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The genus Trochus is very diverse, and identification at the species level is often difficult.
Some species, such as Trochus firmus, Trochus erythreus, Trochus flammulatus, and Trochus maculatus, have very similar shell morphologies, making it difficult to distinguish them based on external characteristics alone. In addition, some initial descriptions are incomplete.
Today, new turban shells are identified by morphological characteristics of the shells, supported by 3D modeling techniques, and mainly by DNA barcoding.
Trochus parvus and the new species Trochus nanhai, also discovered there, were collected and identified from coral reef habitats in the South China Sea.
Description of the shell:
It is a small, conical shell with a pointed tip.
The shell surface has conspicuous reddish-brown longitudinal stripes that taper to spots towards the base; the tip is typically red.
The shell consists of 6 flat whorls with 3–4 spiral rows of densely arranged granules. These granules are round, bead-like or slightly compressed, with the upper whorls smaller than the lower ones.
The edge of the whorls has a spiral crest consisting of conspicuous, evenly arranged pustules.
The body whorl is decorated with compact, almost square, flattened pearls that form a rounded profile.
The base is slightly concave, with 7–8 concentric granular lirae separated by spaces as wide as the ridges.
The columella is oblique and bears 3–4 densely packed, folded teeth that form a false umbilicus.
The inner lip contains 4 folds, and the inside of the shell is pearly with fine spiral liration.
The shells examined reached a height of 11.0–13.0 mm and a shell width of 10.4–14.0 mm.
Description of the radula:
The radula has a central tooth with a V-shaped tip and a broad trapezoidal shaft, symmetrically flanked by eight small teeth.
On each side there are five lateral teeth, each with a fold on the shaft that is firmly interlocked with the shaft of the adjacent tooth, and bearing 3–5 small teeth on only one side.
The fifth lateral tooth has a distinct paddle-shaped tip. The marginal teeth are narrow and sickle-shaped; the innermost 9–12 marginal teeth each bear 2–3 denticles.
From the 10th to the 13th marginal tooth, the tooth size gradually decreases, while the number of denticles increases, forming a crest or feather-like structures.
Detailed information on the weight of the animals, water depth, and water temperature is missing from the initial description.
Etymology:
The species name “parvus” comes from Latin and means “small”; it refers to the relatively small size of the shell of the new species, which differs significantly from other species of this genus.
Literature reference:
Zhu P-J, Yan C-R, Yang H-Q, Hu L-S, Dong Y-W (2025)
Description of two new species of the genus Trochus Linnaeus, 1758 (Gastropoda, Trochidae) from the South China Sea. ZooKeys 1264: 265-280.
https://doi.org/10.3897/zookeys.1264.167854
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Some species, such as Trochus firmus, Trochus erythreus, Trochus flammulatus, and Trochus maculatus, have very similar shell morphologies, making it difficult to distinguish them based on external characteristics alone. In addition, some initial descriptions are incomplete.
Today, new turban shells are identified by morphological characteristics of the shells, supported by 3D modeling techniques, and mainly by DNA barcoding.
Trochus parvus and the new species Trochus nanhai, also discovered there, were collected and identified from coral reef habitats in the South China Sea.
Description of the shell:
It is a small, conical shell with a pointed tip.
The shell surface has conspicuous reddish-brown longitudinal stripes that taper to spots towards the base; the tip is typically red.
The shell consists of 6 flat whorls with 3–4 spiral rows of densely arranged granules. These granules are round, bead-like or slightly compressed, with the upper whorls smaller than the lower ones.
The edge of the whorls has a spiral crest consisting of conspicuous, evenly arranged pustules.
The body whorl is decorated with compact, almost square, flattened pearls that form a rounded profile.
The base is slightly concave, with 7–8 concentric granular lirae separated by spaces as wide as the ridges.
The columella is oblique and bears 3–4 densely packed, folded teeth that form a false umbilicus.
The inner lip contains 4 folds, and the inside of the shell is pearly with fine spiral liration.
The shells examined reached a height of 11.0–13.0 mm and a shell width of 10.4–14.0 mm.
Description of the radula:
The radula has a central tooth with a V-shaped tip and a broad trapezoidal shaft, symmetrically flanked by eight small teeth.
On each side there are five lateral teeth, each with a fold on the shaft that is firmly interlocked with the shaft of the adjacent tooth, and bearing 3–5 small teeth on only one side.
The fifth lateral tooth has a distinct paddle-shaped tip. The marginal teeth are narrow and sickle-shaped; the innermost 9–12 marginal teeth each bear 2–3 denticles.
From the 10th to the 13th marginal tooth, the tooth size gradually decreases, while the number of denticles increases, forming a crest or feather-like structures.
Detailed information on the weight of the animals, water depth, and water temperature is missing from the initial description.
Etymology:
The species name “parvus” comes from Latin and means “small”; it refers to the relatively small size of the shell of the new species, which differs significantly from other species of this genus.
Literature reference:
Zhu P-J, Yan C-R, Yang H-Q, Hu L-S, Dong Y-W (2025)
Description of two new species of the genus Trochus Linnaeus, 1758 (Gastropoda, Trochidae) from the South China Sea. ZooKeys 1264: 265-280.
https://doi.org/10.3897/zookeys.1264.167854
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
