Luidia changi, Liu, Wei, Liao, Yulin & Li, Xinzheng, 2006

Liu, Wei, Liao, Yulin & Li, Xinzheng, 2006, Luidia changi, a new sea star species (Echinodermata: Asteroidea: Luidiidae) from the Yellow Sea, with a review of two related species, Zootaxa 1315, pp. 57-68 : 62-67

Luidia changi sp. nov.

( Figs. 1 , 4 , 5 E, F, 6C, F)

Material examined: Holotype — IOCAS­E1110, [34°N, 124.30°E], depth 79 m, soft mud, AT, coll. Baolin Zhang, 1 Nov.2000. Paratypes ­ 1 ex., CN 10­6, [40.31°N, 121.65°E], sand, 42m, 19 Oct.1958; 1 ex., CN H196B­39, [37.78°N, 121.75°E], sandy mud, 23m, 14 Jan.1959;1 ex., CN 3­2, [35.06°N, 123.75°E], soft mud, 77m, 20 Jan.1959; 1 ex., CN 12­6, [39.5°N, 124°E], sandy mud, 22m, 22 Jan.1959; 1 ex., CN H0013­17, [38.5°N, 122°E], soft mud, 53m, coll. Hu, 23 Jan.1959; 4 ex., CN 22­5, [39°N, 124°E], sandy mud, 57m, 23 Jan.1959; 3 ex., CN 23­7, [38.5°N, 122.75°E], mud, 56m, 25 Jan.1959; 1ex., CN 30­10, [38.73°N, 121.75°E], 26 Jan.1954; 1ex., CN 28­61, [39°N, 122.13°E], 26 Jan.1959; 1 ex., CN 32­11, [35.6°N, 122.5°E], soft mud, 56m, coll. Hu, 26 Jan.1959; 1ex., CN H0047­13, [35°N, 122.5°E], 29 Jan.1959; 1 ex., CN H64B­10, [35.5°N, 123.65°E], coll.Jiang, 13 Apr.1959; 1 ex., CN H69B­13, [38°N, 123.75°E], sandy mud, 68m, coll. Hu, 14 Apr.1959; 1ex., CN H71B­15, [39°N, 124°E], 15 Apr.1959; 1 ex., CN y170B­3, [39.25°N, 123°E], soft mud, 27m, coll. Chen, 18 Apr.1959; 1 ex., CN y180B­13, [37.75°N, 121.5°E], soft mud, 21m, coll. Huang, 23 Apr.1959; 1 ex., CN y178A­1, [38.13°N, 121.5°E], soft mud, 45m, coll. Chen, 23 Apr.1959; 1 ex., CN H01B­20, [34°N, 123.75°E], 13 Apr.1959; 1 ex., CN y186B­3, 25 Apr.1959; 1 ex., CN y186B­3, [38.27°N, 121.25°E], 25 Apr.1959; 1 ex., CN H132B­17, [35.05°N, 122°E], soft mud, 45m, coll. Hu, 28 Apr.1959; 2 ex., CN 14­4, [39.72°N, 123.25°E], soft mud, 15m, 22 Jun.1959; 1 ex., CN H154A­9, [36°N, 123.75°E], soft mud, 76m, coll. Jiang, 8 Jul.1959; 6 ex., CN H162B­24, [39.75°N, 123.75°E], muddy sand, 15m, coll. Jiang, 9 Jul.1959; 1 ex., CN H171B­19, [38°N, 122.75°E], soft mud, 54m, coll. Chen, 11 Jul.1959; 1ex., CN y262B­43, [37.25°N, 123°E], soft mud, 32m, 11 Jul.1959; 1 ex., CN H177B­18, [37.5°N, 122.63°E], 36.5m, 12 Jul.1959; 1 ex., CN 51­26, [38.75°N, 122.25°E]; 2 ex., CN H188B­1, [39°N, 122.5°E], 13 Jul.1959; 1ex., CN H191B­2, [38.75°N, 122.75°E], soft mud, 49m, coll. Jiang, 14 Jul.1959; 2 ex., CN y291B­15, [35.3°N, 123°E], soft mud, 66m, 14 Jul.1959; 1 ex., CN y287b­28, [36°N, 121.5°E], soft mud, 35m, coll. Hu, 14 Jul.1959; 1ex., CN 6­6, [34.5°N, 122.5°E], 52m, 13 Oct.1958; 22ex., CN 16­13, sand, 18m, coll. Tang, 14 Oct.1959; 3 ex., CN H272B­8, [38.25°N, 123.25°E], muddy sand, 32m, coll. Huang, 18 Oct.1959; 1 ex., CN y363B­15, [39.5°N, 123.5°E], sand, 35m, coll. Chen, 18 Oct.1959; 1 ex., CN H274B­ 8, [38.05°N, 122.87°E], sandy mud, 37m, coll. Jiang, 19 Oct.1959; 1 ex., CN H286A­8, [38.05°N, 122.25°E], soft mud, 48.8m, 20 Oct.1959; 1 ex., CN 16­20, [35.5°N, 121°E], 32m, 20 Oct.1959; 10 ex., CN H181B­21, [38.25°N, 122.13°E], soft mud, 22.7m, coll. Jiang, 26 Oct.1959; 2 ex., CN y416B­25, [34.58°N, 121°E], muddy sand, 19m, coll. Chen, 30 Oct.1959; 1 ex., CN y423B­41, [35°N, 121°E], muddy sand, 36m, coll. Hu, 31 Oct.1959; 3 ex., CN C91B­6, [33.4°N, 122.5°E], mud, 36m, 6 Dec.1959; 1 ex., CN C71B­ 20, [33.5°N, 123°E], mud, 53m, 25 Dec.1959; 1 ex., CN 30­8, [36°N, 122.5°E], 27 Oct.1959.

