taxonID	type	description	language	source
63276A58F4015F39988B8225248F17B5.taxon	description	Figs 9, 10, 11	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
63276A58F4015F39988B8225248F17B5.taxon	diagnosis	Diagnosis. Body elongated, cylindrical, gradually tapering at both ends. Color yellowish white. Skin fragile, glass-like. Mouth ventral, oral disc with front-suspended dorsal papillae, anus terminal. Peltate tentacles 20. Dorsal papillae arranged in two rows along each dorsal ambulacrum. Ventrolateral papillae arranged in a single row. Ventrolateral tube feet arranged in a single row on each side. Midventral ambulacrum placed in alternate two rows. Dorsal body wall tables with short or high 4 - pillared spires and 0 – 2 transverse beams. Papillae tables and widened midrods, tables with higher spires, four or more usually fused pillars, and three or four transverse beams. Ventral body wall with smaller tables, spires truncate, without transverse beams. Tube feet tables with truncate and high pillars. Tentacles support rods.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
63276A58F4015F39988B8225248F17B5.taxon	description	Description. Body long and cylindrical, slightly slender at both ends (Fig. 9 A, B), ventral flattened. Body 28 cm long, 2.5 cm wide mid-body before fixation (Fig. 9 C). Color yellowish white, body wall thin, calcareous, and fragile. Mouth ventral, anteriorly overhung by a few dorsal papillae (Fig. 9 C, D), anus terminal. Peltate tentacles 20, measuring 0.25 – 0.3 cm in diameter after fixation (Fig. 9 D). Two paired conical papillae placed in a single series on each dorsal radius (four rows across dorsally), each up to 1 cm long after fixation. Ventrolateral papillae arranged in a single row, ~ 22 on each body side, up to 1.5 cm long after fixation. Irregular tube feet relatively large and placed in single rows on ventrolateral radii, ~ 60 in each row. Midventral tube feet small, placed in alternate two rows, ~ 80 in each row. Longitudinal muscles undivided, tentacle ampullae absent, and gonads arranged in clusters. Ossicles. Dorsal body wall tables (Fig. 10 A – J), discs perforated plates, edges usually incomplete, 220 – 370 μm across, with numerous perforations of similar size, spires with four pillars (mainly) or more pillars (Fig. 10 G, H, J), short or relatively high, lacking or possessing one (rarely) or two transverse beams. Short pillars lacking or with one beam, ~ 50 – 80 μm in length (Fig. 10 A – C, F – J), relatively high pillars with two beams, 100 – 120 μm in length (Fig. 10 D, E). Spires of tables in dorsal and lateral papillae possessing much higher and firmer spires (Fig. 10 K – W) than those in dorsal body wall, discs up to 400 μm across, with four large central perforations and many small outer perforations, four or more pillars, up to 150 μm in length, usually fused, making the number of transverse beams uncertain, some spires of tables possibly possessing 3 – 4 transverse beams; widened midrods in papillae up to 600 μm long, with marginal projections (Fig. 10 X). Ventral body wall with smaller tables (Fig. 11 A), discs 144 – 267 μm across, edges more complete and smooth, spires truncate, without transverse beams. Tentacles predominantly rods, curved, bearing irregular marginal projections, up to 803 μm long (Fig. 11 B). Tube feet support rods straight to curved, widened midrods bearing irregular marginal projections, some placing through the entire length (Fig. 11 C – E); tables with truncate pillars (Fig. 11 F), without transverse beams; tables with high pillars, possessing four beams (Fig. 11 G).	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
63276A58F4015F39988B8225248F17B5.taxon	etymology	Etymology. The specific name refers to the Ganquan Plateau, where the holotype was sampled.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
63276A58F4015F39988B8225248F17B5.taxon	distribution	Distribution. Currently known from the type locality.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
