Paragomphus clausnitzerorum Dijkstra, Meziere & Papazian, sp. nov.

Paragomphus clausnitzerorum Dijkstra, Mézière & Papazian sp. nov. – Clausnitzers’ Hooktail

(Type Photo 38, Fig. 23)

Taxonomy

The black Paragomphus species of rainforest are often identified as P. n i g r o viridis Cammaerts, 1969, which Dijkstra & Clausnitzer (2014) included in the cognatus -group (see P. cammaertsi sp. nov.). COI analysis, often of more easily obtained larvae and female adults, showed that not all species with truncated and diverging cerci are closely related and that P.cognatus itself may be a species-complex (Tree 6). Moreover, distinct and geographically overlapping clusters are apparent among these dark forest specimens. By male morphology these could be assigned to P. n i g r o viridis as well as P. kiautai Legrand, 1992, P. machadoi Pinhey, 1961, P.tournieri Legrand, 1992 and at least two clades from Gabon with no available name. The latter have distinctive male appendages, as well as other morphological differences, and are named here. The holotype of P.machadoi in MRAC lacks its secondary genitalia and appendages, but is close to P.interruptus Cammaerts, 1968 in coloration and the shape of the anal triangle (Cammaerts 1968). Pinhey (1961 a) illustrated similar cerci and the Angolan type locality lies between records from Congo-Kinshasa and Gabon, so we propose to synonymize them [new synonymy]. The species recalls P. nigroviridis by (a) the largely black face and occiput; and (b) the largely black thorax with narrow but prominent green postdorsal, mesepimeral and metepimeral stripes, but variable and typically strongly reduced or fragmented ante-humeral and metepisternal stripes [S 3–6]. However, (1) may be slightly larger, Hw 24.0–27.0 mm (n = 6) rather than 23.5 –24.0 mm (n = 2); (2) the postdorsal stripes are clearly separated from the collar; (3) the outer border of the anal triangle is sharply, almost rectangularly, kinked at its most distal cell, rather than shallowly excavated; and (4) the cerci narrow quite abruptly at their tips, often bearing a prominent distal spine (Fig. 23).

Material studied

Holotype ♂. RMNH.INS.502545, Gabon, Haut-Ogooué Province, 34 km SE of Franceville, Franceville-Kessala Road, second stream E of Onkoua, sandy river in rainforest, 403 m a.s.l. (1.8181 ° S 13.8446 ° E), 09-i- 2010, leg. N. Mézière, RMNH.

Further material. GABON (Haut-Ogooué Province): 1 ♂ (RMNH.INS.506158), Moanda-Bakoumba road, forest road on right 25 km from Moanda, Botoso, springs and streamlets (less than <1 m wide) with muddy and swampy edges, 530 m a.s.l. (1.6939 ° S 13.0739 ° E), 14 -ii- 2012, leg. N. Mézière, RMNH. 1 ♂, forest behind CLAO, Osskama, sandy stream in forest (near source, 3–4 m wide, 40 cm deep), 444 m a.s.l. (1.1116 ° S 13.8740 ° E), 16 -i- 2011, leg. N. Mézière, RMNH. 1 ♂, Franceville-Okondja road, 2 km before Okila, muddy and gravelly stream in forest (4 m wide, <50 cm deep), 364 m a.s.l. (1.0790 ° S 13.5669 ° E), 23 -ix- 2010, leg. N. Mézière, RMNH. 2 ♀ (RMNH.INS.554421, RMNH.INS.554422), Alanga-Aboumi road, Moyol, gravelly and sandy forest river (2–3 m wide, 10–50 cm deep), 424 m a.s.l. (0.8403 ° S 13.9386 ° E), 28 -ix- 2012, leg. N. Mézière, RMNH. GABON (Ngounie Province): 3 ♂ (RMNH.INS.506204, RMNH.INS.506209, RMNH.INS.506226), Mimongo-Mouila road, mountain stream with falls, rapids and large rocks, 478 m a.s.l. (1.7289 ° S 11.3072 ° E), 07-iv- 2012, leg. N. Mézière, RMNH. 1 ♀ (RMNH.INS.508792), same locality, 26 -iii- 2013, leg. N. Mézière, RMNH. GABON (Ogooué-Ivindo Province): 1 ♂ (RMNH.INS.508053, 5 km SE of Bakouaka at Okondja-Makokou road, sandy stream in dense forest, 531 m a.s.l. (0.1298 ° N 13.6772 ° E), 23 -ix- 2014, leg. J. Kipping, CJKL.

Genetics

Seven unique haplotypes (n = 9); a possible relationship with P. darwalli sp. nov. and P. nigroviridis is poorly supported (Tree 6).

Male morphological diagnosis

Recalls P. nigroviridis by (a) the largely black face including the occiput; (b)the largely black thorax with prominent green postdorsal, mesepimeral and metepimeral stripes, but reduced ante-humeral and metepisternal stripes; (c) the postdorsal stripes fused to the collar, together appearing like an inverted seven; and (d) the apices of the cerci that diverge in dorsal view (Fig. 23). However, (1) may be slightly larger, Hw 24.5 –26.0 mm (n = 5) rather than 23.5 –24.0 mm (n = 2); (2) the black labrum typically bears a pair of green spots, rather than having these fused into a single bar; (3) the ante-humeral stripe is usually completely absent, rather than reduced to a spot that lies close to the dorsal end of the postdorsal stripe; (4) in lateral view the cerci are more markedly curved up in their basal half and down in their apical half, with a prominent angle between these halves dorsally; and (5) the tips of the cerci are more strongly curved and relatively thick and rounded, with four large and equal teeth, rather than curved more gradually, tapering to a slender and truncated tip with about seven smaller teeth, of which the most terminal stands apart and is often longer (Fig. 23).

Etymology

Named in honour of Mr Hans-Joachim Clausnitzer and his daughter Dr Viola Clausnitzer, chair of the IUCN Dragonfly Specialist Group, who together made many contributions to the knowledge of African Odonata (plural genitive noun).

Range and ecology

Sandy and gravelly rainforest streams between 350 and 550 m a.s.l. in southern Gabon.