Suborder Macrocnemina Haddon & Shackleton, 1891

Material examined: BBB 2016: St. 18; St. 21; St. 40. PD BB 2017: St. 29; St. 43.

Remarks: All the colonies were associated with octocorals and polyps were linked by stolons or by a continuous coenenchyme. The column and sometimes the coenenchyme were encrusted with sand, which made histological and microanatomy analysis difficult.

Our preliminar analysis showed two morphotypes. The morphotype I (four lots BBB 2016: St. 40 (2), St. 18, St. 21) are colonies with columns and coenenchyme heavily encrusted, and the morphotype II (two lots PD BB 2017: St. 43 and St. 29) are colonies with less sand incrustations in the column. The morphotype I was found associated to Alcyonium sollasi and octocoral axes while the morphotype II was found on primnoid colonies ( Thouarella spp). Histological and molecular analyses are in progress to define their taxonomic status.

There is only one record of zoanthids in the Argentinian continental shelf. Schejter & Mantelatto (2011) cited Epizoanthus paguricola off Buenos Aires coast (85–131 m), but the records of the present study represent the first in Sub-antarctic waters .