8A278E91808F5D6AA61494861A9BA6E2.taxon	diagnosis	Diagnosis. Body wall calcareous, brittle, similar to that of the elasipodid family Deimatidae. Mouth ventral, peltate tentacles 20. Dorsal and lateral body with long conical calcareous papillae, including a ventrolateral series. Body flat ventrally, tube feet in ambulacral series or scattered. Anus subdorsal posterior. Ossicles in body wall large table discs with many perforations, discs variably with or lacking spires often comprising three or four pillars, sometimes with more fused pillars, without distal spines or teeth, spires sometimes reduced to short unconnected pillars [adapted from O’Loughlin et al. 2013: 38].	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
8A278E91808F5D6AA61494861A9BA6E2.taxon	type_taxon	Type species. Amphigymnas multipes Walsh, 1891 accepted as Amphigymnas woodmasoni (Walsh, 1891).	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
7C8F86E94A9251B38050F3740D59E862.taxon	description	Figs 6, 7, 8	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
7C8F86E94A9251B38050F3740D59E862.taxon	diagnosis	Diagnosis. Body elongated, dorsally convex, ventrally flattened. Mouth ventral, anus dorsal. Tentacles 18. Dorsal papillae arranged in six longitudinal rows. Brim formed by small ventrolateral papillae. Tube feet irregularly scattered on the ventral surface. Dorsal body wall containing tables with cross-shaped discs, four (rarely five) pillars of tables bearing numerous large spines, and four to six transverse beams; small tables with annular discs; perforated plates. Dorsal papillae with perforated plates, tables with cross-shaped discs, and support rods. Ventral body wall ossicles similar to those in the dorsal body wall, except for some tables with much higher spires. Tube feet with perforated plates, irregularly shaped ossicles, and small tables with annular discs. Tentacles with spiny rods.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
7C8F86E94A9251B38050F3740D59E862.taxon	description	Description. Body elongated, slightly pointed at each extremity, dorsal slightly arched, ventral flattened (Fig. 6 A – C). Color in life faint yellow, sub-transparent, dorsal papillae, tube feet, and tentacles darker (Fig. 6 B, C). Body 15 cm long and 5 cm wide before fixation (Fig. 6 B, C). Mouth ventral, anus dorsal and surrounded by numerous small papillae (Fig. 6 B, C). Peltate tentacles 18. Dorsal surface densely covered with approximately equal conical papillae, arranged in six longitudinal rows, with ~ 14 – 18 papillae in each row (Fig. 6 A, B). The jagged edges on both sides of the body formed by a single row of numerous smaller papillae. Tube feet irregularly arranged longitudinally throughout the ventral sole, ~ 86 in each row. Ossicles. Tables of two types in the dorsal body wall (Fig. 7 A 1 – A 7): 1) Cross-shaped discs (Fig. 7 A 1 – A 4) with four arms, each arm bearing small spines, 100 – 200 μm in length, with a number of perforations at the ends, four (rarely five) pillars bearing numerous large spines, four to six transverse beams, the spires measuring 108 – 200 μm in height, tips formed by fused pillars. 2) Annular discs (Fig. 7 A 5 – A 7) with four large holes formed by simple diagonal bars, discs ~ 58 μm in diameter, the spires 30 – 42 μm high, with one or two transverse beams. Dorsal papillae with most tables (Fig. 7 B 1 – B 4) similar to those of the dorsal body wall (first type), rarely smaller tables with four transverse beams (Fig. 7 B 4); perforated plates, measuring 400 μm in diameter (Fig. 7 B 5); spinous rods up to 366 μm in length (Fig. 7 B 4). Ventral body wall tables with four-armed discs, small tables with annular discs, and perforated plates (Fig. 7 C 1, C 2 and Fig. 8), most ossicles of similar features to those in the dorsal body wall, except that a few tables with really high spire, measuring 245 μm in height (Fig. 8 A, B). In tentacles (Fig. 7 D) rods 70 – 500 μm long. Tube feet with four types of ossicles: 1) perforated plates (Fig. 7 E 1); 2) smaller tables with annular discs (Fig. 7 E 2 – E 7), ~ 88 μm in diameter, the spires of tables higher than those in the dorsal body wall (second type), measuring 48 – 64 μm high, four spiny pillars with three transverse beams; 3) rods up to 404 μm in length (Fig. 7 E 8).	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
7C8F86E94A9251B38050F3740D59E862.taxon	etymology	Etymology. The species is named after one of the pioneers in the study of holothuroid fauna in China, Professor Yulin Liao.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
7C8F86E94A9251B38050F3740D59E862.taxon	distribution	Distribution. Only known from its type locality.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
