Pseudagrion tanganyicum Dijkstra & Kipping, sp. nov.

Pseudagrion tanganyicum Dijkstra & Kipping sp. nov. – Tanganyika Sprite (Type Photo 23, Photos 35–36, Fig. 12) Taxonomy

Structurally probably indistinguishable from P. massaicum Sjöstedt, 1909, but coloration and ecology of this potentially sympatric species (Map 5) differ strongly, and the two were treated as distinct by Dijkstra & Clausnitzer (2014). The two are also inseparable by COI sequence, but this is notably frequent in the Pseudagrion B-group, including the well-differentiated pairs P. acaciae and P. vaalense, P. camerunense (Karsch, 1899) and P. glaucum (Sjöstedt, 1900), P. coeleste Longfield, 1947 and P. nubicum Selys, 1876, and P. commoniae (Förster, 1902) and P. hamoni Fraser, 1955.

Material studied

Holotype ♂ . Tanzania, Kigoma Region, Kibirizi, Lake Tanganyika at Nondwa point, sandy and reedy lakeshore, 770 m a.s.l. (4.86 ° S 29.61 ° E), 20 -viii- - 2009, leg. K.-D.B. Dijkstra, RMNH.

Further material. TANZANIA (Kigoma Region): 11 ♂ (RMNH.INS.502706, RMNH.INS.502707, RMNH.INS.502715), as holotype, RMNH. 8 ♂ (RMNH.INS.502811, RMNH.INS.502816, RMNH.INS.502820), 6 km SW of Ilagala, Lower Malagarasi Basin, Lake Tanganyika at mouth of Malagarasi, reedy and sandy lakeshore, 770 m a.s.l. (5.3256 ° S 29.8021 ° E), 15 -viii- 2009, leg. K.-D.B. Dijkstra, RMNH. ZAMBIA (Northern Province): 2 ♂ (RMNH.INS.508095), Lake Tanganyika, Isanga Bay Lodge, 15 km NE of Mpulungu, rocky and sandy lake shore (Photo 36), 777 m a.s.l. (8.6549 ° S 31.1932 ° E), 09-xii- 2014, leg. J. Kipping, RMNH. 5 ♂, same locality, same dates, CJKL. 13 ♂ 1 ♀, same locality, 10 -xii- 2014, leg. J. Kipping, CJKL.

Genetics

Six haplotypes (n= 7), of which one shared with P. massaicum (n = 8; three additional haplotypes); all nine haplotypes are very similar and mixed.

Male morphological diagnosis

Structurally like P. massaicum with (a) the fairly small size, Hw 17.0– 19.0mm (n = 24); (b) the pointed lateral and apical lobes of the penis; (c)the similarly long cerci and paraprocts; and (c) the paraprocts with a short blunt apex and a prominent dorsal knob in lateral view (Fig. 12). However, with maturity (1) the face, eyes and postocular spots are yellow rather than red; (2) the ante-humeral stripes are green rather than red; and (3) the thorax is quite uniformly pale blue below the humeral suture rather than red grading to bluish pruinose below the metapleural suture.

Etymology The name is an amalgam of “Tanganyika” and the specific epithet of P. massaicum (neuter adjective). Range and ecology

Inhabits sandy and rocky beaches and wave-battered reeds in shallows of Lake Tanganyika (elevation around 770 m a.s.l.), i.e., notably different from the marshy fringes of pools and streams favoured by P. massaicum. Known sites are over 400 km apart, suggesting the species occurs all around the lake, just like the similarly endemic Platycypha pinheyi Fraser, 1950 that prefers rocky shores.