Schizoporella Hincks, 1877

Ryland, John S., Holt, Rohan, Loxton, Jennifer, Spencer Jones, Mary E. & Porter, Joanne S., 2014, First occurrence of the non-native bryozoan Schizoporella japonica Ortmann (1890) in Western Europe, Zootaxa 3780 (3), pp. 481-502 : 484

Genus Schizoporella Hincks, 1877

Type species. Lepralia unicornis Johnston in Wood, 1844.

Diagnosis. Colony encrusting, unilaminar to multilaminar, sheet-like or mammillate, or developing partially erect plates and mounds. Autozooids with an evenly perforated cryptocystidean frontal shield. Orifice with clearly differentiated anter and poster, the latter more or less narrowed to form a sinus; condyles well defined. Avicularia adventitious, occasionally dimorphic, typically adjacent to the autozooid orifice. Oral spines impermanent or absent. Ovicell recumbent on distally succeeding autozooid, prominent, spherical or subglobular, perforate, ribbed or umbonate. Vertical walls with uniporous or multiporous septula ( Hayward & Ryland 1999).

Remarks. The species of Schizoporella fall into two fairly distinct groups, based on the shape of the sinus. In the first, the sinus is broadly and shallowly U-shaped, wider than deep; in the second, the sinus is narrow, as deep— or deeper—than its greatest width. All the species to be discussed in this paper ( S. errata , S. japonica , S. pseudoerrata and S. unicornis ) belong in the first group. The main characters traditionally used for species separation in this group are: size, budding pattern, and layering of the colony; the shape of the orifice (including that of the sinus); the appearance of the porous frontal wall; and the morphology of the ovicell, especially ribbing and distribution of pores.

Despite being reasonably distinct, the above species have often been confused with each other, especially when found in fouling communities, usually as a result of ignoring well-described characteristics. Known British species (also including S. errata , which has not yet been recorded from Britain) have been described by Hayward & Ryland (1995, 1999), while SEM-illustrated redescriptions of the type specimens of two of these ( S. errata and S. unicornis ) have been recently published ( Tompsett et al. 2009). Details of the specimens we have studied are given in Appendix 1.