Galápagos Damselfish :: Azurina eupalama

Bad at Goodbyes :: Episode 075

On today’s show we learn about the Galápagos Damselfish, a critically endangered, possibly extinct marine fish native to the ocean waters of the Galápagos Islands, an archipelago in the Pacific Ocean, a province of Ecuador, roughly 600 miles west of the South American Ecuadorian coast. Its scientific name is Azurina eupalama and it was first described in 1903.

• (00:05) Intro
• (02:05) Species Information
• (23:33) Citations
• (25:41) Music
• (31:44) Pledge

For more information about conservation on the Galápagos Islands, please see the Galápagos Conservancy at https://www.galapagos.org.

Research for today’s show was compiled from:

• Aguilar-Medrano, R., Frédérich, B., De Luna, E., Balart, E. F. "Patterns of morphological evolution of the cephalic region in damselfishes (Perciformes: Pomacentridae) of the Eastern Pacific". Biological Journal of the Linnean Society, Volume 102, Issue 3, March 2011, Pages 593–613. – https://doi.org/10.1111/j.1095-8312.2010.01586.x
• Butler, Rhett Ayers. "Is the Galápagos damselfish extinct?" Mongabay, April 7, 2026. – https://news.mongabay.com/2026/04/is-the-galapagos-damselfish-extinct/
• Climate Change Vulnerability Assessment of the Galápagos Islands. 2011. Eds. I. Larrea and G. Di Carlo. WWF and Conservation International, USA – https://www.cbd.int/doc/lifeweb/Ecuador/images/ClimateChangeReport.pdf
• Cominsky, E. 2020. "Azurina eupalama" (On-line), Animal Diversity Web. Accessed April 20, 2026. – https://animaldiversity.org/accounts/Azurina_eupalama/
• Grove, J.S., Bensted-Smith, W., Brandt, M., Domínguez, O., Espinoza, E., Keith, I., Rivera, F.E., Suárez, J., Tapia, I. & Tirado-Sánchez, N. 2023. "Azurina eupalama". The IUCN Red List of Threatened Species 2023: e.T184017A217449660. – https://dx.doi.org/10.2305/IUCN.UK.2023-1.RLTS.T184017A217449660.en
• Grove, J. S., & Victor, B. C. (2025). "Has climate change driven the Galapagos Damselfish, Azurina eupalama, to extinction?" Journal of the Ocean Science Foundation, 42, 7–14.. – https://doi.org/10.5281/zenodo.14846312
• Grove, Jack. (1985). "Influence of the 1982/1983 El Niño event on the icthyofauna of the Galapagos islands". Tropical Ocean-Atmospheric Newsletter Vol.28 pp. 18-19. – https://www.google.com/books/edition/Tropical_Ocean_atmosphere_Newsletter/xR4eAQAAMAAJ?hl=en&gbpv=1&pg=RA24-PA18&printsec=frontcover&dq=%22ichthyofauna%20on%20the%20Gal%C3%A1pagos%22
• Heller, Edmund and Snodgrass, Robert Evans. (1903). "Papers from the Hopkins Stanford Galapagos expedition, 1898-1899. XV. New fishes." Proceedings of the Washington Academy of Sciences 5: 189-229. Washington, D.C: The Academy. – https://www.biodiversitylibrary.org/page/17224271
• iNaturalist – https://www.inaturalist.org/observations?nelat=1.6818345&nelng=-89.2412769&swlat=-1.4112351&swlng=-92.0089666
• Kelly, J., Pan, Y., Menzer, A., Dong, H. 2023 "Hydrodynamics of body–body interactions in dense synchronous elongated fish schools". Physics of Fluids v. 35 (4): 041906. – https://doi.org/10.1063/5.0142950
• McCosker, John E., and Richard H. Rosenblatt. 2010. "The Fishes of the Galápagos Archipelago: An Update." Proceedings of the California Academy of Sciences, ser. 4, 61, Supplement II, no. 11: 167–95. – https://www.biodiversitylibrary.org/page/63419300
• Parmentier, Eric, David Lecchini, and David A. Mann. 2016. "Sound Production in Damselfishes." In Biology of Damselfishes, edited by Bruno Frédérich and Eric Parmentier, 204–228. Boca Raton: CRC Press. – https://www.hawaii.edu/behavior/490E/Parmentier%20et%20al.%202010.%20Sound%20production%20in%20damselfishes.pdf
• Rastoin-Laplane, E., Salinas-de-León, P., Goetze, J.S., Saunders, B.J., McKinley, S.J., Norris, C., Gosby, C., Mattingly, A., Garcia, R., Harvey, E.S. "Fluctuations of Galapagos mid-water and benthic reef fish populations during the 2015–16 ENSO". Estuarine, Coastal and Shelf Science, v. 294 (2023). – https://doi.org/10.1016/j.ecss.2023.108523
• Simons, Eric. "The Fish We Never Knew: A Brief History of an Extinct Fish and What to Think About It." Bay Nature, April 16, 2014 (updated August 19, 2021). – https://baynature.org/2014/04/16/science-nature/wildlife/fish-never-knew/
• Wainwright, D. K., Karan, E. A., Collar, D. C. "Evolutionary patterns of scale morphology in damselfishes (Pomacentridae)". Biological Journal of the Linnean Society, Volume 135, Issue 1, January 2022, Pages 138–158. – https://doi.org/10.1093/biolinnean/blab140
• Wikipedia – https://en.wikipedia.org/wiki/Galapagos_damsel

