Gaeolaelaps ahangarani Kazemi & Beaulieu

Kazemi, Shahrooz, Rajaei, Asma & Beaulieu, Frédéric, 2014, Two new species of Gaeolaelaps (Acari: Mesostigmata: Laelapidae) from Iran, with a revised generic concept and notes on significant morphological characters in the genus, Zootaxa 3861 (6), pp. 501-530 : 514-516

Gaeolaelaps ahangarani Kazemi & Beaulieu sp. nov.

( Figs 29–40 )

Diagnosis (based on adult female). Dorsal shield suboval, reticulated throughout, covering almost all dorsal idiosoma, leaving exposed a narrow lateral band of soft cuticle which bears four pairs of marginal setae (R1–R2, R4–5); shield with 37 pairs of short, needle-like dorsal setae, setae Px2–3 and unpaired setae Jx absent, with 21 pairs of pore-like structures, including six pairs of gland pores (gd2 and gd6 present). Sternal shield longer than wide (length/width ratio ≈1.35), reticulate throughout except for a narrow smooth area posteriorly; anterolateral arms of shield broadly fused to endopodals between coxae I–II, and posterior margin of shield slightly convex. Epigynal shield tongue-shaped, only slightly widened posteriorly, with eight cells surrounded by a Λ-shaped line, with cell borders sinuous. Post-stigmatic region of peritrematal shield short, extending slightly beyond level of mid-coxa IV. Soft opisthogastric cuticle with ten pairs of short setae, with alveoli surrounded by relatively thick sclerotised rings. Anal shield somewhat pear-shaped, broadly rounded anteriorly; anal opening almost entirely on anterior half of shield; cribrum spicules not extending significantly anteriorly. Peritremes long, reaching anterior margin of coxae I. Epistome margin rounded, with variously sized denticles. Deutosternum with six rows of 17–20 denticles. Fixed digit of chelicera with seven teeth. Internal malae with two pairs of lateral fringed projections in addition to the pair of long median projections. Palp apotele 2-tined. Femur II with av seta thickened, tarsi II-IV with most subapical setae thickened or spine-like; setae av1, pv1 on tarsus II, pl2–3 on tarsus IV, and pl1 on tibia IV apically blunt, spur-like; tarsus IV with pd2 slightly longer than other setae, otherwise without significantly elongate setae, ad3 and pd3 very short; most dorsal setae of genu IV and tibia IV short.

Description. Female (n=2). Dorsal idiosoma ( Fig. 29 ). Idiosoma 486–494 long, 266–271 wide. Dorsal shield 486–494 long, 247–252 wide, suboval, reticulate throughout, more distinctly on opisthonotal region, and with cells more elongate between setae j5 and j6; shield broadest at level of setae r3, ratio of widths at the level of r3 / S3 =1.2; shield covering most of dorsal idiosoma, leaving exposed a narrow marginal band of soft cuticle. Dorsal shield with 37 pairs of short setae, setae Px2–3 absent, setae j2–4, z4, s3, r2–3, Z5 longest (20–25), z1 shortest (6–8), other setae 12–17 long; Z5 usually with 1–2 minute barbs. Setae R1–R2 (12–14), R4 (14–15), R5 (11–12) and one pair of poroids (idR3) on soft lateral cuticle. Dorsal shield with 16 pairs of discernible poroids (oval-shaped symbols) and six pairs of gland pores (circular symbols).

