Copelatus ankaratra Ranarilalatiana & Bergsten
Ranarilalatiana, Tolotra, Raveloson Ravaomanarivo, Lala Harivelo & Bergsten, Johannes, 2019, Taxonomic revision of the genus Copelatus of Madagascar (Coleoptera, Dytiscidae, Copelatinae): the non- erichsonii group species, ZooKeys 869, pp. 19-90: 19
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|Copelatus ankaratra Ranarilalatiana & Bergsten|
Manjakatompo Ankaratra Reserve, Tsiafajavona mountain [19.35163S, 47.24278E] [Madagascar, Vakinankaratra region, Ambatolampy district]
Antananarivo. Vakinankaratra: Ambatolampy: -HT♂ (GP) ( NHRS): // NHRS-JLKB | 000065412 // Madagascar: Ambatolampy: Manjaka- | tompo Ankaratra Reserve: MAD16-11: | Tsiafajavona mountain: S-19.35163; | E47.24278; 2597 m: stream near source: | 07/02/2016; Leg. T. Ranarialalatiana // Holotype | Copelatus ankaratra sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 // Paratypes: -12♂ GP, 10♀, 77 ex. (Alc) ( NHRS, NHMUK, DEUA & PBZT/MBC): // NHRS-JLKB | 000010644-59, 10863-7, 65704, 10778(Alc.) // Madagascar: Ambatolampy: Manjaka- | tompo Ankaratra Reserve: MAD16-11: | Tsiafajavona mountain: S-19.35163; | E47.24278; 2597 m: stream near source: | 07/02/2016; Leg. T. Ranarialalatiana // Paratype | Copelatus ankaratra sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 // -6♂ (GP), 3♀, 60 ex. (Alc) ( NHRS, DEUA & PBZT/MBC): // NHRS-JLKB | 000010612-7, 65750-1, 10870, 10776(Alc.) // Madagascar: Antananarivo: | Vakinankaratra: Manjakatompo Stn | forestière: Anosiarivo: S19.344889 E | 047.304139, 2073 m. 24.I.2012: lake near source | Field# MJK12-13 : Leg. T. | Ranarilalatiana & J.H. Randriamihaja // Paratype | Copelatus ankaratra sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 // -12♂ GP, 6♀, 115 ex. (Alc.) ( NHRS, DEUA & PBZT/MBC): // NHRS-JLKB | 000010628-43, 10868-9, 10777(Alc.) // Madagascar: Ambatolampy: Manjaka- | tompo Ankaratra Reserve: MAD16-08: | Anosiarivo: S-19.34505; E47.30384; | 2062 m: large pond in stream source: | 06/02/2016; Leg. T. Ranarialalatiana // Paratype | Copelatus ankaratra sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //
The best diagnostic character for the species is the angled base of penis in posteroventral view ( Fig. 6D View Figure 6 ) which separates the species from all other species in the C. insuetus complex. The penis also lacks any apical dorsal ridge crossing dorsal posterior margin in left lateral view and is devoid of any sulcation ventrolaterally other than a faint microsculpture.
Body length 4.4-5.2 mm. Body shape very elongate and subparallel. Head infuscated around eyes and medially, testaceous on clypeus and as a posterior band. Pronotum entirely infuscated except lateral margins and especially the anterolateral corners more broadly testaceous. Elytra in same dark brown colour as infuscated parts of head and pronotum, except an irregular basal testaceous band ( Fig. 10A View Figure 10 ). Testaceous basal band overall narrower than in C. insuetus . All appendages testaceous.
Elytra with six clearly impressed discal and one submarginal stria. First to fourth elytral striae more or less full length, fifth and sixth striae slightly abbreviated anteriorly; submarginal stria starting 1/3rd to 1/2 posterior of base and does not reach apex. Head, pronotum, and elytra microreticulate and finely micropunctate. Posterior third to posterior half of pronotum striolate. Strioles on average coarser than in C. insuetus and in some specimens more extensive onto disc and posteromedially.
Ventral side similar to C. insuetus , slightly darker on average so that medial light area around metacoxal lines may be more contrasting. Strioles on metacoxa rather short. Prosternal process more rhomboid and apex more strongly raised medially than in C. insuetus . Lateral parts of metaventrite rather broad. Metacoxal lines long and anteriorly diverging, similar to C. insuetus .
