Azurina eupalamaGalapagos damsel

Geographic Range

Galápagos damsels (Azurina eupalama) are marine fish found primarily in the eastern-central Pacific Ocean, specifically near the Cocos and Galapagos Islands. They are non-migratory and are is classified as a tropical fish species. (Allen, et al., 2010; Reyes and Luna, 2008)

Habitat

Galápagos damsels live in rocky reefs and open waters from 5 to 30 m. However, Galápagos damsels have not been seen since 1983, during the El Niño event of 1982 to 1983. During this event, warm waters spread throughout the central and eastern-central Pacific Ocean. Scientists believe that they are likely extinct in the waters surrounding the Cocos and Galápagos islands, and it is unsure whether or not they moved elsewhere in order to survive. (Allen, et al., 2010; Carlowicz and Schollaert, 2017; Reyes and Luna, 2008)

  • Range depth
    5 to 30 m
    16.40 to 98.43 ft

Physical Description

The most identifiable features of Galápagos damsels are their long, slender bodies, pointed heads, and their gray-, white-, and blue-colored bodies. The word "Azurina" in the scientific name Azurina eupalama is Latin for pale blue, which is one of main colors found on Galápagos damsels. They can reach sizes of up to 15 cm and have 13 dorsal spines, 10 to 11 dorsal soft rays, 2 anal spines, and 11 to 12 anal soft rays. (Allen, et al., 2010; Grove and Lavenberg, 1997; Reyes and Luna, 2008)

  • Sexual Dimorphism
  • male larger
  • Average length
    15 cm
    5.91 in

Development

Galápagos damsels have pelagic larvae and produce benthic offspring. Their pelagic larvae disperse over large distances and may be moved away from their original habitats. Benthic fish, like adult Galápagos damsels, live on or near the bottom of the sea; depths can vary based on the different habitats. Researchers determine the sex of Galápagos damsels by analyzing the appearance of offspring. Males tend to have slimmer yet larger bodies than females as well as more pointed fins. Unfortunately, other information like the involvement of metamorphosis and indeterminate growth in Galápagos damsels is unknown at this time. (Aguilar-Medrano, 2018; Froese and Pauly, 2020; Reyes and Luna, 2008)

  • Development - Life Cycle
  • neotenic/paedomorphic

Reproduction

There is currently little information on the mating systems of Galápagos damsels. However, it is known that there is distinct pairing during breeding and that they are oviparous fish. (Reyes and Luna, 2008)

Galápagos damsels are oviparous fish, meaning they lays eggs. Their eggs are demersal, which means they stay at the bottom of the sea and essentially adhere to the bottom layer of the sea. Galápagos damsel males protect and aerate eggs. Not much else is known about the reproduction habits in Galápagos damsels at this time. This information includes breeding and spawning seasons, time to hatch, and birth information. (Grove and Lavenberg, 1997; Reyes and Luna, 2008)

  • Breeding interval
    There is currently no information about the breeding intervals of Galápagos damsels.
  • Breeding season
    There is currently no information about the breeding season of Galápagos damsels.

Not much is known about parental investment in Galápagos damsels. However, what is known is that males protect and aerate eggs before they hatch. (Reyes and Luna, 2008)

  • Parental Investment
  • pre-hatching/birth
    • protecting
      • male

Lifespan/Longevity

There is currently no information about the lifespan of Galápagos damsels in captivity or in the wild. However, they have not been sighted since 1983 during the El Niño event of 1982 to 1983>>. (Bernardi, et al., 2014; Simons, 2014)

Behavior

Galápagos damsels are a motile, natatorial fish that prefer open waters near reefs and drop-offs up to a depth of 30 m. (Grove and Lavenberg, 1997; Reyes and Luna, 2008)

Home Range

Galápagos damsels are non-migratory fish, distributed in the Eastern Central Pacific Ocean - more specifically the Cocos and Galapagos Islands. Currently, there is no information on the activity patterns, sociability, or other aspects on the behavior of Galápagos damsels. (Allen, et al., 2010; Grove and Lavenberg, 1997; Reyes and Luna, 2008)

Communication and Perception

Galápagos damsels perceive their environment through the use of touch, taste, and smell. At this time, no other forms of communication and perception are known for Galápagos damsels. (Monte-Luna, et al., 2007; Reyes and Luna, 2008)

Food Habits

Galápagos damsels feed mostly on plankton and are considered to be planktivores. More specifically, they have been known to feed on zooplankton, pelagic fish larvae, pelagic crustacea, and pelagic fish eggs. (Grove and Lavenberg, 1997; Reyes and Luna, 2008)

  • Primary Diet
  • carnivore
    • eats eggs
    • eats non-insect arthropods
    • eats other marine invertebrates
  • planktivore

Predation

Currently, there is no information on the predation of Galápagos damsels.

