Omicrogiton, D'ORCHYMONT, 1919

Angus, Robert B, Sadílek, David, Shaarawi, Fatma, Dollimore, Hayley, Liu, Hsing-Che, Seidel, Matthias, Sýkora, Vít & Fikáček, Martin, 2021, Karyotypes of water scavenger beetles (Coleoptera: Hydrophilidae): new data and review of published records, Zoological Journal of the Linnean Society 192 (3), pp. 958-958 : 958-

GENUS OMICROGITON DʼORCHYMONT, 1919

( FIG. 14C–D, H )

Material examined: Omicrogiton insularis dʼ Orchymont, 1919: 1 male, 1 female (BMNH): Taiwan, 4.8 km SEE of Tonglin, Beikeng Creek Trail , 24.04791°N 120.78434°E, 3.x.2018, rotten banana stem, M. Fikáček, H.-C. Liu, F.-S. Hu & W.-R. Liang lgt.

Karyotype: 2 n = 24 + Xy (♂). Autosome pairs 1–3 and the X chromosome are metacentric and clearly larger than the other pairs. Pairs 4 and 7–12 are subacrocentric to acrocentric, and the smallest autosome is about a quarter the length of the largest. The Y chromosome is dot like.

Figures

Figure 14. Karyotypes of the Omicrini and Sphaeridiini, without treatment. A–F, Omicrini: (A–B) Noteropagus sp. from Taiwan, meiotic karyotypes from testes; (C–D) Omicrogiton insularis, mitotic karyotype, midgut; (E–F) Paromicrus sp. from Taiwan, mitotic karyotype, midgut. G–I, habitus of examined specimens: (G) Noteropagus sp.; (H) Omicrogiton insularis; (I) Paromicrus sp. J–P, Sphaeridiini: Sphaeridium; (J–K) Sphaeridium lunatum (J, testes, mitosis; K, midgut, mitosis); (L) Sphaeridium scarabaeoides, mitosis, midgut; (M) Sphaeridium bipustulatum, mitosis, midgut; (N–P) meiosis, metaphase I, testes: (N) Sphaeridium scarabaeoides; (O) Sphaeridium bipustulatum; (P) Sphaeridium lunatum. Q, habitus of Sphaeridium scarabaeoides.