Short Communication Disease profiles of juvenile edible crabs (Cancer pagurus L.) differ at two geographically-close intertidal sites Tara J. Thrupp a , Edward C. Pope a , Miranda M.A. Whitten a,b , James C. Bull a , Emma C. Wootton a , Morgan Edwards a , Claire L. Vogan b , Andrew F. Rowley a,⇑ a Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, Wales, UK b College of Medicine, Swansea University, Swansea SA2 8PP, Wales, UK article info Article history: Received 19 December 2014 Revised 7 April 2015 Accepted 11 April 2015 Available online 17 April 2015 Keywords: Mikrocytid infection Pink crab disease Disease ecology Crab fisheries Hematodinium abstract The prevalence of disease in edible crabs (Cancer pagurus) was assessed at two sites in South West Wales; one estuarine (Pembroke Ferry) and another facing open water (Freshwater East). Diseases included pink crab disease caused by Hematodinium sp., an infection of the antennal gland caused by Paramikrocytos canceri and an idiopathic inflammatory condition of the connective tissue surrounding the anterior ganglionic masses. This latter condition was only found in crabs from Pembroke Ferry. There was a significantly higher prevalence of pink crab disease at Freshwater East than Pembroke Ferry, although both sites had similar levels of infection by P. canceri. Ó 2015 Elsevier Inc. All rights reserved. 1. Introduction Infectious diseases can have profound effects on aquatic ecosys- tems. Our understanding of disease processes in the marine environment has been revolutionized as a result of a greater research focus and the development of new approaches to investi- gate host–pathogen interactions. Indeed, as a consequence of these studies, it has been discovered that climate change is driving changes in the range and severity of some diseases in various taxa resulting in epizootic outbreaks (e.g. Harvell et al., 2002; Burge et al., 2014). In terms of shellfish of commercial importance, sev- eral studies have shown how such diseases may be increasing lead- ing to potential economic loss (e.g. Travers et al., 2009; Mackenzie et al., 2014). The importance of baseline surveys of disease amongst shellfish of economic importance are essential reference points for later studies aiming to determine whether climate change can alter the relationship between host and pathogen (e.g. Rowley et al., 2014). The edible crab, Cancer pagurus, is an economically important species in Northern Europe. Landings of edible crabs from U.K. registered vessels have increased by 40% from 1996 to 2012 to a current level of 32 thousand tons p.a. with a current commercial value of over £40 million (MMO, 2013). Juvenile (pre-recruit) edibles live for 2–3 years within the intertidal and subtidal zones. They then migrate into deeper waters, only to return back on-shore to breed. Both pre-recruit and recruit C. pagurus are subject to a range of diseases caused by micro- and macro-parasites (Stentiford, 2008; Bateman et al., 2011). Of potential importance to the sustainability of the edible crab fishery is a disease caused by the dinoflagellate, Hematodinium sp. (Stentiford et al., 2002). Studies in Gower (South Wales, U.K.) have reported a high level of infection (ca. 30%) caused by this parasite in juvenile edible crabs, suggesting that it could be a major cause of mortality (Smith et al., 2015). Similarly, the recently discovered mikrocytid parasite, Paramikrocytos canceri, that infects the antennal gland of juvenile C. pagurus (Bateman et al., 2011; Hartikainen et al., 2014), has also been found at a high prevalence in these animals in the intertidal zone in Pembrokeshire (South West Wales, U.K.) but whether this results in their mortality, and hence loss from the fishery, is unclear (Thrupp et al., 2013). For fisheries scientists to model the potential influence of these and other diseases on populations of C. pagurus, it is important to ascertain if the prevalence of each condition varies within a par- ticular region and at different times of the year. As it is relatively easy to survey juvenile crabs while they are onshore, this approach can give valuable insight into the likelihood of losses caused by dis- ease in pre-recruits and the long-term impact of any reductions in their numbers to the fishery. Thus, in the current study, a survey was carried out of disease prevalence in pre-recruit populations http://dx.doi.org/10.1016/j.jip.2015.04.003 0022-2011/Ó 2015 Elsevier Inc. All rights reserved. ⇑ Corresponding author. E-mail address: a.f.rowley@swansea.ac.uk (A.F. Rowley). Journal of Invertebrate Pathology 128 (2015) 1–5 Contents lists available at ScienceDirect Journal of Invertebrate Pathology journal homepage: www.elsevier.com/locate/jip