Sternopriscus browni
Ordo: Coleoptera
Familia: Dytiscidae
Genus: Sternopriscus
Name
Sternopriscus browni Sharp, 1882
Type locality
King George Sound [Albany], Western Australia.
Type material
Sternopriscus browni: Lectotype: male, "Sternopriscus browni Type D.S. K. Geo. Sound", "Lectotype", "Type", "Australia", "W.Australia", "Sharp Coll. 1905-313", "Type 159 Sternopriscus browni", "Sternopriscus browni Sharp 1971 Det. C. Watts 1979" (BMNH). - Paralectotypes: 10 exs. (4 male, 6 female) with same data as lectotype but "Paralectotype", previously with BMNH "Type" label; 2 male, "Paralectotype", "Australia", "Sharp Coll. 1905-313", "Sternopriscus browni Shp det. Sharp", "Sternopriscus browni Sharp, Det C. Watts 1979" (BMNH). Sternopriscus obscurus: Lectotype: female, "Sternopriscus obscurus Type D.S. K. Geo. Sound", "Lectotype", "Type", "Australia", "W. Australia", "Sharp Coll. 1905-313", "Type 160 Sternopriscus obscurus", "Sternopriscus obscurus Sharp Det. C. Watts 1974" (BMNH). Paralectotype: female, "Sternopriscus obscurus male Ind. Typ., D.S. K. Geo. Sound D.S.", "Paralectotype", "Cotype", "W. Australia", "Sharp Coll. 1905-313", "Sternopriscus obscurus Sharp Det. C. Watts 1974" (BMNH).
DNA Sequences
European Nucleotide Archive (ENA)
Description
Measurements: Males: TL = 3.48 - 3.60 mm, TL-H = 3.12 - 3.20 mm; width = 1.76 - 1.80 mm. Females: TL = 2.84 - 3.12 mm, TL-H = 2.56 - 2.80 mm; width = 1.48 - 1.64 mm.
Colour: Head dark brown, with small testaceous basal spot, anterior margin testaceous tending to be broken up into six spots; pronotum brown, widely testaceous laterally, with two testaceous spots occasionally connected in midline. Elytron reddish brown with numerous diffuse testaceous mottlings tending to form about 12 alternating dark and light patches along margin. Ventral surface dark brown to black; sides of prosternum and appendages lighter.
Sculpture: Strongly and closely reticulate throughout; strongly and densely rugose-punctate, punctures on head weaker but well marked. Pronotum with moderately distinct plicae, reaching about two-thirds of way along pronotum, with transverse depression between them. Elytral margin weakly serrate, especially towards apex of elytra. Prothoracic process narrow, flat, very long, narrow between procoxae, not reaching mesosternum, well separated from mesocoxae which touch, portion of mesosternum supporting the prothoracic process, directed forward. Midline of metasternum strongly keeled anteriorly but not raised to meet prothoracic process. Metacoxal lines strongly raised, well separated, weakly diverging in anterior third.
Male: Antennal segments 4 and 5 very small, segment 8 greatly and narrowly produced outwards, segments 9 and 10 with prominent inturned flanges, segments 6 and 7 somewhat expanded. Apical segment of labial palpus enlarged, deeply bifid. Protrochanter strongly produced apically. Profemur strongly produced apically on rear ventral edge; protibia rather narrow, curved, weakly excavated on inner edge near middle; protarsus weakly expanded. Basal segments of mesotarsus weakly expanded, apical segment immensely expanded dorsoventrally, segment 4 moderately so, thickly covered with long setae; mesotibia elongate, strongly curved, expanded apically; mesofemur elongate with two rows of long golden setae on posterior edges. Metatarsus elongate, expanded dorsoventrally. Median lobe of aedeagus simple, relatively broad, rapidly narrowing to point, bulbous apically; parameres thin.
Female: Smaller. Appendages simple, apical segment of labial palpus weaker, basal segments of pro- and mesotarsi weakly expanded.
Affinities
Male specimens are readily distinguished by their greatly expanded antennae and the uniquely expanded apical segment of the mesotarsi. The species is restricted to the southwest were females can be confused with S. browni and S. wattsi. The lack of flanged elytra separate it from S. browni and the absence of small medial backward extensions to the mesocoxae separate it from S. wattsi in which they are present.
Habitat
Sternopriscus browni is the most common species of the genus in southwestern Australia and inhabits all kinds of standing and slow flowing water, from sea level up to an altitude of 450 m. It is most abundant in peaty and often temporary pools in coastal wetlands, swamps and riverine ponds and has been found in the following specific habitats: I. Large (30 - 40 sqm), shallow (up to 15 cm), semi-exposed, salty pools near seashore with a bottom of sand and broken shells. II. Permanent and slow flowing streams (width 1 - 2 m, depth 10 - 30 cm), partly shaded with a bottom of sand and larger stones. Vegetation: Utricularia and green algae. III. Isolated floodzone ponds of the Blackwood River, partly shaded, and up to 50 cm deep. IV. Summerdry peatland and Melaleuca sedge swamps (pH 5.0), up to 20 cm deep, with dense stands of various sedges and submerged vegetation. V. Shaded pools of intermittent streams in Jarrah and Karri forests, with bottom of sand and pebbles, often with a thin layer of leaves and twigs. Sternopriscus browni is sympatric and often syntopic with Sternopriscus minimus, S. marginatus, S. multimaculatus, S. storeyi and S. wattsi.
Distribution
Southwestern coastal Australia, Western Australia (Watts 1978, Lawrence et al. 1987). South and southwest of a line between Perth and the Stirling Ranges. Some records along coastal areas north of Perth.
Images
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References
- Hendrich, L.; Watts, C.H.S. 2004: Taxonomic revision of the Australian genus Sternopriscus Sharp, 1882 (Coleoptera: Dytiscidae, Hydroporinae). Koleopterologische Rundschau, 74: 75–142.
