A taxonomic review of the genus Acanella (Cnidaria: Octocorallia: Isididae) in the North Atlantic Ocean, with descriptions of two new species Author France, Scott C. text Zootaxa 2017 2017-09-22 4323 3 359 390 journal article 32016 10.11646/zootaxa.4323.3.2 e6ed2164-d69d-41e9-b0c1-814b1b6b967e 1175-5326 919804 282Cfa84-60F8-464A-Acc4-Bfcbbc69F6A9 Acanella rigida Wright & Studer, 1889 Figure 10 Acanella rigida Wright & Studer, 1889 : 31 , pl. 9, fig 4; Thomson & Henderson, 1906 : 33 Acanella sibogae Nutting, 1910 : 14 , pl. 3, figs, 2, 2a. pl. 5 fig 4; Kükenthal, 1915 : 120 ; Kükenthal, 1924 : 419 ; Grant, 1976 : 26 , figs. 23¯24; Bayer, 1990 : 212 , fig 5 Acanella jaPonica Kükenthal, 1915 : 120 ; Kükenthal, 1919 : 582 , pl. 44, fig. 76; Grant, 1976 : 25 , figs. 20¯21 Type : Collected via dredge. Station 194, off Banda Islands , Indonesia . 220 fathoms depth. Deposited in the Natural History Museum , London. Reg no. 1889.5.27.22. For description see: Wright & Studer 1889 FIGURE 10. SEM images of Acanella rigida (Haplotype E, CP3652/3). A) Tentacle sclerites. B) Coenenchyme sclerites. C) Polyp body sclerites. Remarks: Specimens with Haplotype E ( Figure 10 ) match the description of A. rigida , with tall (4̄ 5 mm ) polyps and long (3̄ 5 mm ) curved fusiform sclerites that extend the length of the polyp, twisting around the body and protruding past the base of the tentacles. The sclerites are irregular in shape, large and all have more-or-less well-developed tubercles. A. rigida , A. robusta , and A. verticillata have similar characteristics, all with large obliquely placed sclerites that curve around the polyp body and project between the base of the tentacles, and Bayer (1990) suggested they might be the same species. However, Bayer (1990) and Grant (1975) note the following differences among the species: A. rigida has tall (4̄ 5 mm ) polyps whereas the other two have short ( 2 mm ) polyps; all three have sclerites strongly projecting between the tentacles but A. robusta has sclerites that are heavily covered by small sharp tubercles. Distribution: Our collection expands the known range of A. rigida from off the coast of Japan , Philippines , and Indonesia , to east of Papua New Guinea ; the depth range remains the same at 350̄ 700 m ( Figure 3 ).