taxonID	type	description	language	source
43D0DB643EC35E38B2DBE0F0A2E6A5B8.taxon	type_taxon	Type species. Hemicorallium tricolor Johnson, 1899.	en	Hu, Xuying, Zhang, Qian, Ge, Meiling, Li, Xinlong, Wang, Zongling, Zhang, Xuelei, Xu, Qinzeng (2025): Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean. Zoosystematics and Evolution 101 (1): 317-339, DOI: 10.3897/zse.101.139350
43D0DB643EC35E38B2DBE0F0A2E6A5B8.taxon	diagnosis	Diagnosis. Modified from Tu et al. (2016) and Nonaka and Hayashibara (2021). Polyps are dimorphic, consisting of autozooids and siphonozooids. Autozooids are prominent, oval and usually distributed on one side of the colony. When contracted, the autozooids cannot fully retract into the cortex. Siphonozooids are fertile, usually inconspicuous or appear as papillae and are distributed near the base of autozooids. Sclerites include small rods, crosses, 6 -, 7 - and 8 - radiates; double clubs are only present in some species and vary in shape. Long rods or spindles are usually present in tentacles.	en	Hu, Xuying, Zhang, Qian, Ge, Meiling, Li, Xinlong, Wang, Zongling, Zhang, Xuelei, Xu, Qinzeng (2025): Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean. Zoosystematics and Evolution 101 (1): 317-339, DOI: 10.3897/zse.101.139350
A6910D9251AD552CB421828A76AA282A.taxon	description	Description. Colony. The specimen FIO-IND 72 - JLBEN 22003 is part of a colony, nearly 22 cm in height and the thickest stem is less than 1 cm in diameter (Fig. 4 a). Two main branches exhibit dichotomous branching in one plane with an acute angle. The branchlets are abundant and mostly arranged in an irregular pinnate pattern on one plane. Some of them grow at an acute angle, resulting in closely-spaced and overlapping branchlets. A brittle star is entwined amongst the branches. Paratype NDSC-IND 72 - JLBEN 22001 retained only the white basal part and the thicker lower branches (Fig. 4 i). The branches are light red, with the colour becoming paler towards the base. Small branches with autozooids are distributed across half of the colony’s plane. Polys. The autozooids are cylindrical and non-retracted, distributed on one side of the colony and are mostly alternately arranged on the branchlets (Fig. 4 b). At the tips of the branchlets, two symmetrical autozooids form a Y-shape. Autozooids are 2.483 ± 0.348 mm in height and 1.515 ± 0.174 mm in width. They are abundant with most branchlets hosting fifteen or more. Each autozooid features eight longitudinal grooves that extend from the tentacle tips about two-thirds down to the base (Fig. 4 d). Siphonozooids form subtle protrusions on the cortex. Axis. The axis is solid and rigid, with no presence of canals inside (Fig. 4 c and Suppl. materials 7 – 9). It is covered by yellowish mesoglea tissue between the axis and the cortex (coenenchyme). The surface of the axis is uneven (Fig. 4 f), featuring irregular, sharp, thorn-like projections (Fig. 4 d). Colour. In underwater in situ videos, it appears light pink. The base of the colony is white. The fresh coenenchyme and polyps are pale red, turning pink when dried. Specimens preserved in alcohol retain a pale red colour. The axis is red and sclerites observed under a microscope appear pale red. Sclerites. The predominant sclerite type in this species is the distinctive double clubs (65.720 ± 5.630 μm in length, Fig. 5 d, e), constituting about 70 % of all radiate sclerites (21 / 30 from tentacles, 24 / 33 from coenenchyme). This double club shapes are quite special, typically derived from 8 - radiates. According to the model of radiates (Fig. 3 k), the R 1, R 4, R 6, R 7 and R 8 of the 8 - radiates in this specimen are enlarged to form smoother and more globular rays, while the R 2, R 3 and R 5 remain smaller with multilobular ornaments. Due to the fusion of rays, some double clubs cannot identify their terminal rays (R 1, R 8), making it uncertain whether they are derived from 8 - radiates (maybe 6 -, 7 - radiates). A few radiate sclerites may be in the process of developing where the rays become more globular (Fig. 5 f). A few 6 -, 7 - or 8 - radiates (not double clubs) are found in the coenenchyme with 74.520 ± 5.213 μm (Fig. 5 g) and they are less numerous compared to the double clubs. Rods are found only in the tentacles, with an average length of 113.211 ± 9.298 μm (Fig. 5 a, b). Some thick rods are elongated multi-radiates with 108.878 ± 13.299 μm (Fig. 5 c). The surface and both ends of the rods exhibit distinct irregular protrusions. Additionally, crosses (Fig. 5 h) and asymmetric multi-radiates (Fig. 5 i) are presented in the coenenchyme.	en	Hu, Xuying, Zhang, Qian, Ge, Meiling, Li, Xinlong, Wang, Zongling, Zhang, Xuelei, Xu, Qinzeng (2025): Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean. Zoosystematics and Evolution 101 (1): 317-339, DOI: 10.3897/zse.101.139350
