Arrenurus (Megaluracarus) anitahoffmannae, Ramírez-Sánchez, Marcia M. & Rivas, Gerardo, 2013

Ramírez-Sánchez, Marcia M. & Rivas, Gerardo, 2013, New species of subgenus Megaluracarus (Acari: Hydrachnidiae: Arrenuridae: Arrenurus) from Mexico, Zootaxa 3718 (4), pp. 317-330: 318-321

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Arrenurus (Megaluracarus) anitahoffmannae

sp. nov.

Arrenurus (Megaluracarus) anitahoffmannae  sp. nov.

( FIGURES 1View FIGURE 1 A, 2 A, 3 A, 4 A –B, 5–11)

Type material. Holotype male from Del Negro lake, Villahermosa, Tabasco, 3 masl 18 º00’ 31 ” N 92 º 55 ’08” W, 19 April 2001, coll. C. Cramer. Paratypes: One female, same locality as holotype, 9 April 2000, coll. C. Cramer; three males (CNAC007180) and one female, same data as holotype. Other material: 11 males and 11 females, same locality as the holotype, 2 November 2000, coll. C. Cramer. One male, small lake at km 12 on route Villahermosa—Nacajuca, Nacajuca, Tabasco, 8 masl 18 º06’ 26 ” N 92 º 57 ’ 50 ” W, 20 April 2001, coll. C. Cramer. 13 males, Polo canal, Centla, Tabasco, 0 masl 18 º 30 ’ 15 ”N 92 º 38 ’ 58 ” W, 23 September 2001, coll. G. Rivas and M. Ramírez-Sánchez. Four males, San Pedrito lake, Centla, Tabasco, 0 masl 18 º 23 ’ 24 ” N 92 º 47 ’ 58 ” W, 6 February 2002, coll. G. Rivas et al. Five males, roadside pond on route 186 at km 6, Villahermosa, Tabasco, 5 masl 18 º00’08” N 92 º 52 ’ 25 ” W, 4 February 2003, coll. G. Rivas et al. 13 males and 8 females, Loma del Caballo lake, route 180 km 7.5, Centro, Tabasco, 9 masl 17 º 59 ’01”N 93 º00’04” W, 17 August 2003, coll. G. Rivas and M. Ramírez-Sánchez.

Diagnosis. Cauda well differentiated and elegantly proportionate, anterior part of idiosoma stout ( Fig. 1View FIGURE 1 A, 5); P-II stocky without medial setae ( Fig. 7View FIGURES 5 – 11); idiosoma with a big hump rostral to the cauda base, cauda dorso-ventrally thick (best notable in lateral view Fig. 2 A). Integument coloration in legs and idiosoma uniformly bluish.

Description. MALE: Idiosoma 725 (670–709) long and 515 (473–520) wide; anterior idiosoma is stout, with smooth margins in dorsal view ( Fig. 5View FIGURES 5 – 11). Greatest width of dorsal shield 410 (373–410); dorsal shield length (cauda included) 651 (604–630). D 2 setae are separated from the D 2 glands, which are antero-medially located with respect to the D 3 glands; both pairs of D 2 and D 3 glands located on the widest portion of the dorsal shield viewed dorsally ( Fig. 5View FIGURES 5 – 11). Cauda well differentiated 240 (218–238) long; proximal width of cauda 238 (235–238), distal width of cauda 294 (284); posterior end has indistinct lateral extensions ( Fig. 1View FIGURE 1 A, 5); cauda narrowed in steps towards its tip, with a distinct dorsal hump in the D 4 region (Fig 2 A, 6). In lateral view, there is a dorsal hump just at the middle part of the idiosoma (Fig. 2 A, 6). Second and third coxae separated by two rows of body pores ( Fig. 3View FIGURE 3 A), first pair of coxae with sharply projecting anterior corners not extending beyond the anterior margin of idiosoma; medial separation between posterior pairs of coxae begins with three rows of pores between the third pair and ends with only one in the inferior corner of the fourth pair, antero-medial corner of third coxae and postero-medial corner of fourth coxae convex; posterior margin of fourth coxae slightly concave. Subtle bulges over each epimeroglandularia (E 4). Acetabular plates short, wing-shaped not projecting beyond the ventral surface. Dorsal lengths of palpal segments ( Fig. 7View FIGURES 5 – 11): P-I 30 (28–30); P-II 55 (58–60); P-III 33 (33–35); P-IV 53 (43–45), P- V 35 (33–40). P-II stocky, without medial setae; distoventral portion of P-IV angular with one large antagonistic seta, 25 in length. Dorsal lengths of distal segments of first leg ( Fig. 8View FIGURES 5 – 11): I-Leg- 4 100 (95–103); I-Leg- 5 105 (110– 116); I-Leg- 6 148 (143–150). Dorsal lengths of distal segments of fourth leg ( Fig. 9View FIGURES 5 – 11): IV-Leg- 4 130 (133–137), 165 (170–179) to tip of distal extension; IV-Leg- 5 163 (155–160); IV-Leg- 6 150 (163); III-Leg- 4 bears short stiff setae; III-Leg- 5 bears both short and long stiff setae; IV-Leg- 4 and 5 bear long stiff setae; IV-Leg- 4 distal process without setae; dorsal surface of IV-Leg- 5 bears four spine-like setae in a line.

