Table 3 in Description of two species of the genus Astrodia Verrill, 1899 (Ophiuroidea, Euryalida, Asteronychidae), including a new species from seamounts in the West Pacific

Table 3. Comparison of key morphological characters among species in the genus Astrodia. SpeciesArm spinesGenital slitsExternal ossiclesLateral arm plates on middle to distal portion of armsOral papillaeReferenceAstrodia abyssicola (Lyman, 1879)0-2very short, ~1/5 (height of disc)plate-shaped on peripheryshapes: crescent; projections: absentdomed granule-shapedLyman (1879), Okanishi and Fujita (2014), This studyAstrodia excavata (Lütken & Mortensen, 1899)0-3large, ~2/3 (height of disc)granule-shaped near radial shields and genital slitsshapes: bar-like; projections: presentdomed granule-shapedLütken and Mortensen (1899), Okanishi and Fujita (2014)Astrodia plana (Lütken & Mortensen, 1899)0-3short, ~1/4 (height of disc)absentshapes: oblong; projections: absentdomed granule-shapedLütken and Mortensen (1899), Döderlein (1927), Okanishi and Fujita (2014)Astrodia tenuispina (Verrill, 1884)0-3, occasionally 4short, ~1/2 (height of disc)plate-shaped on periphery, granule-shaped in centershapes: unknown; projections: absentdomed granule-shaped, small and shortVerrill (1884), Koehler (1906), Koehler (1922), Baker (1980), Gage et al. (1983), Manso (2010), Okanishi and Fujita (2014)Astrodia duospina sp. nov.0-2, occasionally 3short, ~1/4 (height of disc)plate-shaped on periphery and in centershapes: crescent; projections: absentindistinct or underdevelopedThis study表3 星棘属（Astrodia）各物种种间关键形态特征对比 物种 腕棘 生殖裂 外骨片 腕部中至远端侧腕板 口乳头 参考文献 深渊星棘（Astrodia abyssicola，Lyman, 1879） 0~2枚 极短，约为盘高的1/5 边缘呈板状 形态为新月形，无突起 半球形颗粒状 Lyman (1879)、Okanishi与Fujita (2014)、本研究 凹陷星棘（Astrodia excavata，Lütken & Mortensen, 1899） 0~3枚 粗大，约为盘高的2/3 辐盾与生殖裂附近呈颗粒状 形态为杆状，具突起 半球形颗粒状 Lütken与Mortensen (1899)、Okanishi与Fujita (2014) 扁平星棘（Astrodia plana，Lütken & Mortensen, 1899） 0~3枚 短，约为盘高的1/4 无 形态为长圆形，无突起 半球形颗粒状 Lütken与Mortensen (1899)、Döderlein (1927)、Okanishi与Fujita (2014) 细棘星棘（Astrodia tenuispina，Verrill, 1884） 0~3枚，偶见4枚 短，约为盘高的1/2 边缘呈板状，中央呈颗粒状 形态未知，无突起 小型短柄半球形颗粒状 Verrill (1884)、Koehler (1906)、Koehler (1922)、Baker (1980)、Gage等(1983)、Manso (2010)、Okanishi与Fujita (2014) 双棘新种（Astrodia duospina sp. nov.） 0~2枚，偶见3枚 短，约为盘高的1/4 边缘与中央均呈板状 形态为新月形，无突起 不明显或发育不全 本研究