Geayia (Geayidea) guianaensis Smit & Pešić, 2022

K, Harry Smit, Pešić, Vladimir, K & K, Simon Clavier, 2022, Water mites from French Guiana, with the description of 14 new species (Acari: Hydrachnidia), Acarologia 62 (4), pp. 1119-1153 : 1145-1152

Geayia (Geayidea) guianaensis Smit & Pešić sp. nov.

Zoobank: E269F036-6722-4A8A-9EBE-230220FB26A5

( Figures 18 A-E, 19A-E, 20K, 21E-F)

Material examined — Holotype female, Petit-Saut Lake , date unknown, between 2007

and 2017, 4.939997°N, 53.044167°W, leg. S. Clavier, dissected (gnathosoma, palps and legs mounted on slide, dorsal and ventral shield in Koenike fluid) ( RMNH). Paratypes: 2[one of them juvenile]/3/0, same data as the holotype, one male dissected (gnathosoma, palps and legs mounted on slide, dorsal and ventral shield in Koenike fluid) ( RMNH).

Diagnosis — Dorsum and venter without a colour pattern; gnathosoma L/W ratio 3.3-3.5, gnathosomal rostrum subrectangular in shape, posterior margin with a U-shaped cleft, not flanked by a pair of lateral extensions; genital field as long as wide or slightly wider.

Description — General features – Dorsal and ventral shield present; dorsal shield complete; dorsal and ventral shields without a colour pattern ( Figure 20K). Dorsal portion of gnathosomal bay rounded and projecting well forward; on each side one row of body pores between Cx-II and Cx-II ( Figure 18A). Genital field with three pairs of acetabula. Palp: two long setae on medial surface of P2 inserted near middle of segment, antagonistic bristle of P4 long and whip-like;

P5 inserted dorsally at distal end of P5 ( Figure 18 D-E). Gnathosomal rostrum subrectangular in shape, posterior margin with a U-shaped cleft, not flanked by a pair of lateral extensions ( Figures 18B, 21 E-F).

Female (holotype) – Dorsal shield long 756 and 731 wide; ventral shield 1050 long and 1013 wide. Genital field 273 long and 275 wide, gonopore 241 long and 166 wide. Palp: dorsal length/height, dorsal length/height ratio: P1, 19/48, 0.39; P2, 66/53, 1.24; P3, 48/48, 1.0; P4, 66/46(basal), 1.43; P5, 34/19, 1.8. Gnathosoma 294 long and 84 wide, length/width ratio 3.5.

Dorsal length of I-leg-2-5: 72, 103, 125, 131, 152; dorsal length of IV-leg: 138, 141, 159,

191, 200, 184. Swimming setae: II-leg-4, 5-6; II-leg-5, 5; III-leg-3, 3; III-leg-4, 13; III-leg-5,

10; IV-leg-3, 11; IV-leg-4, 14; IV-leg-5, 12.

Male (paratype, n=1) – Dorsal shield ( Figure 19B) long 625 and 594 wide; ventral shield ( Figure 19A) 888 long and 837 wide. Genital field ( Figure 19D) 209 long and 214 wide, gonopore 152 long and 53 wide. Ejaculatory complex 313 long. Palp ( Figure 19E): dorsal length L/height, dorsal length/height ratio: P1, -/-,-; P2, 61/55, 1.11; P3, 48/47, 1.03; P4, 58/42(basal), 1.37; P5, 31/14, 2.2; L ratio P2/P4 1.05. Gnathosoma ( Figure 19C) 269 long and

81 wide, length/width ratio 3.3.

Dorsal length of I-leg-3-6: 142, 178, 197, 197; dorsal length of IV-leg-2-6: 78, 97, 120,

138, 169; IV-leg-3 and -4 without a row of enlarged setae on dorsal surface characteristic for Geayella . Swimming setae: II-leg-4, 4; II-leg-5, 4; III-leg-4, 9; III-leg-5, 13; IV-leg-4, 10; IV-leg-5, 10.

Etymology — Named for its occurrence in the Guianas.

Discussion — With regard to the shape of the gnathosoma (elongated with a subrectangular gnathosomal rostrum, posterior margin with a U-shaped cleft, not flanked by a pair of lateral extension), the new species from French Guinea most closely resembles G. micronycha K.

Viets, 1954. The latter species was originally described based on two male specimens from Rio Ipojuca near Escada (Pernambuco State) in northeastern Brazil (K. Viets 1954a). Later on, K.

Viets (1959) described the female of G. micronycha from Igarapé Caranã in the Amazon region. From the new species from French Guinea, G. micronycha (in parentheses measurements from K. Viets 1954b and K. Viets 1956) differs in the dorsal shield with a dark blue patch forming a cross-shaped pattern, and a yellow mushroom-like shaped patch with a central pair of glandularia in the middle of the cross-shaped figure, male genital field elongated, elliptic, distinctly longer than wide (L/W 228/157), and in both sexes the gnathosoma is more elongated (L/W 437/ 85 in ♂, 460/ 87 in ♀), posteriorly strongly tapering (see Figures 141 in K. Viets

1954a and Figure 41 in K. Viets 1959).

Distribution — French Guiana.

─ Maroni river): G – ventral view; H – gnathosoma and palps, dorsal view.