Lamprops donghaensis sp. n. (Crustacea, Cumacea, Lampropidae), a new species from Korean waters

Abstract A new species of Cumacea belonging to the genus Lamprops Sars was collected from the East Sea of Korea. This new species resembles Lamprops comatus Zimmer, Lamprops carinatus Hart, Lamprops flavus Harada, Lamprops pumilio Zimmer, Lamprops tomalesi Gladfelter, and Lamprops obfuscatus (Gladfelter) in lacking lateral oblique ridges on the carapace and lateral setae on the telson. The new species, however, is distinguished from its congeners by having a dorsal concave groove and a lateral rounded depressed area on pereonite 2. The new species is fully illustrated and compared with related species. A key to the world Lamprops species lacking lateral ridges on the carapace is also provided.


Introduction
The genus Lamprops Sars, 1863, belonging to the family Lampropidae, commonly inhabits cool water, is bipolar in distribution and is also a shallow water marine benthos (Day 1978;Tsareva and Kepel 2001). This genus is morphologically characterized by having a distinct antennal notch, telson with 3-5 apical setae and male lacking pleopods (Given 1964;Gamô 1967;Kim et al. 2015). To date, 22 species have been reported worldwide (Tzareva and Vassilenko 2006;Roccatagliata and Mühlendhardt-Siegel 2012;WoRMS 2015). For the study on the Korean lampropid species, lampropid specimens were collected from the East Sea of Korea. Recently, two Lamprops species, L. carinatus Hart, 1930 andL. pseudosarsi Tsareva &Vassilenko, 1993 were reported for the first time in Korean waters (Kim et al. 2015) and here we describe and illustrate a new species of the genus. Therefore, a total of four species of the lampropid species including Hemilamprops californicus (Zimmer, 1936) are reported from Korea.

Material and methods
The specimens were collected using a light-trap (Holmes and O'Connor 1988;Kim 1992) from shallow water at Geojin Port, Goseong-gun, Gangwon-do, Korea. The specimens were fixed in 70-80% ethanol and dissected in glycerol on cobb's aluminum hole slides. Drawings and measurements were performed with the aid of a drawing tube. Measurements for the body length were made from the anterior tip of the carapace to the last abdominal segment and for each appendage were made along the mid-line of the articles, exclusive of the inflated outer angle. Type specimens were deposited at the National Institute of Biological Resources (NIBR), Incheon, Korea and at the Department of Biological Science, Dankook University (DKU), Cheonan, Korea. The terminology for the setae follows that used by Watling (1989) and Gerken (2010Gerken ( , 2013.
Right mandible (Fig. 2F) similar to left one except incisor with 3 cusps and lacking lacinia mobilis.
Habitat. The new species was collected together with Lamprops carinatus and L. pseudosarsi at the same location, in Geojin Port, Goseong-gun, Korea, which is a sandy substrate.
Key to the species of genus Lamprops (without oblique ridge of carapace)  (Gladfelter, 1975)