Cybister
Cybister ('kybistētēr' = diver, tumbler), is a genus of beetle in family Dytiscidae. They are found in much of the world, including all continents except Antarctica.[1][2] As of 2021 there are 96 species and 9 additional subspecies among four subgenera in the genus.[3]
| Cybister | |
|---|---|
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| Cybister fimbriolatus | |
| Scientific classification  | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Arthropoda | 
| Class: | Insecta | 
| Order: | Coleoptera | 
| Family: | Dytiscidae | 
| Subfamily: | Cybistrinae | 
| Tribe: | Cybistrini | 
| Genus: | Cybister Curtis, 1827  | 

Description
    
Adult Cybister have broad hind legs with unequal tarsal claws (the inner claw being smaller and sometimes absent) and a fringe on the outer margin of the tarsus.[4] They range in length from 13 mm (C. parvus from Brazil) to 43 mm (C. bimaculatus from the Afrotropics).[5] Adult males of the North American species have several ridges on the coxae of the hind legs, forming a stridulatory device.[5]
Larvae have a frontal tooth on the head and lack cerci. North American species can grow up to 80 mm long.[4]
Ecology
    
Cybister live in lentic (still fresh water) habitats that have vegetation.[6]
Like other diving beetles, Cybister are predatory. Larvae of C. japonicus prey on insects (mainly Odonata nymphs and the backswimmer Notonecta triguttata) in their first two instars, while third-instar larvae prey on vertebrates (tadpoles and fish).[7] Larvae of C. rugosus feed on both invertebrates and vertebrates in all instars.[8]
Importance
    
Cybister chinensis (sometimes misidentified as C. japonicus) is used in a game in Korea. The water beetle game (mul bang gae nori) is played in an oval, water-filled tank with vertical flanges along its inner edge and prizes on the tank rim. The game is played by dropping a C. chinensis through a funnel into the center of the tank, after which it swims towards the edge of the tank and stops in one of the slots formed by the metal flanges. If a prize is above this slot, the player wins it.[9]
The swimming behaviour of C. lateralimarginalis has inspired (biomimetics) the design of a legged underwater robot.[10]
List of species
    
    Subgenus Cybister Curtis, 1827
    
- Cybister alluaudi Guignot, 1936
 - Cybister bengalensis Aubé, 1838
 - Cybister buqueti Aubé, 1838
 - Cybister cardoni Severin, 1890
 - Cybister celebensis Sharp, 1882
 - Cybister cephalotes Sharp, 1882
 - Cybister chinensis Motschulsky, 1854
 - Cybister cinctus Sharp, 1882
 - Cybister cognatus Sharp, 1882
 - Cybister concessor Guignot, 1947
 - Cybister confusus Sharp, 1882
 - Cybister crassipes Sharp, 1882
 - Cybister crassiusculus Régimbart, 1895
 - Cybister dejeanii Aubé, 1838
 - Cybister dytiscoides Sharp, 1882
 - Cybister ellipticus LeConte, 1852
 - Cybister explanatus LeConte, 1852
 - Cybister extenuans (Walker, 1858)
 - Cybister favareli Guignot, 1936
 - Cybister fimbriolatus (Say, 1823)
 - Cybister fumatus Sharp, 1882
 - Cybister godeffroyi (Wehncke, 1876)
 - Cybister gracilis Sharp, 1882
 - Cybister gschwendtneri Guignot, 1935
 - Cybister guerini Aubé, 1838
 - Cybister guignoti Gschwendtner, 1936
- Cybister guignoti pseudosenegalensis Guignot, 1936
 
 - Cybister hypomelas Régimbart, 1892
 - Cybister janczyki Mouchamps, 1957
 - Cybister javanus Aubé, 1838
 - Cybister laevis Falkenström, 1936
 - Cybister lateralimarginalis (De Geer, 1774)
- Cybister lateralimarginalis ponticus Sharp, 1882
 - Cybister lateralimarginalis torquatus (Fischer von Waldheim, 1829)
 
 - Cybister lewisianus Sharp, 1873
 - Cybister limbatus (Fabricius, 1775)
 - Cybister loxidiscus Wilke, 1920
 - Cybister natalensis (Wehncke, 1876)
 - Cybister nebulosus Gschwendtner, 1931
 - Cybister occidentalis Aubé, 1838
 - Cybister pectoralis Sharp, 1882
 - Cybister pederzanii Rocchi, 1979
 - Cybister reichei Aubé, 1838
 - Cybister rugosus (W.S.Macleay, 1825)
 - Cybister rugulosus (Redtenbacher, 1844)
 - Cybister schoutedeni Gschwendtner, 1932
 - Cybister semiaciculatus Schaufuss, 1887
 - Cybister senegalensis Aubé, 1838
 - Cybister straeleni Guignot, 1952
 - Cybister tibialis Sharp, 1882
 - Cybister tripunctatus (Olivier, 1795)
- Cybister tripunctatus africanus Laporte, 1835
 - Cybister tripunctatus lateralis (Fabricius, 1798)
 - Cybister tripunctatus temnenkii Aubé, 1838
 
 - Cybister ventralis Sharp, 1882
 - Cybister weckwerthi Hendrich, 1997
 - Cybister wittmeri Brancucci, 1979
 - Cybister yulensis Guignot, 1956
 
