Hydrachna mysorensis Cook, 1967

Smit, Harry, 2014, Australian water mites of the genus Hydrachna Müller, with the description of five new species (Acari: Hydrachnidia: Hydrachnidae), Zootaxa 3827 (2), pp. 170-186 : 178

Hydrachna mysorensis Cook, 1967

Hydrachna similans (non Marshall, 1928)—Lundblad (1969), K.O. Viets (1981).

Material examined. Queensland. 1/0/0, Fitzroy River, 15-iii-1983, leg. A.P. Mackay; 2/0/0, Shallow pool along road to Hanush Waterhole, Lakefield NP, 4-ix-2000; 1/1/2, White Lily Lagoon, Lakefield NP, 4-ix-2000; 1/2/2, Billabong W of Wenlock River, near crossing with roads to Iron Range NP, 10-ix-2000. Northern Territory. 0/1/0, Small billabong, Yellow Waters, Kakadu NP, 22-vii-1994; 0/1/0, Manton Dam, 12º 51.726 S 131º 0 7.148 E, 24-ix- 2005; 0/1 (juvenile)/2, Lake Jabiru, 12º 40.264 S 132º 50.436 E, alt 43 m asl, 27-ix-2005.

Remarks. Lundblad (1969) considered Hydrachna mysorensis a synonym of H. similans Marshall, 1928 , together with H. kloomi Imamura, 1964 and H. similis Cook, 1967 . However, given the much smaller dorsal shield of H. similans , I disagree with his conclusions. Moreover, the sketchy illustrations by Marshall (1928), lacking many important details, do not allow such conclusions. The males from Australia measure 802–896 in length and 786–875 in width, and therefore match the description of H. mysorensis . Hydrachna kloomi and H. similis are much smaller ( Cook 1967).

The dorsal plate of most of the Australian females covers about ¾ to almost the whole dorsum. Only in one juvenile female is the dorsal plate smaller. Cook’s (1967) description and illustration suggests that the dorsal plate of the Indian females is smaller. Previously known from the Northern Territory ( K.O. Viets 1981), India and Burma.