Cybister
Cybister, is a genus of beetle in family Dytiscidae. They are found in much of the world, including all continents except Antarctica. As of 2024 there are 98 species and 9 additional subspecies among four subgenera in the genus.
Description
Adult Cybister have broad hind legs with unequal tarsal claws and a fringe on the outer margin of the tarsus. They range in length up to 43 mm. Adult males of the North American species have several ridges on the coxae of the hind legs, forming a stridulatory device.Larvae have a frontal tooth on the head and lack cerci. North American species can grow up to 80 mm long.
Ecology
Cybister live in lentic habitats that have vegetation.Like other diving beetles, Cybister are predatory. Larvae of C. japonicus prey on insects in their first two instars, while third-instar larvae prey on vertebrates. Larvae of C. rugosus feed on both invertebrates and vertebrates in all instars.
Importance
Cybister chinensis is used in a game in Korea. The water beetle game 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.The swimming behaviour of C. lateralimarginalis has inspired the design of a legged underwater robot.
List of species
Subgenus ''Cybister'' Curtis, 1827
Cybister alluaudi Guignot, 1936Cybister bengalensis Aubé, 1838Cybister buqueti Aubé, 1838Cybister cardoni Severin, 1890Cybister celebensis Sharp, 1882Cybister cephalotes Sharp, 1882Cybister chinensis Motschulsky, 1854Cybister cinctus Sharp, 1882Cybister cognatus Sharp, 1882Cybister concessor Guignot, 1947Cybister confusus Sharp, 1882Cybister crassipes Sharp, 1882Cybister crassiusculus Régimbart, 1895Cybister dejeanii Aubé, 1838Cybister dytiscoides Sharp, 1882Cybister ellipticus LeConte, 1852Cybister explanatus LeConte, 1852Cybister extenuans Cybister favareli Guignot, 1936Cybister fimbriolatus Cybister fumatus Sharp, 1882Cybister godeffroyi Cybister gracilis Sharp, 1882Cybister gschwendtneri Guignot, 1935Cybister guerini Aubé, 1838Cybister guignoti Gschwendtner, 1936- * Cybister guignoti pseudosenegalensis Guignot, 1936Cybister hypomelas Régimbart, 1892Cybister janczyki Mouchamps, 1957Cybister javanus Aubé, 1838Cybister laevis Falkenström, 1936Cybister lateralimarginalis
- * Cybister lateralimarginalis ponticus Sharp, 1882
- * Cybister lateralimarginalis torquatus Cybister lewisianus Sharp, 1873Cybister limbatus Cybister loxidiscus Wilke, 1920Cybister natalensis Cybister nebulosus Gschwendtner, 1931Cybister occidentalis Aubé, 1838Cybister pectoralis Sharp, 1882Cybister pederzanii Rocchi, 1979Cybister poblanus Arce-Pérez, Novelo-Gutiérrez, & Fery, 2021Cybister reichei Aubé, 1838Cybister rugosus Cybister rugulosus Cybister schoutedeni Gschwendtner, 1932Cybister semiaciculatus Schaufuss, 1887Cybister senegalensis Aubé, 1838Cybister straeleni Guignot, 1952Cybister tibialis Sharp, 1882Cybister tripunctatus
- * Cybister tripunctatus africanus Laporte, 1835
- * Cybister tripunctatus lateralis
- * Cybister tripunctatus temnenkii Aubé, 1838Cybister ventralis Sharp, 1882Cybister weckwerthi Hendrich, 1997Cybister wittmeri Brancucci, 1979Cybister yulensis Guignot, 1956
Subgenus ''Megadytoides'' Brinck, 1945
Cybister marginicollis Boheman, 1848Subgenus ''Melanectes'' Brinck, 1945
Cybister alemon Guignot, 1948Cybister aterrimus Régimbart, 1899Cybister basilewskyi Guignot, 1950Cybister bellicosus Guignot, 1947Cybister bimaculatus Aubé, 1838Cybister blotei Guignot, 1936Cybister brevis Aubé, 1838Cybister burgeoni Guignot, 1947Cybister convexus Sharp, 1882Cybister danxiaensis Jiang, Zhao, Mai, Jia & Hendrich, 2023Cybister dehaanii Aubé, 1838Cybister desjardinsii Aubé, 1838Cybister dissentiens Mouchamps, 1957Cybister distinctus Régimbart, 1878Cybister ertli Zimmermann, 1917Cybister feraudi Guignot, 1934Cybister griphodes Guignot, 1942Cybister immarginatus Fabricius, 1798) Cybister insignis Sharp, 1882- * Cybister insignis caprai Guignot, 1949
- * Cybister insignis purpureovirgatus Guignot, 1946Cybister irritans Cybister longulus Gschwendtner, 1932Cybister lynceus J.Balfour-Browne, 1950Cybister mesomelas Guignot, 1942Cybister mocquerysi Régimbart, 1895Cybister modestus Sharp, 1882Cybister nigrescens Gschwendtner, 1933Cybister nigripes Wehncke, 1876Cybister operosus Sharp, 1882Cybister owas Laporte, 1835Cybister papuanus Guignot, 1956Cybister pinguis Régimbart, 1895Cybister posticus Aubé, 1838Cybister procax Guignot, 1947
- *Cybister procax vicinatus Mouchamps, 1957Cybister prolixus Sharp, 1882Cybister semirugosus Harold, 1878Cybister siamensis Sharp, 1882Cybister smaragdinus Régimbart, 1895Cybister sugillatus Erichson, 1834Cybister sumatrensis Régimbart, 1883Cybister thermolytes Guignot, 1947Cybister vicinus Zimmermann, 1917Cybister vulneratus Klug, 1834Cybister zimmermanni Mouchamps, 1957
Subgenus ''Neocybister'' K.B. Miller, Bergsten & Whiting, 2007
Cybister festae Griffini, 1895Subgenus unknown
Cybister parvus Trémouilles, 1984Fossil 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