Papuanatula ( Papuanatula ) batanlenos Kaltenbach, Kovács & Gattolliat, 2025

Kaltenbach, Thomas, Kovács, Tibor & Gattolliat, Jean-Luc, 2025, New species of Papuanatula Lugo-Ortiz & McCafferty, 1999 from New Guinea (Ephemeroptera, Baetidae) with focus on Batanta Island, ZooKeys 1259, pp. 1-55 : 1-55

Papuanatula ( Papuanatula) batanlenos Kaltenbach, Kovács & Gattolliat sp. nov.

Figs 15 , 16 , 17 , 18 , 19

Type material.

Holotype. Indonesia • larva; West Papua, Batanta Island, Kalijakut River ; 00°52'27"S, 130°37'52"E; 420 m; 09. ii. 2024; leg. T. Kovács; on slide; GBIFCH 01221820 ; 2024-12, EPHTYP-11; MM . Paratypes. • 14 larvae; same data as holotype ; • 2 larvae on slides; GBIFCH 00975879 , GBIFCH 01221821 (gonostyli), GBIFCH 01221824 ; MZL ; • 12 larvae in alcohol; GBIFCH 00975880 , GBIFCH 00975881 , GBIFCH 00975878 , GBIFCH 01581951 ; MZL • 3 subimagos; same data as holotype; at light, in alcohol; GBIFCH 00975863 ( ♂, ♀), GBIFCH 00975864 ( ♀); MZL • 2 larvae; West Papua, Batanta Island, Kalijakut River ; between 00°53'39"S, 130°38'30"E and 00°53'03"S, 130°38'13"E; 52 m – 182 m; 08. ii. 2024; leg. T. Kovács; in alcohol; GBIFCH 00975874 , GBIFCH 00975875 ; MZL • 4 larvae; West Papua, Batanta Island, valley of Waridor River ; 00°51'52"S, 130°32'26"E; 55 m; 19. i. 2014; leg. T. Kovács, R. Horváth, P. Juhász; 1 on slide; GBIFCH 00975994 ; 3 in alcohol; GBIFCH 00975995 , GBIFCH 00975996 ; MZL • 1 ♂ imago, 3 subimagos; West Papua, Batanta Island, valley of Kalijakut River ; 00°52'49"S, 130°38'05"E; 232 m; 19. ii. 2020; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; 1 ♂ imago on slide, thorax in alcohol; GBIFCH 01221780 ; GBIFCH 00975967 ; 3 subimagos in alcohol; GBIFCH 00975965 ( ♂, ♀), GBIFCH 00975966 ( ♂); MZL • 1 imago, 2 subimagos; West Papua, Batanta Island, valley of Kalijakut River ; 00°53'03"S, 130°38'13"E; 182 m; 15. ii. 2023; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; 1 ♂ imago on slide, thorax in alcohol; GBIFCH 01221779 , GBIFCH 00975970 ; 1 subimago on slide; GBIFCH 00975968 ( ♂); 1 subimago in alcohol; GBIFCH 00975969 ( ♀); MZL • 1 ♂ imago; West Papua, Batanta Island, valley of Tanjung Lampu River ; 00°53'43"S, 130°36'39"E; 175 m; 21. ii. 2018; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; on slide, thorax in alcohol; GBIFCH 01221776 , GBIFCH 00975964 ; MZL • 5 subimagos; West Papua, Batanta Island, valley of Wailebet Stream ; 00°53'22"S, 130°39'07"E; 150 m; 19. ii. 2018; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; 4 in alcohol; GBIFCH 00975961 ( 1 ♂, 2 ♀), GBIFCH 00975962 ( ♀); 1 on slide; GBIFCH 00975963 ( ♀); MZL • 3 ♀ subimagos; West Papua, Batanta Island, valley of Wailebet Stream , waterfall; 00°53'07"S, 130°39'00"E; 285 m; 28. ii. 2017; at light; leg. T. Kovács, R. Horváth, P. Juhász, K. Sauyai, R. Sauyai; in alcohol; GBIFCH 00975959 , GBIFCH 00975960 ; MZL • 15 larvae; West Papua, Batanta Island, Waridor River ( shallow, rocky, fast-flowing); 00°52'06"S, 130°31'30"E; 32 m; 14. ii. 2025; leg. T. Kovács; 6 in alcohol; GBIFCH 01582001 ; MZL; 9 in alcohol; 2025-12, EPHTYP-12; MM • 10 larvae; Indonesia, West Papua, Batanta Island, Kalijakut River ; 00°53'03"S, 130°38'13"E; 182 m; 19. ii. 2025; leg. T. Kovács; in alcohol; 2025-17, EPHTYP-13; MM • 15 larvae; West Papua, Batanta Island, Kalijakut River ; 00°52'27"S, 130°37'52"E; 420 m; 20. ii. 2025; leg. T. Kovács; in alcohol; 2025-18.a, EPHTYP-14; MM • 3 larvae; West Papua, Batanta Island, right side stream of Kalijakut River ; 00°52'16"S, 130°37'45.5"E; 545 m; 21. ii. 2025; leg. T. Kovács; in alcohol; 2025-19, EPHTYP-15; MM .

