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Edwardsiidae is one of the most speciose families within order Actiniaria with ~75 valid species of burrowing sea anemones. Five edwardsiids have been recorded in South Atlantic waters with only two species known for Brazil:Nematostella vectensisandEdwardsia migottoi. Such low diversity is probably the result of a historical small number of specialists in the region combined with difficulties in collecting and identifying these small burrowing animals. Although edwardsiids have been reported from Brazil since at least the 1960s, these reports did not include proper descriptions or specific identification, making comparison to other valid species impossible. Here we describe a new genus,Isoscolanthusgen. nov., and two new species:Isoscolanthus iemanjaesp. nov.,Isoscolanthus janainaesp. nov. and we also describeScolanthus crypticussp. nov., the first species of the genus for Brazil.Isoscolanthusgen. nov. is easily distinguished from other edwardsiid genera by a combination of external (i.e. presence of periderm and nemathybomes in proximal end and 12 tentacles), microanatomical (i.e. four microcnemes) and cnidom features (i.e. pterotrichs in nemathybomes). In addition to the description of the new genus and species, we expand the range distribution ofNematostella vectensisandEdwardsia migottoiin the South-western Atlantic. The number of edwardsiids known from Brazil is raised from two to five species, substantially increasing the diversity of soft-bottom sea anemones for South Atlantic waters.

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Different reproducti ve strategies (both sexual and asexual) that may occur in individuals of the same species may explain the success of sea anemones (Cnidaria:Actiniaria) in colonizing different ecosystems around the planet. Here we provide the fi rst record of a Bunodosoma specimen with two oral discs and discuss the possibility of asexual reproduction in this genus. One individual of Bunodosoma cangicum was found in Carneiros beach (Pernambuco state, Brazil) with two fully individualized oral discs but with column and pedal disc still connected. Our fi nding may represent a clue to longitudinal fi ssion in Bunodosoma. Yet, despite the number of different studies carried out so far, the absence of data regarding asexual reproduction in Bunodosoma suggests that it might be rare in this genus, occurring only in sporadic cases such as recovery from injury.