Corresponding author: Haibin Zhang (
Academic editor: A. Martynov
The ophiuroid genus
Nethupul H, Stöhr S, Zhang H (2022) Review of
The ophiuroid family
The genus
This study covers deep waters around the Northwest Pacific region near southwest Guam Island, and in the South China Sea (Xisha Islands and Haima cold seep). Here, we present an account of the ophiuroid species collected. Our goal is to present a diagnosis of the morphological features of these species, combined with molecular details, to complement the limited original descriptions and the lack of figures in the literature. We present comprehensive tabular keys for all species within the genera
The manned submersible vehicle ‘Shenhaiyongshi’ was used to collect samples for this study on a seamount near Xisha Islands and on the Haima cold seep in the South China Sea,
Collecting stations in this study
Specimens were photographed through a dissecting stereo microscope (OLYMPUS SZX7) to identify external morphological characters. Arm skeletons were photographed by a scanning electron microscope
Type material and one other specimen of
DNA of identified specimens was extracted by using the TIANamp Marine Animals DNA kit (TianGen, Beijing) following the manufacturer’s protocol. We sequenced cytochrome c oxidase I (
We constructed a maximum likelihood (
Localities, voucher information, and GenBank accession numbers for all specimens used in this study.
Species | Locality | Voucher number |
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Mariana Trench: Southwest of Guam island |
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Mariana Trench: Southwest of Guam island |
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Northwest Pacific Ocean: Caiwei Guyot | RSIO410611 |
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Mariana Trench: Southwest of Guam island |
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Northwest Pacific Ocean: St. RC-ROV08 | RSIO56058 |
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South China Sea: Xisha islands |
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Papua New Guinea | MNHN BP32 |
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Northwest Pacific Ocean: St. RC-ROV08 | RSIO56057 |
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Mariana Trench: Southwest of Guam island |
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Australia: Tasman Sea | MV F144758 |
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New Zealand | MV F188868 |
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Northwest Pacific Ocean: St. RC-ROV05 | RSIO56060 |
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Mariana Trench: Southwest of Guam island |
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Mariana Trench: Southwest of Guam island |
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Mariana Trench: Southwest of Guam island |
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Canada: British Columbia, Kyoquot Sound | RBCM EC00208 |
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Canada: British Columbia, Kyoquot Sound | RBCM EC00186 |
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South China Sea: Haima cold seep |
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South China Sea: Haima cold seep |
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New Zealand | MVF95868 |
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Japan: Sagami Sea |
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The following abbreviations are used in the text, tables, and figures:
Seven species of
A total of 21
Maximum likelihood (
Two main clades were detected within the
No. | Species | P-distance (%) | ||||||||||||||||||||
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1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | ||
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0.90% | 1.15% | 1.16% | 2.13% | 1.64% | 1.86% | 1.92% | 1.59% | 1.91% | 1.60% | 2.01% | 2.01% | 1.97% | 2.02% | 3.60% | 3.80% | 3.12% | 3.11% | 3.47% | 3.54% | ||
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4.27% | 0.26% | 1.17% | 2.11% | 1.63% | 1.81% | 1.97% | 1.60% | 1.89% | 1.60% | 1.68% | 1.94% | 1.85% | 1.89% | 3.70% | 3.97% | 3.24% | 3.23% | 3.37% | 3.52% | ||