FEMALE: Idiosoma 767–777 long, 656–693 wide; dorsal shield 662–683 long, 515–567 wide; bears the postocularia and three pairs of glandularia; idiosoma margin rounded ( Fig. 4View FIGURE 4 A, 10); genital field 399 wide, acetabular plates short and bowed, directed laterally; gonopore 158–175 long, 148–158 wide; two rows of idiosoma pores between the second and third coxae, three rows between the left and right posterior coxal groups ( Fig. 4View FIGURE 4 B, 11). Dorsal lengths of palpal segments: P-I 30–35; P-II 55–60; P-III 40–41; P-IV 50–52; P-V 32–35; structure and chaetotaxy of palp as given for the male; P-IV disto-ventral portion angular with one large antagonistic seta, 27 in length. Dorsal lengths of distal segments of first leg: I-Leg- 4 105–127; I-Leg- 5 107–112; I- Leg- 6 132–137. Dorsal lengths of distal segments of fourth leg: IV-Leg- 4 142–150; IV-Leg- 5 150–162; IV-Leg- 6 132–157; III-Leg- 4 and 5 bear stiff setae; IV-Leg- 3 bears long and flexible swimming setae; dorsal surface of IV- Leg- 5 bears four spine-like setae in a straight line. Idiosoma and legs bluish or occasionally brownish.

Etymology. This species is named in memoriam of Dr. Anita Hoffmann Mendizábal, a pioneering Mexican acarologist, remarkable teacher, and innate humorist.

Discussion. A. anitahoffmannae  sp. nov. is similar in terms of the overall shape of the idiosoma to A. bartonensis Cook 1954  from the USA, A. bonettoi Rosso  de Ferradás 1973 from Argentina and Uruguay and A. campechensis Cook 1980  from Mexico, but the positions of the post-ocularia and D 1 -D 4 are different in these species. The major difference is the setae pattern of the medial surface of P-II: A. bartonensis  , A. bonettoi  and A. campechensis  have numerous large setae whereas A. anitahoffmannae  has no setae. A. undulicauda Lundblad  from Brazil and Paraguay (Lundblad, 1944), as well is lacking setae in the medial surface of P-II and is similar in shape to A. anitahoffmannae  . However A. undulicauda  is clearly differing from the new species in having more marked bumps in the margins of cauda.

FIIGURE 2. SEM images of the idiosoma in lateral view of males of (A) Arrenurus (Megaluracarus) anitahoffmannae  sp. nov., (B) Arrenurus (Megaluracarus) olmeca  sp. nov., (C) Arrenurus (Megaluracarus) maya  sp. nov., and (D) Arrenurus (Megaluracarus) urbanus  sp. nov.. Scale bars 100 µm.