Gems of the southern Japanese seas - four new species of Edwardsianthus (Anthozoa, Actiniaria, Edwardsiidae) with redescriptions of two species Author Izumi, Takato Molecular Invertebrate Systematics and Ecology Laboratory, Department of Biology, Chemistry, and Marine Sciences, Faculty of Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903 - 0213, Japan iz.takato@gmail.com Author Fujii, Takuma Kagoshima City Aquarium, 3 - 1 Honko-shinmachi, Kagoshima, 892 - 0814, Japan & International Center for Island Studies Amami Station, Kagoshima University, 15 - 1 Naze-Minatomachi, Amami, Kagoshima 894 - 0026, Japan & The Kagoshima University Museum, 1 - 21 - 30 Korimoto, Kagoshima 890 - 0065, Japan text ZooKeys 2021 2021-12-10 1076 151 182 http://dx.doi.org/10.3897/zookeys.1076.69025 journal article http://dx.doi.org/10.3897/zookeys.1076.69025 1313-2970-1076-151 7B4E12710B60450480B368028E4B1AD6 8DB0FAF7DD4E5718A2A57AFD9CC3A7EE Edwardsianthus pudicus (Klunzinger, 1877) New Japanese name: nanyo-mushimodoki-ginchaku Figs 2 , 3A-E Edwardsia pudica Klunzinger, 1877: 80-81, pl. 6, fig. 3; Carlgren, 1931: 18-20, figs 16, 17. Edwardsiella pudica Andres, 1883: 309. Edwardsia adenensis Faurot, 1895: 121, pl. 6, fig. 5, pl. 7, fig. 6. Edwardsia bocki Carlgren, 1931: 7-9, figs 5, 6. Edwardsia stephensoni Carlgren, 1950: 128-129, figs 1, 2. Edwardsianthus pudica : England, 1987: 224-229, fig. 10. Material examined. NSMT-Co 1702: histological sections, dissected tissues, and prepared nematocysts, collected by SCUBA diving on 7 November 2015 off Kurasaki seashore, Amami-Oshima Island, Kagoshima , Japan , at ca. 20 m depth , by Takuma Fujii . Description. External anatomy . Size: ca. 120-200 mm in whole length, and ca. 12-15 mm in width in living specimen, and ca. 80-130 mm in length and ca. 8-10 mm in width in preserved specimen (Fig. 2A ). Column: cylinder-like form, and the proximal part narrower to some extent; consisting of capitulum, scapus, and physa. The distal-most part capitulum, translucent and visible magenta mesenteries within, short, without nemathybomes. Scapus with very thick and easily removed periderm-like cuticle, dark gray color in living and preserved animals, and with tiny, pale white in color, densely scattered nemathybomes (Fig. 2A ). Tentacles: 20 in number in two cycles, inner tentacle 8 and outer 12, magenta pink or purple in color with brown obscure patches in living animals (Fig. 2B ; these colors are lost in preserved specimen), without acrospheres. Inner tentacles short, slender, ca. 5-6 mm in length, and outer ones long and slender, 10-14 mm in length in preserved. Mouth: at the center of oral disc, apparently swollen, showing white color in live specimens. Internal anatomy . Mesenterial arrangement: eight perfect mesenteries, all macrocnemes. Four dorsal and ventral directives, and four lateral mesenteries not paired with other macrocnemes. All macrocnemes present along whole length of the body from oral to aboral end and bearing distinct retractor and parietal muscles. Twelve tiny microcnemes, without muscles, confined only in distal-most part. Four microcnemes between dorsal directives and dorso-lateral mesenteries, four between dorso-and ventro-lateral mesenteries, and four between ventro-lateral mesenteries and ventral directives. Retractor muscles: at the mid part of column, strongly developed and diffused (Fig. 2F ), pennon-like, arranged with ca. 100 muscular processes. Processes except some basal ones simple or slightly branched, and pinnate in some parts. Some processes nearest to body wall extremely well-branched, with secondary and tertiary branches (Fig. 2F ; England, 1981: fig. 10). Parietal muscles: developed, comparatively distinct, egg-shaped, elongated along mesenteries, with ca. 15-20 simple or slightly branched muscular processes on each side (Fig. 2E ). Others: existence of siphonoglyph unknown because of the contracted state of the specimen. Each with one tentacle from each endo- or exocoels. Tentacular circular muscle indistinct (Fig. 2C ), and longitudinal muscle distinct, ectodermal (Fig. 2D ). Mesoglea thickest in body wall,> 200 μm in thickness in some parts, and comparatively thick in physa and mesenteries, but thinner in parietal muscles and tentacles (Fig. 2C-E ). Nemathybomes sunk into mesoglea. Marginal sphincter muscle and basilar muscle absent (Fig. 2G ). Gametogenic tissue not attached to retractor muscles, distinct, but no mature gametocytes observed in our specimen (Fig. 2F ). Cnidom . Basitrichs, spirocysts, and microbasic p -mastigophores. See Fig. 3A-E and Table 4 for sizes and distributions of cnidae on this study. Table 4. Cnidoms of the species of Edwardsianthus pudicus , Edwardsianthus gilbertensis and Edwardsianthus carbunculus sp. nov.
