Paroster michaelseni Régimbart, 1908

Hendrich, Lars & Fery, Hans, 2008, Paroster baylyi sp. n., P. ursulae sp. n. (Col. Dytiscidae, Hydroporinae) and the water beetle diversity of pan-gnammas on isolated granite outcrops in the Mallee of south-western Australia, Zootaxa 1704, pp. 27-41 : 36-37

Paroster michaelseni Régimbart, 1908

Paroster michaelseni Régimbart, 1908: 312 (orig. descr.).

Paroster michaelseni Régimbart, 1908 : Watts 1978: 55; Watts 1985: 24; Lawrence et al. 1987: 340; Pinder et al. 2000: 159; Nilsson 2001: 180; Watts 2002: 45.

Type locality: “Petite lagune sur une roche granitique, Boorabbin”, Western Australia, ca. 31.19S 120.32E {9}.

Type material. Holotype: Male: a reddish brown plastic-like triangular card on which probably the holotype originally has been pinned or glued, “ Paroster Michaelseni Rég. type unic. [sic!]” [hw Régimbart], “Exped. Michaelsen et Hartmeyer” [hw Régimbart], “Boorabbin Regenwassertümpel 3.VII ” [hw?], “Hamb. S.-W.-Austr. Exped. 1905. Stat. 96” [printed, except “96”], “Museum Paris Coll. Maurice Régimbart 1908 ” [printed], “le seul Paroster de la coll. Régimbart” [possibly hw F. Guignot] {9} ( MNHN). Notes: The holotype is lacking the left hind tarsus; the left pro-leg is glued beside the specimen; the left elytron is impressed in the anterior half and somewhat torn in the posterior half; the right elytron shows a hole in its anterior half from where the specimen must have been pinned by the collector or subsequently by Régimbart. We suppose that the holotype has been glued on the card by C. Watts.

Additional material studied: 1 male, “WA Remlap Homestead Rock, Beacon,. 30 0 2 S 117 38 E, B. Timms 5/8/[20]04”, “ DNA Voucher”, “ SAMA Database No. 25- 012899 ” {4} ( SAMA); 1 male, 1 female, “Dingo Rock WA, J.McRae 6/8/[19]98”, “ SAMA Database No. 25-004-930”; both specimens mounted on one glue card {5} ( SAMA); 1 male, “WA Dingo Rock, SPS070, Calm 8/8/[19]98”, “Remnents [sic!]—others used for DNA ”, “ Paroster michaelseni Reg , det CHS Watts”, “ SAMA Database No. 25-004930”; specimen totally dissected {5} ( SAMA); 2 males, 3 females, “WA Yannemooning Rock,. 30 40 50 S 118 33 10 E, 11/9/ [19]99 Calm”, “ SAMA Database No. 25- 012896 ”; one of the males with additional “ DNA Voucher 2”, one of the females with “ DNA Voucher 1” {6} ( SAMA); 1 male, “WA Yannermooni Rock [sic!], SPS126, Calm 11/ 9/[19]99”, “Tarsi [?], Gen [= genitalia] on slide” {6} ( SAMA); 1 female, “Yellowdine RK [= Rock], large pool, 5.VIII.1964 ”, on reverse “D.H.D. Edwrd”, “ SAMA Database No. 25-005179” {7} ( SAMA); 1 male, “ 182 m [iles?] E Merrodin [sic! = Merredin], WA 7/[19]64. Edward”, “ Paroster michaeleseni [sic!] Reg, Det. C. Watts 1991”, “ SAMA Database No. 25-005181” ( Watts 1978:56 gives “ 202 km east of Merredin”) {8} ( SAMA); 1 male, “WA Emu Rock, Heyden 32 28 S 119 25 E, B. Timms 3/8/[20]04”, “ DNA Voucher”, “ SAMA Database No. 25- 012898 ” {11} ( SAMA); 1 male, “WA Disappointment Rock, Norseman 32 0 8 S 120 56 E, B. Timms 16/7/[20]04”, “ DNA Voucher”, “ SAMA Database No. 25- 012897 ” {12} ( SAMA); 1 female, “WA Disappointment Rock, Norseman 32 0 8 S 120 56 E, B. Timms 16/7/[20]04”, “ SAMA Database No. 25- 012897 ”, “Photographed” {12} ( SAMA); 1 male, “Buldania Rks. [= Rocks], SWA. 12/[19]59”, “ SAMA Database No. 25-005178” {13} ( SAMA).

