dc.check.embargoformat	Not applicable	en
dc.check.info	No embargo required	en
dc.check.opt-out	No	en
dc.check.reason	No embargo required	en
dc.check.type	No Embargo Required
dc.contributor.advisor	Culloty, Sarah C.	en
dc.contributor.advisor	O'Riordan, Ruth M.	en
dc.contributor.author	Cross, Maud E.	en
dc.contributor.funder	European Commission	en
dc.date.accessioned	2014-12-08T14:40:22Z
dc.date.available	2014-12-08T14:40:22Z
dc.date.issued	2014
dc.date.submitted	2014
dc.description.abstract	This study was undertaken to investigate the general biology, including the reproductive cycle and health status, of two clam taxa in Irish waters, with particular reference to the Irish Sea area. Monthly samples of the soft shell clam, Mya arenaria, were collected from Bannow Bay, Co. Wexford, Ireland, for sixteen months, and of the razor clam, Ensis spp. from the Skerries region (Irish Sea) between June 2010 and September 2011. In 2010, M. arenaria in Bannow Bay matured over the summer months, with both sexes either ripe or spawning by August. The gonads of both sexes of E. siliqua developed over autumn and winter 2010, with the first spawning individuals being recorded in January 2011. Two unusually cold winters, followed by a warmer than average spring, appear to have affected M. arenaria and E. siliqua gametogenesis at these sites. It was noted that wet weight of E. siliqua dropped significantly in the summer of both 2010 and 2011, after spawning, which may impact on the economic viability of fishing during this period. Additional samples of M. arenaria were collected at Flaxfort (Ireland), and Ensis spp. at Oxwich (Wales), and the pathology of all clams was examined using both histological and molecular methods. No pathogenic conditions were observed in M. arenaria while Prokaryote inclusions, trematode parasites, Nematopsis spp. and inflammatory pathologies were observed at low incidences in razor clams from Ireland but not from Wales; the first time these conditions have been reported in Ensis spp. in northern European waters. Mya arenaria from sites in Europe and eastern and western North America were investigated for genetic variation using both mitochondrial (cytochrome oxidase I (COI) and 16S ribosomal RNA genes) and nuclear markers (10 microsatellite loci). Both mitochondrial CO1 and all nuclear markers showed reduced levels of variation in certain European samples, with significant differences in haplotype and allelic composition between most samples, particularly those from the two different continents, but with the same common haplotypes or alleles throughout the range. The appearance of certain unique rare haplotypes and microsatellite alleles in the European samples suggest a complicated origin involving North American colonization but also possible southern European Pleistocene refugia. Specimens of Ensis spp. were obtained from five coastal areas around Ireland and Wales and species-specific PCR primers were used to amplify the internal transcribed spacer region 1 (ITS1) and the mitochondrial DNA CO1 gene and all but 15 razor clams were identified as Ensis siliqua. Future investigations should focus on continued monitoring of reproductive biology and pathology of the two clam taxa (in particular, to assess the influence of environmental change), and on genetics of southern European M. arenaria and sequencing the CO1 gene in Ensis individuals to clarify species identity	en
dc.description.sponsorship	European Commission (Ireland Wales Programme 2007-2013 INTERREG 4A European Regional Development Fund)	en
dc.description.status	Not peer reviewed	en
dc.description.version	Accepted Version
dc.format.mimetype	application/pdf	en
dc.identifier.citation	Cross, M.E. 2014. Aspects of the biology of Mya arenaria and Ensis spp. (Mollusca; Bivalvia) in the Irish Sea and adjacent areas. PhD Thesis, University College Cork.	en
dc.identifier.endpage	190
dc.identifier.uri	https://hdl.handle.net/10468/1723
dc.language.iso	en	en
dc.publisher	University College Cork	en
dc.rights	© 2014, Maud E. Cross	en
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/	en
dc.subject	Mya arenaria	en
dc.subject	Ensis siliqua	en
dc.subject	Irish Sea	en
dc.subject	Histology	en
dc.subject	Molecular ecology	en
dc.subject	Population genetics	en
dc.subject	Marine biology	en
dc.thesis.opt-out	false
dc.title	Aspects of the biology of Mya arenaria and Ensis spp. (Mollusca; Bivalvia) in the Irish Sea and adjacent areas	en
dc.type	Doctoral thesis	en
dc.type.qualificationlevel	Doctoral	en
dc.type.qualificationname	PhD (Science)	en
ucc.workflow.supervisor	s.culloty@ucc.ie

Aspects of the biology of Mya arenaria and Ensis spp. (Mollusca; Bivalvia) in the Irish Sea and adjacent areas

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