Two new species of the genus Emertonia Wilson, 1932 from Korean waters (Copepoda, Harpacticoida, Paramesochridae)

Abstract

Two new species of the genus Emertonia were found from the west coast of Korea. The first new species, E. koreana sp. n., is closely related to E. acutifurcata. However, the new species is clearly distinguished by the presence of two modified pinnate setae on the P5 baseoendopodal lobe. All body somites of the new species except for the last two urosomites have strongly developed hyaline frills forming quadrilateral lappets. The second new species, E. simplex sp. n., superficially resembles E. mielkei in the structure of antennary exopod (with five setae), and the shape of P5. However, this new species differs from its congener mainly by having a caudal ramus 3.5 times as long as width, and P1 enp-2 with two claw-like setae. In addition, a key to the worldwide species of Emertonia is provided.

Deep sea without limits—four new closely related species of Emertonia Wilson, 1932 (Copepoda: Harpacticoida: Paramesochridae) show characters with a world-wide distribution

“…Based on WoRMS Editorial Board (2017), the genus Emertonia contains at present 48 species, including the four new species presented herein. The most recently described species are Emertonia clausi and E. ingridae by Pointner et al (2013) and E. koreana Back & Lee, 2017and E. simplex Back & Lee, 2017by Back & Lee (2017, in addition to those originally described as Kliopsyllus species: E. andeep (Veit-Köhler, 2004), E. diva (Veit-Köhler, 2005, E. brevicaudata (Kornev & Chertoprud, 2008), E. schminkei (Veit-Köhler & Drewes, 2009) and E. minor (Vasconcelos, Veit-Köhler, Drewes & Parreira dos Santos, 2009) (Veit-Köhler 20042005;Kornev & Chertoprud 2008;Vasconcelos et al 2009;.…”

“…Therefore, this generic placement is based on the combination of characteristics for Emertonia, as given by Veit-Köhler ( 2004): the two-segmented rami of P1, the 3-segmented exopod of P2-P4, the presence of two setae on P4 exp3 and the 1-segmented endopod bearing one seta in P2 and P3. Within the genus the four new species are assigned to the "andeep-group" established by Back & Lee (2017). The species of this group are characterized by the 2-segmented endopod of P4.…”

“…For instance, Emertonia can readily be distinguished from the other genera of the subfamily Paramesochrinae by their one-segmented endopods on the second and third swimming legs which bear one apical seta (Veit-Köhler 2004). Back & Lee (2017) amended the diagnosis of Emertonia and established five groups within the genus. All four new species belong to the "andeep-group", which is characterized by a two-segmented endopod on the fourth swimming leg.…”