Aplysia kurodai (Baba, 1937)

Location: Tanoura, Oita, Japan
Date
Length: 300mm
Depth: 5.0m
Water temperature: 18.0℃

Description

The most common large sea hare in Japanese coastal waters. Body reaches 350–400 mm in length, swollen behind and narrowing in front, with a long neck and head. At the anterior end of the head is a vertical slit-like mouth flanked by a pair of large folded anterior tentacles. The rhinophores are cylindrical with an upper outward-facing slit. The parapodial lobes, arising postero-laterally, are ample and free throughout, separated both in front and behind. The mantle is oval with a median foramen communicating with the shell cavity; this foramen is very small in young individuals and may take the form of a minute papilla in adults. Posteriorly, the mantle is produced into a short rolled anal siphon. A purple gland develops along the right margin of the mantle. The dorsal skin is soft and smooth. The opaline gland exudes a milky-white fluid through multiple pores. The genital groove begins at the common genital orifice in front of the ctenidium and runs forward to the penial orifice at the outer base of the right anterior tentacle. The foot is large, truncate in front and tapering to a blunt tail behind.

Coloration

The upper surface is brownish or purplish-black, densely covered with small, oval, or irregular grayish mottles, which in some individuals are so large and abundant that they obscure the ground colour. The sole is uniformly dark. The ctenidium is yellow; the opaline gland yellowish-white.

Distribution

Type locality: Formosa (Takahasi, 1934), with additional records from Tomioka (Amakusa), Misaki, and Tateyama, Japan (Baba, January–June 1936; very common).

Etymology

The original description (Baba, 1937) states: "It is here named T. kurodai in honour of the malacologist, Mr. Tokubei Kuroda." Tokubei Kuroda (1886–1987) was a pioneering Japanese malacologist; Baba acknowledges him in Part I as one of the colleagues who provided access to the literature.

Remarks

Originally described in the genus Tethys (later replaced by Aplysia because Tethys was preoccupied by a coelenterate genus). In the family Aplysiidae (Anaspidea). Externally and anatomically similar to the Atlantic and Mediterranean Tethys punctata (Cuvier) but distinguished by the parapodial lobes being separated behind, a slightly larger radular formula, a smaller mantle foramen, and a different shell shape.

Photographed by 今川郁

Description

Coloration

Distribution

Etymology

Remarks

References

A Kindle field guide by the site author

Seasonality

Shooting Locations

Photos of Aplysia kurodai

Same Genus Nudibranchs

Similar Colors Nudibranchs

Academic Database