How to distinguish the blue Felimare

Any diver with a certain experience searching for opisthobranchs in the Mediterranean or Eastern Atlantic could tell you that, sometimes, it is pretty difficult to tell apart which species of blue Felimare nudibranch you are looking at. The new genus Felimare recently replaced the classic denomination Hypselodoris that is found in most printed books.

Felimare tricolor by Enric Madrenas

Felimare opisthobranchs of the Mediterranean and Atlantic Ocean were revised by Ortea et al in 1996. Still there is a certain controversy regarding some species, for instance, Ortea denominates Hypselodoris tricolor to the same species that Gosliner described as Hyselodoris midatlantica in 1990. In this work, Ortea also considers H. elegans, H. valenciennesi and H. webbi as Hypselodoris picta.

Here we include the main traits of the most common Felimare species:

Felimare tricolor has following characteristics :

  • Felimare tricolor - Rhinophore

    Felimare tricolor

    Felimare tricolor - Branchs

    Felimare tricolor

    The dorsum is blue, with a yellow border, a median longitudinal yellow or white line that  finished between the rhinophores, it may have some white yellow spots.

  • The foot is blue with a white or yellow line along the sides.
  • The rhinophores are blue with white tips.
  • The gills are blue with a thin yellow line on the external side of each gill.

 

Felimare fontandraui has following characteristics:

  • Felimare fontandraui

    Felimare fontandraui

    Felimare fontandraui

    Felimare fontandraui

    The dorsum is blue, with a yellow border, a median longitudinal white line and some white spots. The median line extends ahead of the rhinophores and finishes with a ‘T’ or anchor shape

  • The foot is blue with a pattern of irregular white lines on the sides.
  • The rhinophores are uniform blue.
  • The gills are either uniform blue or they may have two triangular yellow lines on the external side, and one yellow line on the internal side of each gill leaf.

Felimare villafranca has following characteristics :

  • Felimare villafranca

    Felimare villafranca

    Felimare villafranca

    Felimare villafranca

    The dorsum is blue, with a yellow border, and a pattern of longitudinal yellow and/or white lines. The dorsal yellow lines encircle the gills.

  • The foot is blue with a pattern of thin yellow and/or white lines on the sides.
  • The rhinophores are blue with longitudinal white line on the back.
  • The gills have a white line on the external and internal side of each gill leaf.

Felimare orsinii has following characteristics :

  • Felimare orsinii

    Felimare orsinii

    Felimare orsinii

    Felimare orsinii

    Small sized.

  • The dorsum is blue, bordered in yellow, with a median longitudinal thin white line. The mantle is covered with small blue tubercles.
  • The foot is blue with a white or yellow line on the sides.
  • The rhinophores are uniform blue.
  • The gills are uniform blue.

 

Felimare bilineata has several colour variants. The typical colour form is recognisable according to following characteristics :

  • Felimare bilineata

    Felimare bilineata

    Felimare bilineata

    Felimare bilineata

    The body is black or dark blue with yellow lines and blue spots

  • The mantle has a black border with another yellow border inside, and two median yellow longitudinal lines that encircle the rhinophores and gills on each end. The region between the yellow border and median yellow lines is filled with blue spots. In northern specimens the median yellow lines tend to merge into a single line, while in African specimens the median yellow lines are separated by a broad region filled with yellow / white lines..
  • The foot has longitudinal yellow lines on each side.
  • The rhinophores are black or dark blue, with a longitudinal yellow line on the back side.
  • The gills are black or dark blue with two triangular yellow lines on the external side and one yellow line on the internal side of each gill leaf.

Felimare cantabrica has following characteristics :

  • Felimare cantabrica

    Felimare cantabrica

    Felimare cantabrica

    Felimare cantabrica

    The dorsum is blue, bordered in yellow, with a median longitudinal yellow line and some yellow spots.

  • The foot is blue with numerous yellow spots.
  • The rhinophores are blue with a longitudinal yellow line on the back.
  • The gills are blue with two triangular yellow lines on the external side and one yellow line on the internal side of each gill leaf.
  • This species is absent from the Mediterranean

Here it is a comparative drawing to sinthetize the explanations above.

 Source: Nembro by Marina Poddubetskaia

Cite this article as:

Miquel Pontes (2012-2019) "How to distinguish the blue Felimare" in OPK-Opistobranquis, Published: 17/10/2013, Accessed: 22/07/2019 at (https://opistobranquis.info/en/nBuhB)

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Miquel Pontes

Informàtic de profesió, és fotògraf submarí i naturalista aficionat. Submarinista des del 1994, el seu “logbook” compta amb unes 700 immersions al mar Mediterrani i als oceans Atlàntic, Índic i Pacífic. Ha participat i participa en tota mena de projectes divulgatius (llibres, revistes, webs, conferències, exposicions…) com a mitjà per difondre el seu interès principal: protegir els mars i els éssers que hi habiten. Fundador del Grup d’Estudis M@re Nostrum (www.marenostrum.org) Soci fundador del GROC (Grup Recerca d’Opistobranquis der Catalunya). Soci Fundador del VIMAR (Vida Marina). Va descobrir l’interessant mon dels opistobranquis el 1997 de la ma dels seus companys d’immersió i des de llavors ha estat una línia de treball continuada, aportant fotos submarines, observacions fetes al medi i donant suport informàtic per a la difusió d’aquests continguts.