Ventral idiosoma ( Fig. 30 ). Tritosternum with a narrow columnar base, 32–33 long, 10–11 wide at base, 7–8 wide at apex, and two free pilose laciniae (68–71). Presternal area weakly sclerotised, granulate-lineate. Sternal shield 146–150 long, 109–111 wide, distinctly reticulate throughout except for a narrow smooth area posteriorly; anterior margin of shield straight, posterior margin slightly convex with a small median depression; anterolateral corners broadly fused to endopodal platelets between coxae I-II, bearing gland pores gvb; shield bearing three pairs of smooth setae st1 (24–25), st2 (26–27) and st3 (26–28), and two pairs of poroids, iv1 slit-like and iv2 sub-oval. Metasternal setae (26–28) and poroids iv3 on soft cuticle (iv3 asymmetrically captured by sternal shield in one specimen). Epigynal shield tongue-shape, very slightly broadened posteriorly, 166–169 long, and 81–83 from st5 to posterior margin, 70–72 wide; anterior hyaline margin slightly convex, irregular, covering posterior smooth area of sternal shield; epigynal shield with a Λ–shape line delimiting posteriorly eight cells with sinuous borders; setae st5 (20–21) on lateral margins of shield, almost at level of posterior edge of coxae IV. Paragenital poroids iv5 on soft cuticle, near level of coxae IV posterior edges. Anal shield somewhat pear-shaped, anterior margin of shield broadly rounded, 67–70 long, 56–58 wide, lineate-reticulate anteriorly and laterally; circumanal setae smooth, postanal seta (20–22) longer than para-anal setae (15–16); cribrum well developed, with three rows of spicules (four medially), the two anteriormost rows only slightly extending anteriorly of postanal seta; anal opening located almost entirely on anterior half of shield; para-anal gland pores gv3 on lateral shield margins at level of the posterior edge of anal opening. Peritrematal shields relatively well developed throughout, anteriorly fused to dorsal shield behind setae z1, bearing one pair of gland pores near external margin of shield at level of anterior edge of coxae III and one pair of poroids at level of posterior edge of coxae II; poststigmatic region with a longitudinal line from stigmata to shield apex, and with two pairs of poroids and one pair of gland pores. Peritremes long (236–243), reaching anterior margin of coxae I. Exopodal platelet between coxae II-III well developed, exopodal between coxae III-IV fused to parapodal. Opisthogastric soft integument with pair of primary metapodal platelets moderately small, narrow, laterad of ZV1–2; 2–3 additional pair(s) of minute metapodal platelets anterior to and inbetween ZV1 and primary metapodals; paragenital platelets minute, at level of ZV1; five pairs of poroids and 10 pairs of short, needle-like setae JV1–5, ZV1–5, 14–20 long.

Gnathosoma ( Figs 31–34 ). Anterior margin of epistome somewhat rounded, with about 17 variously sized teeth ( Fig. 31 ). Corniculi horn-like, 45–47 long. Salivary stylets narrow and apically pointed, aligned beneath corniculi. Internal malae fringed, with a pair of adjacent median pilose projections, flanked by two pairs of shorter and thinner lateral projections. Labrum acuminate, pilose, considerably longer than corniculi. Hypostomal and capitular setae smooth, h3 (46–49)> h1 (34–37)> pc (26–27)> h2 (19–21). Deutosternal groove with six rows of 17–20 denticles each; lateral margins of deutosternum subparallel ( Fig. 32 ). Basal segment of chelicerae 50–52 long, second segment 140–143 long, 46–48 wide; fixed digit of chelicera 40–42 long, with seven teeth, including subapical offset tooth (gabelzhan), followed by two small teeth, and four larger teeth proximal to the short and setiform pilus dentilis; dorsal seta short and setiform. Movable digit of chelicera 48–50 long, bidentate ( Fig. 33 ). Palp 146–149 long, palp chaetotaxy normal for Laelapidae ; all setae smooth, al1 and al2 on palpgenu and al on palpfemur thick and subspatulate, ad on palpfemur slightly thickened, somewhat spine-like; palptarsus apotele 2- tined, anterior tine with spatulate hyaline margin ( Fig. 34 ).

Legs ( Figs 35–40 ). Leg chaetotaxy normal for Laelapidae (sensu Evans & Till, 1965). Legs II–III with largest claws and pulvillus, and broadest ambulacral stalk; leg I with narrowest stalk, claws and pulvillus; lengths of legs I- IV 435–438, 335–341, 289–292 and 432–440, respectively. Lengths of femora I 70 –73, II 57 –59, III 56 –59, IV 89 –92; genua I 62 –65, II 62 –63, III 38, IV 62 –67; tibiae I 70 –72, II 51 –54, III 38, IV 62; tarsi I 116–119, II 73 –76, III 83 –86, IV 113–121. Leg setae mostly thin and moderately long, except: trochanter I with al and ad short and slightly thickened; trochanter II with al slightly thickened; trochanter IV with pv1 slightly thickened; femur II with av and pd1 slightly thickened, ad3 and al2 short; femur III with al and ad1 thickened, ad2, pd and pl short; femur IV with ad1 and av slightly thickened, ad2, pd and pl short; genu II with pd2 slightly thickened, and genua III-IV with ventrals slightly thickened; tibiae II-III with pv thickened; tibia IV with av and pv thickened, pl1 thick, somewhat spur-like, pd2–3 very short; tarsus II with al2–3 and pl2–3 slightly thickened, av1 and pv1 stout, spurlike (apically blunt), al1, pl1 and md stout and spine-like, mv, av2 and pv2 thick; tarsus III with pl2–3 slightly thickened, ad2, pd2, pv2 and al3 thickened, av1–2, pv1–2, al1–2, mv and pl1 thickened, somewhat spine-like, md stout, spine-like; tarsus IV with most setae thickened and of moderate length, and pl2–3 somewhat spur-like, pl3 half as long as pl2, pd2 slightly longer than other setae, ad3 and pd3 short and thin. Coxa I bearing two gland pores (gc) ( Fig. 30 ).