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A note on accuracy: I strive for it! These episodes are well-researched and built from scholarly sources, hoping to provide an informed and accurate portrait of these species. That said, I’m a musician! I am not an academic and have limited scientific background. I may get things wrong! If you are using this podcast for scholarship of any kind, please see the cited sources and double-check all information.

Welcome to Bad at Goodbyes.

On today’s show we consider the Galápagos Damselfish.

The Galápagos Damselfish is a critically endangered, possibly extinct marine fish native to the ocean waters of the Galápagos Islands, an archipelago in the Pacific Ocean, a province of Ecuador, roughly 600 miles west of the South American Ecuadorian coast. Its scientific name is Azurina eupalama and it was first described in 1903.

The Galápagos Damselfish is an ocean-dwelling, saltwater, medium-sized damselfish roughly 6 inches in length, 1-2 inches in height with a slender body, roughly an inch wide. They are scaled across their body; the scales are grey-ish with a pale blue and silvery tint. Damselfish scales are a biocomposite of layers of organic and inorganic material, made of the protein collagen, layered with minerals: calcium-deficient hydroxyapatite that is calcium and phosphorus with traces of magnesium, iron, zinc. The collagen provides a flexible base of living tissue and the minerals crystalize, hardening at the outermost surface of the scale to provide a kind of defensive armor. Additionally the scales overlap, like say shingles on roof, to help prevent injury from coral or sharp stone, and to deter the access and attachment of tiny ocean parasites to the damselfish's skin. The scale arrangement also is hydrodynamic; not unlike the divots in a golfball, the scale architecture streamlines the damselfish, minimizing drag to swim more quickly, smoothly, and easily through the water.

The Galápagos Damselfish has seven fins, one long dorsal fin across the topside, two ventral fins on the bottom front, two pectoral fins on the sides just behind the gills, one anal fin on the bottom back, and one caudal fin, the tail fin which is forked into two lobes. The dorsal and ventral fins are for stabilization, keeping the fish upright. The pectoral fins and tail fin are used for navigation and locomotion. And the anal fin is used for both stabilization and navigation.

The Galápagos Damselfish has two medium sized dark eyes on each side of their head, a short snout, and a somewhat upturned mouth.

The Galápagos Damselfish is a planktivore; it eats plankton. Plankton are tiny organisms, ranging from microscope to roughly an inch in size, that drift on ocean currents. Phytoplankton are tiny plants, zooplankton are tiny animals. The Galápagos Damselfish consumes zooplankton: fish eggs and larvae, crustacean larvae, and small invertebrates like copepods and mysis shrimp.

They feed in water columns. Here's how this works: The Galápagos Damselfish will forage near sea floor drop offs, in shallow waters less than a few dozen feet from the ocean's surface but near areas where the sea rapidly increases in depth, as much as 90 feet down. These steep oceanic slopes result in upwelling currents, water that rises from the depths toward the surface and carries with it the zooplankton that the Galápagos Damselfish feeds upon. They simply swim into the water column, dense with prey, and suction water into their mouths, water rich with the tiny organisms that comprise most of their diet.

The Galápagos Damselfish is diurnal, meaning it is most active during the day, then at night retreats, sheltering in reef crevices or secluded among coral growths to avoid nocturnal predators.

