Copelatus pseudostriatus 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

Copelatus pseudostriatus Ranarilalatiana & Bergsten sp. nov. Figs 4C , 10B

Type locality.

Tsaratanana reserve, Antetikalambazaha Camp [14.1824S, 48.9448E] [Madagascar, Sofia region, Bealanana district].

Type material.

Mahajanga. Sofia: Bealanana: -HT♂ (GP) (NHRS): // BMNH-672729 // HOLOTYPE // Madagascar: Tsaratanana NP | [Antetykalambazaha Camp], 14.1824S, | 48.9448E, 1700 m, 20-24.xii.2004 | P32, Leg. Lees_D, Ranaivosolo_R // DNA Voucher | BMNH <672729> | MSL027:A07 // Holotype | Copelatus | pseudostriatus sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 // Paratypes: -1♀ (NHRS): // BMNH-672728 // PARATYPE // Madagascar: Tsaratanana NP | [Antetykalambazaha Camp], 14.1824S, | 48.9448E, 1700 m, 20-24.xii.2004 | P32, Leg. Lees_D, Ranaivosolo_R // DNA Voucher | BMNH <672728> | MSL027:A06 // Paratype | Copelatus | pseudostriatus sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 // -1♀ (NHMUK): // BMNH-672727 // PARATYPE // Madagascar: Tsaratanana NP | [Antetykalambazaha Camp], 14.1824S, | 48.9448E, 1700 m, 20-24.xii.2004 | P32, Leg. Lees_D, Ranaivosolo_R // DNA Voucher | BMNH <672727> | MSL027:A05 // Paratype | Copelatus | pseudostriatus sp. nov. | Det. Ranarilalatiana | & Bergsten, 2019 //

Diagnosis.

The best diagnostic character for the species is the pseudostriae between first and second, and second and third striae ( Fig. 10B ), which separates the species from all other Copelatus species from Madagascar; the penis is gently curved from base to apex and parameres are long and thin ( Fig. 4C ).

Description.

Body length 5.3-5.6 mm. Body shape elongate oval. Head and pronotum of all three specimens exposed to DNA extraction lysis buffer which has discoloured them slightly. Colour descriptions of head and pronotum below should therefore be taken with caution and can differ somewhat from other specimens. Head and pronotum rather uniformly brown but head likely infuscated between and around eyes (more visible in one paratype) and pronotum may have been infuscated medially prior to exposure to lysis buffer. Elytra uniformly testaceous brown with a faint suggestion of a darker transverse field preapically ( Fig. 10B ). Appendages testaceous.

Elytra with six clearly impressed striae and one submarginal stria. Stria five distincly shorter basally and the submarginal stria starts 1/4th to 1/3rd posterior from the base. Between first and second, and between second and third striae, there are irregular traces of intermediate striae, or “pseudostriae”, extending from just after base until 1/4th from the apex ( Fig. 10B ). Anteriorly they are continuous or almost so and posteriorly they become fragmented. Few traces of pseudostriae can also be seen between the third and fourth striae but only anteriorly, and these are fragmented. Head, pronotum, and elytra microreticulate and finely micropunctate. Pronotum rather weakly striolate along posterior margin, slightly more at posterolateral corners, and sporadically anteriorly and on disc.

Ventral side largely ferrugineous, a little lighter testaceous-ferrugineous around metacoxal processes, medially on the metaventrite and on sternite II. Prosternal process short, medially raised and rounded and with a fairly pointed apex. Lateral parts of metaventrite medium broad. Metacoxal lines anteriorly diverging and abbreviated well before metaventral margin. Metacoxal plate distinctly striolate with short strioles.

Male: first three pro- and mesotarsomeres widened. Protibia modified, narrow but not bisinuate with an angulate ventral margin at base, broadened, almost club-like, distally. Protarsal and mesotarsal claws unmodified. Penis in ventral view narrowed one third from apex and the very last apical tip angled to the left; in lateral view evenly and weakly curved from base to apex ( Fig. 4C ). Parameres as in Figure 4C , long and thin and form an evenly curved elongated triangle.

Female: elytral structure similar to male.

Etymology.

The name pseudostriatus is a compound word formed from pseudo - (false) and striatus (furrowed or striated) and refers to the intermediate non-complete striae in-between the complete continuous striae on the elytra in this species. It is the only species of Copelatus on Madagascar with this characteristic. The word striatus (masculine) is a participle (verb as adjective) in the nominative singular (ICZN 11.9.1.1).

Distribution.

Endemic to Madagascar, only known from the type series from Tsaratanana Massif ( Fig. 12A ).

Habitat and ecology.

Not known, but the type series of specimens were collected in 2004 likely from a stream, near Antetikalambazaha Camp at an altitude of 1700 m.

Comments.

Species group assignment of Copelatus pseudostriatus sp. nov. is hardly possible: based on the complete striae it would fall in the irinus group, but the incomplete pseudostriae are likely reduced striae of an ancestor with a higher number of complete striae. This is a very distinct species with no recognisable close relatives, either based on genitalia or the CO1 gene. Tsaratanana Massif contains the highest peak in Madagascar at 2876 m and possibly this species is endemic to the Tsaratanana Massif. However, Hjalmarsson et al. (2013) showed that a high-altitude diving beetle species, Rhantus manjakatompo Pederzani & Rocchi, 2009, collected at the same place and time as the type series of C. pseudostriatus , is a species shared between Tsaratanana and Ankaratra Massif in central Madagascar.

Figures

Figure 4. Male genitalia. From left to right, aedeagus in right lateral, ventral, left lateral views and left paramere. A Copelatus peridinus B Copelatus distinguendus C Copelatus pseudostriatus sp. nov.

Figure 10. Habitus, dorsal view. A Female: Copelatus ankaratra sp. nov. B Male: Copelatus pseudostriatus sp. nov. C Male: Copelatus safiotra sp. nov. D Female: Copelatus befasicus.

Figure 12. Distribution maps of Copelatus species. A C. insuetus (circle), C. pseudostriatus sp. nov. (square) B C. kely sp. nov. (circle), C. vokoka sp. nov. (square) C C. ankaratra sp. nov. (circle), C. sp. 3 (square) D C. safiotra sp. nov. (circle), C. befasicus (square).