Simognathus euphractus, Tiago, Almir Rogério Pepato Cláudio Gonçalves, 2004

Tiago, Almir Rogério Pepato Cláudio Gonçalves, 2004, The genera Acaromantis and Simognathus (Simognathinae, Halacaridae) on the north coast of São Paulo State, Brazil, Zootaxa 615, pp. 1-16 : 8-11

Simognathus euphractus sp. nov.

( Fig. 4 , 5 )

Holotype: Female ( MZUSP), on Padina gymnospora (Kützing, 1859) Sonder, 1871 , from intertidal rocky shore at Cigarras Beach (23 43’ S, 45 23’ W), 24 November 2000, coll. E. Nascimento.

Paratype: Deutonymph (author's collection), on Sargassum cymosum C. Agardh, 1820 , from intertidal rocky shore at Lázaro Beach, (23 30’ S, 45 08’ W), November 1990, coll. R. Curvêlo.

Description

Female: Idiosoma 358 m long and 219 m wide at level of leg III insertion. Dorsal and ventral plates separated by membranous cuticle, with dorsal plates foveate throughout. AD 159 m long and 92 m wide; posterior half of plate shows conspicuous brown pigmentation. AD bearing a well­developed cornea near anterior edge and gp­1 anterior to ds­ 1 and near the laterals edge of plate. Pair of ds­1 lies at 0.42 of AD length.

Pairs of ds­3 near posterior edge of AD. Pair of ds­2 inserted on striated membrane near anterior margin of OC. Ocular plate triangular 38 m long and 17 m wide, with a cornea covering most of plate. Pair of ds­4 near anterior margin of PD, ds­5 at 0.62 of its length. Adanal setae on PD near anal papilla. PD 138 m long and 92 m wide.

Medial AE and anterior GA are punctuated. AE with epimeral processes well­developed on epimera I. AE with three pairs of setae and a pair of epimeral vesicles near insertion of leg II. PE with three ventral and one dorsal setae.

Two conspicuos apodemes underneath membranous cuticule, posterior to AE. Genitoanal plate 132 m long and 92 m wide, bearing four pairs of setae. Genital opening 47 m long and 28 m wide. Distance between anterior edge of GA and GO equaling 2.4 times the length of GO.

Gnathosoma 96 m long. Three­segmented palp with one ventral seta close to a knob on P2. Palp as long as 0.6 of overall length of gnathosoma, P2 2.2 times longer than P3.

Leg chaetotaxy: leg I, 1,2,2,4,5,6; leg II, 1,2,2,4,5,6; leg III and IV, 1,1,2,3,5,5. Integument of legs I to IV ornamented with large foveae. Length of tibia and telofemur II almost the same. Length/height ratio from segments of leg I as follows: tarsus, 1.9; tibia 1.8; telofemur, 1.3.

Dorsal setae of telofemur III dissimilar in size; on telofemur IV setae of same length. Claw­like seta of tibia I with a proximal swelling. Ventro­medial seta of tibia I absent but represented by the insertion site.

Tarsus I with a ventral spine inserted in the middle of segment, pair of claw­fossa setae and parambulacral setae similar in size and shape. Tarsus II with one ventral seta and a pair of parambulacral setae. Tarsus III and IV with two ventral setae, one in the middle of segment and other distal.

Medial claw of tarsus I larger and stouter than the lateral ones, which are seta­like. Legs II­IV bearing a reduced medial claw and lateral claws with accessory process and dorsal pecten.

Male: Unknown.

Deutonymph: Idiosoma 350 m long. Strips of membranous cuticle between dorsal and ventral plates much broader than female ones. AD 79 m long and 71 m wide, bearing the pairs of ds­1 and gp. Pairs of ds­2, ds­3 and ds­4 lie on membranous integument. OC 25 m long and 16 m wide, almost covered by a large cornea. PD 42 m long and 55 m wide, bearing a pair of ds­5 inserted near its anterior edge and a pair of adanal setae near anal papilla.

AE 129 m long, with a pair of epimeral vesicles and three pairs of setae. Medial AE punctuated by canaliculi, fovea restricted to laterals of the plate. PE with three ventral setae and a dorsal one. Genital plate 31 m long and 38 m wide, with two pairs of setae. Chaetotaxy similar to female.

Etymology: Euphractus is a common genus of Brazilian armadillos that have strong claws, resembling superficially the claws of the species belonging to genus Simognathus .

Remarks: S. euphractus sp. nov. has well­developed ocular plates; medial AE and anterior GA punctuated by canaliculus; ventral knob close to ventral seta on P2; features shared with S. adriaticus Viets, 1940 ; S. hulingsi Newell, 1984 ; S. similis Bartsch, 1977 and S. latitarsus ProcheŞ, 2002.

S. euphractus sp. nov. differs from the three former species by the possession of a heavy seta on tibia I, with a proximal swelling.

S. latitarsus and S. similis deutonymphs display a large posterior areola on AE that almost reaches the posterior medial portion of this plate ( Bartsch, 1977; ProcheŞ, pers. comm.), whereas the adults have smaller areolae. S. euphractus sp. nov. adults and deutonymphs have areolae on AE similar in size. S. latitarsus also differs from S. euphractus sp. nov. by the rounded shape of OC and insertion site of adanal setae, which lies ventrally on anal papilla ( ProcheŞ, 2002). S. similis with a single pair of setae on genital plate of deutonymph instead of two, as found in the species described here. Also with ds­3 on striated cuticle and ds­2 on a corner of OC ( Bartsch, 1977).

Moreover, S. hulingsi has the same color in AD throughout and ds­2 on a corner of OC ( Newell, 1984); S. adriaticus has a narrowed OC.

Figures

FIGURE 4: Simognathus euphractus sp. nov., female: A— Idiosoma, dorsal view. B— Idiosoma, ventral view. C— Palp, lateral view. D— Tarsus I, lateral view. E— Leg II, lateral view. F— Leg I, lateral view. G— Leg III, lateral view. H— Leg IV, lateral view. Scale bars: 50 m.

FIGURE 5: Simognathus euphractus sp. nov., deutonymph: A— Idiosoma, dorsal view. B— Idiosoma, ventral view. C— Leg I, lateral view. D— Leg II, lateral view. E— Perna IV, medial view of a folded apendice. F— Leg III, lateral view. Scale bars: A and B: 50 m. C, D, E and F: 25 m.