Bryopesanser tiara, 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 : 59-60

Bryopesanser tiara n. sp.

( Figures 52–55 , Table 1)

Mastigophora honoluluensis: Canu & Bassler 1927: 36 , pl. 8 fig. 6.

Material. Holotype (here selected): USNM 8463, Albatross Stn 3813, Diamond Head Light, south coast of Oahu, 21°15’25” N, 157°48’34” W, 335–483 m (264–183 fms), encrusting coral.

Description. Colony large, approx. 24 mm 2. Autozooids 0.70–0.90 x 0.50–0.60 mm, irregularly polygonal, distinct, separated by shallow grooves. Frontal shield almost smooth, slightly convex, evenly perforated by small multiporous pores, only obvious after abrasion, 6-8 areolar septular pores, at lateral and proximal angles. Primary orifice rounded, as wide as long, ca 0.12 x 0.12 mm excluding sinus, anter deeply arched, proximal border straight, condyles smooth dipping medially towards drop-shaped sinus, as wide as long. Oral spines 9, evenly spaced. Proximal peristome flared, a slight median mucro developing with ontogeny. Avicularia originating lateral to the second most proximal pair of spines, rostra small with smooth edges, open-ended distally, crossbar complete, slightly distomedially directed. Ovicell hyperstomial, producing a slightly thickened proximal edge. Ovicellate zooids with 8 oral spines, the distalmost pair incorporated into ovicell.

Etymology. Latin tiara , headdress, alluding to the type locality, Diamond Head.

Remarks. Bryopesanser tiara n. sp. is characterised by the details of its primary orifice, the number of oral spines, and its frontal-shield morphology with numerous areolar septular pores. The species differs from B. pesanseris in having nine oral spines as in B. baderae n. sp. and B. thricyng n. sp. These three species are separated by the shape of the primary orifice, the extent of the orificial peristome, ovicell ornamentation, and the size and direction of the avicularian rostra.

Bryopesanser tiara n. sp. is known from a single abraded colony encrusting a small piece of coral. Canu & Bassler (1927) recorded this specimen as Mastigophora honoluluensis , based on Chorizopora honoluluensis Busk, 1885 but Busk’s Challenger specimen (NHMUK 1887.12.9.584) does not belong to Bryopesanser or to the family Escharinidae ; it is in fact a celleporid and it requires further examination to determine the correct generic placement. Canu & Bassler (1927, p. 36, pl. 8, fig. 5) also recorded Mastigophora pesanseris from Hawaii, but although the specimen illustrated appears to be a species of Bryopesanser , specific assignment is not possible from the figure alone and their original material is missing (JoAnn Sanner, pers. comm.. 2011).

Distribution. Bryopesanser tiara n. sp. is known only from a single abraded colony found at depth off the southernmost tip of the Hawaiian Island of Oahu.

Figures

FIGURES 52 - 55, Bryopesanser tiara n. sp. Holotype specimen, USNM 8463. Scale bars: 52, 200 µm; 53, 200 µm; 54, 100 µm; 55, 1000 µm.