Micropathus fuscus Richards, 1968

Micropathus fuscus Richards, 1968 View in CoL

Figs 1–2 View Fig View Fig , 7 View Fig , Table 1

Micropathus fuscus Richards, 1968: 171–174 View in CoL , fig. 2.

Micropathus fuscus View in CoL – Richards 1971: 579 (in key); 1974: 252 (in key).

Diagnosis

Micropathus fuscus has a dark brown body colouration mottled with lighter brown patterning ( Fig. 7 View Fig ). The apices of the hind femora variably bear an apical spine on the retrolateral side. Micropathus fuscus is the only known member of Micropathus with ventral linear spines on both the prolateral and retrolateral sides of the hind femora, although we note the former does not occur in all individuals due to intraspecific variation. In other species, ventral linear spines either occur on the retrolateral side only, with no variation ( M. cavernicolus , M. montanus , M. zubat sp. nov. Beasley-Hall), or the hind femora lack these spines entirely ( M. ditto Beasley-Hall sp. nov., M. kiernani , M. tasmaniensis ). The distal margin of the suranal in M. fuscus has a medial notch in both sexes ( Fig. 2 View Fig ). The female subgenital plate bears long lobes originating from the plate’s distal surface and in contact throughout their entire length. The lobes are usually rounded at the apex but may be broken in adults.

Etymology

Not explained by Richards. The Latin adjective ‘ fuscus ’ means ‘dark’ or ‘brown’, referring to the body colour of the species.

Type material

Holotype

AUSTRALIA – Tasmania • ♂; unnamed cave 34 chains N of Heka , 3 miles NW of Gunns Plains; 6 May 1967; A. Goede leg.; ANIC 14-042010 About ANIC ; ANIC.

Paratype

AUSTRALIA – Tasmania • ♀; same data as for holotype; molecular data only; GenBank : PV440717 ( COI); ANIC 14-008969 About ANIC ; ANIC .

Other material examined

AUSTRALIA – Tasmania • 1 ♀; Julius River Forest Reserve ; 41.143° S, 145.04° E; 130 m a.s.l.; 28 Feb. 2021; B. Costello leg.; photograph; iNaturalist 70307645 GoogleMaps .

Redescription

As in Richards (1968), with exceptions as follows: male suranal plate with distal margin curved ventrally and with a dentate fringe of small, dark brown tubercles underneath, but without pronounced spine-like projections. Hind femur variably bearing a small retrolateral apical spine and 0–1 prolateral and 3–6 retrolateral ventral linear spines. Hind tibia with 22–31 prolateral and 20–30 retrolateral dorsal linear spines. First segment of hind tarsus with 0–2 prolateral and 1–3 retrolateral dorsal linear spines. Second tarsal segment with 0–2 dorsal linear spines prolaterally and retrolaterally.

Distribution

Micropathus fuscus was described from caves in the Gunns Plains karst in northern Tasmania ( Fig. 1b View Fig ). Richards later observed the species at Loongana in Leven Cave (L3) and further west at Trowutta Arch. We have been unable to examine material from Loongana, but a photograph from the citizen science platform iNaturalist suggests the presence of the species approximately 1 km from Trowutta based on its distinctive body colouration ( Fig 7 View Fig ; see Other material examined). Micropathus fuscus is not known from elevations above 300 m ( Richards 1987) and so far all records of the species have been from caves.

Remarks

While the holotype label of M. fuscus states it was collected 3 miles northwest of Gunns Plains, the species description reads “ 5 km southwest”, making it difficult to pinpoint a precise type locality. Richards differentiated M. fuscus from other members of the genus by a lack of spine-like projections on the distal margin of the male suranal plate ( Richards 1974). However, upon inspecting the holotype we observed a convex, dentate fringe of dark brown tubercles on either side of the distomedial notch. While the species indeed lacks clearly pronounced spine-like projections compared to some other members of Micropathus , it appears this character is more variable than originally described by Richards. Both M. fuscus and M. kiernani can be distinguished by their dark brown body colouration, with other members of Micropathus being a light to mid brown.