Armadillo officinalis Dumeril 1816

Characters of A. officinalis suitable for diagnostic purposes: comparison with A. mayeti (Figures 7 (A–G), 8(A–D), 9(A–D)) Armadillo officinalis is easily recognised by its dark grey-brown colour with yellow typical muscle spots, antenna, pleon, pleotelson, pereopods and uropods strongly pigmented (Figure 7 (A)), bigger size (male 12.5 mm; female 10.5 mm), smooth integument and more numerous (14) ommatidia (Figure 7 (C)); tergite pereonite I showing denser and smaller scale-setae (Figure 7 (C)) with two divergent lobes (Figure 7 (D)). It differs also from A. mayeti in having narrower antenna, with the fifth article 1.5-times as long as the flagellum (Figure 8 (A)), pereonite I with lateral groove deeper in anterior part, inner lobe not surpassing posterior margin of outer lobe (Figure 7 (B)), caudal lamellar process with rounded apex (Figure 7 (E)), telson nearly twice as wide as long, basal two-times longer than distal part (Figure 9 (A)), stridulation apparatus on propodus of pereopods 4 and 5 forming row of juxtaposed globular scales (Figure 7 (F, G)) having a less diverse chemical composition and richer in Ca (54.75%), followed by carbon rate (30.82%) and oxygen (Table 1). Pereopds 1 and 7 (Figure 8 (B, C)) are similar to those of A. mayeti, but the carpus 1 and 7 are nearly twice as long as the merus. Male pleopods 1 and 2 (Figure 9 (C, D)) of both species are quite similar. Regarding the uropod, the protopod, nearly as long as wide, has a shorter distal part (Figure 8 (D)); the exopodite insertion is slightly posterior to the narrowest part of the telson (Figure 9 (B)) in A. officinalis.