Antarctic yoldia Yoldia eightsi

Yoldia eightsi is found in Antarctica and the Antarctic Peninsula, South Shetland Islands, South Orkney Islands, South Sandwich Islands, South Georgia Island, Kerguelen Island, Argentina, Chile, and Falkland Islands at depths from intertidal to 824 meters [1,2,3,4,5,8,11,12]. Y. eightsi is most common shallower than 100 meters depth [5].The shell covering (periostracum) of Y. eightsi is glossy yellow-olive or brown with well-defined brown growth rings between small yellow or orange zones; it may be dark brown in larger animals [3,9,12]. Shell size of Y. eightsi can reach 4.65 centimeters [3]. Using growth rate calculations, Y. eightsi at 3.5 centimeters in length are about 65 years old; those at 4.5 centimeters are about 150 years old [4,7].

Yoldia eightsi is found in soft sediment and burrows relatively shallow compared to other Yoldia, adopting a more horizontal shell orientation when burrowed [4,6]. Y. eightsi is both a deposit feeder on mud and a suspension feeder on diatoms [6].

The muricid gastropod Trophon longstaffi is a predator of Y. eightsi [13]. The brittle star Ophiosparte gigas has been found with Y. eightsi in its gut contents [10].

1: FAO Species Identification Sheets for Fishery Purposes : Southern Ocean (Fishing Areas 48, 58 and 88) (CCAMLR Convention Area). W Fischer & JC Hureau, eds. Rome : Food and Agriculture Organization of the United Nations, 1985; 2: Antarctic Journal of the United States 11:94):222-225, 1976; 3: Journal of Natural History 13(2):161-183, 1979; 4: Marine Biology 117(2):235-241, 1993; 5: Bulletin of the Royal Society of New Zealand 27:1-311, 1990; 6: Proceedings of the Royal Society of London 232(1269):431-442, 1988; 7: Marine Biology 117(2):243-250, 1993; 8: Antarctic Mollusca : with Special Reference to the Fauna of the Ross Sea. RK Dell. Wellington, NZ : Royal Society of New Zealand, 1990. Bulletin 27, Royal Society of New Zealand; 9: Biogeografia de la Peninsula Antartica, Archipielagos y Mares Adyacentes. N Bellisio & A Tomo. Buenos Aires : Servicio de Hidrografia Naval, 1974; 10: Polar Biology 16(5):309-320, 1996; 11: Scientia Marina 63(Supplement 1):399-407, 1999; 12: Moluscos Magallanicos : Guia de los Moluscos de la Patagonia y del Sur de Chile. DO Forcelli. Buenos Aires, Argentina : Vazquez Mazzini, 2000; 13: Polar Biology 26(3):208-217, 2003

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