SYDNEY, Sept. 22 (Xinhua) -- Endangered black teatfish sea cucumbers can live for more than 100 years, far longer than previously thought, highlighting the species' vulnerability to overfishing, an Australian study finds.
The findings suggested black teatfish sea cucumber populations recovered much more slowly from fishing pressure than previously thought, with implications for commercial fishery catch limits, according to a statement released Tuesday by the Australian Institute of Marine Science (AIMS).
In a genetic mark-recapture study, researchers compared DNA samples from black teatfish collected in a no-take zone of Australia's Great Barrier Reef Marine Park in 2000 with samples from the same location 24 years later.
Small biopsies were taken from the animals, which were then returned, while modelling was used to estimate their lifespan. Of 55 animals sampled, 33, or 60 percent, were identified as the same as those sampled in 2000.
The findings showed the sea cucumbers lived for at least 24 to 27 years on average, while some survived for more than a century, said Sven Uthicke, a senior principal research scientist at the AIMS and lead author of the study published in iScience.
"Most of the recaptured animals had grown very little over the 24 years, and many had become smaller," Uthicke said, calling for more conservative harvesting to avoid possible extinction and preserve the species' ecological functions.
Sea cucumbers play a vital role in tropical marine ecosystems by recycling nutrients and mixing sediment, and healthy populations can also enhance coral health, researchers said.
Black teatfish are classified as Endangered by the International Union for Conservation of Nature and listed under Appendix II of the Convention on International Trade in Endangered Species. ■
