Armadillo officinalis, Dumeril, 1816

Charfi-Cheikhrouha, Faouzia, Hamaied, Sonia & Medini-Bouaziz, Lamia, 2024, Redescription of the terrestrial isopod Armadillo mayeti Simon, 1885 and its comparison with Armadillo officinalis Duméril, 1816 from Tunisian populations, Journal of Natural History 58 (41 - 44), pp. 1961-1977 : 1966-1970

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 .

Figures

Figure 7. Male Armadillo officinalis. (A) Body, lateral view. (B) Pereion-epimera I and II latero-ventral view. (C) Cephalon and tergite I, dorsal view. (D) Setae on tergite I. (E) Pleotelson ventral view (pereopods 7 removed) with pereopods 6, pleopods l and 2, uropods, telson apex. (F) Stridulation apparatus on propodus 5. (G) Enlarged scale.

Figure 8. Male Armadillo officinalis. (A) Antenna. (B) Pereopod 1. (C) Pereopod 7. (D) Uropod, ventral view.

Figure 9. Male Armadillo officinalis. (A) Telson with uropods, dorsal view. (B) Uropod exopodite insertion, dorsal view. (C) Pleopod 2. (D) Pleopod 1.

Tables

Table 1. Scale chemical composition of stridulation apparatus in the two Armadillo species.

Elements %	C	Ca	O	Al	Na	K	Si	Fe	Cu	Mg	Total
A. mayeti	58.71	19.63	13.98	4.81	0.32	0.43	0.20	0.63	1.02	−	100%
A. officinalis	30.82	54.75	13.57	0.39	0.04	−	0.30	−	−	0.14	100%