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This species has been observed on Reunion and Mauritius Islands

Order : Anaspidea Superfamily : Aplysioidea Family : Aplysiidae Distribution : Circumglobal, found in all warm water regions of the world. Maximal size : 300 mm Abundance : Seldom if ever... Species characteristics : The parapodia join posteriorly, the "join" forming quite a high wall partially enclosing the mantle cavity. The exhalent siphon seems to be poking out posteriorly, over a wall. It can be distinguished in having a circular posterior portion of the foot that is used as a sucker to adhere to the substrate. A. juliana lacks the ink gland which produces the characteristic reddish purple ink.
	Showing species characteristics...	Photo Philibert Bidgrain Réunion, Kelonia center, Saint Leu, less 1 m, 29 December 2006, size : 100 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Carlo Magenta-da-Cunha
    Synonymous : (according Worms)
               - Aplysia brunnea Hutton, 1875                        - Aplysia hamiltoni Kirk, 1882
               - Aplysia sibogae Bergh, 1905   

Bibliographic data :

There are quite a few colour forms of this species which are at present unable to be separated on anatomical grounds. The brownish form with pale spots is one of the most common forms, as is one with a uniform black colouration.
    Aplysia juliana is unusual in that the posterior end of the foot can form a temporary sucker. When the animal crawls along it can use the sucker to anchor itself then greatly extend its head and neck like a leech. Another aplysiid that does this is Dolabrifera dolabrifera. When the animals are "sitting" the posterior part off the foot is enlarged and rounded into a sucker. This is very characteristic of A. juliana and others of this non inking group. Inking species usually have the parapodia separate posteriorly and have a more tapering "tail".
    The egg mass string is bright yellow and looking like someone's pile of "instant noodles".
    This species dont really swim.
    Aplysia juliana is one of the few species of Aplysia that lacks the ink gland which produces the characteristic reddish purple ink. Instead the opaline gland, produces a milky white secretion.
    It feeds mainly on green algae such as Ulva or Enteromorpha which could explain why it doesn't produce red or purple ink as the ink pigment seems to be derived from pigments found in red algae.
    Aplysia juliana is a moderately common species that is largely restricted to rocky habitats where there is an extensive growth of the green alga Ulva on which it feeds. It occurs at depths of 1 to 2 m at protected to moderately exposed locations, usually where there is some fresh water and nutrient seepage.

References :

Bill Rudman Seaslug site : Sea Slug Forum : Aplysia juliana
   Nudipixel Aplysia juliana

Publications :

Bebbington, A. (1974) Aplysiid species from East Africa with notes on the Indian Ocean Aplysiomorpha (Gastropoda: Opisthobranchia). Zoological Journal of the Linnean Society, 54 : 63-99
    Quoy, J.R. & Gaimard, J.P. (1832). Voyage de decouvertes de L'Astrolabe pendant les annees 1826-1827-1828-1829, sous le commandement de M.J. Dumont D'Urville, Zoologie, 2 : 1-686.

Other photos of Aplysia juliana :

Philibert Bidgrain Réunion, Kelonia center, Saint Leu, less 1 m, 29 December 2006, size : 100 mm	The brownish form with pale spots is one of the most common forms

	Geoffrey Summers Mauritius, Ile Marianne, less 1 m, 11 October 2014, size : 90 mm

Christophe Cadet Reunion, La Saline lagoon, less 1 m, 28 September 2010

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