Arrenurus male specie incerta

Arrenurus Dorsal view

Here an is Arrenurus which looks like Arrenurus Securiformis but which may be not of this specie.

Length 1.2mm.

Element that doesn’t match Arrenurus Securiformis.

  • The shape of the cauda looks less lixke an axe than Securiformis (shape of an axe in latin).
  • The end of the cauda is not blueish.
  • The size is 1.2mm against 1.0/1.1mm for the Securiformis.
  • The line of the second and first coxae plates are more linear than in Securiformis.
  • The 2 points in the cauda are invisible.
  • The color is globally more yellowish (but it may not be very variable in hydracarinae)
  • Much less blue (back, cauda, epimera…) than in Securiformis

Help required.

If you have an idea on the identification of this arrenurus male, you can leave a comment on this site. Thanks.

Remark : it may be a young form of Securiformis ?

Idea of identification.

  • Arrenurus Claviger :  Soar & Williamson – Page 117 vol 3. But : Petiolus ressembling a flask ?? Large double tubercule on the dorsum well back on the cauda ??
  • Arrenurus Bicuspidator : not the same global shape : see
  • Arrenurus Globator :  Soar & Williamson – Page 129 vol 3 . But length of male Globator up to 0.8mm ? Greatest breadth about the third pair of epimera ? Dorsal groove passing down the side of the cauda ?
  • Arrenurus moebii Piersig 1899 (=arrenurus zachariae Koenike, 1886). Piersig – 1900 – Deutschlands Hydrachniden – P721 : a lot of similarity on the general shape level. P290 : text
  • arrenurus zachariae Koenike, 1886. Piersig P631 + Tafel XXIX fig 76a. The dorsal furrow is not visible on my pictures.
  • Arrenurus cylindratus : Piersig – 1900 – Deutschlands Hydrachniden – P580 tafel XL fig 112. Not ok : first epimera.
  • Arrenurus tubulator : Piersig – 1900 – Deutschlands Hydrachniden – P580 tafel XL fig 116. Not ok : cauda less like securifiormis.
  • Arrenurus buccinator. Müller – 1781 – Hydrachnae, quas in aquis Daniae palustribus  – plate III fig 1 :  Some similarity with the shape of the cauda.

Other pictures.

  • Arrenurus Cauda

    Arrenurus Coxae plates

    Arrenurus genital area

    Arrenurus frontal

    Arrenurus frontal ventral


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