Prevalence, intensity, and aneuploidy patterns of disseminated neoplasia in cockles (Cerastoderma edule) from Arcachon Bay: Seasonal variation and position in sediment

Influence of disseminated neoplasia, trematode infections and gametogenesis on surfacing and mortality in the cockle Cerastoderma edule

“…Neoplasms in C. edule were initially recorded in 1982 in Cork Harbour, Ireland, and in that same year they were also reported in Brittany, France (Twomey & Mulcahy 1988, Twomey 1994, Villalba et al 2001, Romalde et al 2007, Le Grand et al 2010. Disseminated neoplasia is a proliferative disorder of the haemocytes and is of unknown origin; it is characterised by very large, mitotically active, pleomorphic and highly invasive cells (Twomey 1994, Krishnakumar et al 1999, Collins & Mulcahy 2003, Barber 2004, Ciocan et al 2006, Le Grand et al 2010, Díaz et al 2011.…”

“…Neoplasms in C. edule were initially recorded in 1982 in Cork Harbour, Ireland, and in that same year they were also reported in Brittany, France (Twomey & Mulcahy 1988, Twomey 1994, Villalba et al 2001, Romalde et al 2007, Le Grand et al 2010. Disseminated neoplasia is a proliferative disorder of the haemocytes and is of unknown origin; it is characterised by very large, mitotically active, pleomorphic and highly invasive cells (Twomey 1994, Krishnakumar et al 1999, Collins & Mulcahy 2003, Barber 2004, Ciocan et al 2006, Le Grand et al 2010, Díaz et al 2011.Throughout their range Cerastoderma edule are known to act as the first or second intermediate host for at least 16 digenean parasites from 7 different families, of which the family Echinostomatidae is the most dominant (de Montaudouin et al 2009). A recent study along the southwest coast of Ireland found 8 species of digenean parasites in C. edule, and Meiogymnophallus minutus (synonym Parvatrema minutus, Scholz 2002) was the most common in terms of prevalence and intensity of infection (Fermer et al 2009).…”

“…In another study, Le Grand et al (2010) classified the degree of neoplasia by means of 3 different techniques and scales: assessment of haemolymph cell monolayers, histological examination and flow cytometry of the DNA content in the cockle cells. Generally the condition was localised within the tissues and few cockles displayed the neoplastic condition throughout all of the tissues.The prevalence of neoplasia has been in some cases linked to higher temperatures, such as in a previous Irish study (Twomey 1994); however, in a study of disseminated neoplasia in Cerastoderma edule from Arcachon Bay, France, prevalence of neoplasia was not related to water temperature (Le Grand et al 2010). In the present study the highest prevalence of neoplasia among moribund and buried cockles was observed in July, so the influence of temperature on neoplasia development may be only one of a range of factors that are significant.…”

Parasites, pathological conditions and resistance to Marteilia cochillia in lagoon cockle Cerastoderma glaucum from Galicia (NW Spain)

“…High mortality linked with neoplasia has been reported from Galician common cockle C. edule beds (Carballal et al 2001, Villalba et al 2001, Ordás & Figueras 2005, Díaz et al 2016; this disease was also reported in cockles C. edule from Ireland (Twomey & Mulcahy 1988) and France (Poder & Auffret 1986, Le Grand et al 2010. In lagoon cockles, this disease had been reported in a single cockle C. glaucum from the Ría de Vigo (Rodríguez et al 1997).…”

Infection of Manila clams Ruditapes philippinarum from Galicia (NW Spain) with a Mikrocytos-like parasite

“…The rise to the surface of infaunal molluscs can be considered a precursor to death (Desclaux et al 2002, Le Grand et al 2010) when they are heavily stressed. In fact, surface clams showed either lower condition index or lower weight than buried clams while differences in size (length) were not significant, which suggests higher stress in surface clams.…”