Marcusadorea jamaicensis, 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 : 59-61

Marcusadorea jamaicensis n. sp.

( Figures 1–5 , 16–17 ; Table 1)

Coleopora corderoi: Winston 1986: 16 , figs 68–69. Non Coleopora corderoi Marcus 1949 .

Holotype. VMNH 13359 ; Marcusadorea jamaicensis ; Rio Bueno , Jamaica, 10 m, coll. J.B.C. Jackson, 1978.

Paratypes. VMNH 13660–13662 ; Marcusadorea jamaicensis ; Rio Bueno , Jamaica, 10 m, coll. J.B.C. Jackson, 1978, 3 colonies .

Description. Colonies encrusting, unilaminar; living colonies bright orange. Autozooids large (averaging 0.975 mm long, 0.615 mm wide), irregularly polygonal to rectangular, separated by distinctly raised lateral wall junctions. Frontal shield convex, surface granular with small scattered pores, these becoming obscured by a tuberculated frontal wall with increasing calcification; some larger marginal areolar pores remaining visible. Primary orifice bell-shaped, wider proximally, anter arched, U-shaped, separated from broad and shallow poster by barely projecting condyles (mean, N=3, 0.140 mm length by 0.178 mm width of illustrated specimen VMNH 13662, Figure 17 , primary orifice 0.172 mm length by 0.210 mm width). No oral spines. Peristome tubular, entire or proximally incomplete. Secondary orifice mostly rounded to oblong, with U- to Vshaped proximal edge (0.262 mm length by 0.227 mm width). Suboral avicularium occasional, positioned laterally on inner side of peristome, in pseudosinus, with curved and cuspidate mandible; rostrum triangular, hooked distally, directed frontally, crossbar complete. Vicarious avicularia lacking. Ooecium prominent, globular (0.239 mm long, 0.439 mm wide), with porous surface, opening inside peristome. Embryos cherry red. Polypides with 20–22 tentacles. Ancestrula not observed.

Remarks. As noted below, 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 similar to the Jamaican specimens, but colonies with larger zooids (MCZ Hassler Box 36) as described by Marcus (1949) also were found. The morphology of the two species is very similar, and the zooid length of Jamaican specimens overlaps (barely) with those from Brazil (MCZ Hassler Box 33). Since M. corderoi is a species that shows considerable variability in zooid size and shape, this could be considered geographic variation within one species. However, the dimensions of the secondary orifice and its proportion relative to zooid length raise difficulties that are best resolved by considering the Jamaican material as belonging to a second, previously undescribed species. This species, described under the name of Marcusadorea jamaicensis , has a zooid length only 81% and 76% of the M. corderoi specimens from MCZ Box 33 and Box 36 respectively. The length of the secondary orifice in M. jamaicensis is 60% and 51% of M. corderoi from MCZ Box 33 and MCZ Box 36 respectively. Moreover, the ratio of zooid length to secondary orifice length is about 3.7–1 for M. jamaicensis specimens, versus 2.4–1 and 2.9–1 for Box 33 and Box 36, respectively.

Marcusadorea jamaicensis is characterized by an almost cleithridiate secondary orifice in most zooids; rarely the peristome may be proximally incomplete as a U-shaped slit.

Distribution. Western Atlantic – Jamaica. Cryptic reef habitats, 10– 20 m.

Figures

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.

FIGURES 16–19. Internal view of Marcusadorea species. 16–17, Marcusadorea jamaicensis n. sp.; VMNH 13662 (Paratype), Rio Bueno, Jamaica. 16, Frontal shield of two autozooids; 17, close-up of orifice, note the barely projecting condyles. 18–19, Marcusadorea tubulosa (Canu & Bassler, 1928); MZUSP 0176 Alagoas, Brazil. 18, Frontal shield of two autozooids; 19, close-up of orifice.