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

Figs 6 , 7 , 8

Type material.

Holotype. Indonesia • larva; West Papua, Batanta Island, right side stream of Kalijakut River ; 00°52'16"S, 130°37'45.5"E; 545 m; 10. ii. 2024; leg. T. Kovács and R. Sauyai; on slides; GBIFCH 00975887 , GBIFCH 01221819 ; 2024-13.b, EPHTYP-1; MM . Paratypes. 4 larvae; same data as holotype; 2 on slides; GBIFCH 00975888 , GBIFCH 01221825 , GBIFCH 01221826 ; 2 in alcohol; GBIFCH 00975886 ; MZL • 13 larvae; partly same data as holotype; 21. ii. 2025; leg. T. Kovács; 2 in alcohol; GBIFCH 01582004 ; MZL; 11 in alcohol; 2025-19, EPHTYP-2; MM • 1 larva; West Papua, Batanta Island, right side stream of Kalijakut River , side spring area; 00°52'27"S, 130°37'51"E; 432 m; 20. ii. 2025; leg. T. Kovács; in alcohol; 2025-18.b, EPHTYP-3; MM .

Diagnosis.

Larva. The following combination of characters distinguishes P. batantaraja sp. nov. from other species of Papuanatula s. str.: large species (> 7 mm body length); body dorsally without row of long, fine, simple setae along midline; fore protoptera posteromedially with pair of minute, broad protuberances and one minute, rather pointed protuberance between them; metanotum and abdominal terga I – X medially with conspicuous, long, pointed protuberance, slightly bent posteriad; left mandible without subtriangular process; femur anteriorly with angulate blank in basal ½; transparent, semicircular scales on anterior surface of femur and dorsal surface of abdominal terga; paracercus vestigial.

Description.

Larva (Figs 6 – 8 ). Body length 7.0– 7.5 mm, largest Papuanatula species known so far. Cerci ~ 2 × as long as body length.

Cuticular coloration (Figs 6 a – c , 8 e ). Head, thorax and abdomen dorsally uniform grey-brown. Head, thorax and abdomen ventrally beige. Legs yellow-brown, femur basally with angulate blank, apically blank. Caudalii yellow-brown.

Hypodermal coloration (Fig. 6 a, b ). Thorax dorsally with few blackish markings. Abdominal terga with narrow dark brown to blackish transverse band along posterior margins; sigillae blackish.

Head. Antenna (Fig. 7 j ). Length ~ 1.5 × head length. Flagellum distally with brown dots.

Developing turbinate eyes in last instar male larva unknown.

Labrum (Fig. 7 a, b ). Very wide, length 0.5 × maximum width, laterally angulate. Dorsal, sub-marginal arc with> 40 densely articulated, feathered setae.

Right mandible (Fig. 7 d ). Margin between prostheca and mola straight, smooth. Otherwise, as typical for the subgenus.

Left mandible (Fig. 7 c ). Margin between prostheca and mola straight, smooth; subtriangular process not developed. Otherwise, as typical for the subgenus.

Hypopharynx (Fig. 7 f ). Apical tuft of spine-like setae laterally denser, giving the impression of a pair of tufts. Otherwise, as typical for the genus.

Maxilla (Fig. 7 g ). Maxillary palp slightly longer than galea-lacinia; palp segment II approx. as long as segment I; segment I thicker than segment II. Otherwise, as typical for the genus.

Labium (Fig. 7 e ). Paraglossa dorsally with one spine-like seta near inner, distolateral margin. Labial palp with segment I 0.9 × length of segments II and III combined. Segment II with very small, rounded, distomedial protuberance, dorsally with row of five spine-like setae near outer, distolateral margin. Segment III slightly pentagonal, pointed, 0.8 × length of segment II. Otherwise, as typical for the genus.

Thorax. Sterna. Protuberances not developed.

Terga (Fig. 8 e ). Metanotum posteromedially with long, pointed protuberance, slightly bent posteriad. Fore protoptera posteromedially with pair of minute, broad protuberances and one minute, rather pointed protuberance between them.

Legs (Fig. 8 a – d ). Ratio of leg segments: fore leg 1.1: 1.0: 0.3: 0.1, middle leg 1.0: 1.0: 0.3: 0.1 and hind leg 1.1: 1.0: 0.3: 0.1. Femur. Length ~ 3 × maximum width. Anterior surface with transparent, semicircular scales. Claw with one row of 7–9 denticles, apical denticle larger than other ones, and one or two posterior setae, and one or two short, reduced setae opposite to posterior setae. Otherwise, as typical for the subgenus.

Abdomen. Terga (Figs 6 a, b , 8 e – g ). Abdominal terga I – X posteromedially with conspicuous, long, pointed protuberance, slightly bent posteriad; Posterior margin of terga: I – IX with minute, pointed denticles, slightly increasing in size toward IX. Surface with scattered transparent, semicircular scales.

Tergalii (Fig. 7 h, i ). Present on terga II – VII. Broad oblique ovoid; tracheation strongly developed; with grey pigmentation, especially in anal ½; margins smooth, with many short, fine, simple setae. Tergalius II as long as abdominal terga III and IV combined, tergalius IV as long as terga V, VI and ⅓ VII combined, tergalius VII reaching beginning of tergum X.

Paraproct (Fig. 8 j ). Posterior margin expanded, smooth.

Caudalii (Fig. 8 h, i ) Cerci without swimming setae. Paracercus vestigial.

Pose of subimaginal gonostyli under larval cuticle. Unknown.

Subimago. Unknown.

Imago. Unknown.

Egg. Unknown.

Biological aspects.

The species is known from the highest watercourse of Batanta, the Kalijakut River system, on altitudes between 430 m and 545 m. The upper habitat (Fig. 29 a , type locality) has volcanic bedrock, the side branch is very fast-flowing, the larvae live on the stones of the steep run. It co-occurs with larvae of P. batanlenos sp. nov. and P. cukiclara sp. nov. In the lower habitat (Fig. 29 b ), the species is living in fast flowing water on steep, calcareous surfaces, associated with P. cukiclara sp. nov.

Etymology.

The species name batantaraja refers to the Indonesian island Batanta, where the species was found, and the Indonesian word “ raja ” meaning king, because it is the largest species known in the genus Papuanatula .

Distribution.

New Guinea, Batanta Island (Fig. 30 ).

Figures

Figure 6. Papuanatula (Papuanatula) batantaraja sp. nov., larva, habitus. a. Dorsal view; b. Lateral view; c. Ventral view. Scale bars: 1 mm.

Figure 7. Papuanatula (Papuanatula) batantaraja sp. nov., larva. a. Labrum; b. Labrum, submarginal arc of setae; c. Right mandible; d. Left mandible; e. Labium; f. Hypopharynx and superlinguae; g. Maxilla; h, i. Tergalius IV; j. Head. Scale bars: 100 µm (j), 20 µm (a, c – h), 10 µm (b, i).

Figure 8. Papuanatula (Papuanatula) batantaraja sp. nov., larva. a. Hind leg; b. Hind femur, outer margin; c. Hind femur, surface; d. Hind tarsus, claw (arrow: posterior seta); e. Abdomen (arrow: protuberance on fore protoptera); f. Abdominal tergum V, surface; g. Abdominal terga; h. Paracercus; i. Cercus; j. Paraproct. Scale bars: 100 µm (e), 50 µm (a), 20 µm (b, d, h, j), 10 µm (c, f, g, i).

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).