Diagnosis.

Larva. The following combination of characters distinguishes P. batanlenos sp. nov. from other species of Papuanatula s. str.: body dorsally without row of long, fine, simple setae along midline; body dorsally without protuberances; abdomen dorsally grey-brown, abdominal terga IV, VII, and VIII with trough-like, dark grey-brown marking, abdominal terga III, V, and VI with dark grey-brown, oblique, lateral streaks; femur with irregular, shoe-shaped marking in large, basal blank; paracercus with 14–16 segments; paraproct without posterior prolongation.

Description.

Larva (Figs 15 – 17 ). Body length 3.5–4.0 mm, cerci ~ 1.6 × body length.

Cuticular coloration (Figs 15 a – c , 17 e ). Head, thorax and abdomen dorsally grey-brown, thorax darker; abdominal terga IV, VII, and VIII with trough-like, dark grey-brown marking; abdominal terga III, V, and VI with dark grey-brown, oblique, lateral streaks (dorsal abdominal pattern slightly varying). Head, thorax and abdomen ventrally grey-brown. Legs grey-brown, with large blank in basal area. Caudalii yellow-brown.

Hypodermal coloration (Fig. 15 a – c ). Abdominal terga I – IX with narrow, dark brown, transverse band along posterior margin. Femur anteriorly with dark brown, irregular, shoe-shaped marking in basal ½ (somewhat variable in shape; sometimes poorly developed); posteriorly with dark brown streak distally close to outer margin.

Head. Antenna (Fig. 16 j ). Length ~ 2.5 × head length. As typical for the subgenus.

Developing turbinate eyes in last instar male larva (Fig. 15 a ) large, round, nearly touching each other in the middle.

Labrum (Fig. 16 a, b ). Length 0.5 × maximum width, laterally convex. Dorsal, sub-marginal arc with ~ 15 feathered setae.

Right mandible (Fig. 16 d ). Margin between prostheca and mola straight, with few minute denticles. Otherwise, as typical for subgenus.

Left mandible (Fig. 16 c ). Margin between prostheca and mola straight, with few minute denticles. Subtriangular process with undulating margins, outer margin with denticles. Otherwise, as typical for subgenus.

Hypopharynx (Fig. 16 f ). Medial tuft of spine-like setae laterally denser, giving the impression of a pair of tufts. Otherwise, as typical for the genus.

Maxilla (Fig. 16 g ). Maxillary palp slightly longer than galea-lacinia; palp segment II ~ 1.2 × length of segment I. Otherwise, as typical for the genus.

Labium (Fig. 16 e ). Paraglossa with two spine-like setae on inner, distolateral margin. Labial palp with segment I ~ 0.8 × length of segments II and III combined. Segment II without distomedial protuberance, dorsally with row of four spine-like setae near outer, distolateral margin. Segment III broad pentagonal, pointed, 0.8 × length of segment II. Otherwise, as typical for the genus.

Thorax. Sterna without protuberances.

Terga without protuberances.

Legs (Fig. 17 a – d ). Ratio of leg segments: fore leg 1.0: 1.0: 0.2: 0.1, middle leg 1.0: 1.0: 0.2: 0.1 and hind leg 1.1: 1.0: 0.2: 0.1. Femur. Length 3 × maximum width. Many short, spine-like setae along ventral margin. Claw with one row of six or seven denticles, distalmost denticle with distance to other denticles; one or two posterior setae. Otherwise, as typical for subgenus.

Abdomen. Terga (Fig. 17 f ). Abdominal terga without protuberances. Posterior margin of terga: I smooth, without denticles; II – IX with triangular, pointed denticles.

Tergalii (Fig. 16 h, i ). Ovoid, tracheation rather well developed; margin with minute serration and short, fine, simple setae. Tergalius II as long as abdominal terga III, IV, and ¼ V combined, tergalius IV as long as terga V, VI and ⅓ VII combined, tergalius VII as long as terga VIII and ⅓ IX combined.

Paraproct (Fig. 17 g ). Posterior margin without prolongation, smooth, without denticles.

Caudalii (Fig. 17 h, i ). Cerci without swimming setae. Paracercus with 14–16 segments.

Pose of subimaginal gonostyli under larval cuticle (Fig. 16 k ). Segment III conical. Otherwise, as typical for the subgenus.

Subimago (Fig. 19 b – f ). Body length 4.2–4.5 mm. Turbinate eyes of male ochre. Thorax brown. Wing membrane colourless, veins pale yellow-brown, base of wings brown, microtrichia pale yellow-brown. Legs very pale brown; coxa with hypodermal, dark brown fleck; femur anteriorly with hypodermal, shoe-shaped, dark brown marking in basal ½; femur posteriorly with hypodermal, dark brown distal streak and fleck in basal ½. Abdomen yellow-brown; male with hypodermal, dark brown, trough-shaped marking on terga III, IV, VII, and VIII, and sublateral, oblique, dark brown streaks on terga II, V and VI; female with same hypodermal markings, but more diffuse; all terga of both sexes with hypodermal, narrow, transvers, dark brown band on posterior margin. Cerci colourless.

