(24) Ascidiella scabra (Müller, 1776)

Status in U.K. – cryptogenic.

Ascidiella scabra has been recorded from many monitoring programme sites, each year since 2012, from scrape, settlement panel and rapid assessment samples.

Genetic studies (Nishikawa et al. 2014) have confirmed the distinction between this species and A. aspersa, to which it is very similar and the two species share the same type locality. It is likewise considered invasive in Japan but has been listed as cryptogenic in the Mediterranean (López-Legentil and Legentil 2015). It should be considered cryptogenic in British waters until its origin has been determined.

NMS voucher reference number: NMS.Z.2017.144.120.