Baeolidia palythoae    Gosliner, 1985

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This species has been observed on Madagascar Island

Order : Nudibranchia
Suborder : Dexiarchia
Superfamily : Aeolidioidea
Family : Aeolidiidae
Distribution : South Africa and Madagascar
Maximal size : 13 mm
Abundance : Seldom if ever on the fore reef zone

Species characteristics :

Light brown with a network of darker brown reticulations on the notum, cerata, oral tentacles and rhinophores except for the tip and the ends of the papillae, which are yellowish white

The cerata are dorsoventrally flattened (leaf like). They are relatively large and lie out from the body, arranged in almost horizontal rows with a slight anterior downwards slope.

Papillate rhinophore with only a few long papillae


baeolidia palythoae
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Photo Alain-Benoît Rassat
Madagascar, Nosy Bé, ledge, 10 m, 9 April 2016: size : 5 mm

See more about : Sightening and mating periods

Remarks :

Identification confirmed by Terry Gosliner and Hsini Lin
    Synonymous (according worms) :
          - No other name

Bibliographic data :

It is one of those nudibranchs which takes zooxanthellae from its coelenterate prey and 'farms' them in its own body. The network of brown we can see in all parts of the body, are specialised ramifications of the digestive gland where the zooxanthellae are housed.
    The cerata are dorsoventrally flattened, broadly rounded along the anterior edge and with an angle about midway along the posterior edge. They are relatively large and lie out from the body, either held horizontally, or sometimes following the contour of the side of the body before extending out horizontally. The cerata are arranged in almost horizontal rows with a slight anterior downwards slope. They are arranged so that only the anterior edge of each ceras is shaded by the ceras in front.
    Anterior foot corners rounded
    Feeds on zoanthids especially Palythoa nelliae in the lower intertidal zone
    Baeolidia ransoni, B. harrietae and B. palythoae are very similar from a morphological point of view. However,
          - B. harrietae and B. polythoae have papillate rhinophores, B. ransoni has smooth ones.
          - B.palythoae differ from B. harrietae by several features such as the number of cerata per row (49 in B. harrietae and 35 in B. paylothoae), the position of the gonopore, the number of oral glands...

References :

Publications :

Gosliner T.M. 1985. The aeolid nudibranch family Aeolidiidae (Gastropoda: Opisthobranchia) from tropical southern Africa. Annals of the South African Museum , 95(6): 233-267
    Carmona, Leila, Pola, Marta, Gosliner, Terrence M., et al. Review of Baeolidia, the largest genus of Aeolidiidae (Mollusca: Nudibranchia), with the description of five new species. Zootaxa , 2014, vol. 3802, no 4, p. 477-514.

Other photos of Baeolidia palythoea :

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