No abstract

We describe two species from the genus Triconia Böttger-Schnack, 1999 in the family Oncaeidae from the northeastern equatorial Pacific, both belonging to the conifera-subgroup. Both sexes of T. derivata (Heron & Bradford-Grieve, 1995) are redescribed, including morphological features not noted in earlier descriptions, such as the posterior face of the labrum. Specimens of T. derivata from the northeastern equatorial Pacific differ slightly from the original descriptions in some morphometric characters, and their differentiation from T. furcula (Farran, 1936), which is closely related, is summarized. The male of T. hirsuta Wi, Böttger-Schnack & Soh, 2010 is described for the first time and the morphology of the female is redescribed. The female holotype of T. hirsuta from Korean waters is reexamined and discrepancies between text and figures in the original description regarding the endopodal spine lengths on swimming leg 2 are clarified. A revised version of the respective part of the original figure is included in the present paper. An indication of the variation in endopodal spine lengths on swimming legs 2 to 4 is provided for both sexes of the two species. It is pointed out that morphometric characters required for unequivocal identification of species of the conifera-subgroup are still not sufficiently well defined. The records of T. derivata and T. hirsuta to date are summarized and indicate a wide zoogeographical distribution of the former species.

Three species of the similis-subgroup of the genus Triconia Böttger-Schnack, 1999 in the family Oncaeidae Giesbrecht, 1893 ["1892"] are described based on specimens collected by using a fine mesh net in the northeastern equatorial Pacific Ocean. One species is newly recorded in the equatorial Pacific, and the other two species are new to science. Triconia komo n. sp. is closely related to T. hawii (Böttger-Schnack & Boxshall, 1990), but differs distinctly in the relative length of the outer basal seta on P5 in the female as well as slightly in the relative length of the seta VI on caudal ramus in both sexes. Triconia onnuri n. sp. closely resembles T. similis (Sars, 1918), but females can be distinguished by the relative length of the outer exopodal seta and the outer basal seta on P5. Both sexes differ from T. similis in the relative lengths of endopodal spines on swimming legs 3 and 4 as well as in the form of caudal seta VI. The female of Triconia denticula Wi, Shin & Soh, 2011, which is newly recorded in the equatorial Pacific, is redescribed including morphological details and differences compared to the original description from Korean waters. The type material of T.

We report the occurrence of the genus Bicorniphontodes George, Glatzel & Schröder, 2019 in Korean waters, with descriptions of three new species: Bicorniphontodes lacuna sp. nov., B. comptus sp. nov., and B. huysi sp. nov. Morphology analysis was carried out to reconstruct the phylogenetic relationships of Bicorniphontodes species, including the three new species. Parsimony analysis based on 41 characters revealed that the three new species are clustered together as a monophyletic clade, of which B. horstgeorgei (George & Gheerardyn, 2015) is a sister species. The monophyletic status of three new species was supported by five synapomorphies, such as the micro-morphological conditions of the exopodal segments of the first leg, coxae of the second to fourth legs, exopod of the fifth leg in the female and baseoendopod of the fifth leg in the male, and the maxillular endopod represented by two setae. These three species can be easily distinguished based on the morphology of the rostrum, cephalothoracic processes, female genital double-somite, caudal rami, and second endopodal segment of the third leg in the male. The taxonomic position of B. bicornis sensu Kim, 2013 in Korean fauna was reevaluated based on the newly collected material from Udo Islet near Jeju Island; this resulted in a synonym of B. huysi sp. nov.