3):631-653, 1974; 8: Ophelia 24(3):155-175, 1985; 9: Antarctic Science 14(1):3- 10, 2002

Text ©Peter Brueggeman. Photograph ©Canadian Museum of Nature (Kathleen Conlan). Photograph may not be used in any form without the express written permission of Canadian Museum of Nature (Kathleen Conlan).