Discussion
Parasites can have a range of negative effects on their crustacean hosts, from reducing growth to increasing mortality. Recent reported declines in velvet crab in Ireland lead to the finding of several microparasites infecting these crabs, with a particularly high incidence of a protozoan parasite
Paramarteilia sp. The genus
Paramarteilia currently consists of three species. Parasites of this genus have been found in other crustacean hosts such as the brown and spider crabs (Ward
et al., 2016) and
Paramarteilia sp. is thought to use a vertical transmission pathway, from mother to offspring, in
Echinogammarus marinus (Guler
et al., 2018). As an important commercial species in Ireland, velvet crab provide an income source to smaller inshore fishers. However, little is known about the prevalence, abundance and potential impacts of the parasites found on these crab hosts. Due to the potential effects that parasites can have on commercial crustacean species and their associated fisheries, further research is required. We assessed the presence and prevalence of microparasites in velvet crab in Galway Bay across four seasons. Of the crabs analysed so far, approximately 50% of crabs have been found with
Paramarteilia sp. The parasite’s presence was identified following histological preparations of tissue, and average counts were calculated for each tissue positive for
Paramarteilia sp. The prevalence of the parasite varied by season, with infection higher in winter and spring. Prevalence also varied by crab size, and between males and females, and these findings will be presented. Further work will involve additional seasonal sampling and investigating the presence of the parasite
Paramarteilia sp. in other crustacean species. Findings from this study will contribute to our understanding of host-parasite interactions and to the effective management of velvet crab fisheries in Ireland.
References:
Guler, Y.
et al. (2018) ‘Population screening and transmission experiments indicate paramyxid-microsporidian co-infection in
Echinogammarus marinus represents a non-hyperparasitic relationship between specific parasite strains’,
Scientific Reports. Springer US, 8(1), pp. 8–15. doi: 10.1038/s41598-018-22276-y.
Ward, G. M.
et al. (2016) ‘A new phylogeny and environmental DNA insight into paramyxids: an increasingly important but enigmatic clade of protistan parasites of marine invertebrates’,
International Journal for Parasitology. Elsevier Ltd, 46(10), pp. 605–619. doi: 10.1016/j.ijpara.2016.04.010.
