Acentrella (Liebebiella) vera (Muller-Liebenau, 1982) sensu Kluge & Novikova, 2011

Tungpairojwong, Nisarat, Phlai-Ngam, Sirikamon & Jacobus, Luke M., 2022, A new species of Acentrella Bengtsson, 1912 (Ephemeroptera: Baetidae) from Thailand, Zootaxa 5125 (4), pp. 351-378 : 367-371

Acentrella (Liebebiella) vera

( Figs 13–17 )

Acentrella (Liebebiella) difficila ( Müller-Liebenau, 1982) sensu Kluge & Novikova 2011

Acentrella (Liebebiella) vera ( Müller-Liebenau, 1982) sensu Kluge & Novikova 2011

Liebebiella deigma Waltz & McCafferty, 1987 (syn. by Kluge & Novikova 2011)

Liebebiella difficila ( Müller-Liebenau, 1982) sensu Waltz & McCafferty 1987

Liebebiella vera ( Müller-Liebenau, 1982) sensu Waltz & McCafferty 1987

Platybaetis arunachalae Selvakumar, Sundar & Sivaramakrishnan, 2012 (syn. by Kluge et al. 2013)

Pseudocloeon sp. 1 : Ulmer, 1939

Pseudocloeon kraepelini sensu Müller-Liebenau, 1981 , non Pseudocloeon kraepelini Klapálek, 1905 ; Kluge & Novikova 2011

Pseudocloeon difficilum Müller-Liebenau, 1982 (syn. by Kluge et al. 2013)

Pseudocloeon verum Müller-Liebenau, 1982

Material examined. 39 nymphal instar in ethanol [ KKU-AIC], two nymphs in ethanol [ KKU-AIC], one associated male imago on slides [ KKU-AIC], Khon Kaen province, Nong Wai Weir, Phong River, Nam Phong district (16°43’34.00”N, 102°48’27.03”E, alt. 120 m a.s.l.), 20.vi.2015 ; Loei province: 16 nymphs in ethanol [ KKU-AIC], San River, Phu Rue district (17°25’54.52”N, 101°16’48.45”E, alt. 526 m a.s.l.), 12.iii.2016 ; Chiang Mai province: five nymphs in ethanol [ KKU-AIC], Mae Klang waterfall, Jom Thong district (18º29’39.72”N, 98º40’06.65”E, alt. 337 m a.s.l.), 1.ii.2015 ; 11 nymphs in ethanol, Mon Tha Than waterfall, Suthep district (18º49’02.41”N, 98º55’23.23”E, alt. 713 m a.s.l.), 2.ii.2015 ; 16 nymphs in ethanol [ KKU-AIC], Nam Kuang stream, Doi Saket district (18º57’51.16”N, 99º14’14.88”E, alt. 444 m a.s.l.), 3.ii.2015 ; Chiang Rai province: five nymphs in ethanol [ KKU-AIC], Ban Tung Pak Kud stream, Phan district (19º33’48.33”N, 099º40’43.98”E, alt. 481 m a.s.l.), 4.ii.2015 ; Phatthalung province: 12 nymphs in ethanol [ KKU-AIC], Khao Kram stream, Srinakarin district (07°31’14.52”N; 99°52’45.00”E, alt. 60 m a.s.l.), 16.v.2016 ; Nakhon Sri Thammarat province: 27 nymphs in ethanol [ KKU-AIC], Kiriwong upstream, Lansaka district (08°27’13.02”N; 099°44’22.32”E, alt. 238 m a.s.l.), 17.v.2016 ; 19 nymphs in ethanol [ KKU-AIC], Kiriwong downstream, Lansaka district (08°25’59.94”N; 099°46’59.76”E, alt. 45 m a.s.l.), 17.v.2016 ; Songkhla province: eight nymphs in ethanol [ KKU-AIC], Tone Nga Chang stream, Hat Yai district (06°59’01.70”N; 100°21’18.11”E, alt. 558 m a.s.l.), 19.v.2016 ; Nakhon Nayok province: 5 nymphs in ethanol [ KKU-AIC], Wang Takai waterfall, Muang district (14°20’07.97”N; 101°18’22.12”E, alt. 63 m a.s.l.), 23.iv.2016 ; Sara Buri province: 22 nymphs in ethanol [ KKU-AIC], Muak Lek stream, Muak Lek district (14°40’50.47”N; 101°12’06.03”E, alt. 234 m a.s.l.), 23.iv.2019 ; Kanchanaburi province: seven nymphs in ethanol [ KKU-AIC], Saiyok district , Ban Nong Pla (14°12’7.97”N; 99°03’07.84”E, alt. 66 m a.s.l.), 23.ix.2019 ; Ratchaburi province: 11 nymphs in ethanol [ KKU-AIC], Suan Pueng district , Ban Bo Wi (13°30’17.36”N; 99°15’57.56”E, alt. 147 m a.s.l.), 25.ix.2019 ; Phetchaburi province: six nymphs in ethanol [ KKU-AIC], Ta Yang district , Khi Phra Khom stream (12°55’26.19”N; 99°47’40.40”E, alt. 47 m a.s.l.), 24.ix.2019 .

