Rhantus manjakatompo Pederzani & Rocchi, 2009

Hjalmarsson, Anna Emilia, Bukontaite, Rasa, Ranarilalatiana, Tolotra, Randriamihaja, Jacquelin Herisahala & Bergsten, Johannes, 2013, Taxonomic revision of Madagascan Rhantus (Coleoptera, Dytiscidae, Colymbetinae) with an emphasis on Manjakatompo as a conservation priority, ZooKeys 350, pp. 21-45 : 24-28

Rhantus manjakatompo Pederzani & Rocchi, 2009 Figures 2 a–b, 3 a–c, 4a, 5 a–b, 6 a–b, 7 a–b, g

Rhantus manjakatompo Pederzani & Rocchi, 2009: 88

Type locality.

Madagascar, Antananarivo province, Ankaratra mountains, Manjakatompo reserve.

Type material (NMW). Holotype ♂ "Madagascar, Ankaratra (Antananarivo), Reserve Manjakatompo, spring stream exp. SE. N deviation to Analamitana (left affl. MD 107) m 1850 asl, 8.x.2001, 16.0°C, 0.003 mS/cm. Gerecke & Goldschmidt collectors BMNH (E) 2004-46", "Holotype Rhantus manjakatompo Pederzani & Rocchi 2008", "Data in NHRS-JLKB 000030412" "DNA Voucher".

Additional material studied (NHRS, BMNH, DEUA, see Appendix): Sofia region (former provinces: Mahajanga): 2♂, 2♀ (Cat. No. BMNH-672731, 672730, 672726, 672725): Tsaratanana [Antetykalambazaha Camp], 14.1824S, 48.9448E, 1700m, 20-24.xii.2004, Malaisetrap, Leg. Lees, Ranaivosolo.

Vakinankaratra region (former provinces: Antananarivo): 4spp. (Cat. No. NHRS-JLKB000021018) Manjakatompo [Analamitana] [swamp near stream][MJK12-02], 19.3640S, 47.2991E, 1760m, 22.i.2012, Leg. Ranarilalatiana, Randriamihaja, 1sp. (Cat. No. NHRS-JLKB000021019) Manjakatompo [Tavolatara][swamp near stream][MJK12-08], 19.3491S, 47.2784E, 2050m, 24.i.2012, Leg. Ranarilalatiana, Randriamihaja, 5spp. (Cat. No. NHRS-JLKB000021020) Manjakatompo [Tavolatara][pool near stream][MJK12-09], 19.3491S, 47.2780E, 2050m, 24.i.2012, Leg. Ranarilalatiana, Randriamihaja, 11spp. (Cat. No. NHRS-JLKB000021021) Manjakatompo [Tavolatara][swamp near source][MJK12-10], 19.3496S, 47.2779E, 2050m, 24.i.2012, Leg. Ranarilalatiana, Randriamihaja, 3spp. (Cat. No. NHRS-JLKB000021022) Manjakatompo [Anosiarivo][lake near source][MJK12-13], 19.3449S, 47.3041E, 2070m, 24.i.2012, Leg. Ranarilalatiana, Randriamihaja, 1spp. (Cat. No. NHRS-JLKB000021023) Manjakatompo [Andongolongo][pool near source][MJK12-12], 19.3536S, 47.3006E, 1900m, 24.i.2012, Leg. Ranarilalatiana, Randriamihaja.

Diagnosis.

Pronotum entirely testaceous or with two small dark spots medially (Figure 2 a–b). Black irrorations of elytra somewhat confluent subapically (Figure 2 a–b). Male protarsal claws equally long, evenly curved, apex acute (Figure 5 a–b). Male mesotarsal claws equally long but posterior claw distinctly thicker than anterior claw (Figure 6 a–b). Penis short and robust (Figure 7 a–b), Parameres evenly curved and tapering to apex (Figure 7g). 11.5-12.5 mm long.

Description.

Size: ML 11.5-12.5 mm; MW 5.7-5.9 mm; Lp 1.4 mm; Epb 4.7-4.9 mm; Le 8.4-9.0 mm (n = 5).

Head. Testaceous with black areas posteriorly and inside eyes. Interocular black pattern narrowly separated medially (Figure 2 a–b). Dense reticulation of well impressed meshes, very fine punctuation within and at edges of meshes.

Pronotum. Testaceous to ferrugineous with two small dark spots medially (Figure 2b), which may be absent (Figure 2a). Rim at lateral margin clearly visible to indistinct. Dense reticulation of well impressed meshes, very fine punctuation within and at edges of meshes (Figure 3a).

Elytra. Testaceous with black irrorations, leaving paler sides and yellow sutural lines (Figure 2 a–b). Black irrorations somewhat confluent subapically. Reticulation of polygonal meshes simple anteriorly and double at middle and posteriorly, meshes are somewhat less impressed than on pronotum and larger posteriorly. Very fine punctuation within and at edges of meshes (Figure 3 b–c).

Ventral side. Dark brown to black. Epiplura testaceous. Metafemora infuscated (Figure 4a).

Male. Protarsal claws equally long, evenly curved, apex acute (Figure 5 a–b). Mesotarsal claws equally long but posterior claw distinctly thicker than anterior claw (Figure 6 a–b). Penis short and robust, shape as Figure 7 a–b. Parameres evenly curved and tapering to apex (Figure 7g).

Remarks.

In 2004 David Lees and Ravomiarana Ranaivosolo collected material of what seemed to be a new Rhantus species from the mountain massif of Tsaratanana, North Madagascar. Rhantus manjakatompo was described in 2009 based on a single male specimen from Ankaratra mountains, 70km south of Antananarivo in central Madagascar. Despite variation in color and impression of a lateral rim of pronotum, molecular data indicate that the studied material from Ankaratra and Tsaratanana are conspecific or at least not an old enough divergence to be recognised based on COI sequence (genetic distance 0.008-0.011). As also male tarsal claws, aedeagus and parameres were identical, we consider the specimens from Tsaratanana mountains conspecific with the holotype of Rhantus manjakatompo .

Habitat.

Associated with sources and streams, and surrounding water assemblages like nearby pools and marshes at altitudes between 1700 to 2070 m a.s.l. In Manjakatompo, the species was most numerous at elevations above 2000 m.

Distribution.

Endemic to Madagascar. Only known from Tsaratanana mountains and Manjakatompo forestry station in the Ankaratra mountains (Figure 8).