Gasterogramma spp.: Introduction

(Order Polydesmida, family Dalodesmidae)

There are eight known species in this H+20 genus. Atypically for Tasmanian millipedes, the genus seems to have an 'ecologically restricted' range, being almost entirely confined to those parts of Tasmania with an annual rainfall of at least 1000 mm (shaded areas on map at right). Adults are up to 20 mm long and body colour in different species ranges from pinkish white to dark, mottled purple-brown. The same colour range is found in the single species G. psi, which is also the only Gasterogramma with a 'harlequin' patterning of dark, round, lateral spots on a light background (above, bottom right). Several of the pink-purple species have a very strong-smelling defensive secretion, which has earned them the nickname 'stinky pinkies'.

It can be very difficult to separate Gasterogramma species without examining the gonopods of mature males (see the identification page). However, the seven species other than the widespread G. psi have a mosaic distribution (see the distribution page), and location can sometimes help in assigning females and juveniles to species.

Gasterogramma are forest-dwelling, burrowing millipedes which are more likely to be found in the soil than in leaf litter or rotting wood. All species seem well-adapted to disturbance. G. psi and G. wynyardense (Bonham et al. 2002) and G. rusticum (Mesibov 2005a) are abundant in Pinus radiata plantations, and G. austrinum is abundant in eucalypt regrowth arising from clearfall-and-burn silviculture (Mesibov 1997b).

More information:
 
Taxonomy - Jeekel (1982b), Mesibov (2003b)
Distribution, conservation and general - Mesibov (1993b), Mesibov et al. (1995), Mesibov (1997b), Mesibov (1998a), Mesibov (1999), Bonham et al. (2002), Mesibov (2003b), Mesibov (2005a)