- Edwardsianthus pudicus Edwardsianthus gilbertensis Edwardsianthus carbunculus sp. n.
- NSMT-Co 1702 CMNH-ZG 06527 CMNH-ZG 05954
Length x Width (µm) Mean (µm) SD (µm) n frequency Length x Width (µm) Mean (µm) SD (µm) n frequency Length x Width (µm) Mean (µm) SD (µm) n frequency
Tentacle
basitrichs 20.1-34.0 x 2.9-4.2 27.4 x 3.6 3.09 x 0.30 57 numerous 13.2-26.4 x 2.8-4.6 20.5 x 3.6 3.23 x 0.44 50 numerous 25.9-34.6 x 2.7-4.3 30.0 x 3.3 2.05 x 0.29 94 numerous
spirocysts 11.9-20.1 x 2.2-3.6 15.1 x 2.9 1.88 x 0.32 25 numerous 8.5-14.3 x 3.0-4.4 11.0 x 3.4 1.43 x 0.35 12 few 11.8-21.0 x 2.5-3.7 16.6 x 3.1 1.83 x 0.28 57 numerous
Actinopharynx
basitrichs S 17.4-24.2 x 1.9-3.0 20.8 x 2.5 2.02 x 0.44 15 numerous 16.3-21.1 x 2.4-3.9 18.4 x 3.1 1.24 x 0.39 12 few 14.3-16.9 x 3.5-3.9 16.0 x 3.7 0.99 x 0.19 4 rare
L 34.8-42.6 x 3.3-5.4 38.4 x 4.5 1.80 x 0.44 47 numerous 26.5-34.3 x 3.0-4.5 30.8 x 3.7 1.71 x 0.35 66 numerous 36.1-48.8 x 3.2-5.0 42.5 x 4.2 2.85 x 0.40 76 numerous
microbasic p -mastigophores 30.3-35.6 x 6.6-7.1 33.4 x 6.7 1.92 x 0.17 5 few 28.9-35.5 x 6.6-8.4 32.5 x 7.6 2.71 x 0.78 3 rare - - - - -
Nemathybome
basitrichs S - - - - - - - - - - 16.6-19.9 x 3.9-4.1 18.4 x 4.0 1.35 x 0.08 4 rare
L 46.8-56.6 x 3.2-5.6 41.7 x 51.7 1.95 x 0.43 44 numerou 34.0-45.2 x 3.0-4.8 39.6 x 3.8 2.02 x 0.38 75 numerous 46.8-56.6 x 3.2-5.6 51.7 x 4.3 2.08 x 0.47 44 numerous
Column
basitrichs 15.8-17.5 x 3.4-3.8 16.8 x 3.7 0.72 x 0.18 3 rare 9.8-14.4 x 2.8-4.1 12.0 x 3.3 1.12 x 0.41 12 few 47.9-53.8 x 3.4-4.8 50.8 x 4.0 1.62 x 0.33 24 numerous
Filament
basitrichs S 25.1-31.7 x 2.4-4.1 29.0 x 3.3 1.69 x 0.34 49 numerous 12.9-19.2 x 2.8-4.2 14.8 x 3.4 1.32 x 0.33 61 numerous 22.4-32.2 x 3.2-5.0 28.3 x 4.0 2.29 x 0.43 43 numerous
L 29.4-42.7 x 4.2-5.9 37.3 x 4.9 3.09 x 0.31 29 numerous - - - - - 27.6-44.3 x 4.1-5.8 34.8 x 4.8 5.87 x 0.51 11 few
microbasic p -mastigophores 29.7-34.1 x 5.2-7.6 31.6 x 6.2 1.26 x 0.62 11 few 33.0-38.4 x 8.2-10.9 36.3 x 9.3 1.63 x 0.72 12 few 30.1-31.8 x 5.3-5.9 30.9 x 5.6 0.87 x 0.29 2 rare
Figure 2. External and internal morphology of Edwardsianthus pudicus (NSMT-Co 1702) A outer view of living specimen B oral view of living specimen C longitudinal section of tentacle D transverse section of tentacle E transverse section of parietal muscle F transverse section of macrocnemes G longitudinal section of physa. Abbreviations: cap, capitulum; fi, filament; me, mesoglea; pa, parietal muscle; ph, physa; rm, retractor muscle; scs, scapus; te, tentacle; tlm, tentacular longitudinal muscle. Scale