'anisobranchiate' originates from Greek, specifically the elements 'anisos' and 'branchia', where 'anisos' meant 'unequal' and 'branchia' meant 'gills'.

'anisobranchiate' was formed in modern scientific/Neo-Latin usage from Greek roots (via New Latin 'anisobranchia') with the adjectival suffix '-ate', eventually becoming the English technical adjective 'anisobranchiate'.

Initially the roots referred directly to 'unequal' + 'gills'; the combined scientific term has retained this meaning as 'having unequal gills' in modern usage.