Researchers report that split-fan kelp can reproduce without mates in lab tests, but their survey found no evidence that it was doing so in the wild.
The study was published November 12 in PLOS Biology. The team studied Laminaria pallida, a brown kelp found off southern Africa. They used lab experiments and samples collected in South Africa and Namibia.
Male and female kelp both reproduced without mates in the lab. So did 92% of kelp raised in groups containing only one sex. Researchers found no evidence of this kind of reproduction in 523 wild specimens.
A lab result does not show how often the strategy occurs in nature. In further experiments, kelp were less likely to reproduce without mates when a potential mate was nearby. This was true even when fine mesh kept the individuals apart.
The team suggests that a chemical signal in the water may help kelp detect mates. But the experiments do not show what that signal is. Reproduction without mates also had costs.
It produced fewer offspring. The offspring tended to grow more slowly and have developmental problems. The findings suggest this kind of reproduction may be an option when mates are scarce.
Its role in wild populations remains uncertain.