Yellowtail damselfish (Microspathodon chrysurus)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Ovalentaria incertae sedis · Family: Pomacentridae · Genus: Microspathodon.

Accepted name: Microspathodon chrysurus · Authority: (Cuvier, 1830) · Taxonomic status: accepted · AphiaID: 281571.

Synonyms and superseded combinations recorded for this taxon: Glyphidodon rudis Poey, 1860; Glyphisodon chrysurus Cuvier, 1830; Pomacentrus denegatus Poey, 1860; Pomacentrus niveatus Poey, 1876.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=281571 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

Measured values published by FishBase for Microspathodon chrysurus. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 21 cm · Common length: 15 cm · Depth range: 0–120 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 11 of 100 · Fishery importance: subsistence fisheries · Aquarium trade: commercial.

FishBase notes: A common (Ref. 9710) territorial species that inhabits coral reefs, juveniles usually encountered among branches of yellow stinging coral, Millepora . Adults are found in very shallow waters of coral reefs, usually near top of outer edge where there are caves, holes, and abundant fire coral (Ref. 26938). Feed primarily on algae but also on polyps of fire coral (Ref. 3139) and other invertebrate animal material (Ref. 13442). Juveniles occasionally pick parasites from other species of fish (Ref. 3139). Oviparous, distinct pairing during breeding (Ref. 205). Eggs are demersal and adhere to the substrate (Ref. 205). Males guard and aerate the eggs (Ref. 205). Occasionally marketed fresh (Ref. 3139). Have been reared in captivity (Ref. 35420).

Source: FishBase species summary (SpecCode 1122) — https://www.fishbase.se/summary/Microspathodon-chrysurus.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

33,932 georeferenced occurrence records for Microspathodon chrysurus are published through GBIF from 42 countries or marine areas. The map above plots 127 distinct locations from a sample of 3,000 records, omitting 24 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: United States of America (24,073); Puerto Rico (3,021); Brazil (1,336); Virgin Islands (U.S.) (1,217); Colombia (1,082).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2398749) — https://www.gbif.org/occurrence/search?taxon_key=2398749&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=281571 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Conservation status (IUCN Red List)

The IUCN Red List assesses Microspathodon chrysurus (Cuvier, 1830) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 188617) — https://www.iucnredlist.org/species/188617/0; GBIF IUCN Red List category endpoint (taxonKey 2398749) — https://api.gbif.org/v1/species/2398749/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Adult and young adult damselfish differ significantly in terms of body color. The difference was so stark that researchers believed the adult and young adult forms were two distinct species. Adults are brown with a yellow caudal fin. Young adults are violet with blue spots in their back and transparent caudal fins.

The spawning cycle of the yellowtail damselfish starts at sunrise and lasts approximately 1 hour after male damselfish have prepared nests on dead coral surfaces. Their eggs are demersal, adhering to the substrate where males guard and aerate them. Hatching occurs the morning of the 6th day of incubation. Reproductive activity is highest during the lunar period between full and new moon. At those points in the lunar cycle, the gravitational pull of the sun and the moon are very high resulting in spring tides.

In regards to feeding habits, adults typically graze on algae while juveniles are carnivorous. M. chrysurus is omnivorous with a gradual change in feeding habits throughout development. This change in diet is related to the distribution of adult and young adult damselfish. Gut content analysis of yellowtail damselfish shows a change is food ingested from young adulthood to adulthood. Young adults primarily feed on animal-like nematocysts and zooxanthellae. Adults tend to tend to be more selective in their feeding habits, eating blue-green algae called cyanophytes. However, if there is an abundance of another food source available those are likely to be ingested by the species.

Clutch cannibalism occurs when a parent consumes its brood. Total clutch cannibalism by parental males has been observed in yellowtail damselfish directly and by analysis of gut contents. There are several working hypotheses as to why this behavior has been conserved. It is hypothesized that the decision to stop providing care could be to reallocate time and energy to attract more mates and thus increase lifetime reproductive success. Another possible reason is to increase growth rate or survival of parental damselfish in poorer condition.

The patterns of clutch loss are related to size of the brood. There is a significant tendency for smaller clutches to disappear. Most of the clutches that disappear in M. chrysurus are young, first day clutches. Researchers have not found this pattern of loss to be attributed to reproductive activity.

There is interspecific overlap of feeding areas of M. chrysurus and two other damselfish species—Stegastes dorsopunicans and Stegastes planifrons. All three cohabitants consume the same benthic microalgae and have the same feeding cycles. In terms of defending the feeding grounds from intruders, studies have shown that M. chrysurus is less competent than Stegastes spp. at inhibiting intruders. However, yellowtail damselfish have a competitive advantage because of their size. M. chrysurus are aggressive toward their cohabitants, using their size-based dominance to obtain food.

Source: Wikipedia: Microspathodon chrysurus — https://en.wikipedia.org/wiki/Microspathodon_chrysurus (CC BY-SA 4.0). Accessed 2026-09-23.