parasitic copepod, possibly Eubrachiella antarctica

A common parasitic copepod on Antarctic fish is Eubrachiella antarctica [6,7,8]

Parasitic copepods like these on the tail fin of the Antarctic cod Dissostichus mawsoni are free-swimming as juveniles [1,2].


Females find a host, attach, and are stationary for life, diverting their energy to reproduction; males move or swim around to find females to reproduce [1,2].

Eubrachiella antarctica pygmy males attach to the female E. antarctica near its genital porus [7] This female parasitic copepod is burrowed into the skin, sucking blood and fluids or grinding away at flesh [1,3]. The female stores the male's sperm and fertilizes its eggs as it expels them into chitinous sausage-like ovisacs [3,4]. The ovisacs gradually lengthen as eggs are expelled [4].

In adapting to their parasitic lifestyle, these copepods have changed substantially from non-parasitic copepods in order to secure a hold on the host and increase their reproductive activity [5]. Parasitic copepods developed various grasping mechanisms like antennae or body outgrowths to hold on or embed themselves into hosts [5].

Parasitic copepods can be relatively benign or life-threatening for a fish, depending on the number of parasites, the organ system affected (fins, skin, gills, internal organs), the age of the fish, environmental conditions, and other factors [3].

1: Copepod Parasites of Marine Fishes. NK Pillai. Calcutta : Zoological Survey of India, 1985; 2: Parasitic Copepoda of British Fishes. Z Kabata. London : Ray Society, 1979; 3: Parasitic Copepodes on the Fishes of the USSR = Paraziticheskie Veslonogie Ryb SSSR. AP Markewitch. New Delhi : Published for the Smithsonian Institution and the National Science Foundation by the Indian National Scientific Documentation Centre ; Springfield, VA : available from the National Technical Information Service, 1976; 4: British Parasitic Copepoda. T Scott & A Scott. London : Ray Society, 1913; 5: Copepods Parasitic on Fishes. Z Kabata. Synopses of the British Fauna (New Series) No. 47. Oegstgeest, Netherlands : Universal Book Services/Dr W Backhuys, 1992; 6: Proceedings of the NIPR Symposium on Polar Biology 9:169-177, 1996; 7: Archiv fuer Fischereiwissenschaft 28(2/3):149-156, 1977; 8: Meeresforschung 28(2-3): 146-156, 1980

Text ©Peter Brueggeman. Photographs ©Peter Brueggeman & Paul Cziko. Photographs may not be used in any form without the express written permission of Peter Brueggeman & Paul Cziko.