Zachvatkinia (Zachvatkinia) repressae Negm & Alatawi

Negm, Mohamed W., Nasser, D., Alatawi, Fahad J., Al Ahmad, Azzam M. & Shobrak, Mohammed, 2013, Feather mites of the genus Zachvatkinia Dubinin, 1949 (Astigmata: Analgoidea: Avenzoariidae) from Saudi Arabia: A new species and two new records, Zootaxa 3710 (1), pp. 61-71 : 63-70

Zachvatkinia (Zachvatkinia) repressae Negm & Alatawi sp. n.

( Figs. 1 ̶9)

Type material. Male holotype (KSMA), 8 male and 18 female paratypes ex Sterna repressa Hartert, 1916 ( Charadriiformes : Sternidae ), Jana Island, Arabian Gulf, Saudi Arabia, 27º22'10"N, 49º53'53"E, 11 July 2012, leg. M.G. Nasser. Holotype, most male and female paratypes—KSMA; a paratype female and male—The Acarology Laboratory, Museum of Biological Diversity, The Ohio State University.

Description. Male ( Figs. 1–5) (holotype, range for 4 paratypes in parentheses): gnathosoma length 100 (90– 105), maximum width 80 (80–85). Idiosoma length 710 (650–720) from anterior end of propodosomal shield to level of bases of setae h3 posteriorly, greatest width 340 (322–348) ( Fig. 1). Propodosomal shield: subtriangular, posterolateral angles rounded, posterior margin straight or slightly convex and with a pair of small transversely directed extensions, surface of shield without ornamentation, length along midline 180 (166–180), maximum width 210 (200–228), lengths of scapular setae si 26 (24–26) and se 125 (122–126), distance between setae se-se 180 (173–180) ( Fig. 3 ). Humeral shields well developed, setae c2 35 (32–36) situated on their anterior ends, lanceolate setae c3 45 (44–46) long and macrosetae cp 125 (122–128) long. Hysteronotal shield: anterior margin straight or slightly concave, anterior angles acute, length from anterior margin to the bases of setae h3 530 (515–542), width at anterior margin 300 (288–305). Openings of opisthosomal glands situated anterolateral to setae e1. Terminal cleft narrow, subtriangular, anterior end extending beyond level of setae e2, length of cleft from anterior end to bases of setae h3 250 (248–253). Setae ps1 60 (57–62) long, situated on lateral margins of supranal concavity, their tips almost extending to bases of setae h3. Macrosetae h2 and h3 with noticeably thickened basal part and with long filiform distal part. Distances between hysteronotal setae: c2:d2 165 (161–172), d2:e2 135 (134–143), e2:f2 132 (132–145), f2:h2 33 (25–33), c1:d1 82 (80–86), d1:e1 112 (100–114), e1:h1 188 (178–190), h1:h3 120 (116–122), ps2:ps1 45 (45–50).

Epimerites I fused into a Y, sternum without lateral extensions ( Fig. 2). Setae 1a 40 (38–41) long, situated on coxal fields I close to epimerites II. Coxal field II open. Epimerites III and IIIa fused, coxal field III closed, setae 3b 50 (45–52) long. Setae 3a 37 (35–38) long, situated approximately at same level with setae 3b. Setae 4a 37 (37–42) long, situated at same level with genital papillae. Distances between ventral setae: 1a:1a 105 (102–110), 3b:3b 205 (202–212), 4a:4a 97 (95–99), 3a:3a 45 (44–50), g:g 37 (36–42), ps3:ps3 48 (48–50). Distance from genital arch apex to level of setae ps1 230 (212–241). Genital arch shaped as inverted bowl, free ends of its branches directed outward ( Fig. 4 ). Length of genital arch 37 (35–38), width 50 (47–54). Genital shields represented by small and narrow longitudinal strips widely separated from each other, setae g situated on posterior ends of genital shields. Adanal shields fused and form acute median extensions with two small lateral ledges. One pair of additional adanal sclerites shaped as inverted cups present, closely adjacent or poorly connected to adanal apodemes. Bases of setae g and ps 3 in subrectangular arrangement. Anal suckers rounded, 35 (32–37) in diameter. Legs III extend beyond lobar apices by full tarsus. Tarsus III with seta s thick, spine-like and tridentate apically ( Fig. 5 A). Tarsus IV with two dorsobasal spines and with one apical spine-like extension at base of modified seta e ( Fig. 5 B).

Female ( Figs. 6–9 ) (range for 5 paratypes): gnathosoma length 80–90, width 70–80. Idiosoma: length 440–466 from anterior end of propodosomal shield to level of bases of setae h3, maximum width 280–310 ( Fig. 6 ). Propodosomal shield: subtriangular in shape as in males, posterior margin conspicuously convex, without extensions, lateral angles with small notches posterior to bases of setae se, length along midline 122–130, width at the level of scapular setae se 144–150, distance between scapular setae si - si 92–100 ( Fig. 8 ). One pair of small transverse sclerites situated between propodosomal shield and transverse row of setae c1, c2. Humeral shields narrow, not developed dorsally and not extending beyond anterior ends of hysteronotal shields. Setae c2 situated off humeral shields. Humeral setae cp filiform, 80–88 long, subhumeral setae c3 spiculiform, 33–37 long. Hysteronotal shields: one pair of large longitudinal shields along lateral body margins, separated by wide longitudinally striated area. Setae d1 situated on median striated integument of hysterosoma, close to inner margins of hysteronotal shields. Pygidial shield present, length 21-25, width 70–76. Distances between hysteronotal setae: c2:d2 128–135, d2:e2 110–116, c1:d1 73–77, d1:e1 115–122.