Diagnosis. Mature nymphs ( Figs 13A , 14A–B ): ventrally flattened body, brownish to dark brown color with black markings. Head and thorax ( Fig. 13B ): head capsule with very fine, short setae dorsally and posteriorly ( Fig. 17A ). Antennae ( Fig. 17B ) with scattered short, fine, hairlike setae. Mouthparts compact: labrum widest near the base, anterior margin with shallow medial cleft, and long, feathered bristle present; maxillary palp ( Fig. 15A ): 3-segmented, with scattered small, blunt setae; proximal segment and distal segment subequal in length, distal segment with distinct, small tip at apex. Hind wing pad vestigial ( Fig. 15B ). Legs ( Fig. 15C ): femur with single dorsal row of long, dense multilaterally ciliate bristles, tibia with two well-developed rows of bristles ( Fig. 15D ), tarsus with long preapical seta ( Fig. 15E ). Abdomen ( Figs 13C–D ): surface of abdominal terga ( Figs 15F , 17C–D ) with scattered fine setae, sparse and scale-like along margin, posterior margin of terga with acute denticles accompanied by scattered long-oval translucent scales. Seven gill pairs present, with sparse short, fine setae ( Figs 16A–B , 17E ). Median filament reduced, usually 11 or 12 segments ( Fig. 17F ).

The male adult can be distinguished from A.fimbriata sp.nov. by the shape of the undulating gonovectes( Fig.16C ).

Remarks. Associated female and male adults are shown in Figures 14C–D . Additionally, the description of nymphal and adult stages of A. (Liebebiella) vera was given by Kluge & Novikova (2011); Kluge et al. (2013); and Selvakumar et al. (2012) (as Platybaetis arunachalae ).

Ecology and Distribution. The nymphs of A. (Liebebiella) vera were found in diverse flowing streams with cobble and bedrock habitats. Individuals can be found in diverse running water microhabitats, ranging from cool and clean water to warm and strongly polluted water. Probably, A. (Liebebiella) vera has a wide fundamental ecological niche that allows it to be common and widely distributed.

Our new record data demonstrate that A. (Liebebiella) vera ranges from northern to southern Thailand ( Fig. 18 ). These data bridge an apparent gap in the distribution of populations of the species and supports the hypothesis that this species has a more less continuous occurrence from India to Malaysia and Indonesia (as shown by Kluge et al. 2013: Fig. 3 ).

Figures

FIGURE 3. Acentrella fimbriata sp. nov. nymph, head structures: (A) head capsule, frontal view; (B) antenna; (C) labrum, with different setae emphasized on each side; (D) left (angulate) mandible; (E) right (planate) mandible; (F) incisors of left mandible; (G) incisors of right mandible. Scale bars: A–E = 0.1 mm; F–G = 0.02 mm.

FIGURE 13. Acentrella (Liebebiella) vera, nymph: (A) dorsal habitus; (B) head and thorax, dorsal view; (C) abdomen, dorsal view; (D) abdominal terga V–VII. Scale bars: A = 1 mm; B–D = 0.5 mm.

FIGURE 14. Acentrella (Liebebiella) vera, (A–B) nymphs and (C–D) imagoes: (A) male nymph; (B) final nymphal instar, male; (C) female imago; (D) male imago.

FIGURE 15. Acentrella (Liebebiella) vera, nymph: (A) maxilla; (B) hind wing pad; (C) foreleg; (D) tibia; (E) tarsus and claw; (F) abdominal tergum segment V. Scale bars: A–C, E = 0.2 mm; D = 0.05 mm.

FIGURE 16. Acentrella (Liebebiella) vera, nymph (A–B) and male imago (C): (A) abdominal gills; (B) details of gill V; (C) male genitalia. Scale bars: A–B = 0.2 mm; C = 0.05 mm.

FIGURE 17. Acentrella (Liebebiella) vera, nymph, scanning electron micrographs: (A) head; (B) antenna; (C) middle abdominal terga; (D) tergal surface; (E) gills; (F) median filament and bases of cerci. Scale bar: A = 500 µm; B, C, F = 200 µm; D = 100 µm; E = 300 µm.

FIGURE 18. Distribution map of Acentrella fimbriata sp. nov. and Acentrella (Liebebiella) vera in Thailand. Red squares: Acentrella fimbriata sp. nov. Blue circles: Acentrella (Liebebiella) vera.