Cyloma, SHARP, 1872

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 CYLOMA SHARP, 1872

( FIG. 12D–H )

Material examined: Cyloma guttulatus Sharp, 1884: 1 female (NMPC): New Zealand: Fiordland ( FD), Borland Road 24 km NWW of Monowai , baited pitfall traps (rotten squid) in degraded remnants of Nothofagus forest with numerous rotten logs, 45°41.13’S 167°20.29’E, 320 m, 27.i.2016, M. Seidel, V. Sýkora & M. Fikáček lgt. (2016- NZ 024) .

Cyloma sp. : (undescribed species illustrated in Fig. 12H ). 1 male, 1 female ( NMPC): New Zealand: Fiordland ( FD), Borland Road 24 km NWW of Monowai, on dead possum, 45°41.13’S 167°20.29’E ,

320 m, 27.i.2016, M. Seidel, V. Sýkora & M. Fikáček lgt. (2016- NZ 024) .

Karyotype: 2 n = 22 + Xy (♂). In Cyloma guttulatus , chromosome pairs 1–3 and 5 are metacentric, with pair 2 half the size of pair 1, and the others decreasing in size from half the length of pair 2 to about quarter of the size of pair 2 ( Fig. 12D ). The X chromosomes cannot be identified. Cyloma sp. ( Fig. 12E–G ) has a similar karyotype to Cyloma guttulatus ; however, autosome pair 2 is about two-thirds of the length of pair 1 and the smallest autosomes, and the X chromosome are about a quarter of the length of pair 1.

Figures

Figure 12. Karyotypes of the Cylominae, without treatment. A–B, Adolopus sp., mitosis from midgut. D, Cyloma guttulatus, mitosis from midgut. E–G, Cyloma sp. (E–F, meiotic first metaphase; G, testes, mitosis;). I–M, Cylomissus glabratus: (I–J) mitotic metaphase from midgut; (K–M) meiotic metaphase I from testes. Habitus figures: (C) Adolopus sp.; (H) Cyloma sp., specimen collected with karyotyped voucher; (N) Cylomissus glabratus, from Minoshima et al. (2015).