Testudacarus japonicus Imamura, 1955

O'Neill, Joseph C., Fisher, J. Ray, Nelson, Whitney A., Skvarla, Micheal J., Fisher, Danielle M. & Dowling, Ashley P. G., 2016, Systematics of testudacarine torrent mites (Acari, Hydrachnidia, Torrenticolidae) with descriptions of 13 new species from North America, ZooKeys 582, pp. 13-110 : 86-87

Taxon classification Animalia Trombidiformes Torrenticolidae

Testudacarus japonicus Imamura, 1955

Testudacarus japonicus : Imamura 1955: 182, 186-187; Imamura 1965: 238; Lundblad 1967: 418; Imamura 1976: 283-284; Imamura 1980: 343; Imamura 1986: 381; Viets 1987: 724; Wiles 1997a: 201, 209; Abé 2005: 120; Abé 2006: 6; Abé et al. 2006: 14.

Type series.

Holotype (1♂): Shizuoka, Japan: brook connected with a stream in Takékura, Mishima, Shizuoka, Japan, 15 May 1953, by T. Imamura.

The types were not examined for this publication.

Type deposition.

Holotype (1♂) at Taiji Imamura Collection at Ibaraki Nature Museum, Japan.

Holotype loans are not available from Ibaraki Nature Museum. The museum provided a low-magnification photograph through e-mail, though permission to print the photograph was not obtained.

Diagnosis.

These mites differ from all other Testudacarinae by distribution (Japan), and from Testudacarus tripeltatus by small size (dorsal length <700 µm). Testudacarus japonicus may be conspecific with Testudacarus okadai . More research and updated descriptions are needed for a better diagnosis.

Distribution.

Takékura, Japan ( Imamura 1955).

Remarks.

It is reasonable to assume Imamura (1955) had no knowledge of Habeeb (1954) because he never mentions Testudacarus vulgaris and there are inaccuracies in his description that could have been prevented if he had. Firstly, his “female” type specimen is almost certainly a male as "the genital area [is] relatively more to the posterior than in [females] and the two [dorsal muscle scars] … are located posterior to the [glandularia]" ( Habeeb 1954). Furthermore, in his remarks he states the "Japanese specimen resembles most the Indian species," which with more current information is unlikely. At the time, Testudacarus japanicus would have been most similar in size, color, and shape to either Testudacarus vulgaris or Testudacarus minimus , not Testudacarus tripeltatus . Most importantly, the Testudacarus japonicus type is almost certainly male and therefore shares little morphology with the female Testudacarus tripeltatus . Therefore, the distinctions Imamura (1955) offers that Testudacarus japonicus are "different from [ Testudacarus tripeltatus ] in the anterior tips of the first [coxae], [pedi]palps, situations of [coxae] and genital organ" are unhelpful ( Imamura 1955). He is referring to sexual dimorphism and comparing only the two most disparate species available to him.