| The tooth ornamentation of two shark species of the genus Mustelus were compared. one of the two species, M. mustelus, is a male shark, 49 cm long, collected in the North Sea at Herne Bay, Kent. The other, M. manazo, is a male shark, 82.5 cm long, collected in the waters of Tateyama, Chiba Prefecture, Japan. 8 teeth were collected from the jaws of one shark, 4 from each of the right upper and lower jaws. |
| Plate 1. M. manazo; male, 82.5 cm t.l. Plate 2. M. mustelus; male, 49 cm t.l. The teeth of these two shark species have well-developed costules on both the labial and lingual faces. The lingual face, especially the anterior part of the median protuberance, has a unique structure in addition to the costules. This unique structure is beehive-like, with each honeycomb structure being a crater 10-15 µm in diameter. |
| Plate 3. Aggregation of beehive-like micro-craters |
| Plate 1. M. manazo; male, 82.5 cm t.l. |
| Plate 2. M. mustelus; male, 49 cm t.l. |
| Plate 3. Aggregation of beehive-like micro-craters on the protuberance |
| We examined whether there were any differences in the dental characteristics of two shark species, M. mustelus and M. manazo. The results showed that the first tooth of the upper and lower jaw teeth (UR1 & LR1) was the one that showed differences in tooth characteristics between the two species, In the first tooth of M. mustelus, small hemispherical projections are seen at the anterior part of the protuberannce on the lingual face, but not in M. manazo. |
| Plate 4. Differences in the dental characteristics of two shark species, M. mustelus and M. manazo |
| Ref. BIOLOGIE, 58: 99-126, 1988 Contributions to the study of the comparative morphology of teeth and other relevant ichthyodorulites in living supraspecific taxa of Chondroichthyan fishes Editor: M. STEHMANN Part A: Selachii. No.2a: Order: Carcharhinusformes-Family: Triakidae by J. HERMANN, M. HOVESTADT- EULER and D.C. HOVESTADT |
| ver.1. 20241120 |
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