bars: 5 mm ( A, B ); 1 mm ( C ); 500 µm ( D, F, G ); 100 µm ( E ). Figure 3. Cnidae of Edwardsianthus species A-E E. pudicus (NSMT-Co 1702) A1 spirocyst in tentacle; A2 basitrich in tentacle B1 small basitrich in actinopharynx B2 large basitrich in actinopharynx B3 microbasic p -mastigophore in actinopharynx C basitrich in nemathybome D basitrich in column E1 small basitrich in filament E2 large basitrich in filament E3 microbasic p - mastigophore in filament F-J E. gilbertensis (CMNH-ZG 06527) F1 spirocyst in tentacle F2 basitrich in tentacle G1 small basitrich in actinopharynx G2 large basitrich in actinopharynx G3 microbasic p -mastigophore in actinopharynx H basitrich in nemathybome I basitrich in nemathybome J1 basitrich in filament J2 microbasic p - mastigophore in filament K-O E. carbunculus sp. nov. (CMNH-ZG 05954) K1 spirocyst in tentacle K2 basitrich in tentacle L1 small basitrich in actinopharynx L2 large basitrich in actinopharynx M1 small basitrich in nemathybome M2 large basitrich in nemathybome N basitrich in column O1 small basitrich in filament O2 large basitrich in filament O3 microbasic p -mastigophore in filament. Derivation of Japanese name. see the derivation of genus name. Remarks. This specimen from Amami Oshima Island resembled the features of Edwardsianthus pudicus as stated by England (1987) ; he redescribed this species as Edwardsianthus pudica (Klunzinger, 1877), but the appropriate name is Edwardsianthus pudicus following nomenclatural rules (ICZN 31.2 and 34.2; Ride et al., 1999 ), as in WoRMS (Daly & Fautin, 2021). England (1987) redescribed E. pudicus in detail and designated this species as the type of Edwardsianthus England, 1987. England (1987) mentioned that E. pudicus had a large body, reaching 200 mm in length and 15 mm in width, a thick walled scapus with easily stripped periderm, scattered small nemathybomes, long slender tapered tentacles, swelled mouth, extremely developed and diffused retractor muscles composed of 70-90 muscular processes, well-developed parietal muscle with 20-30 simple or slightly branched processes, and dioecious gametogenic tissue. These features almost completely correspond to the specimen obtained in this study. The tentacles being translucent purple or magenta-pink in color (England, 1987) were also similar to the tentacles and capitulum of our specimen. Moreover, E. pudicus inhabits a broad area of the Indo-Pacific region (Fautin, 2013; Daly & Fautin, 2021), so it is not unexpected to find this species in Japanese waters.