Atractides (Atractides) marizae Pesic, 2023

Pesic, Vladimir, Jovanovic, Milica, Espiridiao Oliveira, Amalia, Pedro, Ana, Freira, Marvin & Morais, Maria Manuela, 2023, New records of water mites (Acari, Hydrachnidia) from Portugal revealed by DNA barcoding, with the description of Atractides marizae sp. nov., ZooKeys 1151, pp. 205-222 : 205

Atractides (Atractides) marizae Pesic sp. nov.

Figs 1 , 2A-D , 3

Type material.

Holotype ♂ (sequenced, CCDB_39397_C02, Table 1 ), dissected and slide mounted (RMNH), Portugal, Santarém, Caniceira stream, 39.4110°N, 8.2615°W, 25.v.2022 leg. Jovanović. Paratypes: 3♂, 2♀, same site and data as the holotype, 2♂, 1♀ sequenced (Table 1 ), 1♂ (CCDB_39397_C0) damaged (one palp and I-legs missing), 1♀ (CCDB_39397_B12) dissected and slide mounted (RMNH).

Diagnosis.

Characters of the Atractides nodipalpis -species group (integument finely striated, muscle insertions unsclerotized; males with anteriorly and posteriorly indented genital field, P-2 with distoventral projection and ventral margin of P-4 projecting); excretory pore smooth, acetabula relatively small, arranged in an obtuse triangle.

Description.

General features -Integument striated, muscle insertions unsclerotized; mediocaudal margin Cx-I strongly convex, apodemes of Cx-II in an acute angle with the median line. Excretory pore smooth; Vgl-1 not fused to Vgl-2. Palp with strong sexual dimorphism in shape of P-2 and P-4, in both sexes medial peg-like seta inserting halfway between ventral setae, seta insertions dividing ventral margin into three equal sectors. I-L-5 proximally subrectangular, distally protruding near insertion S-1, with seta S-1 slender and bluntly pointed, S-2 shorter and pointed, proximally enlarged; I-L-6 slender, curved, basally slightly thickened from the centre to the claw furrow with parallel dorsal and ventral margins (Figs 2C , 3C ). Male -Anterior margin of genital plate with a notch and bead structure, a fine median tip projecting in a deep indentation; caudal margin with a deep indentation extending to about 1/2 L of Ac-3, Ac rounded to subtriangular, arranged in an obtuse triangle (Fig. 1B, C ); ventral margin P-2 with a strongly developed distal extension, P-3 strongly concave, P-4 proximally concave, inflated near proximoventral seta. Female -Caudal apodemes of Cx-I +II strongly protruding, Cx-IV with well-developed apodemes at medial margins (Fig. 3A ), P-2 nearly straight with a right-angled ventrodistal edge, P-3 dorsal margin slightly concave, P-4 more slender than in the male (Fig. 3B ).

Measurements.

Male (holotype, CCDB_39397_C02; in parentheses some measurements of paratype, CCDB_39397_C04)-Idiosoma L 559 (538), W 458 (425); maximum diameter Dgl-4, 28. Coxal shield L 344 (303); Cx-III W 388 (334); Cx-I+II mL 117 (122), Cx-I+II lL 244 (206). Genital field L/W 91(94)/129(117), L Ac-1-3: 25-28 (25-28), 23-27 (26-30), 30-31 (32-34). Ejaculatory complex L 94.

Palp-Total L 338; dL/H, dL/H ratio: P-1, 31/30, 1.05; P-2, 73/58, 1.26; P-3, 83/45, 1.83; P-4, 111/41, 2.73; P-5, 40/14, 2.8; L ratio P-2/P-4, 0.66. Gnathosoma vL 125, chelicera total L 222.

Legs-I-L-5 dL 195, vL 142, dL/vL ratio 1.37, maximum H 49, dL/maximum H 3.99, S-1 L 98, L/W ratio 10.5, S-2 L 78, L/W ratio 4.99, distance S-1-2, 16, dL ratio S-1/2, 1.26; I-L-6 dL 141, central H 22, dL/central H ratio 6.46; L I-L-5/6 ratio 1.38.

Female (CCDB_39397_B12)-Idiosoma L 686, W 531. Coxal shield L 369; Cx-III W 466; Cx-I+II mL 122, Cx-I+II lL 263. Genital field L/W 150/167, genital plates L 122-124, pregenital sclerite 84, gonopore L 119, L Ac-1-3: 41, 39-41, 42.

