Acarochelopodia caissara, Pepato, Almir R., Tiago, Cláudio G. & Rocha, Carlos E. F., 2011

Pepato, Almir R., Tiago, Cláudio G. & Rocha, Carlos E. F., 2011, Psammophilous halacarid mites (Trombidiformes, Halacaridae) from the North Coast of São Paulo State, Brazil, Zootaxa 2823, pp. 47-60 : 57-59

Acarochelopodia caissara sp. nov.

( Fig. 8 )

Material examined. Male holotype (MZSP-AC82), Fazenda Beach, 28 May 2001. Paratypes: 1 male (MZSP- AC83), Picinguaba Beach, same date; 1 female (Pepato’s collection), same site and date; 2 males (Pepato’s collection), Fazenda Beach, same date; 1 male (MZSP-AC84), same locality and date. All mites collected by researchers of BIOTA /FAPESP Program.

Description. Measurements summarized in Table 3.

Female Male

Length Width Length Width Idiosoma 145 69 138–143 63–71 Gnathosoma 47 28 45–46 26–28 AD 40 27 39 28–30 PD 32 22 39–41 21–25 OC 40 12 36– 39 12–19 GA 35 32 35–38 37–39 GO 26 15 20 14 Male. Dorsal and ventral plates without conspicuous ornamentation, except for areas pierced by canaliculi and muscle scars. Anterior dorsal plate with ds-1 at 0.21–0.31 of its total length, AD 1.61–1.77 times longer than wide. Ds-3 and 4 on striated cuticle between dorsal plates. OC without both corneae and pigment, suggesting absence of eyes. PD with ds-5 at 0.30–0.36 of its length, PD 1.60–1.71 times longer than wide. Adanal setae on posterior margin of PD.

Anterior epimeral plate divided into 2 halves by longitudinal strip of striated cuticle. Each half of AE with 2 setae. PE partially divided into 2 halves by winding furrow, anteriorly joined by narrow band, with 2 ventral and 1 lateral setae. GA with 7 pairs of pgs. GO separated from anterior margin of GA by 15-18 or 0.43–0.47 times GA length. On genital sclerites, 3 pairs of subgenital setae, grouped 1:2, anterior pair filiform, both two posterior pairs blunt. Spermatophorotype 32-33 long, reaching beyond anterior margin of GA.

Rostrum triangular, 0.43–0.44 times the overall length of gnathosoma. Basirostral and tritorostral setae on rostrum. P2 with 2 dorsal spines, P3 with medial spine, and P4 with 3 basal setae, 2 spurs and 1 setula on its apical portion.

Leg chaetotaxy, spines on leg I in roman numbers: leg I, 1,2,4(I),5(II),9(VI), 6(I); leg II, 1,2,4,4,5,5; leg III, 2,1,2,3,5,4; leg IV, 1,0,2,3,5,3. Telofemur I with short and strong ventral spine. Genu I with ventromedial and ventrolateral spines, both serrulate and with basal swelling, former measuring approximately half latter’s length. Tibia I with 2 medial and 4 ventral spines. Ventrally, tarsus I with long smooth basal spine, and 2 distal setae. Such basal spine long, almost reaching distal end of tarsus. Tarsus I with 3 dorsal setae, grouped 1:2. Ambulacra I bearing median claw only. Two parambulacral setae unequal; anterior seta bacilliform and posterior slender, approximately twice as long as claw. Setae on remaining legs without setae but with conspicuous pecten, although ventral and medial setae on genua and tibiae II-IV sometimes thicker than dorsal setae. Tarsi II-IV with lateral claws welldeveloped and reduced medial claw.

Female. Similar to male in most features. AD 1.48 times longer than wide, with ds-1 standing at 0.25 of its length. PD 1.45 times longer than wide, with ds-5 at 0.22 of its length. GO apart from anterior edge of GA by 7 or 0.20 of GA length. GA with 3 pairs of pgs, genital sclerites without subgenital setae.

Etymology. The specific name caissara refers to traditional fishermen from Paraná, São Paulo and Rio de Janeiro states, Brazil.

Remarks. Until now, ten species belonging to Acarochelopodia have been described, nine of which having been named. Bartsch (1988) described one species from Hawaii without assigning it to a valid name.

The genus is defined by AE divided into two halves, each with two setae; tritorostral and basirostral setae on rostrum; palpal femur with one or two spines; leg I raptorial, bearing serrulate spines, one on telofemur, two on genu and five to seven on tibia; tarsus I slender with a long ventral spine almost as long as the segment; tarsus I with only medial claw, remaining tarsi with lateral claws well-developed and medial claws reduced.

Acarochelopodia caissara sp. nov. may be distinguished from its congeners by the following combination of characters: rounded posterior AE, PE incompletely spliced, absence of small sclerites anterior to PD, lateral claws smooth, dorsal setae on tarsus I grouped 1:2 AD and PD length: width ratio of 1,61–1,77 and 1,60–1,70, respectively.

Among named species, A. delamarei Angelier, 1954 , A. cuneifera Bartsch, 1977 , A. angelieri Travé, 1972 , A. biunguis Bartsch, 1988 and A. triunguis Bartsch, 1988 share the presence of an acute posterior projection of AE. The species described here, as well as A. aduncispina Bartsch, 1977 , A. saruanlensis Morselli & Mari, 1986 , A. tarentina Morselli, Mari & Sarto, 1998 , and A. lapidaria Bartsch, 1991 have a rounded posterior AE ( Bartsch 1977, 1991, Morselli et al. 1998, Morselli & Mari 1986).

However, Acarochelopodia aduncispina has the PE completely spliced and a pair of small sclerites anterior to the PD. A. saruanlensis also has a pair of sclerites anterior to the PD and lateral claws pectinate.

Acarochelopodia lapidaria and A. tarentina have the dorsal setae on tarsus I equidistant instead of grouped 1:2, as in A. caissara . A. lapidaria also has AD and PD approximately as long as wide instead of a length: width ratio of 1.61–1.77 and 1.60–1.70, respectively, for these plates. A. tarentina has a distal swelling of the lateral claws.

The species described by Bartsch (1988), although nameless, shares with A. aduncispina the outlines of idiosomal plates, having PE completely spliced instead of anteriorly joined by a narrow band.

Figures

FIGURE 8. Acarochelopodia caissara sp. nov.: A, idiosoma of female in dorsal view; B, same in ventral view; C, gnathosoma of female in ventral view; D, palp of female in lateral view; E, Genital area of female; F, leg I of female in lateral view; G, leg IV of female in lateral view; H, leg III of female in lateral view; I, leg II of male in medial view. Scale bars: A – B = 25 μm; C – I = 10 μm.