Symphylella fuko sp. nov.

urn:lsid:zoobank.org:act: 61460AA1-87DF-4E69-B5CD-79799F57955F

Figs 2, 7B

Type material

Holotype Sex unkown, CONGO D.R., A.N.P., secteur sud, riv. Rumanura, affl. Fuko, 1200 m, coll. De Witte, 14 Jul. 1954 (MRAC 22151).

Type locality

CONGO D.R., A.N.P., secteur sud, riv. Rumanura, affl. Fuko, 1200 m.

Etymology

The species name is a noun in apposition taken from the type locality.

Description (holotype)

LENGTH. 2.5 mm.

HEAD. 1.1 times as long as broad with broadest part behind the middle on a level with lateral protuberances (Fig. 2A). Lateral margins nearly straight. Central rod thin, nearly indistinct in the anterior part. Frontal branches present but no median branches. Dorsal surface mostly covered with short setae, the longest are situated in the anterior part and in the lateral margins. Cuticle with faint and dense pubescence (Fig. 2C).

ANTENNAE. Left antenna 19 segments, right 18 (Fig. 2G). First segment smaller, 2 nd and 3 rd segments about 1.2 times as wide as long. The following segments are gradually wider, about 1.8 times as wide as long in the 12 th. Setae about 0.2 times the diameter of the segments; shorter in the most distal segments. No second whorl of setae from dorsal view. Apical segment subglobular, slightly wider than long. All segments with faint pubescence.

TERGITES (Figs 2A, H, 7B). First tergite rudimentary with seven setae arranged in two groups of three and four. Second tergite complete; triangular processes with straight margins and small end-swellings (Fig. 2A, H). Margin between projections straight. One marginal setae between apical and inner basal setae on the left triangular projection, two on the right one; nine posteromarginal setae with equal length, with two central ones; seven lateromarginal setae on each side. Anterolateral setae longer than others. Third tergite with ten lateromarginal setae on the left side, right margin not entirely visible. All tergites with faint pubescence.

LEGS. First pair of legs strongly reduced to spiny spots with two protruding setae and two longer setae on both sides (Fig. 2B, D). Anterior seta as long as protruding seta of the spot. Posterior seta 4 times longer of anterior one and pointing backwards. Last pair of legs barely visible in the holotype, with three longer seta on dorsal part of the femur – one in the proximal part and two in the distal part – and one on the tibia (Fig. 2F). Cuticle with very faint pubescence.

STYLI. Not visible.

CERCI. 2.5 times as long as wide, sides slightly curved (Fig. 2E). Setae generally short, slightly curved and depressed on all sides; 40 visible from the dorsal view. One erect and longer seta on the ventral side of both cerci (Fig. 2F). Cuticle with very faint pubescence. Terminal area not visible in the holotype.

Affinities and differential diagnosis

The combination of a relative high number of setae on the first tergite – four setae on the left half – and on the second tergite – nine posteromarginal and seven lateromarginal setae – is shared by S. fuko sp. nov., S. simplex, S. multisetosa and S. neotropica (Hansen, 1903) . The presence of only three setae on the right half of the first tergite, longer and erect setae on the second and third tergites and the frontal branches of the central rod on the head are characteristic for S. fuko sp. nov. This species also differs from S. multisetosa and S. neotropica in the first pair of legs, which is strongly reduced to spiny spots. The chaetotaxy and morphology of the first three tergites in S. fuko sp. nov. are also similar to those of S. erecta sp. nov., but S. fuko sp. nov. is easily distinguished by the regular size of the inner basal setae on the second tergite and the shorter anterolateral setae.