89A098C40556514F972D0505242DCBB9.taxon	diagnosis	Diagnosis. Tentacles 15 – 20. Mouth ventral, anus dorsal, subdorsal or nearly terminal. Skin rather thick. Body with sole-like ventral side, usually with marginal appendages. Midventral ambulacrum with a few tube feet or naked. Ventrolateral tube feet arranged in a single row or multiple rows. Dorsal papillae more or less distinctly arranged in rows. Tables with cross-shaped disc and a spire formed by 1 – 5 pillars, usually with several transverse beams (rarely without transverse beams); C- shaped bodies may be present [adapted from Solís-Marín 2003: 124].	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
89A098C40556514F972D0505242DCBB9.taxon	type_taxon	Type species. Bathyplotes natans (Sars, 1868) by original designation.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
FAE422C66426522CB71EAE9315D6ACD9.taxon	description	Figs 4, 5	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
FAE422C66426522CB71EAE9315D6ACD9.taxon	diagnosis	Diagnosis. Body elongated, ventrally flattened. Mouth ventral, anus terminal. Peltate tentacles 16. Dorsal surface with scattered large papillae and laterally with a simple row of small papillae. The dorsal side irregularly arranged with several low ‘ fungiform’ whitish warts. Ventral surface with scattered minute tube feet. Dorsal body wall lacking ossicles. Papillae cross-shaped tables and rods, tables with 4 – 7 arms, 3 – 5 pillars, and without transverse beams. Cross-shaped tables with single pillars in low whitish warts. Cross-shaped tables with single pillars, support rods, and irregular shaped ossicles in the ventral body wall. Cross-like discs of tables, perforated plates, and support rods in ventral tube feet. Rods, smaller tables, and irregular deposits in tentacles.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
FAE422C66426522CB71EAE9315D6ACD9.taxon	description	Description. Body elongated, ventrally flattened, body wall thin and pliable. Color pale pink in situ, and orange in life (Fig. 4 A, B). Body 24 cm long and 6.5 cm wide in living specimen (Fig. 4 C, D). Mouth ventral, anus terminal. Peltate tentacles 16. Circum-oral papillae present (Fig. 4 B). Bivium with some scattered large papillae and laterally with a simple row of small papillae (Fig. 4 A, C). A number of low whitish warts arranged along the two dorsal interradii (Fig. 4 C). Trivium with some scattered minute tube feet (Fig. 4 B, D). Ventral surface with three series (a middle series and one lateral series on each side) of tube feet (Fig. 4 D), the middle series forming multiple rows, occupying a third of the ventral surface, other two series forming two or three rows on each side. Brim narrow and retracted, formed by ventrolateral papillae (Fig. 4 A, B). Ossicles. Dorsal body wall lacking ossicles. Dorsal papillae with tables and rods (Fig. 5 A), cross-shaped discs of tables 190 – 260 μm across, with 4 – 7 arms, each arm ~ 45 – 155 μm long, the ends of the arms enlarged and pierced with holes, the spires composed of 3 – 5 pillars, without transverse beams, the top of pillars fused, making the tip of spires spinous; rods curved, 280 – 315 μm long. Ventral body wall with tables, rods and irregularly shaped ossicles (Fig. 5 B), cross-shaped discs of tables with four arms, and only one central pillar (often truncated); rods up to 95 μm. Cross-like discs of tables in ventral tube feet 100 – 222 μm across, with 1 – 4 pillars, without transverse beams, the top of pillars fused; terminal plates and rods also in tube feet (Fig. 5 C). Rods, smaller tables, and irregular deposits in tentacles (Fig. 5 D). Tables with four arms in low whitish warts similar to those in the ventral body wall, and possessing only one central pillar, the top of pillars often irregularly branched or truncated (Fig. 5 E).	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
FAE422C66426522CB71EAE9315D6ACD9.taxon	etymology	Etymology. The Latin word varicolumna means ‘ various pillars’ and is used to describe tables characterized by different types of pillars.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
FAE422C66426522CB71EAE9315D6ACD9.taxon	distribution	Distribution. Only known in its type locality.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
