Justin Waraniak
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marathon-rana.bsky.social
Justin Waraniak
@marathon-rana.bsky.social
380 followers 520 following 57 posts
Molecular ecologist, focusing on landscape genetics and conservation of freshwater ecosystems.
Postdoctoral Researcher, PA Fish & Wildlife Co-op at Penn State
he/him/they/them
Digital illustrator: www.marathonrana.com (Commissions Open)
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marathon-rana.bsky.social
2) Lipids acted as a mediating factor so that fish could maintain reproductive allocation in the presence of parasites, but this came at a cost of lower lipid stores in heavily parasitized fish.

🧵(3/3)
Relationships between lipids as a proportion of dry weight and some of the most important variables that explained variation in lipid content of Cyprinodon tularosa, including the presence of yolked eggs (panel A), gonadosomatic index (GSI, panel B), and parasite density (panel C). Fish with yolked eggs had lower proportions of lipids. Lipid proportions were also negatively correlated with GSI and parasite density
June 4, 2025 at 7:17 PM
marathon-rana.bsky.social
1) Life history traits did not differ much among populations, despite the fact that they occupy very different habitats and have developed very different body shapes.

🧵(2/3)
Redundancy analysis biplot showing associations between variation in life history traits (black labels) and parasite counts (red labels with arrows) for the two most important redundancy analysis axes, accounting for 6.41% and 0.71% of the total variation in life history traits respectively. Individuals are depicted as colored points and 80% confidence interval ellipses are drawn for each population to show the similarity of typical RDA scores among the four populations. All four ellipses have roughly the same center near the origin of the plot and are mostly overlapping. The position of the labels for the life history dependent variables (in black) and the constrained parasite count variables (in red with arrows) indicates the strength and direction of association each variable has with the respective RDA axis. Gonadosomatic index, condition factor, age, wet weight, and length are all along one side of the x-axis, in that order increasing in intensity, and lipid content and dry weight are in the opposite direction. All four of the types of parasites (Gill, Liver, Eye, and Mesentery) are pointed in the same direction as the GSI, Age, Length, etc., indicating that the parasite loads may be positively correlated with those factors and negatively correlated with lipids and dry weight.
June 4, 2025 at 7:17 PM
marathon-rana.bsky.social
I've only ever ordered stickers; pins would be fun though!
June 1, 2025 at 3:53 PM
marathon-rana.bsky.social
That's a nice sketch! The nuchal hump is a mating display on male peacock bass and other cichlids.

Also, this is a pet peeve, but animals don't have genders - sex is the technically correct term.
May 26, 2025 at 2:36 PM
marathon-rana.bsky.social
😑 oops
March 30, 2025 at 5:22 PM
marathon-rana.bsky.social
You can also read more about this work in the Penn State press release here:

www.psu.edu/news/researc...
Threatened by warming waters, brook trout may be able to adapt to hotter weather | Penn State University
Brook trout may have a genetic trick up their scales when it comes to adapting, with limitations, to heatwaves that threaten their existence. A novel study led by researchers at Penn State suggests th...
www.psu.edu
March 18, 2025 at 6:22 PM
marathon-rana.bsky.social
We found specific genes that vary with temperature. As we learn how these genes vary across populations and environmental conditions, we can use them to find fish that are particularly stressed by heat or may be most able to adapt to future climate conditions! (5/5)
A collection of graphs showing how expression of four genes, a cold-shock protein (AN32B, top), a heat-shock protein (HSP47, 2nd row), a splicing factor (TRA2B, 3rd row) and a ubiquitinase (USP9X, bottom) co-varied with temperature. The leftmost graphs show scatterplots of expression versus temperature with lines of best fit, all color coded by stream. The graphs for the cold shock protein shows expression decreased log-linearly with temperature, increased linearly for the heat shock protein, and expression of the splicing factor formed a curve that dipped around 18ºC, but had similar levels of expression at higher and lower temperatures. These three genes showed similar expression in all four streams, but the scatterplot for the ubiquitinase shows a situation where the expression did increase along with temperature in each stream, but all the streams have different levels of expression even when they are at the same temperature. The right side of the figure four graphs through time for each gene, comparing the temperature (dotted line) and gene expression (big circles with arrows) in each stream during the study period.
March 18, 2025 at 6:17 PM
marathon-rana.bsky.social
...which lets us compare the paths that gene expression takes through time in each stream. All the streams followed similar paths, especially during the second heatwave when changes in gene expression were the most pronounced. (4/5)
March 18, 2025 at 6:17 PM
marathon-rana.bsky.social
We used TagSeq to quantify the relative amounts of different mRNAs. Because we sampled the same streams multiple times, we could track how the composition of genes being expressed changed with temperature. We tracked these changes using a trajectory analysis... (3/5)
Graph of a trajectory analysis. The x and y axis are labeled as principal component 1 and 2 respectively. These are composite variables constructed by linear combinations of gene expression data that vary most across the time points and streams. The axis labels also say what biological processes and molecular functions are most related to each part of the axes. The left side of the x-axis is most heavily influenced by genes that make up ribosomal components, there were no clear functions associated with the right side of the x-axis. The low values of the y-axis are driven by expression of genes involved in oxygen carrier activity and the upper values are driven by immune response genes. The graph itself is a scatterplot, with points representing the gene expression of each individual fish sampled, color coded by stream. There are also four sets of numbers (1-8) plotted along with the points showing the average expression across individuals from the same stream for each sample date. The numbers are connected in sequence by arrows, drawing the "paths" gene expression makes in each stream through the two heatwaves. The paths the four streams make are pretty similar, mostly moving along a diagonal with a negative slope. The path segments for most streams tend to be quite short for time points 1-4, but get longer during the second heatwave time points 5-8. The exception to this is East Branch, where the path segments are comparatively long during both the first and second heatwaves.
March 18, 2025 at 6:17 PM