Boreohesperus delicatus, Car, Catherine A. & Harvey, Mark S., 2013

Car, Catherine A. & Harvey, Mark S., 2013, A review of the Western Australian keeled millipede genus Boreohesperus (Diplopoda, Polydesmida, Paradoxosomatidae), ZooKeys 290, pp. 1-19 : 7-9

Boreohesperus delicatus sp. n. Figs 1C49

Type material.

Holotype male: 6 km SE. of Marda Pool, Pilbara Biological Survey site DRW10, Western Australia, Australia, 21°04'11.8"S, 116°12'15.5"E, May 2004, CALM Pilbara Survey (WAM T76070).

Paratypes: 1 male, 1 female and 1 immature male, same data as holotype (WAM T126117); 1 male (gonopod only), 11 km ESE. of Marda Pool, Pilbara Biological Survey site DRW07, Western Australia, Australia, 21°03'20.4"S, 116°15'06"E, May 2004, CALM Pilbara Survey (WAM T76065).

Etymology.

This species is named for its tiny size and delicate gonopods (delicatus, Latin, adjective, dainty).

Diagnosis.

This species is most similar to Boreohesperus undulatus sp. n. but the gonopods of the two species differ in the following ways: (1) in Boreohesperus delicatus sp. n. the femorite and non-seminiferous branch (NSB) together form a relatively narrow boat shape (Figs 4E, F) whereas in Boreohesperus undulatus sp. n. they form a much broader spindle-shaped branch when viewed medially or laterally (Figs 8E, F); (2) the base of the solenomere of Boreohesperus delicatus sp. n. arises approximately midway between the tip of the NSB and the distal end of the prefemur (Figs 4 C–F), whereas that of Boreohesperus undulatus sp. n. arises closer to the prefemur (Figs 8C, F); and (3) Boreohesperus delicatus sp. n. does not possess a posterior process (Fig. 4C), as in Boreohesperus undulatus sp. n. (Fig. 8C).

Description.

Holotype male: Body approximately 7 mm long; mid-body ring approximately 0.75 mm wide dorsally with distinct waist between prozonite and metazonite; legs of moderate length, approximately equal to length of 1 to 2 mid-body rings. Colour bleached by alcohol. Paranota on all but first few body rings small. Sternites, other than those of fifth body ring, with no noticeable features. Anterior spiracles at mid-body flat circular. Antennae distinctly clavate, of moderate length, extending approximately to first body ring behind collum (to body segment 2), antennomeres relatively robust (Figs 4A, B). Gonopod of medium length, extending to posterior edge of fifth body ring; coxa (C) much broader than acropodite and approximately 2 × as long as broad; prefemur (PF) short, sub-globose; femorite (F) short, one-quarter to one-third length of acropodite, noticeably narrower at base, then broadening; non-seminiferous branch (NSB) broadest at solenomere base then narrowing to form roughly triangular shape with broadly rounded tip; process on medial surface of NSB (nsbp) slender, arising approximately midway between NSB tip and base of solenomere (bs), similar in length to NSB, extending well beyond branch tip; solenomere (S) relatively long and slender, arising midway between NSB tip and prefemur, forming a distinct ‘S’ shape when viewed in any orientation; solenomere tip divided into two, main pointed ribbon-like forks, with third small spine-like process (stp) seemingly arising between main forks; solenomere process (sp) absent; separate posterior process (pp) absent (Figs 1C, 4 C–F).

Female: Similar to male, except for genitalic features.

Distribution.

This species is known only from the locality of Marda Pool in the Pilbara Region (Fig. 9) where it was found co-occurring with Boreohesperus undulatus sp. n.