Calanoid copepods are a well-recognized taxonomic group of Crustacea. They were already placed, with one cyclopoid (Scribella) and five calanoid (Acartia, Calanus, Candacia, Euchirus (= Euchaeta), and Pontella) genera, under a single taxonomic unit, the Calanidae, by Dana [1]. Giesbrecht and Sars are the two early principal contributors to the taxonomy of Copepoda, including the Calanoida.

Based on the location of the body articulation, Giesbrecht [2] divided copepods into two groups, the Gymnopleoden and Podopleoden. All copepods, characterized by an articulation between the fifth pedigerous (leg-bearing) somite and genital somite, separating the body into an anterior part (prosome) and a posterior part (urosome), were placed under the suborder Gymnoplea. Podoplea contained all other copepods having this articulation located between the fourth and fifth pedigerous somites. According to the structure of antennules in males, Giesbrecht further divided the Gymnoplea into two tribes, the Amphaskandria (males with both antennules similar) and Heterarthrandria (males with one of the antennules modified).

Sars [3-9], on the other hand, suggested seven distinct types of copepods, Calanus, Harpacticus, Cyclops, Notodelphys, Monstrilla, Caligus, and Lernaea, respectively respresenting seven divisions (Suborders) of the Copepoda, i.e., Calanoida, Harpacticoida, Cyclopoida, Notodelphyoida, Monstrilloida, Caligoida, and Lernaeoida. The Calanoida in Sars [3-9], corresponding to the Gymnoplea in Giesbrecht [2], was divided into three sections: Amphascandria (both antennules in males are alike and only transformed slightly without any genicular structure, in the greater number of the genera the adult males are distinguished by a conspicuous transformation and great reduction in oral parts), Isokerandria (both antennules are without any conspicuous difference and oral part of much the same appearance in the two sexes), and Heterarthrandria (one of the antennules in male similar to that in female, the other peculiarly transformed into a powerful grasping organ).

Modifications of classification within the Calanoida have then been proposed and were reviewed by Huy & Boxshall [10]. In 1974, Andronov [11] proposed the phylogenetic relationships of the higher taxa within the Order Calanoida, and included nine superfamilies: Augapatiloidea, Bathypontioidea, Centropagoidea, Eucalanoidea, Megacalanoidea, Platycopioidea, Pseudocyclopoidea, Pseudocalanoidea, and Riocalanoidea. As the results of Andronov’s [12] change of names of some superfamilies to conform with the International Code of Zoological Nomenclature and subsequently Boxshall and Halsey’s [13] amendment, the Order Calanoida now consists of ten superfamilies and 43 families (30 families, highlighted in red color, present in the China seas).

1. Superfamily Arietelloidea Sars, 1902 (changed from Augaptiloidea) (24, 134)

Family Arietellidae Sars, 1902 (4; 16)

Family Augaptilidae Sars, 1902 (7; 45)

Family Discoidae Gordejeva, 1975

Family Heterorhabdidae Sars, 1902 (7; 36)

Family Hyperbionychidae Ohtskua, Roe et Boxshall, 1993

Family Lucicutiidae Sars, 1902 (1; 20)

Family Metridinidae Sars, 1902 (3; 17)

Family Nullosetigeridae Ohtsuka, Imabayashi et Suh, 1999 (1; 6)

2. Superfamily Bathypontioidea Brodsky, 1950 (1, 7)

Family Bathypontiidae Brodsky, 1950 (1; 7)

3. Superfamily Calanoidea Dana, 1846 (17, 46)

Family Calanidae Dana, 1846 (8; 14)

Family Megacalanidae Sewell, 1947 (2; 3)

Family Paracalanidae Giesbrecht, 1893 (7; 29)

4. Superfamily Clausocalanoidea Giesbrecht, 1893 (changed from Pseudocalanoidea) (41, 185)

Family Aetideidae Giesbrecht, 1893 (12; 63)

Family Clausocalanidae Giesbrecht, 1893 (5; 18)

Family Diaixidae Sars,1902

Family Euchaetidae Giesbrecht, 1893 (2; 36)

Family Mesaiokeratidae Matthews, 1961

Family Phaennidae Sars, 1902 (4; 9)

Family Pseudocyclopiidae Sars, 1902

Family Scolecitrichidae Giesbrecht, 1893 (14; 54)

Family Stephidae Sars, 1902 (1; 1)

Family Tharybidae Sars, 1902 (2; 3)

5. Superfamilly Diaptomoidea Baird, 1850 (changed from Centropagoidea) (15, 149)

Family Acartiidae Sars, 1902 (2; 25)

Family Candaciidae Giesbrecht, 1893 (1; 20)

Family Centropagidae Giesbrecht, 1893 (2; 17)

Family Diaptomidae Baird, 1850

Family Fosshagenidae Suárez-Morales et Iliffe, 1996 (1; 1)

Family Parapontellidae Giesbrecht, 1893

Family Pontellidae Dana, 1853 (6; 53)

Family Pseudodiaptomidae Sars,1902 (1; 16)

Family Sulcanidae Nicholls 1945

Family Temoridae, 1893 (1; 4)

Family Tortanidae Sars, 1902 (1; 19)

6. Superfamily Epacteriscoidea Fosshagen, 1973 (home to new families)

Family Epacteriscidae Fosshagen, 1973

Family Ridgewayiidae M.S.Wilson, 1958 (Now part of the Pseudocyclopidae)

7. Superfamily Eucalanoidea Giesbrecht, 1893 (4, 18)

Family Eucalanidae Giesbrecht, 1893 (2; 7)

Family Rhincalanidae Geletin, 1975 (1; 3)

Family Subeucalanidae Giesbrecht, 1893 (1, 8)

8. Superfamily Pseudocyclopoidea Giesbrecht, 1893 (1, 2)

Family Boholinidae Fosshagen & Iliffe, 1989 (Now part of the Pseudocyclopidae)

Family Pseudocyclopidae Giesbrecht, 1893 (1; 2)

9. Superfamily Ryocalanoidea Andronov, 1974

Family Ryocalanidae Andronov, 1974

10 Superfamily Spinocalanoidea Vervoort, 1951 (split from Pseudocalanoidea) (3, 9).

Family Spinocalanidae Vervoort, 1951 (3; 9)

Platycopioidea is now an independent order by itself. Several changes at the family level have been reported. Boholinidae and Ridgewayiidae are now part of the Pseudocyclopidae. A new family, Kyphocalanidae, was established by Markhaseva & Schulz [14].

Calalnoid copepods are the dominant taxa in marine zooplankton and are often being the focal point in various biological and oceanographic studies, for which reliable species identification is required. The present project aims to provide basic taxonomic information of the species of calanoid copepods occurring in the China seas, i.e., Bohai Sea, Yellow Sea, East China Sea, Taiwan Strait, South China Sea, and east of Taiwan. The website, http://copepodes.obs-banyuls.fr/en, managed by Razouls, C., F. de Bovée, J. Kouwenberg & N. Desreumaux (2005-2919), has been frequently consulted.