Bad at Goodbyes

Rough Transcript

Intro 00:05

Welcome to Bad at Goodbyes.

On today’s show we consider the Galápagos Damselfish.

Species Information 02:05

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.

 

Description

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.

 

Diet

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.

 

Behavior

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.

 

Within a damselfish school, social cohesion and mate-seeking behavior for reproduction is supported by vocal communication. Though we do not have any recordings specifically of the Galápagos Damselfish, damselfish vocalization in general has been widely studied. All studied damselfish species evidence vocal communication, via what are called pops and chirps, audible frequency pulses, that have been linked to different behaviors and vocalized responses. Across a wealth of literature, researchers demonstrate high confidence that information is being encoded, communicated, received and responded to via these vocalizations. For example, in one study, researchers recorded damselfish during courtship, a series of vocalized pulses that resulted in nearby males immediately swimming in an unusual, specific repeated pattern and vocalizing back. A kind of mating song and dance. Later, the researchers played back the recording and males again vocalized a reply and swam in this same specific pattern. Additionally researchers examined a collection of calls recorded by the same species of damselfish from a school in Madagascar (in the Indian Ocean), and compared to a school in French Polynesia (in the South Pacific). So recordings of the same species, with the same contextual behavior, but separated by 9000 miles of ocean. The waveforms showed profound similarity, but with some small consistent differences, suggesting that damselfish of different localities have somewhat different dialects.

 

Reproduction

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

————

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.

————

Habitat

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.

 

This region is still volcanically active, it sits near a fault where tectonic plates meet, and where five major ocean currents converge. And it’s remote, 100s of miles to the nearest landmass. So this very dynamic and isolated environment has given rise to many unique species, found only on the archipelago. These islands are, famously, the inspiration for Charles Darwin’s Theory of Natural Selection, outlined in his “On the Origin of Species”, published in 1859.

 

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.

 

Threats

Human induced climate change, resulting in warming oceans, shifts in ocean currents, and the increased frequency and severity of extreme weather is the primary threat to the Galápagos Damselfish. Though we do not have specific counts, our Damselfish was regularly sighted and collected for study, abundant throughout the 20th Century. Until the early 1980s.

 

1982 and 1983 saw a pronounced El Niño event affect the Galápagos. El Niño is an irregular, global climate phenomenon where an unpredictable convergence of winds, sea temps, and currents in the Pacific Ocean result in shifted weather patterns and warmer air and water temperatures. During the 82/83 El Niño event, sea surface temperatures rose more than 14°F above normal. These significantly warmer waters shifted currents, preventing the upwelling of nutrient-rich water, resulting in a near-total collapse of the Galápagos plankton population. And nearly all of the reef-building corals, bleached, died. And while some species have recovered in the years since, our Galápagos Damselfish, its food source and shelter devastated, has not been sighted.

 

Conservation

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

 

In Spring 2025, scientists performed an environmental DNA study, that was in part, looking for specific genetic evidence of the Galápagos Damselfish. Results of that research have not yet been published.

 

And so the Galápagos Damselfish has been considered critically endangered on the IUCN Red List since 2010, with an estimated population of less than 250 individuals, but lack of sightings and evidence suggests the species may be extinct.

Citations 23:33

Information for today’s show about the Galápagos Damselfish 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

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

Music 25:41

Pledge 31:44

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.