Arminoidea

The arminacean nudibranchs are a small group of species that live in soft substrates, preferably where they can burrow in search of food. Species of the Arminidae family, defining the group type, to which the genus Armina belongs, are characterized by the presence of a large mantle shield-shaped, rounded in the front and sharp in the back side. The mantle can be adorned by some short and rounded tubercles or by longitudinal grooves. There are a couple of small rhinophores located close together and with longitudinal lamellae. The head, located below the front part of the mantle has a pair of flattened lobes that are used to dig into the sediment. Beneath the mantle and the body sides there are laminar extensions, the more anterior axially oriented (lateral lamellae) and behind them there are other oblique and more numerous lamellae than work as gills and that are penetrated by branches of the digestive gland.

Armina neapolitana by Enric Madrenas

The arminaceans of the genus Armina live in soft bottoms, where they find their preys and can roam on the bottom, or buried in it, as they have the front of the body adapted to it. They feed on the group of octocoral cnidarians like pennatulaceans or alcyonaceans. Instead Doridomorpha gardineri lives on and feeds on the blue coral Heliopora coerulea. Some species of the genus Dermatobranchus have been cited to feed on soft corals, gorgonians and stoloniferous cnidarians.

Classification

Molecular phylogenetic analysis conducted in recent years on different groups of nudibranchs have shown that traditional arminaceans are not a monophyletic group. Today we tend to accept that the only real arminaceans are those belonging to the families Doridomorphidae and Arminidae that belong the clade Arminoidea, with the rank of superfamily, after the work by Bouchet et al.(2017).

The phylogenetic affinities of the other families of traditional arminaceans (Bornellidae, Goniaeolididae, Embletoniidae, Heroidae, Pseudovermidae, Phylliroidae, Madrellidae and Pinufiidae) are being resolved, but many have been temporarily joined with other Cladobranchia families of uncertain relationship under the name of “Unassigned Cladobranchia”. So we consider the taxonomy of these families well separated from the Arminoidea.

Actual taxonomy of the Arminoidea, proposed by Bouchet et al.(2017) and accepted by WoRMS is:

  • Superfamily Arminoidea Iredale & O’Donoghue, 1923 (1841)
    • Family Arminidae Iredale & O’Donoghue, 1923 (1841)
      • Genus Armina Rafinesque, 1814
      • Genus Atthila Bergh, 1899
      • Genus Dermatobranchus van Hasselt, 1824
      • Genus Heterodoris Verrill & Emerton, 1882
      • Genus Histiomena Mörch, 1860
      • Genus Pleurophyllidiella Eliot, 1903
      • Genus Pleurophyllidiopsis Tchang, 1934
    • Family Doridomorphidae Er. Marcus & Ev. Marcus, 1960 (1908)
      • Genus Doridomorpha Eliot, 1903

Arminacean species recorded in the Mediterranean or around the Iberian Peninsula:

Armina maculata

Armina maculata

Armina loveni - Photograph ©Bernard Picton

Armina loveni

Armina neapolitana

Armina neapolitana

Armina tigrina by João Pedro Silva

Armina tigrina

Bibliography