Male: first three pro- and mesotarsomeres widened and ventrally equipped with suction cups (same pattern as in C. insuetus ). Protibia modified, bisinuate, angled basally, and broadened distally. Pro- and mesotarsal claws unmodified. Penis in posteroventral view distinctly angled at base ( Fig. 6D View Figure 6 ) so that main blade appears tilted. Penis in lateral view evenly curved, lacking a distinct “shoulder”, long, thin, and simple apex without a dorsal ridge crossing posterior dorsal margin in left lateral view. Faint longitudinal microsculpture visible at high magnification but lacking coarse longitudinal sulci ventrolaterally and lacking serrations as in C. insuetus . Parameres as in Figure 6D View Figure 6 .
Female: all but one specimen examined lack finer elytral striolation and is in elytral structure similar to males. However, the entire pronotum and elytra except apical quarter are coarsely longitudinally striolate in one female specimen examined. Striolation coarser and made up of longer irregular but connected strioles and very different to the short separate fine strioles seen in external intervals of C. insuetus females. Density approx. 5-7 strioles in breadth across an elytral interval.
The new species is named after the mountain massif Ankaratra where it was found and in honour of the newly created Ankaratra Massif Reserve in 2015. The epithet is a noun in apposition (ICZN 22.214.171.124).
Known only from a few localities in the Ankaratra Massif Reserve on the central highland plateau of Madagascar ( Fig. 12C View Figure 12 ).
Habitat and ecology.
This new species was collected in the mountains of Ankaratra at altitudes above 2000 m. The first locality, Anosiarivo forest, consisted of water from a source flowing over grass vegetation at an altitude of 2070 m. The second locality, Tsiafajavona Mountain, was a small stream with grass vegetation downstream but very near to the source at an altitude of 2600 m near Ankaratra peak. Copelatus ankaratra seems to be a high-altitude alpine species associated with spring water.
Copelatus ankaratra sp. nov. belongs to the irinus group, based on the number of elytral striae. It belongs to the Copelatus insuetus species complex radiation on Madagascar and based on its CO1 it is most closely related to C. vokoka from Ivohibe. Notably, both these species have a densely striolated female form. There was a surprisingly large genetic distance (2.3-2.5% uncorrected p-distance) between the locality near the peak (2600 m) and the locality in the forested region ca. 5 km away at a lower altitude (2070 m). We find the male genitalia and other characters very similar and treat them here as conspecific.
The Ankaratra Massif is an area known for several microendemic species not known from anywhere else on Madagascar. This includes two critically endangered micro-endemic frogs, Boophis williamsi ( Guibé, 1974) and Mantidactylus pauliani Guibé, 1974 only found in montane streams at elevations above 2000 m.
Manjakatompo forestry station was established in 1923 in the forested part of the mountains to preserve an area of 8320 ha, out of which only 650 ha is natural forest and 2300 ha has been replanted with exotic trees ( Nicoll and Langrand 1989; Goodman et al. 1996). Even the natural forest part is largely composed of secondary forest mixed with exotic trees. The forests still support endangered highland fauna and are important sites for some of the last remaining central plateau forests ( Hjalmarsson et al. 2013). The higher elevation of the Ankaratra Massif has, until recently, lacked any protection despite the unique faunal components and characteristics ( Vences et al. 2002; Goodman et al. 1996). The area has suffered severe degradation due to anthropogenic activities, mainly heavy deforestation and fire ( Rabemananjara et al. 2012), but also overgrazing by livestock and expanding potato farming ( IUCN SSC Amphibian Specialist Group 2016). However, in 2015 the Ankaratra Massif Reserve was created which encompasses Manjakatompo Special Reserve and the higher elevations where the endangered montane frogs are found ( Moore 2015). It is managed by the local Malagasy conservation association (VIF) in collaboration with Ministère de l’Environnement, de l’Ecologie et des Forêts. This is one of the results of an ambitious conservation programme involving habitat restoration, alternative livelihood initiatives, and public awareness ( Rabemananjara et al. 2012). Nevertheless, during a visit as late as 2016, there were many signs of continuous degradation from “tavy” slash and burn agriculture, commercial logging, and charcoal extraction exposing forest streams. Very large parts of the forest were burnt, causing erosion that spills into the streams. Manjakatompo forest and the Ankaratra Massif are very important forest and montane refugia of highland fauna ( Vences et al. 2002; Goodman et al. 1996; Hjalmarsson et al. 2013; Andreone et al. 2014), and it should be highly prioritised for protection; we hope that the new reserve status on paper will lead to actual changes in practice.
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