Thalassogamasus sidortschukae, Makarova, 2019

Makarova, Olga L., 2019, North Pacific versus North Atlantic: a case with species of the amphiboreal littoral mite genus Thalassogamasus gen. nov. (Parasitifomes, Mesostigmata Parasitidae), Zootaxa 4647 (1), pp. 457-485 : 460-463

Thalassogamasus sidortschukae sp. nov.

Figs 1, 4 , 7–48

Material. Holotype, female: NORTH-EAST ASIA, eastern CHUKOTKA, Lawrence Bay, Mutnyi Brook mouth, 65°31’ N 170°59’ W, maritime sandy beach with Mertensia maritima , Honckenya peploides , Senecio pseudoarnica , Leymus villosissimus , 28 July 2013, O.L. Makarova (ZIRAS) . Paratypes: 10 females, 2 males with same data as for holotype (ZIRAS); 1 female, with same data as for holotype (CNC) ; 1 male, NORTH-EAST ASIA, northern CHUKOTKA, Apapelgyn River mouth, 69°45’37”N 170°36’16”E, sandy beach, seaweed accumulations between cobblestones under a bridge footing, 21 July 2018, O.L. Makarova (CNC) .

Other material: NORTH-EAST ASIA, CHUKOTKA, 11 deutonymphs, 27 protonymphs, 54 larvae, with same data as for holotype, O.L. Makarova ; NORTH-EAST ASIA, MAGADAN REGION, 1 deutonymph, Tauisk surroundings, 59°44’04”N 149°23’15”E, maritime salt marsh, from the sand under Puccinellia phryganodes , July 2017, M. Bizin, B. Efeikin .

Description. Rather large yellowish mites with elongate oval idiosoma and large brownish cheliceral digits. Anterior idiosomal margin truncate, posterior margin roundish. Idiosomal shields weakly sclerotised, very finely punctate, with clearly reticulate ornamentation on nearly all surfaces except central part of podonotal shield, and with reduced peritrematal plates. Dorsal shields rather narrow, particularly opisthonotal shield; lateral soft cuticle with numerous setae. Most idiosomal setae with fine, hair-like tips. Legs of moderate length, tarsi II–IV with large blunt spines and long attenuated setae. Basitarsus IV of normal form. Ambulacrum of all legs on short pedicel. Tarsus I distally with six rod-like sensory setae.

Figures

FIGURES 1–6. Littoral members of the subfamily Parasitinae. 1–3. Females; 4–6. Males; 1, 4. Thalassogamasus sidortschukae;; 2, 5. Thalassogamasus kurilensis; 3, 6. Vulgarogamasus halophilus (Sellnick, 1957). Scale 100 μm.

FIGURES 7–17. Thalassogamasus sidortschukae, female. 7. Dorsal idiosoma; 8. Chelicera; 9. Tritosternum; 10–14. Variant forms of gnathotectum; 15. Tarsus II; 16. Tarsus IV; 17. Subcapitulum.

FIGURES 18–21. Thalassogamasus sidortschukae, female. 18. Ventral idiosoma; 19. Peritrematal shield; 20. Metasternal and epigynal structures; 21. Sclerites of endogynium.

FIGURES 22–27. Thalassogamasus sidortschukae, male. 22. Dorsal idiosoma; 23. Tarsus IV; 24. Chelicera; 25, 26. Variant forms of gnathotectum; 27. Subcapitulum.

FIGURES 28–31. Thalassogamasus sidortschukae, male. 28. Ventral idiosoma; 29. Genital orifice and presternal region; 30. Leg II without coxa and tarsus, ventrally; 31. Leg II without coxa, anterolatrally.

FIGURES 32–38. Thalassogamasus sidortschukae, deutonymph. 32. Dorsal idiosoma; 33. Peritrematal shield; 34. Ventral idiosoma; 35. Chelicera; 36–38. Variant forms of gnathotectum.

FIGURES 39–45. Thalassogamasus sidortschukae. 39–42, 44. Protonymph; 39. Dorsal idiosoma; 40, 41. Variant forms of gnathotectum; 42. Ventral idiosoma; 44. Ambulacrum II; 43. Larva, ambulacrum III; 45. Female, ambulacrum III.

FIGURES 46–48. Thalassogamasus sidortschukae, larva. 46. Idiosomal dorsum; 47. Gnathotectum; 48. Idiosomal ventrum.