Parasmittina, Osburn, 1952

Taylor, Paul D. & Tan, Shau-Hwai Aileen, 2015, Cheilostome Bryozoa from Penang and Langkawi, Malaysia, European Journal of Taxonomy 149, pp. 1-34 : 23

Parasmittina sp. 1

Fig. 12 D–F

Material

MALAYSIA: MSL BRY021b, Kuah jetty, Langkawi, on fouled rope hanging from jetty (with P. winstonae ).

Description

Colony encrusting, multiserial, unilamellar. Ancestrula and early astogeny not observed. Autozooids subhexagonal, small, about 0.30–0.32 mm long by 0.25–0.28 mm wide; boundary walls salient with a fine fissure; frontal shield convex, coarsely pustulose, marginal areolar pores large, no pseudopores; secondary orifice elliptical, about 0.10–0.12 mm wide, lappets highest proximolaterally, lyrula variable, typically narrow, 13–18 μm wide at tip; oral spine bases not observed; ovicell hyperstomial, broad, about 0.12–0.16 mm long by 0.15–0.20 mm wide, ectooecium with about 30 ridged pores, proximal and distal edges of ovicell overgrown by cryptocystal calcification. Avicularia of three types: (1) adventitious acuminate avicularia present on some proximal frontal shields, about 0.11 mm long by 0.07 mm wide, usually distally or distolaterally directed, rostrum an acute triangle, tip raised, rostral shelf shallow, cross-bar calcified, opesia semicircular; (2) adventitious spatulate avicularia present on some frontal shields, about 0.14 mm long by 0.05 mm wide, directed proximally or laterally towards autozooid median line, rostrum rounded with deep shelf, cross-bar calcified, opesia semicircular; (3) vicarious avicularia large, 0.23–0.38 mm long by 0.13–0.15 mm wide, scattered, directed proximally, rostrum initially tapering before becoming parallel-sided, tip well rounded, distal edge slightly serrated, rostral shelf deep, occupying half or more of rostrum length, cross-bar calcified, concave, opesia relatively small, crescent shaped ( Fig. 12F ).

Remarks

It has not been possible to identify this species of Parasmittina despite the combination of distinctive large vicarious avicularia and small adventitious avicularia of spatulate and acuminate types. Pending a more detailed study and a comprehensive comparison with the myriad of species of Parasmittina , it is therefore left in open nomenclature as Parasmittina sp. 1.

Figures

Fig. 12. Parasmittina spp. — A–C. P. raigioidea Liu et al., 2001. Pulau Betong, Penang, MSL BRY020b. A. Part of colony. B. Autozooids and avicularia. C. Orifice with lyrula and proximally directed adventitious avicularium. — D–F. Parasmittina sp. 1. Kuah jetty, Penang, MSL BRY021b. D. Colony (bottom) becoming overgrown by a colony of P. winstonae (top). E. Ovicellate zooids and proximally directed vicarious avicularia. F. Detail showing a proximally directed vicarious avicularium (upper left of centre) with a proximally directed spatulate adventitious avicularium to its lower right and a distally directed acuminate adventitious avicularium to the lower right of that. — G–I. Parasmittina sp. 2. Kampung Kuala Temoyong, Langkawi, MSL BRY012b; encrusting a large gastropod shell. G. Part of colony. H. Group of zooids. I. Autozooids and an adventitious avicularium. Scale bars: A, H = 500 μm; B, E–F = 200 μm; C, I = 100 μm; D, G = 1 mm.