Subgenus Megadytoides Brinck, 1945
    
- Cybister marginicollis Boheman, 1848
 
Subgenus Melanectes Brinck, 1945
    
- Cybister alemon Guignot, 1948
 - Cybister aterrimus Régimbart, 1899
 - Cybister basilewskyi Guignot, 1950
 - Cybister bellicosus Guignot, 1947
 - Cybister bimaculatus Aubé, 1838
 - Cybister blotei Guignot, 1936
 - Cybister brevis Aubé, 1838
 - Cybister burgeoni Guignot, 1947
 - Cybister convexus Sharp, 1882
 - Cybister dehaanii Aubé, 1838
 - Cybister desjardinsii Aubé, 1838
 - Cybister dissentiens Mouchamps, 1957
 - Cybister distinctus Régimbart, 1878
 - Cybister ertli Zimmermann, 1917
 - Cybister feraudi Guignot, 1934
 - Cybister griphodes Guignot, 1942
 - Cybister immarginatus Fabricius, 1798)
 - Cybister insignis Sharp, 1882
- Cybister insignis caprai Guignot, 1949
 - Cybister insignis purpureovirgatus Guignot, 1946
 
 - Cybister irritans (Dohrn, 1875)
 - Cybister longulus Gschwendtner, 1932
 - Cybister lynceus J.Balfour-Browne, 1950
 - Cybister mesomelas Guignot, 1942
 - Cybister mocquerysi Régimbart, 1895
 - Cybister modestus Sharp, 1882
 - Cybister nigrescens Gschwendtner, 1933
 - Cybister nigripes Wehncke, 1876
 - Cybister operosus Sharp, 1882
 - Cybister owas Laporte, 1835
 - Cybister papuanus Guignot, 1956
 - Cybister pinguis Régimbart, 1895
 - Cybister posticus Aubé, 1838
 - Cybister procax Guignot, 1947
- Cybister procax vicinatus Mouchamps, 1957
 
 - Cybister prolixus Sharp, 1882
 - Cybister semirugosus Harold, 1878
 - Cybister siamensis Sharp, 1882
 - Cybister smaragdinus Régimbart, 1895
 - Cybister sugillatus Erichson, 1834
 - Cybister sumatrensis Régimbart, 1883
 - Cybister thermolytes Guignot, 1947
 - Cybister vicinus Zimmermann, 1917
 - Cybister vulneratus Klug, 1834
 - Cybister zimmermanni Mouchamps, 1957
 
Subgenus Neocybister K.B. Miller, Bergsten & Whiting, 2007
    
- Cybister festae Griffini, 1895
 - Cybister puncticollis (Brullé, 1837)
 
Subgenus unknown
    
- Cybister parvus Trémouilles, 1984
 
Fossil species
    
These seven extinct species are known only from fossils:
- †Cybister agassizi Heer, 1862
 - †Cybister atavus Heer, 1862
 - †Cybister fractus Riha, 1974
 - †Cybister imperfectus Riha, 1974
 - †Cybister mancus Riha, 1974
 - †Cybister nicoleti Heer, 1862
 - †Cybister rotundatus Riha, 1974
 
References
    
- Miller, K.B.; J. Bergsten (2016). Diving Beetles of the World: Systematics and Biology of the Dytiscidae. pp. 131–132. ISBN 978-1-4214-2054-7.
 - Roberts, C H (1905). "The Distinctive Characters of the Eastern Species of the Genera Dytiscus and Cybister". Journal of the New York Entomological Society. 13: 103–107.
 - Nilsson, Anders N.; Hájek, Jiří (2021). "A World Catalogue of the Family Dytiscidae or the Diving Beetles (Coleoptera, Adephaga)" (PDF) (1.I.2021 ed.).
 - "Genus Cybister". bugguide.net. Retrieved 2023-03-02.
 - Arce-Pérez, Roberto; Novelo-Gutiérrez, Rodolfo; Fery, Hans (2021-11-04). "Cybister (s. str.) poblanus sp. n. from Mexico and notes on other species of Cybistrinae (Coleoptera: Dytiscidae)". Zootaxa. 5061 (2): 323–339. doi:10.11646/zootaxa.5061.2.5. ISSN 1175-5334.
 - Liao, Wenfei (2018-08-19). "Cybister, an Immigrant in Finland". Wenfei's Blog. Retrieved 2023-03-02.
 - Ohba, Shin-Ya (2009-06-01). "Ontogenetic Dietary Shift in the Larvae of Cybister japonicus (Coleoptera: Dytiscidae) in Japanese Rice Fields". Environmental Entomology. 38 (3): 856–860. doi:10.1603/022.038.0339. ISSN 0046-225X.
 - Yamasaki, Shun; Watanabe, Kohei; Ohba, Shin‐ya (2022). "Larval feeding habits of the large‐bodied diving beetle Cybister rugosus (Coleoptera: Dytiscidae) under laboratory conditions". Entomological Science. 25 (2). doi:10.1111/ens.12510. ISSN 1343-8786.
 - Pemberton, R. W. (1990). "The Korean water beetle game". Pan-Pacific Entomologist. 66 (2): 172–174.
 - Kim, Heejoong; Lee, Jihong (2017). "Design, swimming motion planning and implementation of a legged underwater robot (CALEB10: D.BeeBot) by biomimetic approach". Ocean Engineering. 130: 310–327. doi:10.1016/j.oceaneng.2016.11.006.
 

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