Bryopesanser latesco Tilbrook, 2006

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 : 46

Bryopesanser latesco Tilbrook, 2006

( Figures 11–16 , Table 1)

Schizoporella pes anseris: Waters 1909: 169 .

Mastigophora pesanseris: Canu & Bassler 1929 (part): 412, pl. 58, figs 7, 8. Bryopesanser latesco Tilbrook, 2006: 255 , pl. 55D, pl. 56A–C. Bryopesanser serratus Dick, Tilbrook & Mawatari, 2006: 2233 , fig. 5D–F. Escharina pesanseris: Amui & Kaselowsky 2006: 18 , figs 21–22. Escharina pesanseris: Gluhak et al. 2007: 419 , fig. 26A–B.

Bryopesanser sp. Sanfilippo et al. 2011 (part): 7.

Material examined. Holotype: NHMUK 2003.10.13.1, Magnetic Island, Townsville, Queensland. Other material examined: NHMUK 1998.6.18.10, Hurghada, Red Sea; USNM 8224, Albatross Station 5147, off Sulade Island, Sulu Archipelago, 5°41’40” N, 120°47’10” E, 38 m (21 fms); NHM 2006.7.21.17, Kapa’a Beach Park, Hawaii Island, 1 March 2005, 0.15 m low tide [holotype of B. serratus ]; NHM 2006.7.21.18, Kapa’a Beach Park, Hawaii Island, 1 March 2005, 0.15 m low tide [paratypes of B. serratus ].

Description. Autozooids irregularly polygonal, 0.60–0.75 x 0.45–0.60 mm, separated by shallow grooves. Frontal shield granular, convex, pores small; large areolae, single or paired, lateral or proximal. Primary orifice slightly longer than wide, ca 0.11 x 0.10 mm anter deeply arched, proximal border straight; condyles slightly denticulate, shallow, dipping medially; sinus drop-shaped, wider than long. Autozooids with 7 oral spines, ovicellate zooids with 6 oral spines, the most distal pair slightly incorporated into the ovicell. Proximal peristome widely flared, more raised medially. Avicularia originating lateral to second pair of spines, distomedially directed; rostrum medium-sized, open-ended, crossbar complete, mandible fan-shaped. Ovicell with a raised, pointed frontal process. Ancestrula longer than wide, ca 0.30 x 0.20 mm; 10 spines, 5 closely spaced distally, 5 widely spaced proximally; opesia over half of frontal surface.

Remarks. Bryopesanser latesco is characterised by details of the primary orifice, with its straight proximal border, slightly denticulate shallow condyles that dip medially, wider-than-long sinus, and flared peristome that is raised slightly medially. The position of the avicularia is also characteristic, as is their distomedial orientation. B. latesco produces circular colonies with a maximum area of about 1 cm 2, which is relatively large compared to other species of the genus.

Bryopesanser latesco differs from B. pesanseris in the position of its avicularia, though this can vary slightly within a colony, the medially dipping condyles, and the possession of a flared peristome rather than a peristome developed as a spire-like mucro. Whilst B. tonsillorum n. sp. also develops a peristomial mucro similar to B. latesco , this species differs from B. latesco in having multiporous frontal pores. B. tonsillorum n. sp. has much larger autozooids and smaller colonies than B. latesco .

Dick et al. (2006) noted that the ancestrula of their species was similar in form to subsequent autozooids, if smaller. This appears to be an error (also made by Harmer, 1957: 1000); they have evidently described instead the first recognisable autozooid (broken in their figure; Dick et al. 2006: Fig. 12 C) produced by a missing tatiform ancestrula (cf. Tilbrook 2006: pl. 55D, E). In Bryopesanser , the tatiform ancestrula produces a single primary autozooid distally, which in turn produces a single secondary autozooid distolaterally. The budding pattern then proceeds radially or, as Dick et al. (2006) described, i.e. with zooids of increasing size budded in a spiral pattern. The ancestrula may be subsequently overgrown, and thus obscured, leaving the primary autozooid as the apparent initiator of the colony ( Cook 1968; Winston 1984).

Distribution. Bryopesanser latesco is found throughout the Indo-Pacific from the Red Sea and the Maldives (Ostrovsky & Cáceres unpubl.), the Gulf of Aden ( Amui & Kaselowsky 2006), Thailand ( Sanfilippo et al. 2011), Taiwan ( Gluhak et al. 2007), Philippines ( Canu & Bassler 1929), Coral Sea, east to Hawaii (Dick et al. 2006) and at Bocas del Toro on the Caribbean coast of Panama (Tilbrook unpubl.).

Figures

FIGURES 11 – 16, Bryopesanser latesco. 11, 12. Holotype specimen, NHMUK 2003.10. 13.1, Queensland; 13, 15, USNM 8224, Sulu Archipelago; 14, 16, NHMUK 1998.6. 18.10, Red Sea. Scale bars: 11, 200 µm; 12, 50 µm; 13, 500 µm; 14, 100 µm; 15, 100 µm; 16, 50 µm.