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4.34% | 0.26% | 1.45% | 2.26% | 2.04% | 2.39% | 1.95% | 1.95% | 1.97% | 2.01% | 1.81% | 2.41% | 2.36% | 2.43% | 4.25% | 4.70% | 4.68% | 4.64% | 4.76% | 4.75% | ||
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6.73% | 7.09% | 7.20% | 1.94% | 1.54% | 1.76% | 1.71% | 1.50% | 1.70% | 1.55% | 1.84% | 1.78% | 1.81% | 1.86% | 3.69% | 3.85% | 3.28% | 3.27% | 3.40% | 3.51% | |
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15.13% | 15.34% | 15.59% | 12.50% | 1.01% | 1.41% | 1.29% | 1.22% | 1.39% | 1.36% | 1.98% | 2.23% | 2.16% | 2.21% | 3.90% | 4.33% | 4.70% | 4.68% | 4.54% | 4.32% | ||
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13.34% | 13.29% | 13.89% | 11.47% | 4.17% | 0.73% | 1.03% | 0.85% | 1.04% | 0.95% | 1.84% | 1.92% | 1.84% | 1.88% | 3.86% | 4.33% | 3.64% | 3.66% | 3.60% | 3.66% | |
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13.06% | 12.20% | 11.77% | 11.16% | 5.21% | 2.32% | 1.31% | 0.96% | 1.33% | 1.20% | 2.04% | 2.15% | 2.02% | 2.07% | 4.28% | 4.69% | 3.63% | 3.62% | 3.95% | 4.04% | |
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12.97% | 13.81% | 13.24% | 10.28% | 5.81% | 4.15% | 4.43% | 0.43% | 1.01% | 1.11% | 1.80% | 2.48% | 2.34% | 2.40% | 4.25% | 4.56% | 4.80% | 4.81% | 4.74% | 4.52% | ||
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13.15% | 13.32% | 13.26% | 11.26% | 5.48% | 3.92% | 4.00% | 0.76% | 0.88% | 0.80% | 1.74% | 1.98% | 1.82% | 1.86% | 3.97% | 4.29% | 3.47% | 3.47% | 3.47% | 3.58% | ||
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13.88% | 13.80% | 13.57% | 11.40% | 6.76% | 4.39% | 5.08% | 3.87% | 3.20% | 0.45% | 1.72% | 2.44% | 2.25% | 2.28% | 4.12% | 4.38% | 4.74% | 4.77% | 4.15% | 4.06% | ||
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13.34% | 13.51% | 14.18% | 12.05% | 6.74% | 5.01% | 5.95% | 4.67% | 3.54% | 0.90% | 1.79% | 2.04% | 1.91% | 1.94% | 4.12% | 4.48% | 3.68% | 3.69% | 3.31% | 3.48% | ||
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13.96% | 10.46% | 10.79% | 11.62% | 13.89% | 12.14% | 10.26% | 11.43% | 11.27% | 11.25% | 12.08% | 2.50% | 2.31% | 2.36% | 4.22% | 4.33% | 4.47% | 4.44% | 4.35% | 4.48% | |
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16.84% | 15.90% | 15.96% | 14.17% | 16.99% | 16.45% | 16.04% | 18.62% | 17.81% | 19.72% | 18.21% | 19.37% | 1.70% | 1.68% | 3.59% | 3.78% | 3.16% | 3.14% | 3.59% | 3.58% | |
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17.35% | 15.96% | 17.44% | 14.76% | 15.80% | 15.35% | 15.43% | 16.97% | 15.37% | 17.66% | 16.40% | 18.83% | 12.66% | 0.25% | 3.96% | 4.15% | 3.38% | 3.35% | 3.80% | 3.98% | ||
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17.68% | 16.25% | 17.80% | 15.03% | 16.13% | 15.42% | 15.53% | 17.32% | 15.45% | 17.68% | 16.27% | 19.17% | 12.46% | 0.35% | 3.91% | 4.10% | 3.36% | 3.33% | 3.86% | 4.03% | ||
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35.83% | 36.53% | 39.34% | 35.96% | 38.04% | 39.02% | 34.92% | 41.28% | 39.91% | 41.56% | 41.75% | 41.45% | 35.60% | 39.28% | 39.24% | 2.52% | 2.54% | 2.56% | 3.96% | 3.56% | |
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37.88% | 40.61% | 44.94% | 37.99% | 41.88% | 43.15% | 37.96% | 43.18% | 42.77% | 43.61% | 45.13% | 43.34% | 37.52% | 40.43% | 40.38% | 21.20% | 1.37% | 1.34% | 3.62% | 3.51% | |
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35.29% | 36.45% | 44.60% | 35.71% | 45.98% | 41.04% | 34.51% | 45.59% | 39.18% | 47.62% | 41.61% | 45.15% | 34.14% | 36.18% | 36.04% | 20.86% | 7.31% | 0.24% | 2.99% | 3.13% | ||
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34.99% | 36.15% | 44.08% | 35.41% | 45.50% | 41.04% | 34.51% | 46.09% | 39.18% | 48.09% | 41.61% | 44.68% | 33.56% | 35.58% | 35.43% | 21.17% | 7.06% | 0.35% | 3.00% | 3.15% | ||
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41.60% | 40.93% | 47.22% | 41.42% | 45.76% | 41.96% | 39.47% | 47.33% | 40.93% | 43.09% | 38.75% | 44.10% | 41.77% | 45.04% | 45.07% | 39.60% | 38.90% | 35.26% | 35.54% | 2.05% | |
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41.81% | 41.07% | 46.86% | 40.25% | 43.58% | 40.99% | 38.67% | 44.39% | 40.64% | 41.50% | 39.95% | 44.05% | 41.43% | 45.62% | 46.31% | 35.76% | 35.91% | 35.47% | 35.77% | 17.85% |
The new species, described morphologically below, were confirmed by the molecular analysis
Disc sub-circular and deeply incised interradially to nearly 1/4 disc radius (Fig.
