Phidiana militaris

Phidiana militaris (Alder & Hancock, 1864)

Phidiana militaris @ Hoi Ha Wan Marine Park, Hong Kong (6m) 20°C, 17-04-2016 by Markus Rummel

Class: Gastropoda  Cuvier, 1797
Subclass: Heterobranchia  J.E. Gray, 1840
Clade: Euthyneura  Spengel, 1881
Superorder: Nudipleura  Wägele & Willan, 2000
Order: Nudibranchia  Cuvier, 1817
Suborder: Dexiarchia  Schrödl, Wägele & Willan, 2001
Infraorder: Cladobranchia  Willan & Morton, 1984
Parvorder: Aeolidida  Odhner, 1934
Superfamily: Aeolidioidea  J.E. Gray, 1827
Family: Facelinidae  Bergh, 1889
Genus: Phidiana  J.E. Gray, 1850
Species: Phidiana militaris (Alder & Hancock, 1864) [Eolis]


  • Caloria militaris (Alder & Hancock, 1864)
  • Eolis militaris Alder & Hancock, 1864 (original)
  • Hervia dangeri Risbec, 1953
  • Learchis howensis Burn, 1966

With a maximum length of 30mm (Debelius, 2001), it has an elongate pale flesh or white body terminating behind in a slender tappered tail considerably behind the cerata. A bright orange median line on the head forks anteriorly, with a branch running up the frontal edge of each oral tentacle. Another orange line runs along the posterior edge of each oral tentacle and then runs along each side of the body below the cerata. The cerata are long and smooth, swelling a little in the centre and grow in six groups on the sides of the body, the last groups almost meeting on the back. They are colored brown with a longitudinal orange or red line and with yellowish tips having a bluish line and a terminal tip which is white. The oral tentacles are large, stout and tapering, share the color scheme of cerata. Rhinophores and tentacular foot corners are also tipped with yellow and there is a broad orange band on the rhinophores. The anus is located on the right side of the body.

It feeds on hydroids (George, J.D., 2012). Very similar to Phidiana indica, they can be distinguished by the line between the rhinophores: Phidiana indica has a white line, Phidiana militaris has an orange or red line. Opioid ligands such a “phidianidines” have been obtained from this species (Baker, 2016) for a medical use, although it was later found that they could be easily synthethised.


  • Militaris, from Latin, meaning military man, soldier or warrior, probably related to the orange pattern of the body.

Native to the Indo-Pacific. Originally described from India, it has also been reported from the United Arab Emirates, Sri Lanka, Brunei, Malaysia, Thailand, Hong Kong and Northern Australia. A report on the Scirè U-boat shipwreck, in the Haifa bay, northern Israel, in october 2016 is probably the first cite for the Mediterranean Sea, where it is an alien species.

Known georeferenced records of the species: Phidiana militaris
: GROC 2010-2011
: Enric Madrenas
: João Pedro Silva
: Bernard Picton
: Manuel Ballesteros.
: M@re Nostrum
: Altres fonts
: Marine Regions


    Western Mediterranean:
    Eastern Mediterranean:
    Atlantic Ocean:
This chart displays the observation probability for Phidiana militaris based on our own records.

More pictures


Further reading

Cite this article as:

Pontes, Miquel, Manuel Ballesteros, Enric Madrenas et al. (2012-2017) "Phidiana militaris" in OPK-Opistobranquis, Published: 14/10/2016, Accessed: 18/12/2017 at (

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To Markus Rummel (Euphotic Photography) for his pictures of this species.