#TeleostTalk

Very cool analysis on Paradise fish (Macropodus opercularis) by @nickarjones.bsky.social et al. 🐠 #TeleostTalk

Fig. 6. The Mexican tetra, Astyanax mexicanus, as a model to study nutritional control of development. This species of small fish (~4–6 cm as adults) consists of cave-dwelling morphotypes (cavefish, A, C) and ancestral river-dwelling morphotypes (surface fish, B, D). Cavefish evolved from surface fish in perpetually dark caves and adapted to a nutrient poor diet of bat guano and material brought in by seasonal floods. The fish are easy to maintain in the laboratory and are interfertile. Cavefish larvae (C, 4 days post fertilization (dpf)) have more yolk and the yolk appears more yellow compared to surface fish (C, 4dpf) suggesting a difference in nutritional content. The yolk of F1 surface cave/hybrids produced from cavefish females (E) is more yellow compared to those produced from surface fish females (F). Comparing these reciprocal crosses will be useful for understanding how maternally provided nutrients in the yolk impact development. Scale bars ​= ​0.5mm. (A, B) Images provided by Nicholas Rohner, Stowers Institute for Medical Research. (C–D), Images reproduced with permission from (Riddle et al., 2020). Credit figure and text to Riddle and Hu (2021).

A. mexicanus are a promising model to study nutritional control of development as cavefish larvae yolks are larger & appear more yellow compared to surface fish suggesting differences in nutritional content. Reciprocal crosses show how maternally-provided nutrients impact development. #TeleostTalk 🧪

This image shows a fully grown adult male killifish (Nothobranchius furzeri). Credit to R. Blažek

The African turquoise killifish (Nothobranchius furzeri) is known as one of the fastest ageing vertebrates. It reaches sexual maturity after 14 days post hatching and has an average lifespan of 4-9 months. For more on this model organism, read pmc.ncbi.nlm.nih.gov/articles/PMC... #TeleostTalk 🧪

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Image of a galaxy rasbora (Celestial Pearl Danio) with vibrant blue and orange markings. Image credit to www.aquariumcoop.com

Celestial Pearl Danio (Danio margaritatus) became an instant hit on the aquarium trade for its vibrant color. Commonly referred to as the Galaxy rasbora, Myanmar banned exports of the fish in 2007 due to its popularity. Now, the fish is captive-bred for hobbyists. #TeleostTalk 🧪

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Image of the Aquatic Habitat Module onboard the international space station. Credit to NASA

To infinity and beyond! Japanese rice fish (Oryzias latipes) were the first vertebrate species to mate in orbit on board the space shuttle Columbia in 1994. Physiological research continues on board the International Space Station within the Aquatic Habitat module. #TeleostTalk 🧪

Learn about the unique traits of some our favorite teleost friends with the hashtag: #TeleostTalk 🐡 🐟 🐠 🧪

The blackfin icefish, Chaenocephalus aceratus, lacks hemoglobin and lives in Antarctic waters, where the temperature is often close to the freezing point of seawater. Text credit to New York Times. Image credit to Doug Allan/Nature Picture Library, via Minden Pictures.

An icefish's blood, right, is clear, whereas the blood of its Antarctic relative, the marbled rockrod, left, is crimson and has red blood cells. Text credit to New York Times. Credit image to Northeastern University.

White-blooded Antarctic icefishes are unique among vertebrates because they lack functional hemoglobin genes. Their blood transports ~10% as much oxygen as the blood in other teleosts, making them sensitive to hypoxia and an excellent model for human blood disorders. #TeleostTalk 🧪

Image of a mummichog (Fundulus heteroclitus). Image credit to Julia Wood at NCFishes.com

Toughest fish on Earth? Mummichogs are a euryhaline species, which means they can survive a range of salinities from freshwater to water that has 110g salt/L. Heralded as the first fish species in outer space, they even evolved resistance to toxic chemicals that would kill other fish. #TeleostTalk 🧪

Image of a Xiphophorus hybrid fish with malignant melanoma. Taken from Kneitz et al. BMC Genomics (2016). DOI: 10.1186/s12864-016-2697-z

Xiphophorus fish are one of the oldest animal models for cancer research (dating back to 1920s). It provided the first evidence that cancer has a genetic basis after it was found hybrids of platyfish (X. maculatus) & swordtails (X. hellerii) can develop highly malignant melanomas. #TeleostTalk 🧪