Differential diagnosis: Habitus as in Figs 6, 7 ; in several characters intermediate between P. b a y l y i sp. n. and P. u r s u l a e sp. n., in particular in size. Measurements: holotype: TL: 3.6 mm, TL-H: 3.35 mm, MW: 1.95 mm, TL/MW: 1.85, TL-H/MW: 1.72; additional specimens: males (n = 8): TL: 3.3–3.9 mm (3.61 ± 0.17 mm), TL-H: 3.0– 3.6 mm (3.31 ± 0.17 mm), MW: 1.75–2.1 mm (1.93 ± 0.12 mm), TL/MW: 1.79–1.94 (1.88 ± 0.04), TL-H/MW: 1.65–1.78 (1.72 ± 0.05); females (n = 4): TL: 3.45–3.95 mm (3.73 ± 0.18 mm), TL-H: 3.05–3.6 mm (3.36 ± 0.20 mm), MW: 1.85–2.1 mm (2.01 ± 0.10 mm), TL/MW: 1.76–1.93 (1.85 ± 0.06), TL- H/MW: 1.62–1.76 (1.67 ± 0.05). Notes: A total length of 4.3 mm is given in Watts (1978:55). We cannot explain the discrepancy between his and our results, since all specimens studied by Watts were included in our measurements.

Sides of pronotum behind curved part at anterior angles straight and slightly diverging posteriorly, as in P. baylyi sp. n. However, sides of elytra more rounded and, thus, discontinuity in outline between pronotum and elytra more prominent than in P. baylyi sp. n., but less so than in P. u r s u l a e sp. n.

Colouration of upper surface in general darker than in P. baylyi sp. n., but lighter than in P. u r s u l a e sp. n. Brownish areas on elytra less extended anteriorly than in P. ursulae sp. n., not reaching base. Pronotum with yellowish parts slightly more extended than in P. baylyi sp. n. Antennomeres rather dark, almost as dark as in P. u r s u l a e sp. n.

Punctation on head and pronotum as in P. baylyi sp. n., but on elytra distinctly weaker than in both other species, diameter of punctures not much larger than that of meshes of reticulation; puncture lines also less prominent. Setation indistinct, as in P. baylyi sp. n.

Variability: Similar to that of both other species and mainly concerning extent of dark areas.

Male: Most characters as in P. b a y l y i sp. n. and P. u r s u l a e sp. n., but differing clearly in shape of median lobe in ventral view ( Fig. 8 ); left paramere as in Fig. 11 . Holotype with left side of base of median lobe somewhat damaged (dotted line in Fig. 8 ).

Female: Reticulation of upper surface impressed as in P. baylyi sp. n., thus, appearing matt, but less so than in P. ursulae sp. n. Gonocoxae as in Fig. 14 ; gonocoxosternum as in Fig. 17 , intermediate between both other species.

Distribution: Granite outcrops in the Wheatbelt and Mallee of south-western Australia. East of the Great Northern Highway and south of a line from Wubin to Boorabbin ( Fig. 22 ).

Habitat: All specimens were collected in different ephemeral pools on isolated granite outcrops in the Wheatbelt ( Pinder et al. 2000, Watts pers. com.). The type material of P. michaelseni was collected by the late German zoologists R. Hartmeyer (Berlin) and W. Michaelsen (Hamburg) in 1905 during their expedition across south-western Australia. First notes on the habitat of the species were given by Michaelsen & Hartmeyer (1907, p. 114). According to them, the single specimen was obtained from puddles (“Regenwassertümpel”.....) on a granite outcrop (“.....auf kahler Granitkuppel”) on 3rd July 1905 near Boorabbin. It is noteworthy that the type locality is not far away from that of P. u r s u l a e sp. n. {10}.

Figures

FIGURE 22. Distribution of P. michaelseni (dots) P. baylyi sp. n. (diamonds) and P. ursulae sp. n. (star). The map was made by using MS ENCARTA 2000.

FIGURES 2 – 7. Habitus of 2) Paroster baylyi sp. n. (male); 3) P. baylyi sp. n. (female); 4) P. u r s u l a e sp. n. (male); 5) P. ursulae sp. n. (female); 6) P. michaelseni (holotype, male); 7) P. michaelseni (female).

FIGURES 8 – 19. Median lobe of aedeagus in ventral and lateral view: 8) Paroster michaelseni (holotype), 9) P. baylyi sp. n., 10) P. u r s u l a e sp. n.; Left paramere: 11) P. michaelseni (holotype), 12) P. baylyi sp. n., 13) P. u r s u l a e sp. n.; Gonocoxae: 14) P. michaelseni, 15) P. baylyi sp. n., 16) P. u r s u l a e sp. n.; Gonocoxosternum: 17) P. michaelseni, 18) P. baylyi sp. n., 19) P. u r s u l a e sp. n.