Korealona choi, Jeong & Sinev & Brancelj & Chang & Kotov, 2017

Jeong, Hyun Gi, Sinev, Artem Y., Brancelj, Anton, Chang, Kwang-Hyeon & Kotov, Alexey A., 2017, A new blind groundwater-dwelling genus of the Cladocera (Crustacea: Branchiopoda) from the Korean Peninsula, Zootaxa 4341 (4), pp. 451-474 : 462-468

Korealona choi gen. nov., sp. nov.

( FIGS 8–13 )

Etymology. THIS SPEcIES IS DEDIcATED TO PROF. J.L. CHO, RENOWNED SPEcIALIST FOR THE BATHYNELLAcEAE, WHO cOLLEcTED THE TYPE SERIES OF THE SPEcIES.

Type locality. A SAND bANK (35.2011ºN, 127.6010ºE) IN NAESEOcHEON STREAM (cHEON = STREAM), AN AFFLUENT OF RIVER SEUMJINGANG, JEOLLANAM-DO, SOUTH KOREA (LOcALITY 4 IN FIG. 1 ). THE TYPE SERIES WAS cOLLEcTED bY J.L. CHO.

Type material. Holotype. A PARTHENOGENETIc FEMALE, NIBR 0 0 0 0 307404.

Paratype. A PARTHENOGENETIc FEMALE FROM TYPE LOcALITY, NIBRIV0000740010.

Additional material (expressly excluded from the type series according to case 72.4.6. of ICZN 2000 ). TWO PARTHENOGENETIc FEMALES AND MALE EXUVIUM FROM YEOcHOEN: A SAND bANK OF NAESEONGcHEON STREAM (36.58028ºN, 128.33000ºE), GYEONGSANGbUK-DO, SOUTH KOREA; cOLLEcTED bY J.L. CHO; HGJ, NO NUMbER (LOcALITY 5 IN FIG. 1 ).

ENVIRONMENTAL PARAMETERS: WATER TEMPERATURE,18.0o C; PH, 7.35; cONDUcTIVITY, 251µS cM -1; DISSOLVED OXYGEN, 5.26 MG L -1. TEN PARTHENOGENETIc FEMALES FROM ULJIN : A SANDY DEPOSIT OF NAMDAEcHEON STREAM (36.71944ºN, 129.3972ºE), GYEONGSANGbUK-DO, SOUTH KOREA; cOLLEcTED bY J.L. CHO; HGJ, NO NUMbER (LOcALITY 6 IN FIG. 1 ) . ENVIRONMENTAL PARAMETERS: WATER TEMPERATURE, 14.9o C; PH, 6.98; cONDUcTIVITY, 116 µS cM -1, DISSOLVED OXYGEN, 9.12 MG L -1.

Short description with special attention to differences from previous species. Parthenogenetic female. Habitus SIMILAR TO K. karanovici sp. nov. bUT bODY SOMEWHAT HIGHER (HEIGHT/LENGTH 0.65–0.70) AND WIDER ( FIG. 8A– C , 9A, B ); GAP bETWEEN VALVES MORE OPEN AS cOMPARED WITH K. karanovici sp. nov., POSTERO-DORSAL ANGLE MORE EXPRESSED.

Head. HEAD SHIELD, HEAD PORES ( FIG. 8D, E ; 9C–F), VALVES ( FIG. 8C, F ; 10A, B) AS IN THE PREVIOUS SPEcIES . LAbRUM WITH A SERIES OF MINUTE SETULAE AT TIP ( FIG. 9G, H , ARROW).

Postabdomen. SHAPE AND ARMATURE SAME AS IN THE PREVIOUS SPEcIES ( FIG. 8G–I ; 10C–E). POSTAbDOMINAL cLAW SIMILAR TO THAT IN PREVIOUS SPEcIES, bUT bASAL SPINE SHORTER, ITS LENGTH LESS THAN HALF cLAW LENGTH ( FIG. 8G–I ; 10F–H).

Antenna I WITH SENSORY SETA NOT REAcHING TIP OF ANTENNULAR bODY ( FIG. 9E ).

Antenna II SAME AS IN THE PREVIOUS SPEcIES ( FIG. 8D, J ; 11A–D), bUT SPINE ON PROXIMAL SEGMENT OF EXOPOD bIFURcATED ( FIG. 11C ).

Limb I ( FIG. 12A ) AS IN THE PREVIOUS SPEcIES, bUT AccESSORY SETA LONGER, REAcHING DISTAL END OF ODL; ODL SETA AS LONG AS IDL SETA ( FIG. 12 B ).

Limb II ( FIG. 12C ) WITH EXOPODITE LAcKING A SETA; ScRAPERS 1–2 LONGER THAN ScRAPERS 3–5; GNATHObASE DISTAL bOUNDARY STRONGLY INFLATED, SETAE OF FILTER PLATE INcREASING IN LENGTH.