A6910D9251AD552CB421828A76AA282A.taxon	etymology	Etymology. The specific name indicodensum is proposed for this new species. The name combines Indico, derived from “ Indicus, ” the Latin term for the Indian Ocean, with densi- meaning “ dense ” in Latin. This nomenclature reflects both the origin of the species in the expansive Indian Ocean and its distinctive, densely branched appearance.	en	Hu, Xuying, Zhang, Qian, Ge, Meiling, Li, Xinlong, Wang, Zongling, Zhang, Xuelei, Xu, Qinzeng (2025): Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean. Zoosystematics and Evolution 101 (1): 317-339, DOI: 10.3897/zse.101.139350
90C2C4CFAA8F50BAAAB1F7C416332814.taxon	description	Description. Colony. The specimen FIO-IND 72 - JLBEN 22005 is a branch of the colony, approximately 22 cm tall, with the base being the thickest at about 0.6 cm in diameter (Fig. 6 a). All branches present dichotomous branching on one plane. The branches are slightly curved, with many thinner branchlets appearing. There are remains of tissue where a brittle star had been entwined around the branches (the brittle star has been removed). Polys. The branchlets can hold up to 14 non-retractable autozooids. At the tips of the branchlets, there are pairs of symmetrical polyps forming a Y-shape. These autozooids are distributed only on one side of the colony, with some forming acute angles or being perpendicular to the plane of the colony (Fig. 6 b). The autozooids are 3.312 ± 0.554 mm in height and 1.759 ± 0.147 mm in width, the height of them usually being greater than the distance between them. Siphonozooids are not easily observed and appear as tiny pores on the branches. Axis. The surface of the coenenchyme is uneven, but lacks noticeable protrusions or depressions. The side without autozooids has slight longitudinal grooves (Fig. 6 b). The axis is hard calcareous with no presence of canals inside (Fig. 6 c and Suppl. materials 7 – 9). The surface of the axis without coenenchyme reveals irregular, sharp projections (Fig. 6 h). Colour. In underwater in situ videos, it appears white to light yellow. The base of the colony is white. After being collected and brought on board, the fresh coenenchyme is light yellow. The axis exhibits a translucent milky white appearance (Fig. 6 c) and sclerites observed under a microscope appear pale red. Sclerites. Rods are mainly present in the tentacles and there are two main types: short rods with sharp and large radial projections (86.028 ± 15.155 μm in height, Fig. 7 a) and long rods with small and blunt projections (112.769 ± 19.156 μm in height, Fig. 7 b). Both types of rods have irregular small protrusions at both ends. Crosses, 6 -, 7 - and 8 - radiates and irregular radiates are found in both the autozooids and the axis surface (coenenchyme). Crosses sclerites are rare (Fig. 7 c) and only two sclerites were captured with different crossing angles. They measured 88.388 µm in height and 107.593 µm in width with nearly 90 ° angles and 73.350 µm in height and 60.283 µm in width with nearly 60 ° angles, respectively. The 6 - and 7 - radiates can be either symmetrical or asymmetrical (Fig. 7 d), measuring approximately 65.837 µm to 92.7717 µm in length. The 8 - radiates are the most abundant, with two different types. The ends of the rays in a particular type of 8 - radiates consist of multiple sharp spikes (72.452 ± 8.572 µm in height, Fig. 7 e). They have larger rays and gaps between them are hard to discern due to R 2, R 3, R 4 and R 5, R 6 and R 7 being tightly clustered together. Other 8 - radiates have smaller, but more pronounced rays with spaces between the eight rays (80.418 ± 10.907 µm in height, Fig. 7 f). The irregular radiates (Fig. 7 i) are about 45.257 µm to 103.113 µm in height and typically feature asymmetric shapes or excessively protruding rays. No double clubs have been found in this specimen.	en	Hu, Xuying, Zhang, Qian, Ge, Meiling, Li, Xinlong, Wang, Zongling, Zhang, Xuelei, Xu, Qinzeng (2025): Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean. Zoosystematics and Evolution 101 (1): 317-339, DOI: 10.3897/zse.101.139350
90C2C4CFAA8F50BAAAB1F7C416332814.taxon	etymology	Etymology. This species, Hemicorallium jiaolongensis, is named in recognition of the manned submersible “ Jiaolong ”, which was instrumental in the collection of this specimens. The name honours the dedication and efforts of the Jiaolong crew during the scientific expedition in the western Indian Ocean.	en	Hu, Xuying, Zhang, Qian, Ge, Meiling, Li, Xinlong, Wang, Zongling, Zhang, Xuelei, Xu, Qinzeng (2025): Two new species of deep-sea Red Corals (Coralliidae, Genus Hemicorallium Gray, 1867) from the western Indian Ocean. Zoosystematics and Evolution 101 (1): 317-339, DOI: 10.3897/zse.101.139350
