Adelphopauropus, Scheller, Ulf, 2013

Scheller, Ulf, 2013, Three new species of Pauropoda (Myriapoda) from Brazil with description of a new genus in Diplopauropodidae, Adelphopauropus, Zootaxa 3664 (1), pp. 69-77 : 74-77

Genus Adelphopauropus n. gen.

Type species: Decapauropus manausensis Scheller, 1994 by subsequent designation here.

Diagnosis. A genus in Diplopauropodidae with anterior margin of sternal antennal branch distinctly shorter than posterior margin, legs 1 and 9 5-segmented, interposed pairs 6-segmented, pygidial sternum with two pairs of setae, b 1 and b 2.

The new genus is distinguished easily from Diplopauropus : (1) in having the anterior margin of the sternal antennal branch distinctly shorter than the posterior margin (similarly truncated in the anterior and posterior corners in Diplopauropus ), (2) in having temporal organs without exterior vesicle, and (3) the pygidial sternum with two pairs of setae, b 1 and b 2 (one pair only, b 1, in Diplopauropus ).

Derivation of name. From the Greek adelphos = twin, brother, and the genus name Pauropus , the first described genus in the Pauropoda.

Adelphopauropus ichtyematos n. sp. Figs 18–29

Type locality. Brazil, Central Amazonia, 30 km W of Manaus, at the south bank of Rio Negro, Praja Grande, black-water inundation forest.

Type specimen. Holotype: ad. with 9 pair of legs (Ƥ), April 23, 1981, leg. J. Adis.

Derivation of name. From the Greek ichthyema = fish-scale, referring to the cuticular pattern of the pygidial tergum.

Description. Length. 1.42 mm.

Head (Fig. 18). Setae striate, tergal ones thin, l -setae very thin, median and submedian setae somewhat clavate, posterolateral setae cylindrical, l -setae pointed. Relative lengths of setae: 1st row: a 1=10, a 2=12; 2nd row: a 1=7, a 2=?, a 3=19; 3rd row a 1=7, a 2=12; 4th row: a 1=10, a 2=24, a 3=25, a 4=19; lateral group setae: l 1=35, l 2=30, l 3=20. The ratio a 1/ a 1- a 1 in 1st row=0.9, 2nd row 0.4, 3rd row 0.6, 4th row=0.8. Temporal organs in tergal view reniform, length 2.2 times as long as their shortest interdistance. Cuticle glabrous.

Antennae (Fig. 19). Segment four with at least four thin, cylindrical, striate setae: their relative lengths: p =100, p´=?, p´´=35, r =37. Tergal seta p 1.2 times as long as tergal branch t. The latter branch almost cylindrical, widest in distal half, 4.4 times as long as greatest diameter, 1.8 times as long as sternal branch s, that branch 1.8 times as long as greatest diameter, anterodistal corner distinctly truncate. Seta q as seta p of segment four, almost as long as s. Relative lengths of flagella (basal segments included) and basal segments alone: F 1 = 100, bs 1=9 and 10; F 2=57, bs 2=7; F 3=129, bs 3=11. F 1 and F 2 2.2 and 1.9 times as long as t and s respectively. Distal calyces of F2 and F 3 flattened, distal part of flagella axes fusiformly widened below calyces. Globulus g subspherical with short stalk, ≈15 bracts, capsule somewhat flattened. Diameter of g equal to greatest diameter of t. Antennae glabrous.

Trunk ( Figs 25, 26 ). Setae of collum segment ( Fig. 25 ) furcate, primary branch cylindrical, blunt, striate, secondary branch rudimentary. sublateral setae twice as long as submedian ones. Sternite process short, narrow anteriorly; appendages very short, caps low, flat, divided; process with very short anterior marginal pubescence, appendages glabrous.

Setae on anterior tergites striate, lengthening posteriorly, on anterior parts of tergites somewhat clavate, on posterior parts cylindrical-pointed: tergite I with 4 setae in an anterior row, no posterior row, tergites II-IV with 6+6 and V with 6+4 setae, tergite VI with 4+2. Posterior setae on tergite VI ( Fig. 26 ) long thin tapering pointed, curved outwards, about as long as interdistance and 0.8 of the length of pygidial setae a 1.