The Galápagos Damselfish, unlike more territorial deepwater damselfish, exhibits generally gregarious social behavior, schooling with individuals of their own species as well as with the closely related Scissortail Damselfish. Damselfish schooling behavior has energy efficiency and defensive benefits. Regarding energy efficiency, studies have shown that the wakes and flows of group movement increases overall hydrodynamics so individuals have to expend less energy in a group than when alone, to travel the same distances. For defense, there is simply mathematical safety in numbers, this is called the numerical dilution effect: the probability of an individual being targeted by a predator decreases as group size increases; statistically risk is spread across more individuals. And the synchronized movement of a dense congregation may create perceptual confusion in predators. The predator struggles to target individual prey in a similar-looking group, buying time for the school to escape. Additionally, a group is more likely to sense an approaching threat, the collective perception increases the likelihood of earlier predator detection. And again increasing the probability of escape.

We have very limited information about Galápagos Damselfish mating. But we know that there is monogamous pairing during breeding and that following fertilization, the female lays a clutch of eggs on the ocean floor. These eggs are adhesive, they stick to the rocky seabed. Then the male takes over, guarding the eggs from predators, and aerating the clutch; he fans his fins above the eggs to produce a flow of oxygenated water vital to embryo development. The male only returns to the school after the eggs hatch and the larvae begin to grow into their adulthood.

————

In the dream,

To dream of the before times, of bright reefs and dense algae gardens.

Of teaming schools shimmering in the sunlit shallows.

Of feasting in temperate waters,

Of lives undisturbed, unfolding uninterrupted in their ancient cycles.

A sweet sweet dream of abundance,

Yet now sadly fading, in a harsh new dawn.

in the dream.

————

The Galápagos Damselfish is native to the relatively shallow Pacific Ocean waters near the Galápagos Islands, an Ecuadorian province of twenty-plus islands roughly 600 miles west of the South American mainland.

Historically the Galápagos Damselfish was found across the entire Galápagos Islands archipelago, at ocean depths of roughly 15 to 100 feet, generally about midway between the surface and the seafloor. The seafloor here is volcanic rock, cooled lava, which has formed the islands themselves and formed the Galápagos Platform, shallow shelves near the island coasts that then drop steeply into deep ocean. These thresholds, nearshore shallows at the edge of deeper seas is where we'd find our Galápagos Damselfish. It is an active underwater landscape of coral clusters and fringe reefs, algae-rich and dense with plant, fish, reptile, invertebrate, and mammal life.

Today, this bioregion is classified as the Galápagos Islands Marine Ecoregion. It has a sub-tropical climate. In the warmer, wet season from December to May, air and water temps average in the 80s°F, in the cooler/dry season from June to November air and water temps average in the high 60s°F, low 70s°F.

The Galápagos Damselfish shares the sea near the Galápagos Islands with:

Diamond Stingray, Galápagos Kelp, Bullseye Puffer, Sea Lettuce, White-spotted Eagle Ray, Galápagos Sea Lion, Scissortail Damselfish, Razor Surgeonfish, Red Seaweed, Hair Algae, Marine Iguana, Jellyweed, Forked Ribbon, Coralline Algae, Whitetip Reef Shark, Green Sea Turtle, Ecuadorian Hermit Crab, Red Sea Plume, White Sea Urchin, Flattop Grape, Sea Fan, Pacific Creolefish, Limu 'Aki'aki, Chocolate Chip Sea Star, Galapagos Slate Pencil Urchin, Codium, Blue-barred Parrotfish, Sea Comb, Sally Lightfoot Crab and many many more.

Over the last 40-plus years, researchers and divers have repeatedly attempted to locate the Galápagos Damselfish to no avail.

Information for today’s show about the Galápagos Damselfish was compiled from:

Wikipedia – https://en.wikipedia.org/wiki/Galapagos_damsel

For more information about conservation on the Galápagos Islands, please see the Galápagos Conservancy at https://www.galapagos.org.

I honor the lifeforce of the Galápagos Damselfish. I will commit its name to my record. I am grateful to have shared time on our planet with this being. I lament the ways in which I and my species have harmed and diminished this species. I grieve.

And so, in the name of the Galápagos Damselfish I pledge to reduce my consumption. And my carbon footprint. And curb my wastefulness. I pledge to acknowledge and attempt to address the costs of my actions and inactions. And I pledge to resist the harm of plant and animal kin and their habitat, by individuals, corporations, and governments.

I forever pledge my song to the witness and memory of all life, to a broad celebration of biodiversity, and to the total liberation of all beings.