First occurrence of the non-native bryozoan Schizoporella japonica Ortmann (1890) in Western Europe.

Schizoporella japonica Ortmann was described from Japan but was subsequently introduced on Pacific oysters to the Pacific coast of North America, where it is now well established. In this paper we record it for the first time in European waters. The initial discovery was in a marina at Holyhead, North Wales, in July 2010 but S. japonica has since been observed abundantly in the Orkney Islands (from May 2011) and, subsequently, at other localities in northern Scotland. Introduction seems most likely to have been on an ocean-going vessel. The British material is here fully described and illustrated with SEMs and colour photographs; some unusual characters are discussed. Unlike other recently introduced bryozoans, S. japonica is a cold-water species and its breeding season in Britain extends through the winter. Extensive confusion between this and other species of Schizoporella on the west coast of Canada and the USA led us to make thorough morphometric comparisons between the species concerned (Schizoporella unicornis (Johnston in Wood), Schizoporella errata (Waters) and Schizoporella pseudoerrata Soule, Soule and Chaney). Zooid size in cheilostomate bryozoans is variable and often an unreliable character for species separation but shape (and therefore ratios between variables, which are independent of size) are often valuable: S. japonica zooids have a much greater length:width ratio than the other species. Density of frontal pseudopores provides a useful discriminatory character. Schizoporella unicornis, repeatedly reported in error from the Pacific coast of North America, does not occur there; it is a European species. Full comparisons are made between S. japonica and S. unicornis for European identification and between S. japonica, S. errata and S. pseudoerrata (which are also illustrated) for North American localities.

A checklist of marine bryozoan taxa in Scottish sea regions.

Contemporary and historical bryozoan records were compiled to provide a comprehensive checklist of species in Scottish waters. The checklist comprises 218 species in 58 families, with representatives from each of the extant bryozoan orders. The fauna was relatively sparse compared to other regions for which bryozoan checklists were available e.g. New Zealand and Australia. Six non-indigenous bryozoan species from the Scottish seas region were included in the checklist. Baseline information on species distributions, such as that presented in this checklist, can be used to monitor and manage the impact of human activities on the marine environment, and ultimately preserve marine biodiversity.

Skeletal carbonate mineralogy of Scottish bryozoans.

This paper describes the skeletal carbonate mineralogy of 156 bryozoan species collected from Scotland (sourced both from museum collections and from waters around Scotland) and collated from literature. This collection represents 79% of the species which inhabit Scottish waters and is a greater number and proportion of extant species than any previous regional study. The study is also of significance globally where the data augment the growing database of mineralogical analyses and offers first analyses for 26 genera and four families. Specimens were collated through a combination of field sampling and existing collections and were analysed by X-ray diffraction (XRD) and micro-XRD to determine wt% MgCO3 in calcite and wt% aragonite. Species distribution data and phylogenetic organisation were applied to understand distributional, taxonomic and phylo-mineralogical patterns. Analysis of the skeletal composition of Scottish bryozoans shows that the group is statistically different from neighbouring Arctic fauna but features a range of mineralogy comparable to other temperate regions. As has been previously reported, cyclostomes feature low Mg in calcite and very little aragonite, whereas cheilostomes show much more variability, including bimineralic species. Scotland is a highly variable region, open to biological and environmental influx from all directions, and bryozoans exhibit this in the wide range of within-species mineralogical variability they present. This plasticity in skeletal composition may be driven by a combination of environmentally-induced phenotypic variation, or physiological factors. A flexible response to environment, as manifested in a wide range of skeletal mineralogy within a species, may be one characteristic of successful invasive bryozoans.