Microporella Hincks 1879
Creators: name: Taylor, Paul D.
name: Tan, Shau-Hwai Aileen
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Bryozoa
Gymnolaemata
Cheilostomatida
Microporellidae
Microporella

description: Microporella sp.
Fig. 15 D–G
Material
MALAYSIA: MSL BRY012d, Kampung Kuala Temoyong, Langkawi, colony encrusting interior of large gastropod shell.
Description
Colony encrusting, multiserial, unilamellar. Ancestrula and early astogeny not observed. Autozooids small, about 0.35–0.37 mm long by 0.28 mm wide, subhexagonal, rounded distally; distinct with interzooidal grooves; frontal shield convex, porous, a few elongate areolar pores around perimeter and numerous smaller circular pseudopores elsewhere, coarsely pustulose; orifice semi-elliptical, small, about 0.06 mm long by 0.08–0.09 mm wide, proximal edge straight, without teeth or condyles, distal edge beaded; oral spines numbering three in non-ovicellate zooids, one distal medial and two lateral, level with orifice mid-length, not visible in ovicellate zooids; ascopore crescent-shaped, about 0.04 mm wide, toothed, set in a rugose prominence about 0.06 mm long by 0.08 mm wide, close to proximal edge of orifice, but separated by a narrow band of non-porous frontal shield (Fig. 15E); ovicell personate, proximal border of secondary orifice broadly U-shaped, ooecium broader than long, about 0.16 mm long by 0.20 mm wide, porous except in the most proximal medial part, calcification continuous with that of frontal shield of distal zooid, on which ovicell rests without extending as far distally as ascopore. Adventitious avicularia present in a minority of autozooids, single, located about mid-length on autozooid, directed laterally outwards, small, about 0.08 mm long by 0.06 mm wide; rostrum with concave sides and open end (i.e., channeled); mandible setose, almost twice length of rostrum; opesia semicircular.
Remarks
Microporella is a highly species-rich genus with a global distribution (Taylor & Mawatari 2005). Differences between species can be very subtle. The species described here is characterized by having: (1) unpaired avicularia, often lacking altogether, laterally directed; (2) a broad crescent-shaped ascopore set in a wide rugose prominence; (3) three oral spines; and (4) an orifice lacking both teeth and condyles along the proximal edge but having a beaded distal edge. A beaded (or denticulate) distal orificial edge occurs in relatively few species of Microporella, such as M. serrata Mawatari & Suwa, 1998, M. rogickae Winston, Hayward & Craig, 2000, and M. browni Harmelin, Ostrovsky, Cáceres-Chamizo & Sanner, 2011. In M. serrata the avicularia are located much more distally than in the species from Langkawi and the ascopore is cribriform. Condyles are present at the proximolateral corners of the orifice in both this species and M. rogickae, the latter having 4–5 oral spines (cf. 3 in the species described here) and a much thicker proximal edge to the personate ovicells, whereas in M. serrata 4 oral spines are present and the ovicells are not personate. Although the Langkawi species may be new, its formal description must await additional material.
description: Published as part of Taylor, Paul D. & Tan, Shau-Hwai Aileen, 2015, Cheilostome Bryozoa from Penang and Langkawi, Malaysia, pp. 1-34 in European Journal of Taxonomy 149 on page 28, DOI: 10.5852/ejt.2015.149, http://zenodo.org/record/3787554