Diversity of Edwardsiidae sea anemones (Cnidaria: Anthozoa: Actiniaria) from Brazil, with the description of a new genus and species

Abstract

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.

Supplemental Material for 'Psittacosaurus amitabha, a new species of ceratopsian dinosaur from the Ondai Sayr locality, central Mongolia. (American Museum novitates, no. 3932)'

“…Cnidom: spirocysts, basitrichs, b-mastigophores, and p-mastigophores A. Remarks: We agree with the circumscription of Brandão et al (2019) for the genus Scolanthus, considering the former genus Isoedwardsia Carlgren, 1921, a junior synonym of Scolanthus (Manuel, 1981a) (Carlgren, 1931) Etymology: The specific name "shrimp" honors the Science Research Mentoring Program (SRMP) at the AMNH and their high school students known informally as srmpers. The SRMP supported C.Q., S.L.B., and L.C.G.…”

“…Scolanthus has a convoluted taxonomic history with species and generic reassignments (see Daly and Ljubenkov, 2008;Brandão et al, 2019), but the presence of nemathybomes and periderm on the proximal end, nemathybomes with only basitrichs, and at least eight microcnemes and, thus, 16 tentacles unequivocally place S. shrimp and S. celticus within the genus. The taxonomic position of S. celticus within Scolanthus is further supported by the confirmation of certain diagnostic features in micro-CT scans such as the presence of periderm and nemathybomes on the scapus and proximal end ( fig.…”

“…Scolanthus Gosse, 1853, Edwardsia de Quatrefages, 1842, and Edwardsianthus England, 1987, belong to the subfamily Edwardsiinae Carlgren, 1921, which is characterized by having nemathybomes-hollow, epidermis-lined, nematocyst-dense pockets sunk into the mesoglea of the column (Daly, 2002). Species of Scolanthus are differentiated from other members of the subfamily by having nemathybomes with basitrichs and periderm not only on the scapus but also the proximal end (not a true physa), at least eight microcnemes at the base of tentacles, and 16 or more tentacles in adults (see Brandão et al, 2019). Half of the diversity of Scolanthus has been described in the last 10 years, with most species recorded from the Pacific Ocean (S. ignotus (Carlgren, 1922), S. armatus (Carlgren, 1931), S. triangulus Daly and Ljubenkov, 2008, S. scamiti Daly and Ljubenkov, 2008, S. ena Izumi and Fujita, 2018, S. isei Izumi and Fujita, 2018, S. kopepe Izumi and Fujita, 2018).…”

“…Half of the diversity of Scolanthus has been described in the last 10 years, with most species recorded from the Pacific Ocean (S. ignotus (Carlgren, 1922), S. armatus (Carlgren, 1931), S. triangulus Daly and Ljubenkov, 2008, S. scamiti Daly and Ljubenkov, 2008, S. ena Izumi and Fujita, 2018, S. isei Izumi and Fujita, 2018, S. kopepe Izumi and Fujita, 2018). The remaining species are known from the Mediterranean (S. mediterraneus Ocaña and Çinar, 2018) and Caribbean seas (S. curacaoensis (Pax, 1924), the southwestern Atlantic (S. crypticus Brandão, Gusmão, and Gomes, 2019), and the North Atlantic (S. callimorphus Gosse, 1853;S. ingolfi (Carlgren, 1921), S. nidarosiensis (Carlgren, 1942)).…”

Two New Deep-Sea Species of Burrowing Anemones (Cnidaria: Actiniaria: Edwardsiidae) from Whittard Canyon Off the Southwestern Coast of Ireland

“…Scolanthus Gosse, 1853, Edwardsia de Quatrefages, 1842, and Edwardsianthus England, 1987, belong to the subfamily Edwardsiinae Carlgren, 1921, which is characterized by having nemathybomes-hollow, epidermis-lined, nematocyst-dense pockets sunk into the mesoglea of the column (Daly, 2002). Species of Scolanthus are differentiated from other members of the subfamily by having nemathybomes with basitrichs and periderm not only on the scapus but also the proximal end (not a true physa), at least eight microcnemes at the base of tentacles, and 16 or more tentacles in adults (see Brandao et al, 2019). Half of the diversity of Scolanthus has been described in the last 10 years, with most species recorded from the Pacific Ocean (S, ignotus (Carlgren, 1922), S. armatus (Carlgren, 1931), S. triangulus Daly and Ljubenkov, 2008, S. scamiti Daly and Ljubenkov, 2008, S. ena Izumi and Fujita, 2018, S. isei Izumi and Fujita, 2018, S. kopepe Izumi and Fujita, 2018).…”