Hydaticus is a genus of predatory water beetle belonging to the family Dytiscidae, native to the Palearctic (including Europe), the Afro-tropical region, the Near East, the Nearctic and North Africa. It contains the following species:
Hydaticus abyssinicus Régimbart, 1905 Hydaticus aequabilis Guignot, 1958 Hydaticus agaboides Sharp, 1882 Hydaticus amydrus Guignot, 1955 Hydaticus apiatus Guignot, 1947 Hydaticus arabicus Guignot, 1951 Hydaticus arcuatus Régimbart, 1895 Hydaticus aruspex Clark, 1864 Hydaticus basicollis Régimbart, 1905 Hydaticus batchianensis Sharp, 1882 Hydaticus bengalensis Régimbart, 1899 Hydaticus bihamatus Aubé, 1838 Hydaticus bimarginatus (Say, 1830) Hydaticus bipunctatus Wehncke, 1876 Hydaticus bitalensis Guignot, 1952 Hydaticus bivittatus Laporte, 1835 Hydaticus bowringii Clark, 1864 Hydaticus caffer Boheman, 1848 Hydaticus capicola Aubé, 1838 Hydaticus chrisi Nilsson, 2001 Hydaticus cinctipennis Aubé, 1838 Hydaticus collarti Guignot, 1948 Hydaticus concolor Sharp, 1882 Hydaticus congo Gschwendtner, 1938 Hydaticus consanguineus Aubé, 1838 Hydaticus conspersus Régimbart, 1899 Hydaticus continentalis J.Balfour-Browne, 1944 Hydaticus daemeli Wehncke, 1876 Hydaticus decorus Klug, 1834 Hydaticus devexus Trémouilles, 1996 Hydaticus dineutoides Sharp, 1882 Hydaticus dintelmanni Balke, Hendrich, Sagata & Wewalka, 2005 Hydaticus dorsiger Aubé, 1838 Hydaticus dregei Aubé, 1838 Hydaticus epipleuricus Régimbart, 1891 Hydaticus exclamationis Aubé, 1838 Hydaticus fabricii (W.S.Macleay, 1825) Hydaticus figuratus Régimbart, 1899 Hydaticus fijiensis Régimbart, 1899 Hydaticus finus Watts, 1978 Hydaticus flavolineatus Boheman, 1848 Hydaticus fractifer Walker, 1858 Hydaticus fractivittis Guignot, 1951 Hydaticus fulvoguttatus Guignot, 1951 Hydaticus fulvosparsus Gschwendtner, 1938 Hydaticus galla Guérin-Méneville, 1849 Hydaticus grammicus (Germar, 1827) Hydaticus guignoti Gschwendtner, 1938 Hydaticus histrio Clark, 1864 Hydaticus humeralis Régimbart, 1895 Hydaticus incertus Régimbart, 1888 Hydaticus ineptus Guignot, 1953 Hydaticus inexspectatus Trémouilles, 1996 Hydaticus intermedius Régimbart, 1895 Hydaticus interrogator Mouchamps, 1957 Hydaticus jeanneli Guignot, 1936 Hydaticus kolbei Branden, 1885 Hydaticus laceratus Régimbart, 1895 Hydaticus laetabilis Régimbart, 1899 Hydaticus lateralis Laporte, 1835 Hydaticus latior Régimbart, 1895 Hydaticus lativittis Régimbart, 1895 Hydaticus leander (Rossi, 1790) Hydaticus limnetes Guignot, 1955 Hydaticus litigiosus Régimbart, 1880 Hydaticus luczonicus Aubé, 1838 Hydaticus macularis Régimbart, 1899 Hydaticus madagascariensis Aubé, 1838 Hydaticus major Régimbart, 1899 Hydaticus matruelis Clark, 1864 Hydaticus mexaformis Wewalka, 1979 Hydaticus microdaemeli Watts, 1978 Hydaticus mocquerysi Régimbart, 1895 Hydaticus musivus Guignot, 1952 Hydaticus natalensis Guignot, 1951 Hydaticus nigritulus Régimbart, 1899 Hydaticus nigrotaeniatus Régimbart, 1895 Hydaticus okalehubyi Balke & Hendrich, 1992 Hydaticus opaculus Gschwendtner, 1933 Hydaticus orissaensis Nilsson, 1999 Hydaticus ornatus H.J.Kolbe, 1883 Hydaticus pacificus Aubé, 1838 Hydaticus paganus Clark, 1864 Hydaticus palliatus Aubé, 1838 Hydaticus parallelus Clark, 1864 Hydaticus peregrinus Guignot, 1948 Hydaticus pescheti Gschwendtner, 1930 Hydaticus petitii Aubé, 1838 Hydaticus philippensis Wehncke, 1876 Hydaticus piceus LeConte, 1863 Hydaticus plagiatus Régimbart, 1895 Hydaticus platamboides Régimbart, 1889 Hydaticus platteeuwi Severin, 1890 Hydaticus poecilus Régimbart, 1895 Hydaticus ponticus Sharp, 1882 Hydaticus propinquus Guignot, 1951 Hydaticus pulcher (Clark, 1863) Hydaticus pullatus Guignot, 1952 Hydaticus quadriguttatus Régimbart, 1895 Hydaticus quadrivittatus Blanchard, 1843 Hydaticus reductus Régimbart, 1899 Hydaticus rhantaticoides Régimbart, 1892 Hydaticus rhantoides Sharp, 1882 Hydaticus ricinus Wewalka, 1979 Hydaticus rimosus Aubé, 1838 Hydaticus rivanolis Wewalka, 1979 Hydaticus saecularis Pederzani, 1982 Hydaticus satoi Wewalka, 1975 Hydaticus scapularis Guignot, 1952 Hydaticus schelkovnikovi Zaitzev, 1913 Hydaticus schultzei Zimmermann, 1924 Hydaticus sellatus Régimbart, 1883 Hydaticus seminiger (De Geer, 1774) Hydaticus septemlineatus Zimmermann, 1928 Hydaticus servillianus Aubé, 1838 Hydaticus severini Régimbart, 1895 Hydaticus sexguttatus Régimbart, 1899 Hydaticus sobrinus Aubé, 1838 Hydaticus speciosus Régimbart, 1895 Hydaticus stappersi Peschet, 1915 Hydaticus subfasciatus Laporte, 1835 Hydaticus suffusus Régimbart, 1892 Hydaticus tenuis Gschwendtner, 1938 Hydaticus testudinarius Régimbart, 1895 Hydaticus thermonectoides Sharp, 1884 Hydaticus torosus Guignot, 1947 Hydaticus transversalis (Pontoppidan, 1763) Hydaticus tschoffeni Régimbart, 1895 Hydaticus tuyuensis Trémouilles, 1996 Hydaticus ugandaensis Guignot, 1936 Hydaticus ussherii Clark, 1864 Hydaticus vaziranii Wewalka, 1979 Hydaticus verecundus Clark, 1864 Hydaticus vittatus (Fabricius, 1775) Hydaticus vitticollis Régimbart, 1895 Hydaticus wattsi Daussin, 1980 Hydaticus xanthomelas (Brullé, 1837) Hydaticus zschokkeanus (Heer, 1847)