Platymamersopsis mayottensis Pešić & Smit, 2018

Pešić, Vladimir, Smit, Harry & Mary, Nathalie, 2018, Fifth contribution to the knowledge of water mites (Acari: Hydrachnidia) from the Comoros: a checklist and description of one new genus and four new species, Zootaxa 4483 (2), pp. 331-348 : 334

Platymamersopsis mayottensis Pešić & Smit sp. nov.

( Fig. 2 , 11A–B )

Type series. Holotype male ( MNHN), dissected and slide mounted, Comoros, Mayotte, Koualé River, intermediate, 12°47'50,2375"S, 45°11'08,8249"E, alt. 50 m asl., 28-vii-2016, leg. Mary.

Diagnosis (Female unknown): Dorsal shield elongated, ridge on dorsal shield apically tapering; P-4 with well developed ventral projection, curved, directed anteriorly; I-III-L claws with comb-like ventral clawlets; IV-L-6 slender, with two small terminal setae and a row of three stronger sub-terminal setae.

Description— Idiosoma oval; dorsal shield elongated, L/W 503/350, ratio 1.44, anteriorly rounded, ridge on dorsal shield apically bluntly pointed, caudally dissolved, glandularia far laterally ( Fig. 2A ); ventral shield ( Fig. 2B ) oval, L/W 541/438; coxal field L/W 297/356, anteriorly extending beyond frontal margin, medial margin of Cx-I long (mL 70), medial margin of Cx-III mid-sized (mL 36), mL Cx-I/Cx-III ratio 1.9; Cxgl-2 close to posterior margin of Cx-II, Cxgl-4 at anterior margin of Cx-III; Cx-IV posteriorly and laterally rounded, dorso-laterally extended to the level of Cx-II. Genital field L/W 103/100, rounded, laterally smoothly convex, posteriorly slightly extended beyond genital bay; acetabula mid-sized, L Ac-1-3: 28, 28, 31; a few small setae present on genital flaps; setae of Vgl-1 posterior to caudal corner of Cx-IV, Vgl-3 close to caudo-lateral margin of Cx-IV; excretory pore and Vgl-2 close together, distanced from the posterior margin of ventral shield.

Palp: total L 214, dL/H, dL/H ratio: P-1, 19/43, 0.44; P-2, 83/57, 1.45; P-3, 34/42, 0.82; P-4, 55/33, 1.67; P-5, 23/14, 1.66; P-2/P-4 ratio 1.5; P-2 compact, dorsal margin curved, ventral margin slightly concave, ventral seta mid-sized, pointed; P-4 ventral projection well developed, curved, flanked by a fine subterminal seta ( Fig. 2E ); P-5 with a strong distal claw flanked by two shorter claws.

Legs: Due to the fixation all claws retracted in claw sheath, but comb-like clawlets can be observed; dL of I-L: 52, 63, 56, 81, 86, 106; dL of IV-L-4-6: 83, 98, 105; IV-L-6 slender, with two small terminal setae and a row of three stronger sub-terminal setae ( Fig. 2C ).

Female: Unknown.

Etymology. Named for its presence on Mayotte.

Discussion. The new species belongs to the group of species bearing comb-like ventral clawlets (mysorensis - like species, see Goldschmidt 2008 for discussion). The new species from Mayotte differs from all other species of this group by the characteristic ventral projection at P-4. The only species with a similarly shaped P-4, P. nordenskioeldi K. Viets, 1914 from Cameroon and Liberia (see Cook 1966), differs in simple dorsal and ventral clawlets on I–III-L, a large, rounded dorsal shield, a very short coxal field, not protruding over the frontal margin, and a more concave ventral margin of P-2 ( Cook 1966).

Distribution. Comoros; only known from the type locality.

Figures

FIGURE 2. Platymamersopsis mayottensis sp. nov., male, Koualé River, Mayotte: A = dorsal shield; B = ventral; C = IV-L-5 and -6; D = I-L; E = palp. Scale bars = 100 µm.

FIGURES 11. Photographs of dorsal (A, C–E) and ventral (B, F): A–B Platymamersopsis mayottensis sp. nov., male holotype. C–D Torrenticola mayottensis sp. nov.: C = male holotype, F = female paratype. E–F Djeboa davecooki sp. nov., male holotype.