Canadian study explores methods to trigger spawning in sea cucumber

Ruby Gonzalez
August 17, 2018
By Ruby Gonzalez
Canadian study explores methods to trigger spawning in sea cucumber
Photo: Getty Images
A study at the Memorial University in St. John’s, Newfoundland, Canada investigated methods used to trigger spawning and artificially induce maturation in sea cucumber (Cucumaria frondosa).

“There are several aspects of the biology and ecology of this species that we need to take into consideration when developing for the aquaculture,” Bruno Gianasi said at the Aquaculture Canada Conference 2018 in Quebec, where he presented, Triggers of spawning and oocyte maturation in the commercial sea cucumber Cucumaria frondosa.

The study is part of Gianasi’s thesis at the Department of Ocean Sciences, Memorial University, where he is a Ph. D student

The study showed that live phytoplankton at 1 x 105 cells ml-1 induced the highest proportion of females to spawn, promoted the greatest oocyte release, best quality of eggs and highest survival of embryos.

Mainland China is the main market for Canada’s east coast’s C. frondosa, commonly known as orange-footed cucumber. “It is harvested here in the East Coast, where it receives minimum processing – they are frozen and then sent to Vancouver, where they are shipped to China. They go to auctions to wholesale buyers,” he said.

The most common techniques in spawning temperate and tropical sea cucumbers include temperature shock, desiccation techniques and algal baths. These techniques, however, don’t always provide the desired results.

“Sometimes, they will be induced and all of them will spawn. Sometimes there is a batch that doesn’t even react to any of these stimuli. So there are lot of inconsistent results when it comes to spawning,” he said.

Artificially spawning sea cucumbers is challenging because the oocytes, which are surrounded by follicle cells, have to be removed by dissecting the sea cucumber. He stressed the C. frondosa’s oocyte is particularly small. The chromosomes of the oocytes are trapped in a germinal vesicle, which has to be broken down to release the oocytes inside. It is only after this that the oocytes can be fertilized.

“One objective of my experiment was to investigate potential spawning triggers for Cucumaria frondosa and also potential chemicals that will induce the final maturation of oocytes that were removed from female gametes,” he said.


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