Diagnosis: Rays 5, long and slender, R:r =6.05–9.07, very flat; tapering sharply from base to distal extremity, very attenuate; R/r about 6–9. Abactinal paxillae with fine central and peripheral spines; most central spines with a central spinule, pointed and transparent. Ventral surface of inferomarginal plate with a series of 3–5 small, squamiform spinelets, and also many smaller spinelets. Adambulacral armature consists of 3–4 spines and a large two­jawed pedicellaria. Mouth­plates with 2–4 pairs of stout pedicellariae.

Description: Rays 5, up to R = 112 mm, R:r about 6–9; body thin, moderately long, very flat, tapering sharply from base to distal extremity, very attenuate. Holotype, R= 83.8 mm, r= 11.3 mm, R=7.4 r, breadth of a ray at the base 14.2 mm, and at the terminal plate 2 mm.

There are 3–4 regular longitudinal series of compact, closely fitting, squarish paxillae on either side of ray, those on mid­dorsal arm and central disc plates smaller, with a tendency to become irregular in form. Outermost series function as superomarginals, each bearing 1–2 small but evident, low bivalved pedicellariae, more numerous in proximal portion of ray than distally. Larger paxillae bear about 10–20 central granules on tabulum, most with transparent spinule on top ( Fig. 4 D), and 20–30 peripheral elongated spinelets, relatively smaller and thin.

Inferomarginals each with a robust lateral spine at outer end of plate. Lateral spines, about 1.3–2 mm long, relatively slender and compressed, with tapering tip. Ventral surface of plate with a series of 3–5 small, squamiform spinelets, compressed, tapering, sometimes pointed and relatively broader near lateral margin, much smaller towards inner side. Additional similar spinelets may be present on inner side of this series, also much smaller spinelets are present on side of plate. Some plates, especially near base of arms, with one or sometimes more two­jawed pedicellariae near inner end of plate; rarely a smaller and thicker one may be near base of lateral spines. Dorsal surface of plate, outside of lateral spine, covered with small spinelets similar to those of dorsal paxillae, but long and slender, most with tapering end. Fasciolar grooves wide, covered with capillary spinelets.

Adambulacral plates opposite to inferomarginals in position. Adambulacral armature 3–4 spines and a large two­jawed pedicellariae. Three spines arranged in transverse row, innermost furrow spine shortest, nearly 0.6 mm long, compressed laterally and slightly curved. Second spine at furrow edge robust, nearly 1.3 mm long, bluntly pointed, slightly compressed laterally and slightly curved. Outermost spine subequal in length to second, but nearly straight. Usually a large two­jawed pedicellaria, sometimes two, at adoral side of spine, subequal in length to spine. When 4 spines are present, fourth spine short and slender. On outer edge of plate usually two or three delicate, short, cilia­like spinelets.

Mouth­plates comparatively small. Each plate bears two pairs of large forficiform pedicellariae at its innermost point, sometimes with another 1–2 pairs immediately below. Marginal spines and actinal spines, subequal, diminishing in size distally from the mouth; actinal spines form a series parallel to median suture of mouth­plates.