Disc diameter 12 mm, arm base width 3 mm (Fig.
Arm spine articulations well developed and placed at slight angle to distal edge of lateral arm plate (Fig.
One specimen from same location
2713 m depth, Northwest Pacific, near Mariana trench, Southwest of Guam Island.
Species name derived from a combination of two Latin words,
Deep interradial incisions into the disc, which are lined distally by enlarged disc scales are the main delimiting character of the genus
Tabular key to all species of the genus
Species | No. of arm spines | Radial shields | Oral frame | Tentacle scale | Dorsal arm plate ( |
Arm spine shape and length | Disc spines | References |
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up to 7 | separated proximally but connected at distal ends | 4–5 |
1st pore 2, then 1, elongated, blunt | thorny surface | long, conical |
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up to 10 | separated, L = 2W | up to 4–5 |
1st pore 2–3, 2nd pore 1–2, then 1, spiniform with rounded base, tapering sharply or tip covered in irregular thorns | separated | covered with conspicuous thorns | long, rounded base, with spinelets on lateral surface | ||
up to 5 | separated proximally, connected at distal ends, L = 4W | 4 |
1st pore 2, then 1, oval, pointed, beyond 3rd pore slender spiniform | 1st |
elongated with thorny tip, at periphery with smooth tip | A. H. |
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up to 5 | separated by large single disc scale or connect at distal ends | 4 |
1st pore 2, half |
bifid or thorny pointed tip, cylindrical | this study | |||
up to 6 | separated, L = 4W | 4–5 |
oval to bottle-shaped, |
conical or more rounded with thorns at tip | H. L. |
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up to 6 | separated | 4–5 |
strongly thorny, after 1st pore, with 1 or 2 lateral thorns | stout, cylindrical, glassy, blunt, very thorny | short, stout stump with thorny tip |
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up to 6 | separated, deeply sunken | 5 |
large and flat | cylindrical, glassy, blunt, very thorny | cylindrical, thorny or smooth, thorny tip, spines dense in disc center. | C. W. |
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up to 9 | separated L = 3–4W | 3–4 |
oval to elliptical | cylindrical, terminal crown of thorns | ||||
up to 7 at arm base then 5 | contiguous, ovoid, about half |
4 |
1st pore 2, then 1, leaf-like to narrow, sharply pointed with numerous spinelets at tip | in disc center cylindrical base ending in 2–3 sub-crowns, at periphery short, stout with irregular crown of a dozen or more thorns | A. H. |
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up to 8 | widely separated, small, convex proximally, |
3 |
1st pore 2, oval, conspicuously large, then oval with pointed tip | 1–3 |
minute rough granules | H. L. |
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basally 4 then up to 5 or 7 | distally connected, small, |
3 |
1st pore 2–3, blunt, 1mm long and wide, very thick, somewhat triangular, then less stout, slender pointed | short, stout, but fragile, thorny spines, |
low cylindrical tube | H. L. |
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up to 7 at arm base | separated proximally, connected distally | 4 |
1st pore 1, long, and leaf-like then narrower with pointed tip | thorny surface, conspicuous thorns on |
cylindrical with thorn at tip | |||
up to 6 | separated proximally, connected distally | 4–5 |
large, pointed with 1 or 2 microscopic thorns | long, slender, |
short, stout, with thorny tip, at periphery smooth |
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up to 6 | separated proximally, connected distally | 3–4 |
1st pore 2–3, |
thorny surface | cylindrical, bifid or tip mostly with 3 thorns | |||
up to 7 | contiguous, L = 1.5W | up to 3–4 |
1st pore 1–2, only 1 in following |
stout, tall, bearing numerous distinct thorns laterally or at tip, some bifurcated into two prongs with thorny tips |
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up to 5 | separated oval proximally | up to 5 |
leaf-like, then slightly elongated with pointed tip along arm | flattened, covered by glassy spines | long, thick spinelets with rough thorny lateral surface in disc center, at periphery shorter | John and A. M. Clark (1954) | ||
