Hydrochus sculptissimus, Perkins, 2021

Perkins, Philip D., 2021, Taxonomy of water beetles in the genus Hydrochus Leach, 1817, from Bolivia, Brazil and Paraguay (Coleoptera: Hydrochidae), Zootaxa 4994 (1), pp. 1-93 : 13

H. sculptissimus species group

Figs. 1 , 3 , 45 , 48, 49 , 55 , 57 , 70

Members of the H. sculptissimus species group are recognized by the combination of the following characteristics: 1) small size, ca. 2.25–2.45 mm; 2) black dorsal color; 3) elytral with costate or raised interseries; 4) pronotum deeply sculptured; 5) male genitalia lacking parameres, and lacking distal piece. Currently, three species are recognized: H. ampliarmus , H. casuarius , and H. sculptissimus . All three species are known only from Brazil ( Figs. 55 , 57 ).

Figures

FIGURE 1. Dorsal habitus of Hydrochus species in study area.

FIGURE 3. Dorsal habitus of Hydrochus species in study area.

FIGURE 70. Pictorial aid to species groups of Hydrochus from Bolivia, Brazil and Paraguay, using male genitalia. Not to same scale.

FIGURES 44–45. Habitus and male genitalia of holotypes. 44. Hydrochus longissimus n. sp. 45. Hydrochus casuarius n. sp.

FIGURES 48–49. Habitus and male genitalia of holotypes. 48. Hydrochus sculptissimus n. sp. 49. Hydrochus ampliarmus n. sp.

FIGURES 55–56. Geographical distributions. 55. Endemics and near endemics. 56. H. bicarinatus and H. merkli.

FIGURES 57–58. Geographical distributions. 57. Endemics and near endemics. 58. H. bituberculatus.