Barbronia gwalagwalensis Westergren & Siddall, 2004

Klass, Anna L., Kondakov, Alexander V., Vikhrev, Ilya V., Bespalaya, Yulia V., Lunn, Zau, Chan, Nyein, Gofarov, Mikhail Y. & Bolotov, Ivan N., 2021, Is the South African leech Barbronia gwalagwalensis Westergren & Siddall, 2004 (Hirudinida: Erpobdelliformes: Salifidae) a Paleotropical species?, Zootaxa 4974 (3), pp. 585-595 : 589-591

Barbronia gwalagwalensis Westergren & Siddall, 2004

Figures 3-6

Type. Holotype, AMNH Annelida 5261, fixed in 10% buffered formalin and stored in 70% ethanol (American Museum of Natural History, New York, USA).

Type locality. “ Maia’s Dam , Gwalagwala, a tented-camp near Hoedspruit, South Africa ” ( Westergren & Siddall 2004) .

Material examined. MYANMAR: Salween River drainage, Lake Inle basin, Kyee Phyu Lake , 20.8142°N, 96.9690°E, 23.ii.2018, 2 specimens, fixed in 96% ethanol [voucher RMBH Hir_58_3; one specimen sequenced: COI acc. no. MN 295405 ]. The sample is deposited in the RMBH — Russian Museum of Biodiversity Hotspots, N. Laverov Federal Center for Integrated Arctic Research of the Ural Branch of the Russian Academy of Sciences, Arkhangelsk, Russia .

Morphology of Myanmar’s sample. Small leeches, 10–15 mm long (ethanol-preserved specimens). Body subcylindrical, vermiform, tapering anteriorly and posteriorly. Dorsum light brown. Three pairs of eyespots: first dorsal, on II; second and third pairs dorsolateral on IV, and separated from anterior pair by four complete annuli. Caudal sucker directed ventrally. Clitellum indistinct (juveniles), with male and female gonopores separated by seven and one-half annuli, and with two accessory copulatory pores ventrally: one anterior of the male gonopore at X/XI, and second posterior of the female gonopore at XIII/XIV. Three pairs of pharyngeal stylets. These features correspond well to the protologue of the species, although the type series comprised full-grown adults up to 25 mm long with pronounced clitellum and distinct accessory copulatory pores ( Westergren & Siddall 2004).

Habitat. The specimens were collected on a submerged bamboo stick and an empty shell of the freshwater mussel species Lamellidens ferrugineus (Annandale) found near the shore of a shallow eutrophic lake with silty bottom and rich aquatic plant assemblages. They co-occurred with the freshwater glossiphonid species Alboglossiphonia sp. ( Hirudinida: Glossiphoniidae ) [voucher no. RMBH 58_2; COI acc. no. MN 295404 ] and the triclad species Dugesia sp. (Tricladida: Dugesiidae ) [voucher no. RMBH 58_1]. The Dugesia species was very abundant.

Distribution. This species appears to be widespread throughout the Paleotropical Region as it was found in South Africa, Southeast Asia ( Myanmar), and East Asia ( Korea). The occurrence from the Durance River (Rhône Basin) in southeastern France ( Corse et al. 2017) most likely reflects a recent human-mediated or native dispersal event towards southern Europe.

Comments. The nominal taxon Trocheta quadrioculata Oka, 1922 was described from the Inle Lake in Myanmar ( Oka 1922). The type locality of this species is close to our finding of B. gwalagwalensis (ca. 25-30 km SSW). Currently, Inle Lake’s taxon is placed within Salifidae as Odontobdella quadrioculata (see Nesemann & Sharma 2012). Based on the protologue ( Oka 1922), it does not have accessory copulatory pores and, hence, cannot be linked to the genus Barbronia (see Westergren & Siddall 2004). The fauna of the family Salifidae in Myanmar seems to be largely underestimated, and comprises only two species, i.e. B. gwalagwalensis and O. quadrioculata .

Figures

FIGURES 3-6. Morphology of Barbronia gwalagwalensis Westergren & Siddall, 2004 from Kyee Phyu Lake, Myanmar (ethanol-preserved animals). Fig. 3. Specimen (dorsal view). Scale bar = 1 mm. Figs. 4–5. Arrangement of three pairs of eyespots (4—dorso-lateral view; 5—dorsal view). Red arrows show the eyespots and the eyespot pair’s number. Scale bar = 0.5 mm. Fig. 6. Ventral region of clitellum, with male (m) and female (f) gonopores, and two accessory copulatory pores (ap). Scale bar = 0.5 mm. Photos: Anna L. Klass.