Taxonomic revision of the Nitocra affinis Gurney, 1927 species complex (Harpacticoida, Ameiridae) with descriptions of four new species and re-evaluation of its subspecies Author Yildiz, Nuran Oezlem https://orcid.org/0000-0001-7129-7276 Institute of Marine Sciences and Technology, Dokuz Eyluel University, 35330 Izmir, Turkiye nozlemkoroglu@gmail.com Author Karaytug, Suephan https://orcid.org/0000-0001-8980-4133 Faculty of Science, Department of Biology, Mersin University, 33343 Mersin, Turkiye text ZooKeys 2024 2024-02-07 1191 35 74 http://dx.doi.org/10.3897/zookeys.1191.115545 journal article http://dx.doi.org/10.3897/zookeys.1191.115545 1313-2970-1191-35 CA90F8CAE3994605873CB538C376A168 921A22B336F856C0B52A64380239F01F Nitocra alperi sp. nov. Figs 12 , 13 , 14 Type material. Holotype : India • 1 ♀ (dissected on 7 slides) (NHMUK reg. no. 2023.0000). Indian Ocean, Aldabra; large tide salted lagoon; W. of Point Hadroul. Coll. Pres. K.G. Mc Kenzie, 1968; J.B.J. Wells det. (material originally registered as N. affinis under NHMUK reg. no. 1972.6.13.17-21). Description (adult female holotype). Body (Fig. 12A, B ) similar to N. loweae sp. nov., except for total body length 476 μm ( n = 1) measured tip of the rostrum to posterior end of the caudal rami. Pores and sensilla as figured (Fig. 12A, B ). Figure 12. Nitocra alperi sp. nov. female holotype A habitus, dorsal B habitus, lateral. Scale bars: 50 μm . Anal somite (Figs 12A , 13A, B ), with anal operculum bearing seventeen posterior spinules; with row of robust spinules flanking each side of the anal operculum; with a posterior row of small spinules, and two pair of pores on ventrally. Antennule eight-segmented as in N. affinis. Setal formula 1-[1, plumose], 2-[8 +1 plumose], 3-[8], 4-[3 +1 ae], 5-[2], 6-[3], 7-[4], 8-[5 +acrothek)]. Maximum length/maximum width ratio of antennular segments as 1:1.3:1.3:1.6:1.3:1.1:1.1:1.6. Antenna (Fig. 13C ) similar to that of N. loweae sp. nov. except for allobasis with spinules only on midway inner margin; subdistal seta of exopod weakly pinnate. Figure 13. Nitocra alperi sp. nov. female holotype A urosome, ventral (P5-bearing somite omitted) B right part of anal somite showing spinule ornamentation, ventral C antenna D mandible E maxilla F maxilliped G maxillule. Scale bars: 50 μm ( A-C ); 25 μm ( D-G ). Mandible (Fig. 13D ) similar to that of N. loweae sp. nov. except for exopod with four naked apical setae (two of them basally fused at base) and without spinules. Maxilla (Fig. 13E ) similar to that of N. loweae sp. nov. except for allobasis without spinules along convex margin near the base of endopod; endopod with one long naked seta. Maxilliped (Fig. 13F ) similar to that of N. loweae sp. nov. except for syncoxa unornamented. Maxillule (Fig. 13G ) similar to that of N. loweae sp. nov. except for coxal endite without spinule row. P1 (Fig. 14A ) similar to that of N. loweae sp. nov. except for coxa without spinules on/near inner margin; basis without setules along inner margin; exopod slightly extends the enp-1; enp-1 ~ 2.6 x as long as maximum width, inner margin with less spinules along inner margin, subdistal seta unipinnate and located more proximally than in N. loweae sp. nov.; inner margin of enp-2 with one setule, outer distal margin with few fine spinules not extending to inner margin. Figure 14. Nitocra alperi sp. nov. female holotype A P1, anterior B P2, anterior C P3, anterior D P4, anterior E P5, anterior. Scale bars: 50 μm . P2 (Fig. 14B ) similar to that of N. loweae sp. nov. except for intercoxal sclerite with spinules on anterior surface; basis with setules along inner margin; inner seta of enp-3 uni-plumose and stronger than in N. loweae sp. nov. P3 (Fig. 14C ) similar to that of N. loweae sp. nov. except for intercoxal sclerite with spinules on anterior surface; basis with setules along inner margin; exp-2 with setules along inner margin; innermost seta of enp-3 unipinnate and stronger than in N. loweae sp. nov. P4 (Fig. 14D ) similar to that of N. loweae sp. nov. except for exp-1 with two fine setules along inner margin; middle inner seta of exp-3 bipinnate distal half, longest and stronger than that of N. loweae sp. nov.; innermost seta of enp-3 uni-plumose and stronger than in N. loweae sp. nov. P5 (Fig. 14E ) similar to that of N. loweae sp. nov. except for inner baseoendopod lobe reaching middle of the exopod; exopod tapering apically, and ~ 1.5 x as long as maximum width, outermost seta much longer, seta next to outermost seta slender and naked. Armature formula of swimming legs (not shown) same as in N. loweae sp. nov. Male. Unknown. Etymology. The specific name is given in honours of Associate Professor Dr Alp Alper from Balikesir University for his contribution to copepod taxonomy. It is a noun in the genitive case.