up to 7 | contiguous, L = 1.5W | 4–5 |
1st pore 2, then 1, clavate, terminally spiniferous, longer than |
separated | smooth, |
numerous thorns at cylindrical tip | ||
up to 5 | small, separated proximally, connected distally | 4–5 |
1st pore 3, then 1 | smooth, |
cylindrical with thorny tip or thorny surface laterally, at disc periphery smooth |
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up to 7 | small, separated proximally, connected distally | 4 |
– | cylindrical with 2–3 thorns at tip or lateral thorns, at disc periphery smooth, conical |
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up to 6 or 7 | long, narrow, separated | 10–15 |
1st pore 3, 2nd pore 2, then one, large, pointed tip | first 1–2 |
cylindrical, bifid or mostly with 3 thorns at tip or with lateral thorns | H. L. |
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up to 6 | 3 |
oval, large, rough edges | bifid or mostly with 3 divided thorns at tip, central spines longer than peripheral ones |
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up to 5 or 6 | separated proximally, connected distally | 3 |
triangular | both |
cylindrical with thorny circular tip |
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up to 7 or 8 | separated | 4 |
1st pore 2, then 1, oval to rounded proximally and pointed distally | granules with thorny tip | ||||
up to 7 | separated, narrow | 3–4 |
flat, moderately, large, pointed | separated | rough surface, |
in disc center with long tip dividing into 2–3 thorns, at periphery with spinous tip | H. L. |
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up to 8 | contiguous, L = 2–2.5W | 3–5 |
1st pore 2–3, curved inward, pointed round tip | thorny surface | conical, cylindrical, finely rugose or rarely with few longer thorns | |||
up to 7 | separated proximally, connected distally | 4 |
leaf-like | first two |
thorny, rugose surface, uppermost |
cylindrical with thorny tip in center, at periphery smaller and conical | ||
up to 5 | completely separated or distally connected | 5–6 |
leaf-like | finely thorny | long spines with smooth surface | |||
up to 8 | separated | 3 |
flat, tapering, jagged | stout, cylindrical, glassy, blunt, very thorny | smooth cylindrical |
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up to 7 | separated proximally, connected in distally, L ≈ 2½–3W | 5 |
1st pore 3 or rarely 5, 2nd pore 2–3, 3rd pore 2, then one, large, pointed tip | long, slender, |
short, stout, with thorny tip, or 3 thorns, at periphery smooth spines without thorns | A. H. |
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up to 4 | separated proximally, connected distally | 3 |
small, leaf-like | separated, small | small, thick base | irregular scales with conical tubercles |
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up to 9 | separated proximally, connected in distally, longer than wide | up to 5–7 |
1st pore one or divided into two, then more pointed distalwards along arm | thorny surface | spine with thorny tip, or 3 thorns, at periphery smooth spines without thorns, tip relatively flat with thorns | H. L. |
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up to 6 | contiguous, distally convex, proximally triangular L = 2W | 4–5 |
1st pore 1–2, then 1, leaf-like, but along arm narrower, thorny, pointed; |
both |
disc center: conical or short cylindrical spines, when cylindrical with two sub-thorns; at periphery smooth, conical or short, cylindrical, finely rugose to smooth | this study | ||
up to 6 | separated proximally, connected distally | 4 |
very thick, heavy, smooth but increasingly flatter along arm, smaller, very thorny | first and second |
thorny spine, |
smooth, rounded spine | H. L. |
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up to 7 | separated proximally, connected distally | 4 |
1st pore 2–3, then 1, elongated | – | - |
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Some species share morphological characters with the new species.
One of the most distinguishing characters to delimit the new species from almost all species in the genus
Northwest Pacific • 1 specimen; near Mariana Trench, Southwest of Guam Island, seamount;
Disc diameter 9 mm, arm base width 2 mm (Fig.
2779 m depth, Northwest Pacific, near Mariana trench, Southwest of Guam Island.
