Bryopesanser pesanseris ( Smitt, 1873 )

Tilbrook, Kevin J., 2012, Review of the bryozoan genus Bryopesanser Tilbrook, 2006 (Escharinidae: Cheilostomata) with the description of 11 new species, Zootaxa 3165, pp. 39-63 : 41-42

Bryopesanser pesanseris ( Smitt, 1873)

( Figures 1–4 , Table 1)

Hippothoa pes anseris Smitt, 1873: 43 , pl. 7, figs 159, 160.

Schizoporella pesanseris: Waters 1899: 11 , pl. 3, figs 7, 8.

Escharina pes-anseris: Norman 1909: 302, pl. 40, fig. 7.

Mastigophora pesanseris: Canu & Bassler 1928a: 133 , pl. 21, fig. 9; pl. 34, fig. 4. Mastigophora pesanseris: Canu & Bassler 1928b: 39 , pl. 9, fig.1. Escharina pesanseris: Winston 1984: 26 , figs 53–55.

Bryopesanser pesanseris: Tilbrook 2006: 253 , pl. 55, figs A–C.

Material examined. Holotype: SMNH 1791, West of Tortugas, 77 m. Other material examined: NHMUK 1911.10.1.1212, Madeira 1892, Norman Collection; USNM 7545, Albatross Station D2639, Straits of Florida, 25°04’50” N, 80°15’10” W, 102 m (56 fms); USNM 8572, Norseman Stn 348, East of Bahia, Brazil, 12°48’ S, 38° W, 49 m (27 fms).

Description. Autozooids irregularly polygonal, 0.55–0.65 x 0.35–0.45 mm, separated by shallow grooves. Frontal shield granular, convex, pores small; very small single, or paired lateral areolar septular pores. Primary orifice slightly longer than wide, 0.11 x 0.10 mm excluding sinus, anter deeply arched, proximal border straight, slightly raised medially; condyles shallow, slightly denticulate; sinus drop-shaped. Autozooids with 7 regularly spaced oral spines, ovicellate zooids with 6 oral spines, the distalmost pair slightly incorporated into the ovicell. Proximal peristome raised, a spire-like median mucro developing with ontogeny. Avicularia lateral to most proximal pair of spines, distally directed; medium-sized rostrum, open-ended, crossbar complete; mandible fan-shaped, with 2 prominent ribs. Ovicell with raised process frontally.

Remarks. The distinguishing characters of Bryopesanser pesanseris include the slightly denticulate condyles and a mucro on the proximal part of the peristome and the ovicell. This process is not unique to this species but is characteristic of it. Winston (1984) illustrated the ancestrula of B. pesanseris , which is identical to that of B. latesco as illustrated by Tilbrook (2006).

As well as Bryopesanser pesanseris, Canu & Bassler (1928b) described two other species from Brazil that they attributed to Mastigophora ― M . scopae ( Canu & Bassler, 1928b: 40), redescribed as Rogicka scopae by Viera et al., 2010, and M. parviseta ( Canu & Bassler, 1928b: 41) , which clearly belongs to Bryopesanser but the precise characterisation of this species in relation to its congeners needs verifying.

Distribution. Bryopesanser pesanseris sensu stricto is found with certainty only in the Atlanto-Caribbean region: Florida, Belize, Brazil, Madeira. The material examined from these fairly widespread locations is morphologically identical; a comprehensive molecular study would be required to demonstrate if there are cryptic species in a broader complex.

Figures

FIGURES 1 – 4, Bryopesanser pesanseris. 1, Holotype specimen, SMNH 1971, West of Tortugas; 2, USNM 7545, Straits of Florida; 3, NHMUK 1911.10. 1.1212, Madeira; 4, USNM 8572, Brazil. Scale bars: 1, 200 µm; 2, 100 µm; 3, 200 µm; 4, 100 µm.