Bryopesanser gardineri, Tilbrook, Kevin J., 2012

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 : 49-51

Bryopesanser gardineri n. sp.

( Figures 23–25 , Table 1)

Escharina pesanseris: Harmer, 1957 (part): 998.

Material. Holotype (here selected): NHMUK 1998.6.18.11, Funafuti, Tuvalu, J.S. Gardiner 11.01.1897, 73– 128 m (40–70 fms), 8°31ʹ S, 179°13ʹ E. Paratypes (here selected): NHMUK 1903.1.29.47B–D, Funafuti, Tuvalu, 110 m (60 fms). Other material examined: NHMUK 1903.1.29.47D, Funamanu, Tuvalu, 147 m (80 fms); NHMUK 2000.2.23.6, Siboga Stn 274, off Jedan Island, 5°28’2” S, 134°53’9” E, 26.12.1899, 57 m; NHMUK (SEM#2030), Tailevu ( Viti Levu), Fiji, 17°50ʹ S, 178°30ʹ E.

Description. Colony large, ca 16 mm 2. Autozooids 0.60–0.80 x 0.50–0.65 mm, hexagonal or irregularly polygonal, distinct, separated by shallow grooves. Frontal shield slightly nodular and convex, evenly perforated with numerous small multiporous pores, areolar septular pores laterally and proximally at each angle. Primary orifice as wide as long, ca 0.12 x 0.13 mm excluding sinus, anter deeply arched, proximal border convex, condyles coarsely denticulate, drop-shaped sinus, longer than wide. Oral spines 7, evenly spaced. Proximal peristome widely flared, developed into a raised, median mucro with ontogeny. Avicularia originating lateral to most proximal pair of spines, rostrum medium-sized, with serrated edges, open-ended distally, crossbar complete, distally or distomedially directed, mandible fan-shaped. Ovicell hyperstomial, producing a thickened proximal edge, sometimes with a raised process frontally. Ovicellate zooids with 6 oral spines, the most distal pair incorporated into ovicell.

Etymology. Named for Mr J.S. Gardiner who collected the type material of this species in 1897.

Remarks. Bryopesanser gardineri n. sp. is characterised by the details of the orifice, with its convex proximal border, coarsely denticulate condyles and longer-than-wide sinus, and the widely flared peristome often develops into a proximal mucro. The position of the avicularia (crossbar adjacent to most proximal oral spine) and their serrated edges are also characteristic.

Bryopesanser gardineri n. sp. differs from B. pesanseris in the shape of its oral condyles and in having multiporous frontal pores. These pores appear to develop late in ontogeny, but are also lost quite readily over time, leaving a frontal shield covered in large pores with jagged edges. The flared peristome of B. gardineri n. sp. sometimes develops a mucro, as in B. pesanseris , but the flaring is still visible. Multiporous frontal pores are found in four other Bryopesanser species.

Distribution. Bryopesanser gardineri n. sp. is found in Tuvalu and Fiji in the western Pacific Ocean.

Figures

FIGURES 23 – 25, Bryopesanser gardineri n. sp. 23, 24. Holotype specimen, NHMUK 1998.6. 18.11, Tuvalu; 25, NHMUK 1903.1.29.47 B, Tuvalu. Figures 26 – 28, Bryopesanser puncturella n. sp. Holotype specimen, NHMUK 2000.2. 23.9, Indonesia. Scale bars: 23, 500 µm; 24, 500 µm; 25, 50 µm; 26, 100 µm; 27, 500 µm; 28, 200 µm.