Ever wondered how old a lobster is? New project tries to find the answerSubscribe
24 February 2017
A new Queen's University Belfast (QUB) project, co-funded by Seafish (through the Strategic Investment Programme) and Kilkeel Seafoods aims to work out the relationship between size, age and reproduction of commercially-important UK crustaceans. The species being studied include crab, lobster and Nephrops norvegicus (the Norway lobster or Dublin Bay prawn).
Crustacean stock assessments have long been based on the size of specimens, due to the problem of assessing age and reproductive stage in animals which regularly moult their outer shell.
A new and promising direct-ageing method, published in 2012 by
Kilada et al 1 which involves measuring growth bands (similar to
those found in trees) from parts of the animals which are not
moulted, is being tested on important UK crustacean species.
To date, good progress has been made. Bands or rings have been observed using a variety of methods including x-ray tomography, and by creating histological and petrological sections or slices which can be viewed under a microscope.
The next stage is to determine whether these bands are related to chronological age. This will be achieved by carrying out laboratory experiments on moulting to confirm that structures which exhibit the bands are retained through the moult and are formed annually. It is imperative to confirm this before concluding that the observed rings or bands are an indicator of age in UK crustaceans.
A. Norway lobster Nephrops norvegicus (the Dublin bay prawn) is the most important commercial crusacean species in the UK.
B. Teeth of the gastric mill (stomach) used for age determination.
C. Cuticle bands in gastric tooth: the bands may represent annual growth rings.
D. Labelled live specimen of brown crab Cancer pagurus maintained for moulting experiments.
QUB Lead Researcher on the project, Dr Carola Becker recently attended a meeting of the Seafish Northern Ireland Advisory Committee where she presented the results of this study which is due to be completed in xxx. The project has been welcomed by Northern Irish industry representatives who are keen to ensure that stock assessments are carried out using the best available information to ensure long-term sustainability of commercially important stocks.
1 Kilada R, Sainte-Marie B, Rochette R, Davis N, Vanier C, Campana S. 2012. Direct determination of age in shrimps, crabs, and lobsters. Can J Fish Aquat Sci 69(11): 1728-33.