View all news

Gut reaction: new research reveals crustaceans’ age is in the stomach bones

Categories

Words
Sharlene King
Published
4 April 2013
A Southern Cross University student is developing a novel method for determining the age of crustaceans by analysing calcified structures, including bones from the stomach.

The ground breaking thesis by Jesse Leland, a doctoral candidate in the University’s School of Environment, Science and Engineering, is making waves in the science world.

Jesse has been cited in a Canadian aquatic science journal and recently he was in Canberra to receive the Fisheries Research and Development Corporation Award, worth $17,000, at the 2013 Science and Innovation Awards for Young People in Agriculture, Fisheries and Forestry.

“Knowledge of age, growth rate and lifespan is critical for understanding important events in a species’ life history including reproductive maturity, entry into the fishery and natural mortality,” said Jesse.

“In the past, direct age determination for crustaceans was impossible because it was presumed that growth by moulting excluded the possibility of a permanent growth record in their exoskeleton. Only indirect, and somewhat imprecise, methods for age estimation were available.”

Jesse investigated the idea while working on another invertebrate ageing research project.

“In a previous study, I reported a potential novel approach to crustacean age determination. I used cross-sectional analysis of gastric ossicles (stomach bones) to clearly define growth marks that would be useful for determining the age of crustaceans. Now that earlier work has been validated in a scientific journal.”

Jesse’s supervisor is University fisheries and marine biology expert, Dr Daniel Bucher.

“During his Honours studies at SCU Jesse was the first person to describe regular growth marks in the stomach ossicles of large crustaceans,” Dr Bucher said.

“He concluded that it would revolutionise the management of crustacean fisheries by allowing direct determination of age if it could be shown that the marks were formed annually, rather than less regularly as the animal moults.

“Recently a research team in Canada demonstrated that the marks are indeed annual in the American lobster and some other northern Atlantic species. This publication cited Jesse's original observation. The challenge now is to demonstrate that in warmer waters of the Australian coast the growth rings Jesse originally described in various crabs and lobsters are also annual.”

Jesse said his research, ‘Development of a novel method for crustacean age determination’, had positive implications for Australia’s fishing industry.

“This project will provide validated age and growth parameters for two crustacean species, mud crab and redclaw crayfish. Perhaps, more importantly, it will develop ageing protocols that can be extended to other crustaceans in Australia and overseas, especially long–lived and deep–water species for which even indirect ageing methods are impractical.

“The knowledge obtained from this research will facilitate sustainable management of Australia’s crustacean fisheries – which is of utmost importance to the entire industry.”

Dr Bucher praised Jesse’s innovative thesis.

“If you can tell the age of harvested animals you can determine growth rates, mortality rates, time to maturity, and other parameters necessary for determining sustainable fisheries catches,” said Dr Bucher.

“In years to come this work will be seen as a major advance in crustacean fisheries biology.”

The Australian Government’s Science and Innovation Awards for Young People in Agriculture, Fisheries and Forestry provide recipients, aged 18 to 35 years, with grants of up to $22,000 each to undertake a project exploring an emerging scientific issue or innovation over a 12 month period.

“The Awards have helped advance the careers of more than 180 young scientists (since 2001) through national recognition of research and ideas,” said Senator Joe Ludwig, Minister for Agriculture, Fisheries and Forestry.

“With the objective of keeping Australia’s rural industries sustainable and profitable, the Awards turn ideas into a reality, at the same time showcasing the individual talents of our young scientists to the world.”

PUBLICATIONS

Leland, J., Coughran, J., and Bucher, D. (2011) A preliminary investigation into the potential value of gastric mills for ageing crustaceans. In New Frontiers in Crustacean Biology: Proceedings of the TCS Summer Meeting, Tokyo, Japan, 20–24 September 2009. Edited by A. Asakura. Brill NV, Leiden, Crustac. Monogr. 15: 57– 68.

Kilada, R., Sainte-Marie, B., Rochette, R., Davis, N., Vanier, C., and Campana, S. (2012) Direct determination of age in shrimps, crabs, and lobsters. Can. J. Fish. Aquat. Sci. 69: 1728–1733

Photo: Jesse Leland (left) receiving his award from Fisheries Research and Development Corporation chair The Honourable Harry Woods (Credit: Steve Keough Photography)