Limb III ( FIG. 12D ) WITH EXOPODITE SETA 3 LONGER THAN IN PREVIOUS SPEcIES; POSTERIOR SETAE A–D ON INNER-DISTAL LIMb PORTION SUbEQUAL IN SIZE; ALL SETAE OF GNATHObASE FILTER PLATE SUbEQUAL IN SIZE.

Limb IV ( FIG. 12E ) EXOPODITE WITH SETA 2 bEING LONGEST; SETAE 1 AND 4–6 OF SIMILAR LENGTH, AbOUT 2/3 LENGTH OF SETA 2; POSTERIOR SETAE A–c SUb-EQUAL IN SIZE ( FIG. 12F )..

Limb V ( FIG. 12G ) EXOPODITE HAVING SETAE 2–4 VERY SHORT, OF SIMILAR LENGTH AND ONLY SLIGHTLY LONGER THAN SETA 1; INNER LObE MORE ELONGATED THAN IN THE PREVIOUS SPEcIES; SETA 1 ON IT WITH ARMATURE AS IN SETA 2 .

Juvenile female, ephippial female. NOT FOUND.

Male. ONLY AN EXUVIUM WAS FOUND, THEREFORE SOME STRUcTURES WERE NOT STUDIED. IN cONTRAST TO PREVIOUS TAXON, MALE SHAPE ( FIG. 13F ) IS SIMILAR TO FEMALE ( FIG. 13A–E ); POSTAbDOMEN SUb-REcTANGULAR, WITH SMALL MARGINAL POSTANAL TEETH AND bUNcHES OF SETULAE ON POSTANAL AND ANAL MARGIN ( FIG. 13G ). POSTAbDOMINAL cLAW STRONG AND LONG ( FIG. 13H ); TIP OF cOPULATORY HOOK THIN AND SHARP ( FIG. 13I ).

Size. FEMALE 0.23–0.28 (NAESEOcHEON), 0.22–0.28 (YEcHEON), 0.23–0.28 (ULJIN), 0.23–0.34 MM (NAESEONGcHEON); MALE 0.31 MM (NAESEONGcHEON).

Distribution. THE SPEcIES IS FOUND IN JEOLLANAM-DO AND cENTRAL PORTION OF GYEONGSANGbUK-DO PROVINcES OF SOUTH KOREA.

Figures

FIGURE 1. Southern half of the Korean Peninsula with state borders and hydrographic network. Black squares: localities 1 – 3 of Korealona karanovici sp. nov.; reddish circles: localities 4 – 6 of K. choi sp. nov. Abbreviations for states: GB, Gyeongsangbuk-do; GW, Gangwon-do; JN, Jeollanam-do.

FIGURE 8. Korealona choi sp. nov., parthenogenetic female from a sand bank of Naeseocheon stream, South Korea. A, large adult, lateral view. B, small adult, lateral view. C, large adult, ventral view. D, head. E, dorsal head pores. F, valve posteroventral portion. G – I, postabdomen. J, antenna I. Scale bar 0.1 mm.

FIGURE 9. Korealona choi sp. nov., parthenogenetic female from a sand bank of Naeseocheon stream, South Korea. A, lateral view. B, anterior view. C – D, head in lateral and anterior view. E, rostrum and antenna I. F, dorsal head pores. G – H, labral keel. Scale bar 0.1 mm for A – C; 0.01 mm for D – F, 0.01 mm for G – H.

FIGURE 10. Korealona choi sp. nov., parthenogenetic female from a sand bank of Naeseocheon stream, South Korea. A – B, ventral valve margin. C – D, postabdomen in lateral view. E, dorsal view. F – H, postabdominal claws. Scale bar 0.01 mm.

FIGURE 11. Korealona choi sp. nov., antenna II of parthenogenetic female from a sand bank of Naeseocheon stream, South Korea. A – B, antenna II, general view. C, spine on proximal segment of exopod. D, apical setae. Scale bar 0.01 mm for A – B, D; 0.01 mm for C.

FIGURE 12. Korealona choi sp. nov., thoracic limbs of parthenogenetic female from a sand bank of Naeseocheon stream, South Korea. A, limb I. B, its distal portion. C, limb II. D, limb III. E, limb IV. F, posterior setae on its inner-distal portion. G, limb V. Scale bar 0.1 mm.

FIGURE 13. Korealona choi sp. nov. from a sand bank of Naeseongcheon stream, South Korea. A, large adult parthenogenetic female, lateral view. B, its ventral view. C – E, labral keel. F, exuvium of adult male. G, postabdomen. H, postabdominal claw. I, limb I. Scale bars 0.1 mm.