DF86076A8E6F5CE69DA0C4D84069FA00.taxon	diagnosis	Diagnosis. Body cylindrical or subcylindrical. Tentacles 18 – 20. Ventral surface flattened, without any marginal border. Ventral tube feet and dorsal papillae in longitudinal series, confined to ambulacra. Three zones of tube feet on ventral surface. Body wall with tri- or quadri-radiate tables, the distal ends of the arms with a larger or smaller number of perforations, often lateral processes forming a complex lattice-like network with similar processes of other arms. Spire consisting of a single pillar, terminally divided or perforated, or both [adapted from Solís-Marín 2005: 570 – 571].	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
DF86076A8E6F5CE69DA0C4D84069FA00.taxon	type_taxon	Type species. Synallactes alexandri Ludwig, 1894.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
4AD8E6FC48BE5724A7A2EC01B548452C.taxon	description	Figs 2, 3	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
4AD8E6FC48BE5724A7A2EC01B548452C.taxon	diagnosis	Diagnosis. Body subcylindrical, convex dorsally, flattened ventrally. Mouth and anus terminal. Dorsal papillae conical, scattered on the bivium, with alternating large and small papillae. Ventrolateral papillae placed in a single row on each body side. Midventral radius with one or two small tube feet at the anterior and posterior ends. Ventrolateral tube feet arranged in double alternate rows. Dorsal body wall perforated plates and tables, tables with four or five slender arms. Papillae with tables, spires of tables higher than those of tables in the dorsal body wall. Ventral body wall tables with four or five arms. Tables with 4 – 6 arms in ventral tube feet, the distal ends of the arms enlarged, branched, rarely connected, and possessing a number of perforations.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
4AD8E6FC48BE5724A7A2EC01B548452C.taxon	description	Description. Body subcylindrical, slightly convex dorsally, flattened ventrally. Skin soft and gelatinous. Color red in life (Fig. 2 A, B). After 95 % ethanol fixation, color white, body length 9 cm and width 4 cm (Fig. 2 C, D). Mouth and anus terminal. Tentacles, calcareous ring, and polian vesicles lost. Dorsal surface with numerous large and small papillae, scattered all over the bivium (Fig. 2 A – C). Large papillae arranged in longitudinal rows along dorsal radii, ~ 10 in each row; small papillae mainly distributed in both dorsal interradii, ~ 20 on each body side (Fig. 2 C). Ventrolateral papillae large, forming a simple row around the margin of the brim (Fig. 2 A, B). Ventrolateral tube feet conical, arranged in a double alternate row, ~ 22 on each body side (Fig. 2 D). Midventral tube feet radius with one or two small tube feet at the anterior and posterior ends of the body (Fig. 2 D). Ossicles. Dorsal body wall tables with four or five arms (Fig. 3 A 1 – A 9), arms slightly broader at the tip with one or two perforations, 50 – 70 μm in length, spires with simple tips, often bearing several spines on the side, 82 – 100 μm in height; simple concave perforated plates (Fig. 3 A 10), 75 μm in diameter. Papillae with four-armed tables (Fig. 3 B 1, B 2), the spires significantly higher than those in the dorsal body wall, 110 – 155 μm in height. Ventral body wall with tables similar to those in the dorsal body wall (Fig. 3 C 1 – C 5), except that the end of arms bifurcated or bearing more perforations (up to 5) in some tables. Tables with 4 – 6 arms in ventral tube feet (Fig. 3 D 1 – D 10), irregular in shape, the distal ends of the arms enlarged, branched, and possessing several perforations, sometimes the enlarged ends of the arms connected with one another (Fig. 3 D 1); rarely a four-armed table with two parallel pillars (Fig. 3 D 8), ~ 68 μm in height, without transverse beam.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
4AD8E6FC48BE5724A7A2EC01B548452C.taxon	etymology	Etymology. The name of the new species is a combination of the Latin words tenuis meaning ‘ slender’ and brachium meaning ‘ arm’. It refers to the very slender arms of tables in the body wall.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
4AD8E6FC48BE5724A7A2EC01B548452C.taxon	distribution	Distribution. Only known from its type locality.	en	Xiao, Yunlu, Xiao, Ning (2025): Description of four new synallactid species (Holothuroidea, Synallactida, Synallactidae) from the tropical Western Pacific Ocean. ZooKeys 1231: 347-370, DOI: 10.3897/zookeys.1231.142729
