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Nudibranch Phylogenetics

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I spent an undergrad summer at the California Academy of Sciences Summer Systematics Institute (SSI) REU program. There, I studied a collection of Indo-Pacific nudibranchs, or sea slugs, collected over the course of several decades by Dr. Terrence Gosliner, a world renowned taxonomist and curator of marine invertebrates.

Under the mentorship of Dr. Gosliner and the SSI program coordinators, I dove into a world of marine research, morphometrics, phylogenetics, and cryptic species identification!

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Methods

Summary of Key Findings

More Photos From the REU Internship!

Primary Goal: Increase support for collection as a new genus

Gosliner T, and Ahmad Ali S. A new flabellinid nudibranch reveals a new phylogenetic lineage with unique morphology. Winning Poster presentation at: Michigan State University Undergraduate Research and Arts Forum; 2026 April 17th; East Lansing, MI. Publushed in UURAF 2026 Program Book.

Gosliner T, and Ahmad Ali S. A new flabellinid nudibranch reveals a new phylogenetic lineage with unique morphology. Poster presentation at: 2025 SACNAS NDiSTEM Conference; 2025 October 31-November 2; Columbus, OH.
Thirteen nudibranch specimens (only about 3-6 mm in length!) housed at the California Academy of Sciences, were collected between 1986 and 2017 from the Philippines, Papua New Guinea, and the Marshall Islands. One of which was initially identified as a member of the genus Piseinotecus, but initial gene sequencing and morpholocial comparisons supported the specimen as something comletely separate. My job was to work with the most recent samples.
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Morphological Analysis
The reproductive system was dissected, digitized, and compared visually to that of  a species from the genus Piseinotecus.

The radula (teeth) was dissected and dissolved in Sodium Hydroxide (NaOH), in which photos were taken under a Scanning Electron Microscope (SEM) for comparison to other species.


Genetic Analysis
COI, 16S, and H3 genes were sequenced to build a phylogenetic tree using Geneious Prime, IQ-TREE, and FigTree software.
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Morphological Variation Among Samples
Radulas of all samples are uniseriate (appear in a single row), which is uncommon and seen as a more derived trait. Oddly, samples from the Marshall Islands (A) contain denticles (offshoots from the main teeth) that come to a single point while samples from the philippines (B) have denticles that come to a forked point.

Phylogenetic Analysis
Maximum likelihood tree of 2 samples using sequenced 16S and H3 gene regions. All three cluster in support of a new species in the flabellinid family. This matches the findings of the newly described genus, Hantazuia,  by Korshunova et al. 2025.
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Sea Lion Dissections!
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Catching Amphibians and Reptiles!
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Tidepooling!
Conference Presentations!
Hiking California Coasts!
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