Texture (Fig. 19 e, f ). On all legs of male and female subimagos, terminal tarsomere covered with pointed microlepides; other tarsomeres covered mostly with blunt microlepides, with pointed microlepides near apex.

Imago, male (Figs 18 a – d , 19 a ). Body length ~ 3.8 mm. Head and antennae pale brown. Turbinate eyes pale brown, wide, with facetted surfaces round. Thorax pale brown. Fore wing with membrane colourless, base of wings brownish. Pterostigma with three or four oblique crossveins, basal two crossveins nearly complete. Legs light brownish; coxa with hypodermal, dark brown fleck; femur anteriorly with hypodermal, shoe-shaped, dark brown marking in basal ½; femur posteriorly with hypodermal, dark brown distal streak and fleck in basal ½. Abdominal segments I and VII – X pale brown, II – VI transparent, giving a blueish impression; with hypodermal, dark brown, trough-shaped marking on terga III, IV, VII, and VIII, and sublateral, oblique, dark brown streaks on terga II, V, and VI. Cerci colourless.

Genitalia (Fig. 18 d ). Unistyliger slightly widened apically, with lateral margin slightly concave. Gonostylus with segment I conical and separated from segment II by concavity. Segment II slightly wider in distal ½, bent inward. Terminal segment III narrower than segment II, ovoid, length ~ 1.5 × maximal width. Penial bridge with poorly expressed membranous projection between unistyligers.

Imago, female. Unknown.

Egg. Unknown. Eggs extracted from female subimagos are undeveloped.

Biological aspects.

It is a common species in most riverine habitat types in Batanta, living in the northern and southern watercourses of the island: Kalijakut (Fig. 29 a, d (type locality), f), Tanjung Lampu and Waridor (Fig. 29 e ) Rivers, and Wailebet Stream. It is found from small, high-falling mountain tributaries to the lower, flat sections of the largest rivers at altitudes between 32 m and 545 m. Apart from the extreme habitat of P. cataracta sp. nov., it co-occurs with all Papuanatula species living in Batanta: P. batantaraja sp. nov., P. cukiclara sp. nov., P. horvathrobi sp. nov., and P. longabranchias sp. nov.

Etymology.

The species name batanlenos refers to the type locality on Batanta island and its belonging to the lenos species group.

Distribution.

New Guinea, Batanta Island (Fig. 30 ).

Key to the species of P. lenos species group from New Guinea (larvae)

Based on Kaltenbach et al. 2025.

Figures

Figure 15. Papuanatula (Papuanatula) batanlenos sp. nov., larva, habitus. a. Dorsal view; b. Lateral view; c. Ventral view. Scale bars: 1 mm.

Figure 16. Papuanatula (Papuanatula) batanlenos sp. nov., larva. a. Labrum; b. Labrum, submarginal arc of setae; c. Left mandible; d. Right mandible; e. Labium; f. Hypopharynx and superlinguae; g. Maxilla; h, i. Tergalius IV; j. Head; k. Developing subimaginal gonostyli. Scale bars: 100 µm (j), 20 µm (a, c – h, k), 10 µm (b, i).

Figure 17. Papuanatula (Papuanatula) batanlenos sp. nov., larva. a. Middle leg; b. Middle femur, outer margin; c. Middle tarsus, outer margin; d. Middle claw; e. Abdomen; f. Abdominal terga; g. Paraproct; h. Paracercus; i. Cercus. Scale bars: 100 µm (a, e), 20 µm (h), 10 µm (b – d, f, g, i).

Figure 18. Papuanatula (Papuanatula) batanlenos sp. nov, imago, male. a. Habitus, lateral view; b. Habitus, dorsal view; c. Middle leg; d. Genitalia. Scale bars: 1 mm (a, b), 100 µm (c), 50 µm (d).

Figure 19. Papuanatula (Papuanatula) batanlenos sp. nov. Imago, male. a. Fore wing. Subimagos. b. Habitus, male; c. Habitus, female; d. Middle leg; e. Fore tarsus; f. Middle tarsus. Scale bars: 1 mm (a – c), 100 µm (d), 20 µm (e), 10 µm (f).

Figure 29. Habitats: P. batantaraja sp. nov. (a. Type locality, b); P. cukiclara sp. nov. (a, b, d. Type locality); P. cataracta sp. nov. (c. type locality); P. batanlenos sp. nov. (a, d. Type locality, e, f); P. horvathrobi sp. nov. (e); P. longabranchias sp. nov. (d. Type locality, f).

Figure 30. Distribution of Papuanatula species: yellow dots: known species (Kaltenbach et al. 2025); orange dot: Papuanatula arfak sp. nov. (present study); red dots: species from Batanta – P. batantaraja sp. nov., P. cukiclara sp. nov., P. cataracta sp. nov., P. batanlenos sp. nov., P. horvathrobi sp. nov., P. longabranchias sp. nov. (present study).