Crephelochares abnormalis explained

Crephelochares abnormalis, is a species of water scavenger beetle found in Cambodia, Sri Lanka, Taiwan, Thailand, Vietnam, Ryukyu Islands and Indonesia: Borneo, Java, Sulawesi, Sumatra.^{[1] [2] [3] [4] [5]}

Taxonomy

The species was originally described by David Sharp in 1890 under the genus Philydrus.^[6]

It was transferred to the genus Chasmogenus when Chasmogenus was considered a subgenus of the genus Helochares and a synonym of Crephelochares. Additional details about the taxonomic history of Chasmogenus and Crephelochares can be found in Girón and Short (2021).^[7]

Description

The species is closely related to Chasmogenus orbus, only can be separated by features of the aedeagus: parameres without or with small subapical tooth, where the apex is broadened inwards. Median lobe gradually becomes narrow from apical quarter to apex and widely truncate apically.^[8]

Notes and References

1. Devi. M. Bhubaneshwari. Devi. O. Sandhyarani. Fikáček. Martin. Minoshima. Yûsuke N.. Wanghengbam. Leiphon. 2016-07-27. Redescription and lectotype designation of Chasmogenus abnormalis (Sharp), with notes on its distribution. Zootaxa. 4144. 2. 296–300. 10.11646/zootaxa.4144.2.12. 27470857. 2021-07-30.
2. Jia. Fenglong. Tang. Yu-dan. 2018-02-19. A faunistic study of genus Chasmogenus Sharp, 1882 of China (Coleoptera, Hydrophilidae). ZooKeys. 738. 59–66. 10.3897/zookeys.738.21711. 5904443. 29670421. 2021-07-30. free.
3. Web site: Girón. J. C.. Short. A. E. Z.. 2016. Exploring morphological characters associated with habitat transitions in water scavenger beetles (Coleoptera: Hydrophilidae: Acidocerinae). 2021-07-30. researchgate.net.
4. Hebauer. F.. Ryndevich. S. K.. 2005. New data on the distribution of Old World Hydrophilidae (Coleoptera). Acta Coleopterologica. 21. 1. 43–51.
5. Web site: Chasmogenus abnormalis (Sharp, 1890) . 2021-07-30 . www.gbif.org . en.
6. Sharp. D.. 1890. On some aquatic Coleoptera from Ceylon. Transactions of the Entomological Society of London. 1890. 2. 339–359. 10.1111/j.1365-2311.1890.tb03026.x.
7. Girón. Jennifer C.. Short. Andrew Edward Z.. 2021-06-18. The Acidocerinae (Coleoptera, Hydrophilidae): taxonomy, classification, and catalog of species. ZooKeys. 1045. 1–236. 10.3897/zookeys.1045.63810. 1313-2970. 8233300. 34228772. free.
8. Jia . Fenglong . Tang . Yu-dan . 2018-02-19 . A faunistic study of genus Chasmogenus Sharp, 1882 of China (Coleoptera, Hydrophilidae) . 2021-07-30 . ZooKeys . 738 . 59–66 . 10.3897/zookeys.738.21711 . 5904443 . 29670421. free .