A new species of the genus Caprella Lamarck, 1801 (Crustacea, Amphipoda, Caprellidae) from Korea Author Heo, Jun-Haeng Environmental Impact Assessment Team, National Institute of Ecology, Seocheon, Korea 33657 Author Shin, So-Yeon Department of Biological Sciences, Dankook University, Cheonan, Korea 31116 Author Kim, Young-Hyo Department of Biological Sciences, Dankook University, Cheonan, Korea 31116 text Zootaxa 2024 2024-04-02 5432 3 436 444 http://dx.doi.org/10.11646/zootaxa.5432.3.7 journal article 10.11646/zootaxa.5432.3.7 1175-5326 10906702 7B21A290-CA19-412E-983D-2BFEC263EB1F Key to the Korean species of genus Caprella ( modified from Lee & Hong, 2011 ) 1. Head smoothly rounded................................................................................ 2 Head rounded and with one to several upright projections..................................................... 3 Head angularly produced anteriorly and often with a frontal................................................... 4 2. Body completely smooth............................................................................... 5 Body with projections................................................................................. 6 3. Head with a small projection............................................................................ 7 Head with an acute long projection....................................................................... 8 Head with a pair of small projections............................................. C . acanthogaster Mayer, 1890 Head with small projections.................................................... C . polyacantha Utinomi, 1947 4. Head with a short dorsal projection or angular shape anteriorly................................................. 9 Head with an acute dorsal projection anteriorly............................................................ 10 5. Antenna 1 with longer than half of body.................................................................. 11 Antenna 1 with longer than half of body.................................................................. 12 6. Pereonites with dorsal projections but without lateral projections.............................................. 13 Pereonites without dorsal projections but with lateral projections........................... C . kroyeri De Haan, 1849 Pereonites with small tubercles............................................. C . multituberculum Lee & Lee, 1996 Pereonites with dorsal and lateral projections............................................ C . mutica Schurin, 1935 7. Pereonites with small tubercles.................................................. C . cristibrachium Mayer, 1903 Pereonites with 1–3 dorsal blunt projections............................................................... 14 8. Pereonite 2 without a projection ventrally................................................................. 15 Pereonite 2 with a projection ventrally............................................ C . californica Stimpson, 1856 9. Pereonite 2 without a projection ventrally................................................................. 16 Pereonite 2 with a projection ventrally................................................... C . equilibra Say, 1818 10. Pereopods 5–7, propodi with robust (grasping) setae........................................................ 17 Pereopods 5–7, propodi without robust (grasping) setae..................................................... 18 11. Pereopods 5–7, propodi with robust (grasping) setae proximally............................... C . mixta Mayer, 1903 Pereopods 5–7, propodi with robust (grasping) setae mesially................................ C . subtilis Mayer, 1903 12. Pereopods 5–7, propodi without robust (grasping) setae.................................. C . decipiens Mayer, 1890 Pereopods 5–7, propodi with robust (grasping) setae........................................................ 19 13. Pereonite 5 with a pair of projections dorsally............................................................. 20 Pereonite 5 with two pairs or more of projections dorsally.................................................... 21 14. Pereonite 5 with a projection dorsally................................................ C . arimotoi Takeuchi, 1993 Pereonite 5 with two or more projections dorsally....................................... C . verrucosa Boeck, 1871 15. Pereopods 5–7, propodi with robust (grasping) setae mesially................................................. 22 Pereopods 5–7, propodi with robust (grasping) setae proximally............................................... 23 16. Pereopod 7, propodus without robust (grasping) setae....................................................... 24 Pereopod 7, propodus with robust (grasping) setae.......................................................... 25 17. Pereopods 5–7, palmar margins of propodi concave....................................... C . penantis Leach, 1814 Pereopods 5–7, palmar margins of propodi convex....................................... C . andreae Mayer, 1890 18. Gills 3, 4 elongated............................................................. C . brevirostris Mayer, 1903 Gills 3, 4 rounded................................................................ C . megabranchia sp. nov. 19. Antenna 1 longer than half of body.................................................. C . gracillima Mayer, 1890 Antenna 1 shorter than half of body................................................ C . japonica (Schurin, 1935) 20. Pereopod 7, propodus without robust (grasping) setae...................................... C . simplex Mayer, 1890 Pereopod 7, propodus with robust (grasping) setae...................................... C . monoceros Mayer, 1890 21. Pereonites 1–4 with projection........................................................ C . eximia Mayer, 1890 Pereonites 1–4 without projection.................................................. C . linearis (Linnaeus, 1767) 22. Gnathopod 2, propodus elongated....................................................... C . simia Mayer, 1903 Gnathopod 2, propodus spoon-shaped.............................................. C . gigantochir Mayer, 1903 23. Pereonite 5 with two pairs of projection dorsally....................................... C . scaura Templeton, 1836 Pereonite 5 without projection...................................................... C . chelimana Mayer, 1903 24. Pereopods 5–7, propodi with robust (grasping) setae.................................. C . algaceus Vassilenko, 1967 Pereopods 5–7, propodi without robust (grasping) setae.............................. C . danilevskii Czerniavski, 1868 25. Gnathopod 2 on pereonite 2 is attached anteriorly................................. C . kominatoensis Takeuchi, 1986 Gnathopod 2 on pereonite 2 is attached mesially..................................... C . tsugarensis Utinomi, 1947 Gnathopod 2 on pereonite 2 is attached posteriorly..................................... C . subinermis Mayer, 1890