Fig. 3 H. itoi, nauplius 2 in Naupliar development of Facetotecta (Crustacea: Thecostraca) and the nature of the first nauplius instar in the Crustacea - pro et contra the Hexanauplia concept

Fig. 3 H. itoi, nauplius 2, dorsal side (SEM) a Just moulted, young nauplius with remnants of cuticle of nauplius 1 at posterior end, cuticular plates compressed, anterior end round; bent anteriormost end in upper right. b Mature nauplius with stretched cuticular plates, anterior end elongated. c Mature nauplius, dorsolateral view, pore without setae indicated by asterisks. d Central area of head shield around 'window plate' (W), setae in pores indicated by arrowheads, pores without setae indicated by asterisks. E Papilla of dorsocaudal organ. Abbreviations: bm - boundary of moult between head shield and faciotrunk; dco - papilla of dorsocaudal organ; dcs - dorsocaudal spine; n1-ev - shedding cuticle (exuvium) of nauplius 1. Scale bars in μm