Development of a novel ageing method for European lobsters (RD051)

Project Outcome:

In this project we further developed and tested the use of methylation state at ribosomal DNA (rDNA) sites for predicting age in European lobsters (Homarus gammarus).

We extended the range of known age samples used to build the ageing model to include 59- and 67-month-old samples which allowed the ageing of lobsters known age lobsters to ~2 months accuracy.

We then estimated age in a sample of 100 wild lobsters with unknown age. The mean age was estimated at 7.2 years (range = 5.2 – 11.2 years). This is higher than our previous estimate based on a model that included samples up to 51 months of age and is compatible with age expectations from mark-recapture studies from the 1980s.

We investigated whether different tissues provide stable age predictions by sampling five different tissues from wild caught lobsters – leg, pleopod, antennae, tail notch and tail tissue. All tissues gave similar age predictions with the exception of antennae which gave significantly older estimates than the other tissues.

We investigated the role of the environment on the methylome by placing known age lobsters in two different sites (English Channel off St Austell and Menai Straight in North Wales). We detected no differences in the methylation signal after retrieval of the samples suggesting the ageing model may be robust to environmental differences, at least over the relatively short time-frame of the project and across two geographically similar sites (in comparison to the full range of the European lobster).