Corey Holt – University of Exeter/CEFAS PhD Student
Corey is a PhD student predominantly based at the Centre for Environment, Fisheries & Aquaculture Science (CEFAS), Weymouth. He is currently investigating the gut microbiota of lobsters and other marine invertebrates in the hope of bettering our understanding of how and why this complex microbial community changes in response to environment and disease. Whilst studying for his degree at the University of Exeter, Corey worked on human gut parasites and was introduced to the proposed links between the gut microbiota and a range of health conditions, and has been interested in this emerging area of study ever since.
In conjunction with the National Lobster Hatchery and the University of Exeter, Corey is studying for his PhD within the Pathology and Molecular Systematics team at CEFAS. Together with other stakeholders on the Lobster Grower project, he is working to assess the potential of novel sea-based culturing techniques for on-growing of European lobsters – with potential for both aquaculture and conservation of wild fisheries. Corey will be sequencing the microbes within the digestive tract of ocean-grown lobsters and correlating the results with spatial and temporal changes in their environment, as well as assessing the health of juvenile and adult lobsters through histological and molecular analysis. Corey’s research aims to help us better understand the health status of fished European lobsters, elucidate the role the gut microbiota plays in maintaining lobster health, and even characterising the wild diet of lobsters or several life-stages. His research could also identify ways in which we can manipulate the microbial communities within the gut to improve the growth and survivability of our lobsters
Holt C, Foster R, Daniels CL, Van Der Giezen M, Feist SW, Stentiford GD, & Bass D. (2018) Halioticida noduliformans infection in eggs of lobster (Homarus gammarus) reveals its generalistic parasitic strategy in marine invertebrates. Journal of Invertebrate Pathology. 154: 109–116.
Full text Abstract
A parasite exhibiting Oomycete-like morphology and pathogenesis was isolated from discoloured eggs of the European lobster (Homarus gammarus) and later found in gill tissues of adults. Group-speciﬁc Oomycete primers were designed to amplify the 18S ribosomal small subunit (SSU), which initially identiﬁed the organism as the same as the ‘Haliphthoros’ sp. NJM 0034 strain (AB178865.1) previously isolated from abalone (imported from South Australia to Japan). However, in accordance with other published SSU-based phylogenies, the NJM 0034 isolate did not group with other known Haliphthoros species in our Maximum Likelihood and Bayesian phylogenies. Instead, the strain formed an orphan lineage, diverging before the separation of the Saprolegniales and Pythiales. Based upon 28S large subunit (LSU) phylogeny, our own isolate and the previously unidentiﬁed 0034 strain are both identical to the abalone pathogen Halioticida noduliformans. The genus shares morphological similarities with Haliphthoros and Halocrusticida and forms a clade with these in LSU phylogenies. Here, we conﬁrm the ﬁrst recorded occurrence of H. noduliformans in European lobsters and associate its presence with pathology of the egg mass, likely leading to reduced fecundity.