Bothriotricha (Figs 23, 24). Relative lengths: T 1=100, T 2=129, T 3 = 138, T 4=?, T 5=295 and 296. Axes in T 1 (Fig. 21), T 2 and T 4 thin, in T 3 (Fig. 21) and T 4 moderately thickened. Pubescence of simple straight oblique hairs, short on T 1, T 2, T 4, stronger on T 3, very strong on T 5, particularly on proximal half (Fig. 22).

FIGURES 18 – 24. Adelphopauropus ichtyematos n.sp., holotype ad. 9(Ƥ). 18, head, left half, tergal view. 19, left antenna, sternal view. 20, T 1. 21, T 3. 22, T 5. 23, seta on trochanter of leg 9. 24, tarsus of leg 9. Scale: a: 22; b: 23, 24; c: 20, 21; d: 18, e: 19.

Legs (Figs 23, 24). Setae on coxa and trochanter furcate, on legs 1-8 with rudimentary secondary branch, on leg 9 (Fig. 23) with two subsimilar, cylindrical, blunt, striate branches. Tarsus of leg 9 (Fig. 24) slender, bowshaped, tapering, 5.5 times as long as greatest diameter. Setae thin, with short oblique pubescence, proximal seta tapering, pointed, distal seta cylindrical, blunt; proximal seta 0.3 of the length of tarsus and 2.3 times as long as distal seta. Cuticle almost glabrous.

Pygidium ( Figs 27–29 ). Tergum. Posterior margin rounded, but straight just between st, lateral margin serrate with distinct needle-shaped projections distally. Surface with thickenings forming a pattern similar to fish-scales with rounded part directed anteriorly; a -setae inserted near posterior margin of most posterior row of scales. Relative lengths of setae: a 1=100, a 2=60 and 63, a 3 =57 and 64, st =30 and 31. Setae tapering, pointed, pubescence short, sparse on a -setae, on st denser; a 1, a 2, st directed posteriorly, a 3 also diverging, st converging, a 2 and a 3 curved inwards.

Anal plate of tergum oval, 1.3 times as long as broad, broadly V-shaped posterior indentation.

Sternum ( Figs 28, 29 ). Posterior margin with broad deep V-shaped indentation between setae b 1. Relative lengths of setae (pygidial a 1 = 100): b 1≈96 and 115), b 2=56 and 58. Setae b 1 cylindrical blunt striate, b 2 diverging.

Anal plate of sternum ( Figs 27, 29 ) somewhat smaller than the plate of the tergum, 1.2 times as long as broad, broadest in posterior half, lateral margins somewhat concave, posteriolateral corners cut obliquely, small posteriomedian V-shaped incision: one long cylindrical blunt shortly pubescent appendage protrudes backwards from anterior part of each posteriolateral truncation ( Figs 27, 28 ).

Remarks. The pauropod fauna of Brazil is for the most part unknown. Only 60 named species in 11 genera from three families have been reported almost all from the Manaus region in Central Amazonas (Remy 1956, Hüther 1968, 1985, Scheller 1994, 1999, 2002a, b, 2007). Outside the Manaus region, pauropods are known only from Paraná and Santa Catarina (one species from each, Remy 1956), from Amapá (one species, Hüther 1968) and Mato Grosso (one species, Scheller 2007). However, in his paper from 1985, Hüther said that he had found about 60 species together in the states of Amazonia, Amapá and Pará, but they were unfortunately not described.

The fauna is strongly dominated by the family Pauropodidae .

Figures

FIGURES 25 - 29. Adelphopauropus ichtyematos n. sp., holotype ad. 9 (Ƥ). 25, collum segment, median and left part sternal view. 26, tergite VI, posteriomedian part and right posterior corner. 27, pygidium, tergum, posteriomedian part showing scaly cuticular pattern, anal plate and st, a - setae not drawn, tergal view. 28, pygidium, posteriomedian and left part of sternum and left serrate margin of tergum, sternal view. 29, pygidium, lateral view showing position of anal plates. Scale: a: 29: b: 25, 26; c: 27, 28.