Description, redescription and revision of sixteen putatively closely related species of Echinoderes (Kinorhyncha: Cyclorhagida), with the proposition of a new species group - the Echinoderes dujardinii group Author Sørensen, Martin V. 4143D650-12FC-4914-93F5-2C39339A7156 Natural History Museum of Denmark, University of Copenhagen, DK- 2100 Copenhagen, Denmark. Department of Invertebrate Zoology, Smithsonian National Museum of Natural History, Washington, DC 20560, USA. Department of Biological Science, College of Natural and Life Sciences, Daegu University, Gyeongsan 38453, Korea. Crescent International School, Bario, Govindpur, Dhanbad 828109, Jharkhand, India. Isparta University of Applied Sciences, Department of Aquaculture, 32260 Isparta, Turkey. Department of Biology, University of Copenhagen, DK- 2100 Copenhagen, Denmark. Silifke Vocational School Aquaculture Program, Mersin University, 33940 Mersin, Turkey. Faculty of Arts and Science, Kyushu University, Fukuoka 819 - 0395, Japan. mvsorensen@snm.ku.dk Author Goetz, Freya E. 5849A537-F762-4B25-9493-E8B32690C49D Department of Invertebrate Zoology, Smithsonian National Museum of Natural History, Washington, DC 20560, USA. GoetzF@si.edu Author Herranz, María 2A7DE5DC-FF82-49CC-9DD4-CC0AFA1B281B Natural History Museum of Denmark, University of Copenhagen, DK- 2100 Copenhagen, Denmark. Department of Invertebrate Zoology, Smithsonian National Museum of Natural History, Washington, DC 20560, USA. Department of Biological Science, College of Natural and Life Sciences, Daegu University, Gyeongsan 38453, Korea. Crescent International School, Bario, Govindpur, Dhanbad 828109, Jharkhand, India. Isparta University of Applied Sciences, Department of Aquaculture, 32260 Isparta, Turkey. Department of Biology, University of Copenhagen, DK- 2100 Copenhagen, Denmark. Silifke Vocational School Aquaculture Program, Mersin University, 33940 Mersin, Turkey. Faculty of Arts and Science, Kyushu University, Fukuoka 819 - 0395, Japan. maria.herranz@bio.ku.dk Author Chang, Cheon Young 497A5735-AA95-498A-A1B8-58180C2ACA33 Department of Biological Science, College of Natural and Life Sciences, Daegu University, Gyeongsan 38453, Korea cychang@daegu.ac.kr Author Chatterjee, Tapas F35C0625-55F6-4307-A7BE-93416BE6F0D7 Crescent International School, Bario, Govindpur, Dhanbad 828109, Jharkhand, India. drtchatterjee@gmail.com Author Durucan, Furkan 62189A90-E675-49B1-BE3C-F4657CA40EE4 Isparta University of Applied Sciences, Department of Aquaculture, 32260 Isparta, Turkey. f_durucan@hotmail.com Author Neves, Ricardo C. C2B164FF-E8D8-468E-A07E-C39E1C71E65E Department of Biology, University of Copenhagen, DK- 2100 Copenhagen, Denmark. ricardon.6@gmail.com Author Yildiz, N. Özlem CE2E097A-4499-498C-980E-F21A4156F76E Silifke Vocational School Aquaculture Program, Mersin University, 33940 Mersin, Turkey. nozlemkoroglu@gmail.com Author Norenburg, Jon B8710D9A-1549-4E17-AF4F-6B598744C02E Department of Invertebrate Zoology, Smithsonian National Museum of Natural History, Washington, DC 20560, USA. NORENBUR@si.edu Author Yamasaki, Hiroshi Faculty of Arts and Science, Kyushu University, Fukuoka 819 - 0395, Japan. text European Journal of Taxonomy 2020 2020-12-30 730 1 101 journal article https://doi.org/10.5852/ejt.2020.730.1197 d640faf0-b3db-4fad-baaf-9eeaef7350e4 4418973 857A9432-9083-46B3-B0BF-B34D619EB350 Echinoderes sp. Fig. 25 ; Table 19 Echinoderes cf. ehlersi – Higgins & Rao 1979: 79–83 (specimens USNM-55393, USNM-55396, USNM-55398 to 55400). Table 19. Measurements from light microscopy for Echinoderes sp. from Havelock Island, Andaman Islands (in µm), including number of measured specimens ( n ) and standard deviation (SD).

