Peridinium subinerme, (Paulsen) Loeblich III, 1969

Nunes, Caio Ceza da Silva, Susini-Ribeiro, Sylvia Maria Moreira & Cavalcante, Kaoli Pereira, 2019, Dinoflagellates in tropical estuarine waters from the Maraú River, Camamu Bay, northeastern Brazil, Check List 15 (5), pp. 951-963 : 958-959

Protoperidinium cf. subinerme (Paulsen) Loeblich III, 1969

Figure 8A–C

Brazil, estuary of Maraú River: River Zone Station 1, 14°06′33″S, 039°02′48″W, I.2007 (HUESC 24054); Mixing Zone Station 2, 14°04′52″S, 038°59′12″W, I.2007 (HUESC 24055); Coastal Zone Station 4, 13°54′56″S, 038°58′57″W, X.2006 (HUESC 24045).

Small, pentagonal cell, epitheca conical projecting a short apical pore; hypotheca conical, with two diminute antapical spines; distance between antapical spines 2× cingulum width; cingulum equatorial, strongly excavated with a narrow cingular list; tabulation ortho-hexa; epithecal tabulation asymmetric, with plates 3′, 2′, and 4′ shifted to left side, plate 1′ diamond-shaped, distal sides markedly longer (1.3 times) than proximal sides; plate 1a smaller than plate 3a and plate 2a hexagonal and as wide as plate 4″, thecal surface ornated by weak punctuate polygonal mesh. CL: 33.3 μm, CW: 38.1 μm, EL: 12,3 μm, HL: 15.2 μm, Cw: 5.6 μm (n = 1).

Taxonomic remarks: The specimen from Maraú estuary resembles the species illustrated by Abé (1981: 365–368, fig. 54) as Peridinium subinerme . However, our specimen is smaller than shown by Abé (1981; CL= 47–50 μm, CW=50–55 μm) and the distal sides of plate 1′

are markedly larger than the proximal sides.

Distribution in Brazil: coastal regions of Amapá, Rio Grande do Norte, and Santa Catarina ( Flora do Brasil 2019). This taxon has never been reported in the state of Bahia.

Protoperidinium venustum (Matzenauer) Balech, 1974 Figure 8D, E

Brazil, estuary of Maraú River: Mixing Zone Station 2, 14°04′52″S, 038°59′12″W, I.2007 (HUESC 24055).

Cell longitudinally elongate, dorsiventrally flattened, with a conical apical horn and two pointed antapical horns; cingulum descending not excavate; tabulation ortho-quadra; plate 1′ with distal sides smaller than proximal sides; plate 2a small, wider than long; sulcus

with a small projection towards the epitheca. TL: 85–96 (89.5 ± 5.8 μm), CW: 62.5–69 (65.5 ± 3.3 μm) (n = 3).

Distribution in Brazil: coastal regions of Pernambuco and Rio Grande do Sul ( Flora do Brasil 2019). This is the first record for Bahia.