Epimerites I fused into a Y ( Fig. 7 ). Length of setae 1a 16–18. Epimerites II free, with pointed tips. Remnants of epimerites IIa not fused with humeral shields. Transverse sclerites situated much anterior to the level of epimerites III, not fused to epigynum. Epimerites III and IVa short. Length of setae 3b 25–30. Setae 3a 14–17 situated anteriorly to level of setae 3b, while setae g slightly posterior to them. Distances between ventral setae: 1a:1a 92–105, 3 b:3b 180–205, 3 a:3a 51–55, g:g 72–85, 4 a:4a 48–56. Epigynum semicircular, bow-shaped, length 35–37, width 75–90, its tips extending slightly beyond level of setae 3a but not reaching level of genital papillae ( Fig. 8 ). Oviporus folds moderate in size and extend to level of epimerites IIIa tips. Tarsi, tibiae, genua and femora of legs I– IV longer than wide. Legs IV extend beyond posterior margin of opisthosoma by distal half of tarsus. Tarsus IV twice as long as corresponding tibia.

Differential diagnosis. The new species Z. repressae sp. n. can be differentiated from the morphologically most similar species, Zachvatkinia chlidoniae Mironov, 1989 , by the following characters: In males of Z. repressae sp. n., the branches of the genital arch are slightly curved, so that their free ends are directed outward while the anterior end of the arch forms an acute angle, the anterior end of the adanal shield forms an acute angle ( Fig. 4 ), and the posterior margin of propodosomal shield has a pair of small transversely directed extensions ( Fig. 3 ). In males of Z. chlidoniae , the branches of the genital arch are strongly S-shaped, so that their free ends are bent forward, the front end of the adanal shield forms an obtuse angle, the posterior margin of propodosomal shield is slightly convex and has no extensions. In females of Z. repressae sp. n. the epigynum is 75–90 in width, while in Z. chlidoniae it is shorter (64-72) (Mironov, 1989a).

Etymology. The new species epithet repressae derives from the specific name of the type host.

Remarks. In Saudi Arabia, Sterna repressa occurs during the breeding season in summer in many islands of the Arabian Gulf and Red Sea, where it nests. Sterna repressa is distributed through Bahrain, Djibouti, Egypt, Eritrea, India, Iran, Iraq, Israel, Jordan, Kenya, Kuwait, Maldives, Oman, Pakistan, Qatar, Saudi Arabia, Seychelles, Somalia, South Africa, Sudan, Tanzania, United Arab Emirates and Yemen (Porter & Aspinall 2010).

In his review of the genus Zachvatkinia, Mironov (1989a) largely revised material previously investigated from host species in the Procellariiformes and Charadriiformes in the USSR, resulting in 12 species, of which six were new. Procellariiformes are assumed to be primary hosts for feather mites of the genus Zachvatkinia . The study of host-parasite associations revealed some features of co-evolution both with procellariiform and charadriiform hosts (Mironov, 1991a).

Zachvatkinia (Zachvatkinia) dromae Mironov, 1992

Zachvatkinia (Zachvatkinia) dromae Mironov, 1992: 497 .

Specimens examined. Many males, females and nymphs, from the crab plover, Dromas ardeola Paykull, 1805 ( Charadriiformes : Dromadidae ), Farasan Archipelago, Jazan province, Saudi Arabia, 16º50'4''N, 42º1'38"E, 17 July 2012, leg. M.G. Nasser.

Remarks. In Saudi Arabia, the crab plover breeds during summer in some Red Sea islands including Farasan Archipelago and Umm Al-Qamarie Island and are usually never seen in the mainland. It is distributed through the East African coast, Red Sea, Arabian Gulf and Southern coast of Iran, India, Pakistan and Sri Lanka ( Baker 1929; Porter & Aspinall 2010).

The type specimens of Z. dromae were collected from D. ardeola captured on Providence Island, Madagascar (Mironov 1992: 499). The Saudi specimens are very similar to the description done by Mironov, 1992 who illustrated the propodosomal shield of female without notches at the posterolateral angles; however, some of the Saudi specimens have small notches posterior to scapular setae se. This is the first record of this species in Saudi Arabia. Up to now, Z. dromae is known from just two countries, Madagascar (Mironov 1992) and Saudi Arabia (present study).

Figures

FIGURE 5. Zachvatkinia repressae sp. n., male, A—tarsus III, B—tarsus IV. Abbreviations: as—apical spine-like extension, db—dorsobasal spine-like extensions.

FIGURE 6. Zachvatkinia repressae sp. n., female—dorsum.

FIGURE 7. Zachvatkinia repressae sp. n., female—venter.

FIGURES 8 – 9. Zachvatkinia repressae sp. n., female— 8, propodosomal shield. 9, genital area. Abbreviations: eg—epigynum, gp—genital papillae, of—oviporus fold.

FIGURES 3 - 4. Zachvatkinia repressae sp. n., male— 3, propodosomal shield. 4, genital area. Abbreviations: gp—genital papillae, gap—genital apparatus, gs—genital shield, as—adanal shield, ad—anal disk.