Character	n	Range	Mean	SD
TL MSW-8 MSW-8/TL SW-10 SW-10/TL S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11	5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5	280–321 64–71 21.0–23.2% 59–67 19.0–21.8% 29–32 29–31 30–32 32–37 33–38 34–39 39–41 41–48 43–48 41–46 37–42	299 66 22.1% 62 20.6% 31 30 30 34 36 37 40 43 45 44 41	17.17 2.83 0.83% 3.13% 1.09% 1.41 0.89 0.89 2.35 2.28 2.07 1.00 2.86 1.87 1.87 2.68
MD4 (ac) MD5 (ac) MD6 (ac) MD7 (ac) MD8 (ac)	4 4 4 4 5	14–15 15–19 19–25 23–30 40–48	15 17 22 25 44	0.58 1.71 2.65 3.20 3.77
LV2 (tu) LV5 (tu) LV6 (ac) LV7 (ac) LV8 (ac) LV9 (ac) LD10(tu)	3 5 5 5 5 5 5	23–25 17–23 15–18 17–23 22–26 25–29 20–28	24 20 17 19 24 26 23	1.15 2.19 1.34 2.51 1.48 1.67 3.13
LTS LTS/TL	5 5	161–180 53.7–63.9%	173 58.0%	7.56 5.00%
LTAS	1	48	–	–

Material examined INDIA • 1 ♀ , 4 ♂♂ ; Andaman Islands , Havelock Island , East Point ; 11°54′ N , 093°03′ E ; < 1 m b.s.l. ; 5 Apr. 1974 ; G.C. Rao leg.; intertidal black mud with macroalgae; USNM-55393 , 55396 , and 55398 to 55400 . Specimens mounted for LM on Cobb slide in Hoyer’s medium . The specimens were originally reported as Echinoderes cf. ehlersi ( Higgins & Rao 1979 ) . See Table 1 for an overview. Description The five specimens were collected together with another five specimens that all together were reported as Echinoderes cf. ehlersi by Higgins & Rao (1979) . However, our examinations suggested that the latter five specimens represent a new species. The five specimens, addressed in the following, differ from E. chandrasekharai Sørensen & Chatterjee sp. nov. and as E. ehlersi in some significant points, but since the specimens' condition (e.g., the disability to observe sensory spots consistently) did not provide sufficient information for a complete description and specimens for SEM were not available, we will for now only provide a short description of the observed characters without providing a formal species description. The examined specimens resemble species like E. kozloffi , E. pacificus and E. sublicarum in general trunk appearance ( Fig. 25A ) and dimensions (see Table 19 ). The distribution of glandular cell outlets type 1 ( Fig. 25 B–G) is similar to the distribution in E. pacificus also (see Table 8 ), and so is the distribution of those sensory spots that could be observed. However, the presence or absence of sensory spots could not be confirmed in the following positions: sublateral segment 1, middorsal segment 2, midlateral segment 4 and segment 9. The spine/tube pattern and the approximate dimensions are similar with those of E. kozloffi , i.e., the middorsal spine on segment 8 reaches to a point around the midline of segment 9 ( Fig. 25D, F ), but never onto segment 10. Glandular cell outlets type 2 are present in midlateral positions, but only on segment 8 ( Fig. 25F ). Female papillae are present in ventromedial positions on segments 7 (more lateral) and 8 (more medial) ( Fig. 25E ). The substructures of the papillae on segment 7 are crescentic with a small protuberance in the curved parts of the structures, whereas the substructures on segment 8 form narrow tubes ( Fig. 25E ). Tergal extensions of terminal segment and shape of lateral terminal spines resemble those in E. kozloffi ( Fig. 25G ).