Dascyllus melanurus
(blacktailed humbug)
Marine Fishes
Exotic |
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Common name: blacktailed humbug
Synonyms and Other Names: blacktail dascyllus
Taxonomy: available through
www.itis.gov
Identification: Randall (2005) describes this species as white with a broad black bar from the nape through the eye to the chin, leaving only a small white patch before the eyes and on the lips; a broad black bar from the anterior part of dorsal fin to abdomen and pelvic fins; a broad black bar posteriorly on body extending into dorsal and anal fins; the caudal fin is slightly forked with rounded lobes and black posterior half except for a narrow pale blue margin. This species is similar in appearance to Dascyllus aruanus, but has a black instead of pale caudal fin (Allen and Erdmann 2012).
Size: Maximum size to 8.5 cm total length (Allen and Erdmann 2012)
Native Range: This species is native to the Indo-Pacific from Indonesia, Philippines, Palau, Papua New Guinea, Solomon Islands, Vanuatu, New Caldonia, northern Great Barrier Reef, Caroline Islands, and southern Marshall Islands (Allen and Erdmann 2012).
Nonindigenous Occurrences:
Several sightings have been reported from the Blue Heron Bridge, Riviera Beach, Florida in December 2025 and January 2026; most likely the same individual.
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Dascyllus melanurus are found here.
Table last updated 3/9/2026
† Populations may not be currently present.
Ecology: Dascyllus melanurus inhabit sheltered inshore coral reefs and shallow lagoons (Allen and Erdmann 2012). This species typically occurs in groups that utilize the branching coral for shelter as needed (Allen and Erdmann 2012). The primary diet is zooplankton (Randall 2005). All Dascyllus species are demersal spawners (Parmentier et al. 2009). Males prepare a nest site by removing debris from an area usually near the base of the coral colony or under a rock (Allen1991). The males perform a display of courtship dips called signal jumps to attract the attention of females. The courtship dip consists of a male rising in the water column and then rapidly swimming downwards at the same time as making a pulsed sound (Lobel and Mann 1995). The female lays eggs that stick to the bottom of the nest followed closely by the male who fertilizes the eggs (Allen 1991). Nest-guarding males are extremely aggressive and tend the eggs in the nest until hatching (Allen 1991).
Means of Introduction: probable aquarium release
Status: unknown
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Allen, G.R. 1991. Damselfishes of the world. Mergus Publishers, Melle, Germany.
Allen, G.R., and M.V. Erdmann. 2012. Reed fishes of the East Indies, volume II. Tropical Reef Research, Perth, Australia.
Lobel P.S., and D.A. Mann. 1995. Spawning sounds of the damselfish Dascyllus albisella (Pomacentridae) and relationship to male size. Bioacoustics 6:187–198.
Parmentier E., D. Lecchini, B. Frederich, C. Brie, and D. Mann. 2009. Sound production in four damselfish (Dascyllus) species: phyletic relationships? Biological Journal of the Linnean Society 97:928-940.
Randall, J.E. 2005. Reef and shore fishes of the South Pacific; New Caledonia to Tahiti and the Pitcairn Islands. University of Hawaii Press, Honolulu, USA.
Author:
Brown, M.E.
Revision Date: 1/26/2026
Citation Information:
Brown, M.E., 2026, Dascyllus melanurus Bleeker, 1854: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=3977, Revision Date: 1/26/2026, Access Date: 3/9/2026
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.