The most similar species to
Northwest Pacific • 1 specimen; near Mariana Trench, Southwest of Guam Island, seamount;
Disc diameter 11.5 mm, arm base width 2.5 mm (Fig.
1618–3600 m depth, Southwest of Guam Island, Northwest Pacific, New Caledonia, New Zealand.
Northwest Pacific • 1 specimen; near Mariana Trench, Southwest of Guam Island, seamount;
Disc diameter 12.5 mm, arm base width 1.5 mm (Fig.
1866–2157 m depth, Southwest of Guam Island, Northwest Pacific, Kupuai, Hawaii Islands.
China • 1 specimen; South China Sea, near Xisha Islands archipelago, seamount;
Japan •
Disc diameter 20 mm, arm base width 4.5 mm (Fig.
462–663 m depth, South China Sea, East China Sea, Japan Sea.
Northwest Pacific • 1 specimen; near Mariana Trench, Southeast of Guam Island, seamount,
537–1987 m depth, southwest of Guam Island, Northwest Pacific, Hawaii Islands.
Northwest Pacific • 1 specimen; near Mariana Trench, Southwest of Guam Island, seamount;
385–2000 m depth, Southwest of Guam Island, Caiwei Guyot, Weijia Guyot, Batiza Guyot, Northwest Pacific, New Caledonia, New Zealand, Tasman Sea.
Included species:
Adapted from
100–2194 m depth, North Pacific, Australia, New Zealand, Papua New Guinea, South Africa. Substrate of mud, fine grey sand,
Both names are available, because they have been published with either a description or mention of a type species, and they satisfy articles 10, 11, and 12 of the Code.
Disc circular to sub-pentagonal, covered by dense smooth granules. Radial shields ovoid, naked, and widely separated (Fig.
Disc diameter 9.5 mm, arm base width 1.65 mm, and arm length 45–50 mm (Fig.
Here, we examined 29 paratypes, ranging in disc diameter from 4 mm to 17 mm, and found only few notable variations among them. Large specimens had five arm spines at proximal to middle regions of the arm, then reduced to four arm spines at distal end, but small specimens showed five arm spines only at arm base, then reduced to four along the distal half of the arm. However, the finely serrated surface of the arm spine was similar in both small and large specimens. The number of lateral oral papillae differed from three to four, but most specimens had three papillae. Most specimens had dense granular coverage of the disc except larger specimens (16–17 mm). Color ranges from creamy white to dark among specimens from our collection. The above mentioned variations depend mainly on the size of the disc, and specimens with similar disc diameter showed similar morphological characters.
1378–1408 m in depth, Haima cold seep, South China Sea.
The species name was derived from the Latin word
All specimens of
The molecular phylogenetic analysis of the family
Tabular key to all species of the genus
Species | No. of arm spines | Radial shield | Oral frame | Tentacle scale | Dorsal arm plate ( |
Arm spine shape and length | Disc spine or granular | References |
---|---|---|---|---|---|---|---|---|
up to 7 | small, ovoid, naked, |
3–4 |
one, large, flat, rounded, and distinctly curved outward | 1st |
smooth, slender, tapering spine, |
more or less sparsely with coarse, rounded granules | H. L. |
|
up to 8 | small, ovoid, naked, widely separated | 3 |
one, large, flat, rounded, but become narrow and pointed along the arm | second or third form upper |
stout, pointed, rough spine, scattered coarse granules among spine near |
H. L. |
||
up to 4 | small, ovoid, naked, |
3 |
one, large and oval | 1st |
smooth, slender, blunt, and tapering spine, lowest |
rounded granules or short stump, sparsely spread on the disc | ||
up to 6 | ovoid, naked, distal end well rounded, widely separated | 3–4 |
one, pointed | 1st |
short, stout, longest one nearly 1 × |
dense, smooth or sometime rough minute granules | ||
up to 5 | ovoid, naked, widely separated | 3–4 |
one, slightly elongated blunt tipped, |
1st |
finely |
dense, rounded to cylindrical stumps-like smooth granules, except radial shield and small area at center of disc | this study |
The species in the genus
The authors want to thank the crews of the vessel ‘Tansuo’ 1 and the pilots of the HOV ‘Shenhaiyongshi’. The authors also thank the members of the marine ecology and evolutionary biology laboratory at the Institute of Deep-sea Science and Engineering,
List of 36 references that use the name
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List of 36 references that use the name