Reproduction, egg morphology and development observed in Monographis queenslandica (Diplopoda: Polyxenidae)

This study provides new insight into penicillate sexual behaviour and egg
development as observed in Monographis queenslandicus Huynh et Veenstra, 2013
(Polyxenidae). The developing eggs were found to have two distinct stages, namely the
chorion and pupoid, which both proved to be of 12–14 days duration. Both stages were
characterized by distinctive external morphology. Morphological features observed pre
ecdysis included the development of a smooth, tough membrane of the chorion. In contrast,
the pupoid stage exhibited an embryonic cuticle with tiny spines, which were later being
used to rupture the chorion. Additionally, an aperture bordered by protective sensilla
located on the anterior of the pupoid is described for the first time.