Pontarachna turcica, Pešić & Durucan & Zawal, 2019

Pešić, Vladimir, Durucan, Furkan & Zawal, Andrzej, 2019, Marine mites (Acari: Hydrachnidia) of the Mediterranean Sea: Descriptions of two new species, key for identification and future prospects, Zootaxa 4585 (3), pp. 501-516 : 509-512

Pontarachna turcica sp. nov.

( Figs 6–7 )

Type material. Holotype male ( RMNH), dissected and slide mounted, Turkey, Antalya, Erenkuş beach, 36.865204°N, 30.723791°E, medium coarse sand, 7 m depth, 2.vii.2017 leg. Durucan. Paratype: one female, same data as holotype, dissected and slide mounted ( RMNH) .

Diagnosis. Posterior margin of Cx-IV with broad medial posterior apodemes; sclerotized ring around male gonopore with 12 pairs of setae.

Descrıptıon. Male ( holotype): Idiosoma elongated L 375; coxal field L/W 162/219; Cx-I separated medially; suture lines Cx-II/III incomplete; suture line of Cx-III/IV ending in posteromedial apodemes; posterior margin of Cx-IV with two pairs of short apodemes not reaching level of anterior genital field margin; the medial apodemes much broader than the lateral ones ( Fig. 6A ). Sclerotized ring around gonopore L/W 37/30, with 12 pairs of setae ( Fig. 6a ). Posteriorly of Cx-IV two glandularium like structures, accompanied by a seta (Cxgl-4 and Lgl-3, respectively). Posterior to the genital field a pair of glandularium-like structure ( V3 without a seta sensu Wiles et al. 2002) arranged in a line with a pair of platelets (= acetabular platelet sensu Cook 1996) bearing a pore and two “wheel-like” acetabula. Excretory pore unsclerotized, near the posterior idiosoma margin.

Gnathosoma vL 105; chelicera total L 284; palp total L 173, dL/H ratio: P-1, 17/15, 1.16; P-2, 42/25, 1.69; P- 3, 38/22, 1.75; P-4, 56/16, 3.56; P-5, 20/9, 2.1; dL P-2/P-4 ratio 0.76; P-2 with slightly concave ventral and convexly bowed dorsal margin; P-3 ventral margin straight; P-4 slender, slightly bowed, ventral margin without a tubercle ( Fig. 6D ). Legs: dL of I-L ( Fig. 7C ): 35, 32, 42, 38, 55, 64; I-L-6 H 28, I-L-6 dL/H ratio 2.29; dL of IV-L ( Fig. 6B ): 63, 36, 48, 84, 93, 82; claws strong with ventral and dorsal clawlets; number of swimming setae: IV-L-4, 1; IV-L-5, 2.

Female: Similar to male, except for the shape of the genital field and postgenital area ( Fig. 7A ). Idiosoma L/W 348/211; coxal field L/W 166/202; medial posterior apodemes of Cx-IV not extending posteriorly beyond the postgenital sclerite. Genital field L/W 52/44, pregenital sclerite slightly bowed, W 44, longer than postgenital sclerite (W 28), postgenital sclerite bearing a pair of wheel-like acetabula sensu Cook (1996).

Gnathosoma vL 113; chelicera total L 296; palp total L 182, dL/H ratio: P-1, 20/16, 1.25; P-2, 42/24, 1.74; P-3, 38/24, 1.6; P-4, 61/16, 3.9; P-5, 21/8, 2.7; dL P-2/P-4 ratio 0.69; palp ( Fig. 7C ) as in male. Legs: dL of I-L ( Fig. 7B ): 33, 40, 40, 55, 71; I-L-6 H 31, I-L-6 dL/H ratio 2.26; dL of IV-L-2-6: 41, 49, 89, 100, 77; number of swimming setae: IV-L-4, 1; IV-L-5, 2.

Etymology. The species is named for its presence in Turkey.

Remarks. The presence of broad posteromedial apodemes of Cx-IV makes the new species similar to Pontarachna valkanovi , a species described by Petrova (1978) from the interstitial zone of the marine littoral (0.6- 1.2 m depth) of the Bulgarian Black Sea coast. The latter species can be easily distinguished in the male having a sclerotized ring around gonopore with 5 pairs of setae arranged in a row ( Petrova 1978; Pešić et al. 2013c). From the widely distributed P. communis the new species can be separated by having broad posteromedial apodemes of Cx-IV and sclerotized ring around male gonopore with a lower number of setae.

Distribution. Turkey (Gulf of Antalya); known only from the type locality.

Figures

FIGURE 6. Pontarachna turcica sp. nov., male holotype: A = idiosoma, ventral view; B = IV-L; C = I-L; D = palp. Scale bars = 100 µm.

FIGURE 7. Pontarachna turcica sp. nov., female paratype: A = idiosoma, ventral view; B = I-L-3-6; C = palp (P-1 lacking). Scale bar = 100 µm.