Chaetarthria, STEPHENS, 1835

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 CHAETARTHRIA STEPHENS, 1835

( FIG. 7L–M )

M a t e r i a l e x a m i n e d: C h a e t a r t h r i a s i m i l l i m a Vorst & Cuppen, 2003: 1 male ( BMNH): United Kingdom: England, Oxfordshire, Cothill , R. Angus & F. Shaarawi lgt .

Karyotype: 2 n = 16 + Xy p (♂). There are distinct steps in the size decreases between chromosomes 1 and 2, 2 and 3, and 3 and 4, then a gradual decrease between chromosomes 4 and 6, a slightly larger one between 6 and 7 and a sharp decrease between 7 and 8. The X chromosome is about the same length as autosomes 4–6 and the y is dot like. Chromosomes 1–6 and the X chromosome are metacentric, chromosomes 7 and 8 are subacrocentric.

Note: The karyotype was published by Angus & Shaarawi (1997) under the name Chaetarthria seminulum (Herbst, 1797) . It has been slightly rearranged and improved and it republished here.

SUBFAMILY ENOCHRINAE

Figures

Figure 7. Mitotic karyotypes of Chaetarthriinae from the midgut.A–C: Anacaena: (A) Anacaena gaetanae; (B–C) Anacaena lutescens (B, sexually reproducing specimen; C, parthenogenetic female). E–J, Horelophus walkeri. L, Chaetarthria simillima. A, C-banded; B, C, E–J, L, without treatment. Habitus figures: (D) karyotyped voucher of Anacaena gaetanae; (K) Horelophus walkeri, from Fikáček et al. (2012a); (M) Chaetarthria seminulum, from Fikáček & Liu (2019).