Plate Nº 95 · recorded November 13, 2026
Biology & EvolutionReported finding
Lab study finds split-fan kelp switch to cloning without mates
A study of split-fan kelp found no wild signs of asexual reproduction in 523 samples, while 92% of wild kelp in single-sex lab cultures cloned without a mate nearby.
By Elena Vasquez3 min read603 words
In brief
- Researchers found no evidence of asexual reproduction in 523 wild samples from South Africa and Namibia.
- 92% of wild split-fan kelp grown in single-sex laboratory cultures reproduced asexually.
- Both male and female kelp were more likely to reproduce asexually when a suitable mating partner was absent.
- Asexual reproduction produced fewer offspring that tended to show developmental abnormalities and slower growth.
- The study was published November 12 in PLOS Biology; its formal citation lists 2026.
By Elena Vasquez
Researchers found no evidence of asexual reproduction in 523 wild split-fan kelp samples, but 92% of wild kelp grown in single-sex laboratory cultures reproduced without a mate. The study, published November 12 in the open-access journal PLOS Biology, was led by Daniel Liesner at the Max Planck Institute for Biology in Tübingen, Germany, and colleagues.
What did the experiment show?
Asexual, or clonal, reproduction produces new individuals without fertilization. Most animals reproduce sexually, while asexual reproduction is common in plants, fungi and algae. Many species can do both, but the reason for switching between them has remained poorly understood.
The team studied laboratory and wild populations of Laminaria pallida, a large brown seaweed found along the southern Atlantic coast. Both male and female kelp reproduced asexually under the right conditions. Asexual reproduction produced fewer offspring, which tended to show developmental abnormalities and slower growth.
In single-sex cultures, each group held only males or only females, leaving the kelp without a suitable mating partner. The contrast between those cultures and 523 wild samples from South Africa and Namibia set up the study’s central question: does the presence of another sex suppress asexual reproduction?
Gametes are reproductive cells. The authors wrote:
“Our findings show that kelps have much greater flexibility in how they reproduce than previously appreciated. Remarkably, even male gametes can develop into new individuals without fertilization, providing a potential reproductive backup when mating partners are scarce. This flexibility may help kelp populations persist under challenging environmental conditions.”
Takeaway: Both male and female kelp can reproduce without sex, but cloning carries developmental costs.
How might nearby mates suppress cloning?
Researchers used ribonucleic acid (RNA) sequencing, a method for reading which genetic instructions are active, in male and female kelp at different stages of sexual and asexual reproduction. The two sexes had distinct gene-expression patterns. During asexual reproduction, the male pattern underwent “demasculinization,” meaning it shifted toward the female pattern.
The field survey found no sign of asexual reproduction among the 523 samples collected from South Africa and Namibia. That result does not prove the process never occurs in nature; it means the study detected no evidence in its wild sample. Yet 92% of wild kelp reproduced asexually once grown in single-sex laboratory cultures.
The researchers then placed male and female kelp in the same petri dish, separated by a fine mesh, and tested whether each sex could sense a mate without direct contact. Both sexes were significantly more likely to reproduce asexually when a suitable mating partner was absent; “significantly” here means the difference was unlikely to be random.
That result is consistent with a chemical signal that can diffuse through water and alert kelp to nearby mates. The authors framed the mechanism as a hypothesis, not a fully established chemical pathway.
Takeaway: Nearby mates may suppress asexual reproduction, probably through a cue carried in seawater.
What could this mean for kelp conservation?
The reproductive strategy may provide a backup in sparsely populated habitats or during environmental stress, when suitable mates are scarce. The authors say this flexibility may help kelp populations persist under challenging conditions.
That switch is the life-cycle plasticity named in the paper: the timing of a reproductive strategy changes with conditions. The findings may help conservationists protect this ecologically important marine species in a changing ocean environment.
The paper, “Life-cycle plasticity enables conditional asexual reproduction in a kelp,” carries the formal citation PLOS Biology (2026), DOI 10.1371/journal.pbio.3004065.
Takeaway: Asexual reproduction appears costly and conditional, but it may help kelp persist when mates are scarce.
via phys.org/rss-feed/ (Source)
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Correspondent covering money, funding and market shifts around general science news at SciBeat.
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