Material examined. Holotype: female, northern Iran, Mazandaran Province, Tonekabon County, Tirom Forest (40˚ 62' 69" N; 47˚ 11' 26" E), 1465 m above sea level, from decayed wood of Beech trees, 2 June 2010, coll. Y. Ahangaran, deposited in ACISTE. One paratype female with same collection data, deposited in ACISTE.

Etymology. The species is named in honour of Yazdanfar Ahangaran (General Office of Natural Resources of Mazandaran Province, Nowshahr, Iran), for his help in collecting these mites.

Remarks. Gaeolaelaps ahangarani can most readily be distinguished from all other species in the genus by the following combination of characters: very short dorsal setae, particularly so in the opisthonotal region; the absence of Px2–3; only three pairs of marginal setae on soft lateral cuticle; epigynal shield with posterior cells with sinuous borders; an anal shield broadly rounded anteriorly, with the anus almost entirely in the anterior half of shield; and modified leg setae, such as pl2–3 of tarsus IV and pl1 of tibia IV spur-like, and ad3, pd3 very short.

Many other Gaeolaelaps have short dorsal setae, but the large majority of them possess Px2–3 setae, rarely have the anal opening positioned as anteriorly as in the new species (based on species descriptions), and have other distinctive characters. For instance, G. tenuisetus Rosario (1981) has short setae, but seems to possess Px2–3 (at least on one side; the illustration is difficult to interpret), and has an epigynal shield considerably expanded posteriorly (nearly parallel-sided in G. ahangarani ), and a subtriangular anal shield that is relatively flat anteriorly. Gaeolaelaps analis ( Karg, 1982) has a broader, more oval dorsal shield, Px2 present, and a broader anal shield with anus located on its posterior half. Gaeolaelaps gleba Karg, 1979 (= G. glabra Karg, 1978 ) has Px2–3 setae as well as shortened peritremes.

The few Gaeolaelaps species lacking Px2–3 setae that we are aware of are distinguished from G. ahangarani by at least a few characters. Gaeolaelaps queenslandicus and G. angustus ( Karg, 1965) have a posteriorly tapered dorsal shield, longer dorsal setae, a three-tined palp apotele, and a deutosternum narrowing posteriorly (based on Costa, 1966). Based on the illustrations, Gaeolaelaps tengi ( Gu & Bai, 1991) may appear similar to the new species, but it has longer setae, a broader, subtriangular anal shield that is flatter anteriorly, a sternal shield truncate posteriorly, with st3 setae near the edge, a post-stigmatic region of peritrematal shield almost reaching the posterior margin of coxae IV (shorter in G. ahangarani ), and a narrower deutosternal groove. Gaeolaelaps wufengensis ( Liu & Ma, 2003) also has relatively short setae, but possesses an epigynal shield ornamented by circular lines posteriorly, seven rows of deutosternal denticles, and an acuminate epistome. Gaeolaelaps barbarae ( Strong 1995) , associated with funnel-web spiders, has a more oval dorsal shield, and much longer setae, and a subtriangular epistome. Other arthropod associates also lack Px2–3 (e.g. G. disjuncta Hunter & Yeh, 1969 , G. circularis , G. ruggi , and G. rarosae Rosario, 1981 ), but have fewer setae on the dorsal shield (<37), longer setae, and often a more oval dorsal shield, a shorter, more compact sternal shield, and/or an epigynal shield with distinct ornamentation.

Gaeolaelaps ahangarani shares characters with G. aculeifer and relatives (see Discussion), such as the spinelike setae on tarsi, especially of legs II-III, the deutosternal groove with numerous denticles per row, and similarly shaped and ornamented dorsal, sternal, and epigynal shields (although these shields are similar in several other Gaeolaelaps species). Like G. aculeifer , it also has internal malae with two pairs of short lateral projections. However, it differs from G. aculeifer and relatives by lacking Px2–3 setae, and having only three marginal setae laterad of the dorsal shield, a fixed cheliceral digit with fewer teeth proximal to the pilus dentilis, and shortened leg setae (see Diagnosis). At first glance, the sinuous borders of the cells of the epigynal shield appear as a fairly unique character of G. ahangarani . However, we suspect that such ornamentation occurs in other species, which we may have overlooked, or that are still undescribed.

Figures

FIGURES 29 – 34. Gaeolaelaps ahangarani Female. 29. Dorsal idiosoma; 30. Ventral idiosoma; 31. Epistome; 32. Subcapitulum; 33. Chelicera; 34. Palp.

FIGURES 35 – 40. Gaeolaelaps ahangarani Female. 35. Leg I, posterolateral view; 36 – 38. Legs II-IV, dorsal view; 39. Ambulacrum I; 40. Ambulacrum II.