1 Phycologia Archimer 2020, Volume 59, Issue 1, Pages 6-23 https://doi.org/10.1080/00318884.2019.1663693 https://archimer.ifremer.fr https://archimer.ifremer.fr/doc/00589/70143/ Attributing Ceratocorys, Pentaplacodinium and Protoceratium to Protoceratiaceae (Dinophyceae), with descriptions of Ceratocorys malayensis sp. nov. and Pentaplacodinium usupianum sp. nov Luo Zhaohe 1 , Lim Zhen Fei 2, Mertens Kenneth 3, Krock Bernd 4, Teng Sing Tung 5, Tan Toh Hii 2, Leaw Chui Pin 2, Lim Po Teen 2, Gu Haifeng 1, * 1 Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China 2 Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, Bachok 16310, Malaysia 3 Ifremer, LER BO, Station de Biologie Marine, Place de la Croix, BP40537, Concarneau CEDEX F- 29185, France 4 Alfred Wegener Institute for Polar and Marine Research, Ecological Chemistry, Am Handelshafen 12, Bremerhaven D-27570, Germany 5 Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, Kota Samarahan 94300, Malaysia * Corresponding author : Haifeng Gu, email address :
[email protected] Abstract : The gonyaulacean family Protoceratiaceae is characterised by five precingular plates. It currently encompasses the type genus Ceratocorys and the fossil genus Atopodinium. Fourteen strains of Ceratocorys, Pentaplacodinium, and Protoceratium were established from Malaysian and Hawaiian waters, and their morphologies were examined using light and scanning electron microscopy. Two new species, Ceratocorys malayensis sp. nov. and Pentaplacodinium usupianum sp. nov., were described from Malaysian waters. They share a Kofoidean plate formula of Po, Pt, 3ʹ, 1a, 6ʹʹ, 6C, 6S, 5ʹʹʹ, 1p, 1ʹʹʹʹ. Ceratocorys malayensis has a short first apical plate (1ʹ) with no direct contact with the anterior sulcal plate (Sa) whereas Pentaplacodinium usupianum had a parallelogram-shaped 1ʹ plate which often contacted the Sa plate.