Marcusadorea corderoi ( Marcus, 1949 ) Vieira & Migotto & Winston, 2010

Vieira, Leandro M., Migotto, Alvaro E. & Winston, Judith E., 2010, Marcusadorea, a new genus of lepralioid bryozoan from warm waters, Zootaxa 2348 (1), pp. 57-68 : 61-63

Marcusadorea corderoi ( Marcus, 1949) n. comb.

( Figures 6–11 ; Table 2)

Coleopora corderoi Marcus 1949: 18 , figs 23–25; Vieira, Migotto & Winston 2008: 30.

Material examined. MZC Hassler Expedition Box 33, 36; Coleopora corderoi Marcus ; off North of Rio de Janeiro, Brazil.

Description. Colonies encrusting, unilaminar. Autozooids large (1.251 mm long, 0.766 mm wide for MCZ Hassler colonies), irregularly polygonal to rectangular, separated by distinctly raised lateral wall junctions. Frontal shield convex, surface granular with small scattered pores, these becoming obscured with a tuberculated frontal wall in increasing calcification; some larger marginal areolar pores remain visible. Primary orifice bell-shaped, wider proximally, anter arched, U-shaped, separated from broad and shallow poster by barely projecting condyles (mean 0.140 mm long, 0.178 mm wide for MCZ Hassler colonies). No oral spines. Peristome tubular, entire. Secondary orifice mostly rounded to oblong, with U- to V-shaped proximal edge (0.464 mm long, 0.401 mm wide for MCZ Hassler colonies). Suboral avicularium occasionally present, positioned laterally on inner side of peristome, in V-shaped portion, with curved and cuspidate mandible; none was present on the two colony fragments measured. Vicarious avicularia lacking. Ooecia not observed, but Marcus (1949) described them as prominent, globular, with porous surface, opening inside peristome. Ancestrula not observed.

Remarks. When introducing the new species Coleopora corderoi, Marcus (1949) distinguished it from other Coleopora species by features of the peristome, absence of tubes on frontal wall, presence of avicularia with curved cuspidate mandible, and prominent ooecium opening inside the peristome. He described very large zooids, reaching 1.4–1.8 mm in length and 0.7 mm in width, while his drawing shows zooids about 1.2 mm long (see Marcus 1949: fig. 23). It was not possible to reexamine Marcus’ specimens as the holotype of C. corderoi is missing, along with other Brazilian specimens identified by Ernst Marcus that were deposited in the Museum of Natural History ( UK) (M. Spencer Jones pers. comm., 2009) and Museu de Zoologia of Universidade de São Paulo ( Brazil). Some of the colonies of M. corderoi collected north of Rio de Janeiro by the Hassler Expedition have smaller zooids (MCZ Hassler Box 33), more like those of Marcusadorea jamaicensis specimens, but colonies with large zooids (MCZ Hassler Box 36) as described by Marcus (1949) were also found. The Brazilian colonies found in MCZ collection ( Figures 1–6 ) lack avicularia and ovicells.

Other authors have already described further species with large zooids, raised peristomes, irregularly porous frontal shields, and raised lateral walls adjacent to the areolar pores, which we consider as the diagnostic features of the new genus Marcusadorea . The species M. tubulosa ( Canu & Bassler, 1928) differs from M. corderoi by having smaller zooids and suboral avicularia with curved spatulate mandibles; colonies in which suboral avicularia are lacking might be difficult to identify; however, colonies of Marcusadorea without avicularia may be distinguished by features of the peristome and orifice. Marcusadorea corderoi has an almost rounded secondary orifice at the end of the peristome in most zooids. In the other three species of the genus, the peristome of most zooids is incomplete; there is a characteristically proximally incomplete Ushaped slit in Marcusadorea jamaicensis n. sp., a broader proximal V-shaped to U-shaped gap in M. tubulosa , and a quadrangular to subtriangular one in M. efatensis ( Tilbrook, 2006) .

Distribution. Western Atlantic – Brazil: Rio de Janeiro (present study) and Espírito Santo states ( Vieira et al. 2008).

Figures

FIGURES 6–11. Marcusadorea corderoi (Marcus, 1949) n. comb. 6–8, MCZ Hassler Expedition Box 33, off Rio de Janeiro, Brazil. 6, Group of autozooids; 7, close-up of autozooids; 8, close-up of orifice. 9–11, MCZ Hassler Expedition Box 36, off Rio de Janeiro, Brazil. 9, Small piece with four autozooids; 10, close-up of autozooid; 11, close-up of orifice.

FIGURES 1–5. Marcusadorea jamaicensis n. sp. 1, VMNH 13659 (Holotype), Rio Bueno, Jamaica. Colony with two ooecia. 2–3, AMNH bryozoan collection, Rio Bueno, Jamaica. 2, Group of autozooids; 3, ovicelled zooid in lateral view. 4–5, VMNH 13660 (Paratype), Rio Bueno, Jamaica. 4, Orifice with avicularium; 5, close-up of peristomial avicularium.