Skip to main content

Male Fish Borrows Egg to Clone Itself

A fish created by spontaneous androgenesis is the first known vertebrate to arise naturally by this asexual reproductive phenomenon. 

Written byRuth Williams
| 3 min read

Register for free to listen to this article
Listen with Speechify
0:00
3:00

Squalius alburnoidesISABEL CATALÃOResearchers in Portugal studying a rare type of hybrid fish in the Ocreza River have found an individual that is the exact genomic match to his father. While such androgenesis—the reproduction of a male with no female genetic component—occurs in some non-vertebrates and has been induced in vertebrates artificially, today’s report (May 24) in Royal Society Open Science is the first known description of a vertebrate reproducing this way in the wild.

“I was very surprised,” said Miguel Morgado-Santos, a graduate student at the University of Lisbon in Portugal who co-authored the study. “I thought maybe it was a mistake and we had captured the father.” But, when the researchers examined the animal’s mitochondrial DNA, which can only be inherited from the mother’s egg, they found that it differed from the father’s. “So, it was definitely an androgenetic individual,” he said.

“Although [androgenesis] is very rare, there are a number of species out there that do this and . . . it is interesting that people have found it now in a vertebrate,” said evolutionary biologist Laura Ross of the University of Edinburgh who was not involved in the study.

While the females of many species, including ...

Interested in reading more?

Become a Member of

The Scientist Logo
Receive full access to more than 35 years of archives, as well as TS Digest, digital editions of The Scientist, feature stories, and much more!
Already a member?
Add The Scientist as a preferred source on Google

Add The Scientist as a preferred Google source to see more of our trusted coverage.

Meet the Author

  • ruth williams

    Ruth is a freelance journalist. Before freelancing, Ruth was a news editor for the Journal of Cell Biology in New York and an assistant editor for Nature Reviews Neuroscience in London. Prior to that, she was a bona fide pipette-wielding, test tube–shaking, lab coat–shirking research scientist. She has a PhD in genetics from King’s College London, and was a postdoc in stem cell biology at Imperial College London. Today she lives and writes in Connecticut.

    View Full Profile

Related Topics

The Scientist Digest cover September 2026
September 2026

Multiplex Microscopy Becomes Easier with Encoded Antibodies

A new system that enables researchers to uniquely tag monoclonal antibodies for use in microscopy could help simplify complex imaging studies.

View this Issue
Essential Genes Are Dominantly Activated by Single Transcription Factors

Essential Genes Are Dominantly Activated by Single Transcription Factors

EpiCypher Logo
Rethinking ALS Biomarkers: From Discovery to Clinical Impact

Rethinking ALS Biomarkers: From Discovery to Clinical Impact

Alamar Biosciences logo
Engineering CAR-Neutrophils In Vivo to Target Glioblastoma

Engineering CAR-Neutrophils In Vivo to Target Glioblastoma

Miltenyi
Best Practices for qPCR Assay Design and Optimization

Best Practices for qPCR Assay Design and Optimization

Bio-Rad

Products

Closeup image of a multi channel pipette dispensing pink liquid into a 96-well plate.

The ASSIST PLUS pipetting robot for affordable workflow automation

Integra Logo
Single cells in suspension

Rapidly isolate primary cells and make uniform single-cell suspensions with Corning® Cell Strainers

Corning logo
Abstract image representing cell membranes linked together.

CellBrite® Steady Membrane Stain: Cell surface staining built for real-time imaging

Biotium
sino biological logo

Monod Bio Licenses AI-designed Protein Technologies to SignalChem Biotech for Custom Discovery Assays