Cribrilaria vicariata ( Waters, 1923 ) Jain & Gordon & Huang & Kuklinski & Liow, 2022

Jain, Sudhanshi S., Gordon, Dennis P., Huang, Danwei, Kuklinski, Piotr & Liow, Lee Hsiang, 2022, Targeted collections reveal new species and records of Bryozoa and the discovery of Pterobranchia in Singapore, Raffles Bulletin of Zoology 70, pp. 257-274 : 263

Cribrilaria vicariata ( Waters, 1923) , new combination

( Fig. 3D, E )

Puellina innominata var. vicariata Waters, 1923: 559 , pl. 17, fig. 3.

Colletosia radiata: Harmer, 1926: 475 (part). Non Eschara radiata Moll, 1803 .

Cribrilaria aff. radiata: Ristedt, 1985: 20 , fig. 3e‒h. Non Eschara radiata Moll, 1803 .

Puellina vicariata: Tilbrook & Gordon, 2016: 597 .

Material examined. BLEED 1540 ( University of Oslo ), Pulau Semakau, Singapore, 0 m, 7 May 2019 .

Description. Colony extensive, forming uni‒bilayered sheets up to 4‒5 cm in diameter. Zooids subhexagonal [350‒482 μm long (mean 403 μm), 217‒385 μm wide (mean 292 μm), n = 14]. Costal shield almost flattened, with no recognisable gymnocyst, comprising 18‒24 pinnate costae very variable in length and width, the most proximal ones typically shortest, while even some lateral costae very narrow; no pelmatidia; first row of costae fused medially below the proximal edge of the orifice, forming conspicuous narrow groove with an almost rounded proximal pore; outermost intercostal pores large and rounded; almost 6 intercostal lacunae with 1‒2 minute denticles projecting into each lacuna. Orifice higharched [44‒68 μm long (mean 51 μm), 65‒102 μm wide (mean 74 μm), n = 14] and bordered by 4‒5 (mostly four) narrow spines. Avicularia interzooidal and variable in length [231‒642 μm long (mean 350 μm), 103–173 μm wide (mean 143 μm), n = 4], but notable for their proportionately long, very narrowly curving or rarely straight rostrum that can be weakly denticulate; distal tip rounded, palatal foramen elongate, no mandibular pivots; the proximal cryptocyst smooth. Avicularian cystid asymmetrically wider on one side than the other. Ovicells prominent, resting on concavity of distal costal field [172–239 μm long (mean 200 μm), 152–188 μm wide (mean 175 μm), n = 4]. Ooecium more or less smooth with a slight median keel and imperforate, maternal orifice often larger than non-ovicellate zooids, flanked on each side by a pair of spines. Kenozooids interzooidal, with cribrate frontals and no orifice, commonly occurring in clusters in the colony.

Remarks. This distinctive species has not been described since 1923. It differs from the European species Cribrilaria innominata ( Couch, 1844) in several important respects. The latter has only 9‒14 costae (most commonly 11‒12), 1‒5 intercostal lacunae (none denticulate) and four oral spines in ovicellate zooids; avicularia are proportionally shorter and straight. Cribrilaria vicariata is one of the more robust species of Cribrilaria , forming relatively thick, extensive crusts a few centimetres in diameter. The distinctive kenozooids illustrated by Waters (1923) were observed by us but not illustrated by SEM at the time of collecting (or subsequently).

Tilbrook & Gordon (2016) recorded a second species in Singapore (as Puellina sp. ) but did not determine the species. It is possible that it may correspond to “ Cribrilina radiata ” of Jullien (1881: 205; though not this European species), who reported finding several small colonies on stems of the gorgonian Melithaea australis (as Anicella ). He noted that they were especially remarkable for the straightness of the avicularia, which rules out C. vicariata . Cribrilaria egretta Ryland & Hayward, 1992 (as Puellina ) from Heron Island, Great Barrier Reef, is very close to C. vicariata and may be conspecific. It appears to differ in having oral-spine bases that are wider and close together. We here follow Rosso et al. (2018) in treating the three subgenera of Puellina as full genera.

Figures

Fig. 3. A‒C, Caulibugula mortenseni (Marcus, 1925); A, a single stem from a very large multistemmed colony; B, frontal and abfrontal sides of branches; C, autozooids and two birds-head avicularia; D, E, Cribrilaria vicariata (Waters, 1923); D, autozooids with four oral spine-bases and avicularia; E, a zooid with five oral spine-bases and an ovicell. Scale bars = 2 mm (A); 0.1 mm (B, C); 0.3 mm (D); 0.2 mm (E).