Alcyonium

Alcyonium spp.

Material examined: BBB 2016: St. 23; St. 25; St. 26. PD BB 2017: St. 16; St. 21; St. 26; St. 29; St. 34; St. 43.

Remarks: Several colonies were found in the mentioned sites. They couldn´t be assigned to any of the identified species because they were damaged or broken. A. antarcticum is the only species of Alcyonium recorded at Burdwood bank (Molander 1929; present study), but at least five species were already found in the Subantarctic region of the Atlantic ocean: A. sollasi (Shag Rock), A. patagonicum (Beagle Channel), A. grandis Casas, Ramil & Ofwegen, 1997 (Drake Passage, South Georgia Is.), Alcyonium southgeorgiensis Casas, Ramil & Ofwegen, 1997 (South Georgia Is.), A. paucilobulatum Casas, Ramil & Ofwegen, 1997 (Shag Rocks, Elephant Is. and South Georgia Is.). Four species are first reported herein to Burdwood bank: A. haddoni, A. sollasi, A. varum and A. patagonicum, totalizing five species for the Burdwood bank and 10 for the Subantarctic region of the Atlantic Ocean. Two potentially new species were identified from the Burdwood bank area (NDR and NII), which did not fit in any species described so far. As morphological plasticity is common among species of Alcyonium, further assessments (Scanning Electron Micrographies and COI, MutS sequencing) are needed in order to confirm if they are new species and identify at species level the morphotypes analysed. Alcyonium is one of the most conspicuous group in the study area growing on any hard surface, both natural and biogenic (shells, octocoral axes, etc.).