Palp-Total L 454; dL/H, dL/H ratio: P-1, 38/38, 1.02; P-2, 97/64, 1.51; P-3, 127/52, 2.43; P-4, 147/36, 4.09; P-5, 45/19, 2.41; L ratio P-2/P-4, 0.66. Gnathosoma vL 158, chelicera total L 280.

Legs-I-L-5 dL 277, vL 194, dL/vL ratio 1.43, maximum H 66, dL/maximum H 4.22, S-1 L 145, L/W ratio 12.8, S-2 L 114, L/W ratio 6.1, distance S-1-2, 36, dL ratio S-1/2, 1.27; I-L-6 dL 202, central H 22, dL/central H ratio 9.22; L I-L-5/6 ratio 1.37.

Etymology.

The new species is named in honor of Marisa dos Reis Nunes, known professionally as Mariza, a famous Portuguese fado singer in the appreciation of the enjoyment her music brings to the authors.

Species delimitation using DNA-barcodes.

The final alignment for species delimitation using COI sequence data comprised 674 nucleotide positions (nps) of the 175 Atractides specimens, morphologically assigned to 40 species listed in Suppl. material 1 and one outgroup, Mixobates processifer from Norway to root the tree. The NJ tree is presented in Fig. 4 . The COI tree sequences retrieved from specimens of A. marizae sp. nov. from Portugal appeared as a sister clade of A. ruffoi Gerecke & Di Sabatino, 2013, a rhitrobiontic species endemic to Corsica ( Gerecke and Di Sabatino 2013). The p -distance between the COI sequences of specimens of A. marizae sp. nov. from Portugal and one specimen of A. ruffoi from Corsica was estimated at 13.34 ± 1.3%, indicating genetic separation between these two clades. The mean intraspecific divergence within the clade of new species from Portugal was relatively low (1.09 ± 0.27).

Remarks.

Pešić and Smit (2022), by mistake, assigned the voucher specimen (CCDB 38559A09) of Atractides ruffoi from Corsica to A. giustinii Gerecke & Di Sabatino, 2013, a species endemic to Corsica and Sardinia. Therefore, the sequence NOVMB009-21/ON002561 deposited in BOLD/GenBank belongs to A. ruffoi .

Discussion.

In regard to the striated integument, a characteristic "notch and bead" structure of male genital field, and the shape of the palp in the male (P-2 with distoventral projection, ventral margin of P-4 projecting), the new species resembles A. nodipalpis Thor, 1899, A. robustus (Sokolow, 1940), and A. ruffoi . Both sexes of A. nodipalpis and A. robustus differ by having larger acetabula in a triangular arrangement. Atractides ruffoi differs by the development of a sclerite at the excretory pore ( Gerecke and Di Sabatino 2013).

A characteristic "notch and bead" structure of the male genital plate is found also in A. clavipalpis (Lundblad, 1956), which in males, differ from the new Portuguese species in having the ventral margin of P-2 distally slightly protruding and not forming a projection, and a distally club-shaped P-4 ( Gerecke 2003).

Habitat.

A rhithrobiont. Collected in a low-order stream, with shaded pool reaches having accumulations of leaf litter (Fig. 5 ).

Distribution.

Portugal; only known from the type locality.

Figures

Figure 1. Atractides marizae nov. sp., ♂ A, B holotype, CCDB _ 39397 _ C 02 C paratype, CCDB _ 39397 _ C 04 A idiosoma in ventral view B, C genital field. Scale bars: 100 µm.

Figure 2. A-D Atractides marizae nov. sp., ♂ holotype, CCDB _ 39397 _ C 02 A palp in medial view B palp in lateral view C I-L- 5 and - 6 D excretory pore E A. ruffoi, ♀ CCDB _ 39397 _ C 02, Corsica; excretory pore. Scale bar: 100 µm.

Figure 3. Atractides marizae nov. sp., ♀ paratype, CCDB _ 39397 _ B 12 A idiosoma in ventral view B palp in medial view C I-L- 5 and - 6. Scale bar: 100 µm.

Figure 4. Neighbour-joining tree of the genus Atractides obtained from 175 nucleotide COI sequences.

Figure 5. Photograph of locus typicus (Caniceira stream, Santarem, Portugal) of Atractides marizae sp. nov. (inset). Photographs by M. Jovanovic.