An article co-authored by Associate Professor of Biology Wei-Jen Chang was recently published in the journal Molecular Phylogenetics and Evolution. His co-authors included Patricia Taik ’16, Emily Foley ’16, Alycia Racicot ’16, Hilary Gray ’15 and Katherine Guzzetta ’18. They collaborated with an international team of researchers from China, Japan and Taiwan, including Chang’s former college advisor Yen-Ling Song.
“High Genetic Diversities Between Isolates of the Fish Parasite Cryptocaryon irritans (Ciliophora) Suggest Multiple Cryptic Species,” describes recent findings regarding the parasite Cryptocaryon irritans, which infects marine fish and causes significant losses in mariculture industries when outbreaks occur.
The researchers found that between different C. irritans populations their genetic divergences could be just shy of 10 percent. Since humans and chimpanzees diverge from each other by less than three percent, such a high genetic divergences detected in C. irritans suggests the existence of ‘cryptic’ species, which has not been reported before.
The results may also help explain why vaccinating fish has not been effective against C. irritans because antigenic proteins may vary too much to be targeted by the ‘one-size-fit-all’ vaccine.
The findings provide new insights for the study of this important parasite but they also raise questions about how the parasite might have evolved into genetically distinct populations.