Atrophotergum spp.: Introduction

(Order Polydesmida, family Dalodesmidae)

There are six named and two undescribed Tasmanian species in this H+19 dalodesmid genus, formerly coded as 'genus A'. An adult male of the type species, A. silvaticum, is shown in the left-hand image, above. All Atrophotergum spp. share a number of peculiar characters, including a complex posterior projection on the gonopod (right-hand image above; head is to right) whose shape is important in species-level identification. Adult lengths are in the range 6-14 mm. Atrophotergum spp. are unusual in the Tasmanian Polydesmida in that males are larger than females (see image below).

The distributions of the six named Atrophotergum species form a tightly fitted geographical mosaic (see map). Within their respective ranges, Atrophotergum species are generally found in the upper layers of eucalypt forest litter, and appear to tolerate considerable habitat disturbance. A. montanum is remarkable for its abundance in subalpine habitats on the Central Plateau, and the northwest species A. bonhami and A. silvaticum are found in Pinus radiata plantations (Bonham et al. 2002).

For species information, go to the Atrophotergum identification page.

Adult male (left) and female (right) of A. montanum from Projection Bluff.

More information:
 
Taxonomy - Mesibov (2004a)
Distribution, conservation and general - Mesibov (1999), Bonham et al. (2002) [as 'genus A, sp. 1' = A. silvaticum, and 'genus A, sp. 5' = A. bonhami]