  • Known Predators
    • There are no known predators of A. eupalama at this time.

Ecosystem Roles

At this time, there is little to no information about the ecosystem roles of Galápagos damsels. However, it is likely that they are not a keystone species in their habitat, since there has been no correlation between their population decline and the condition of their former habitats. (Monte-Luna, et al., 2007)

Species Used as Host
  • There are no known species that Galápagos damsels use as hosts at this time.
Mutualist Species
  • There are no known species that Galápagos damsels are mutualistic with at this time.
Commensal/Parasitic Species
  • There are no known species that use Galápagos damsels as hosts at this time.

Economic Importance for Humans: Positive

Currently, there is no information on Galápagos damsels that suggests they have any significant economic impact, negative or positive.

Economic Importance for Humans: Negative

Currently, there is no information on Galápagos damsels that suggests they have any significant economic impact, negative or positive.

Conservation Status

It is known that Galápagos damsels have been listed as a critically endangered species since the El Niño event of 1982 and 1983. During this time, an increase in sea temperatures negatively impacted the marine fauna and flora of the Galápagos islands, ultimately decreasing the food supply ofGalápagos damsels. The IUCN Red List lists them as a critically endangered species. Currently, the U.S. Federal List, CITES, and the State of Michigan List have no status for Galápagos damsels.

Although researchers have continued to search for Galápagos damsels, no conservation efforts are known at this time. However, researchers may potentially look into whether or not they have expanded past their usual habitat in order to survive. (Allen, et al., 2010; Carlowicz and Schollaert, 2017; Grove and Lavenberg, 1997; Reyes and Luna, 2008)

Other Comments

There are no other comments about Azurina eupalama at this time.

Contributors

Erynn Cominsky (author), Colorado State University, Brooke Berger (editor), Colorado State University, Galen Burrell (editor).

Glossary

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map

benthic

Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

freshwater

mainly lives in water that is not salty.

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

natatorial

specialized for swimming

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

planktivore

an animal that mainly eats plankton

reef

structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

sedentary

remains in the same area

tactile

uses touch to communicate

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

References

2017. "Galapagos Damsel" (On-line). Extinction. Accessed March 09, 2020 at https://www.extinction.photo/species/galapagos-damsel/.

Aguilar-Medrano, R. 2018. "Ecomorphological Trajectories of Reef Fish Sister Species (Pomacentridae) from Both Sides of the Isthmus of Panama". Zoomorphology, 137: 315-327. Accessed March 03, 2020 at doi:10.1007/s00435-017-0391-6.

Allen, G., R. Robertson, R. Rivera, G. Edgar, G. Merlen, F. Zapata, E. Barraza. 2010. "Galapagos Damsel" (On-line). IUCN Red List. Accessed March 03, 2020 at https://www.iucnredlist.org/species/184017/8219600#conservation-actions.

Bernardi, G., L. Marina, Y. Alva-Campbell, J. McCosker, G. Bucciarelli, L. Garske, B. Victor, N. Crane. 2014. Darwin's Fishes: Phylogeography of Galápagos Islands Reef Fishes. Bulletin of Marine Science, 90: 533-549. Accessed February 08, 2020 at https://www.ingentaconnect.com/content/umrsmas/bullmar/2014/00000090/00000001/art00022#.

Carlowicz, M., S. Schollaert. 2017. "El Niño" (On-line). NASA Earth Observatory. Accessed March 09, 2020 at https://earthobservatory.nasa.gov/features/ElNino.

Froese, R., D. Pauly. 2020. "Azurina eupalama Heller & Snodgrass, 1903" (On-line). World Resource of Marine Species. Accessed March 09, 2020 at http://www.marinespecies.org/aphia.php?p=taxdetails&id=279851.

Grove, J., R. Lavenberg. 1997. The Fishes of the Galápagos Islands. Stanford: Stanford University Press.

Monte-Luna, P., D. Lluch-Belda, E. Serviere-Zaragoza, R. Carmona, H. Reyes-Bonilla, D. Aurioles-Gamboa, J. Castri-Aguirre, S. Guzman del Proo, O. Trujillo-Millan, B. Brook. 2007. Marine Extinctions Revisted. Fish and Fisheries, 8/2: 107-122. Accessed February 08, 2020 at https://doi.org/10.1111/j.1467-2679.2007.00240.x.

Reyes, R., S. Luna. 2008. "Azurina Eupalama Summary Page" (On-line). FishBase. Accessed March 03, 2020 at www.fishbase.se/summary/Azurina-eupalama.html.

Simons, E. 2014. "The Fish We Never Knew" (On-line). Bay Nature. Accessed March 03, 2020 at https://baynature.org/article/fish-never-knew/.