Phyllodesmium serratum (Baba, 1949)

Location: Futou beach, Tago, Futou, Dougashima, Shizuoka, Japan
Date: 2016/03/04
Length: 12mm
Depth: 5.0m
Water temperature: 15.0℃

Description

A small Aeolidacea, body length 2-4 cm. The rhinophores are simple. Cerata in 6-8 groups per side: 1st group 12 cerata, 2nd 10, 3rd-5th 8 each, 6th onward gradually fewer. The anterior groups are mounted on horseshoe ridges; the posteriormost is in oblique rows. The genital orifice opens below the anterior limb of the first right horseshoe; anus and nephroproct in normal positions. Anterior foot corners tentaculiform. Ground colour yellow-white; the cerata are pale pink with a yellow central vein. The masticatory edge of the jaw plate bears only a single row of 7-8 denticles. Radula formula 14-18×0.1.0. The central tooth is V-shaped with a long, large median cusp flanked by many denticles (16-23) on each side. Some specimens are aberrant, with the two rhinophores fused into a single one.

Distribution

Type locality is Hayama-Najima-Hiraiwa, Sagami Bay (intertidal, April 1939, 2 specimens) and Hayama-Najima Tego-iwa Wari-tori, Sagami Bay (13 m depth, September 1940, 4 specimens, 1 of which is the aberrant single-rhinophore specimen). The original description (Baba, 1949) records the species only from the Najima area in Hayama, Sagami Bay.

Etymology

The specific epithet serrata is Latin for serrate or saw-toothed. The original description does not give an explicit etymology paragraph; the descriptive sense reflects either the denticulate jaw-plate margin or the many denticles flanking the central tooth. The Japanese name "Sagami-mino-umiushi" (Sagami aeolid) reflects the Sagami origin.

Remarks

Originally described as Hervia serrata and later transferred to Phyllodesmium. The V-shaped central tooth with many denticles distinguishes the species from its congeners Hervia lineata, Hervia ceylonica, Hervia japonica, and Hervia affinis.

Photographed by KIMOTO Nobuhiko

Description

Distribution

Etymology

Remarks

References

A Kindle field guide by the site author

Seasonality

Shooting Locations

Photos of Phyllodesmium serratum

Same Genus Nudibranchs

Similar Colors Nudibranchs

Academic Database