Interradial areas very small, containing only 2–4 small plates. A series of ventrolateral plates extends far along ray. Ventrolaterals armed with a series of slender spinelets.

Madreporite hidden by paxillae.

Colouration: In alcohol preserved specimens, with a very dark band, almost black in some specimens, along the median radial line, extending to the centre of the disk, in some specimens fading out gradually at the sides, in others terminating more abruptly.

Etymology: The new species is named in honor of Prof. Feng­Ying Chang (1904–1969), one of the earliest experts to study the Chinese echinoderm fauna.

Distribution: Yellow Sea ( Fig. 1 ). Depth 15– 79 m.

Remarks: This species is closely similar to L. quinaria and L. yesoensis . The morphological characters that consistently distinguish the three species from each other are listed in Table 1 . Luidia changi sp. nov. differs from the other two species in the characters of abactinal plates, abactinal spinelets and R:r of the body. R:r indicate that L. changi has very long and slender arms. The abactinal plates ( Fig. 5 E, F.) are distinctive in having very thin quadrangular paxillae, with flat tops, and between the imbricating large plates very small ossicles can be seen in actinal view. The slightly elongated central abactinal spinelets ( Fig. 6 C, F.),consistently have a large, central, transparent, sharply pointed spinule, and peripheral spinelets are also pointed.

Thanks are due to Baolin Zhang and Fengshan Xu, who helped us to confirm geographic data in the collection. We are also grateful to Jinbao Wang, Baoquan Li, Qingxi Han, Jianmei An, Jin Zhou and other colleagues in our laboratory (IOCAS), for their kind assistance with the manuscript, and Shaoqing Wang, Yongqiang Wang, Lianmei Shuai, and Shiling Li for their kind help in sorting the samples. Finally we are thankful to Guangcheng Wang and Xisheng Wang (Wei Fang Marine Environmental Monitoring Central Station of Shandong Province), for their kindly help in perfecting the manuscript.

Figures

FIGURE 1. Collection localities of the three species, Luidia changi sp. nov., L. quinaria von Martens, 1865 and L. yesoensis Goto, 1914.

FIGURE 4. Luidia changi sp. nov. A, B, holotype, alcohol­preserved specimen IOCAS E­ 1100, R = 83.8 mm; C – F, paratype, dry specimen, BDI 7 B­ 21, R = 76.7 mm. A, abactinal view; B, actinal view; C, abactinal paxillae; D, lateral paxillae, showing transparent spinules on the top (arrow); E, mouth pedicellariae (arrow); F, adambulacral and inferomarginal plates. Scale = 2 mm.

FIGURE 5. Denuded abactinal plates, proximal base of ray. A – B, Luidia quinaria von Martens, 1865; C – D, Luidia yesoensis Goto, 1914; E – F, Luidia changi sp. nov. A, C, aboral view, paxillae with raised top (arrow); B, oral view, thick, with very small plates (arrow); D, oral view, thick, paxillae along the median radial line distinctly smaller (arrow); E, aboral view, paxillae with flat top, with very small lateral paxillae (arrow); F, oral view, thin, with very small plates (arrow). Scale = 2 mm.

FIGURE 6. Abactinal spinelets. A, D, Luidia quinaria von Martens, 1865; B, E, Luidia yesoensis Goto, 1914; C, F, Luidia changi sp. nov. A – C, central granules (arrow); D – F, peripheral spinelets (arrow). Scale = 100 m.

Tables

TABLE 1. Morphological differences among Luidia quinaria, Luidia yesoensis and Luidia changi sp. nov.

Diagnostic characters	Luidia quinaria	Luidia yesoensis	Luidia changi sp. nov.
R:r	6.01±0.10	4.83±0.05	6.97±0.09
Abactinal plates	Thick; convex top; with small ossicles	Thick; convex top; without small ossicles	Thin; flat top; with small ossicles
Abactinal spinelets	Squat; with many subequal transparent spinules	Similar to L. quinaria , but much smaller	Elongated; centrals with very pointed transparent spinules
Mouth pedicellariae	1 or 2 pairs; slender	1 or 2 pairs; obtuse	2–4 pairs; obtuse
Inferomarginal pedicellariae	Large and very slender	Small and obtuse	Small and obtuse
Acknowledgments