The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Epinephelus ongus
Epinephelus ongus
(Summan grouper)
Marine Fishes

Copyright Info
Epinephelus ongus (Bloch, 1790)

Common name: Summan grouper

Taxonomy: available through www.itis.govITIS logo

Identification: Dorsal rays XI (15-16); anal rays III (8); pectoral rays 15-17; lateral-line scales 48-53.  Small teeth, in two rows on midside of lower jaw.  Fleshy margin of operclehighly arched.  Rounded caudal fin.  Coloration of adults (bottom photo) grey-brown with numerous small white spots that tend to join to form irregular longitudinal white bands on body.  Black streak above upper jaw.  Median fins with numerous small white spots and short dashes, a narrow white posterior margin and a broad, black submarginal band.  Juveniles (top photo) are dark brown with well-separated white spots on the head, body and all fins.  From Heemstra and Randall (1993) and Randall et al. (1996).

Also called white-streaked grouper; specklefin grouper; speckled-fin rockcod.

Size: to 40 cm (Randall et al. 1996)

Native Range: Widely distributed across the Indo-West Pacific from the east coast of Africa (northern Mozambique to Kenya) to the Ryuku and Marshall Islands and south to Fiji, New Caledonia and northern Australia.  From Randall et al. (1996).

Interactive maps: Point Distribution Maps

Nonindigenous Occurrences: One specimen photographed off West Palm Beach, Florida in August 2010.

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 Epinephelus ongus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
FL201020101Florida Southeast Coast

Table last updated 7/17/2024

† Populations may not be currently present.

Ecology: Epinephalus ongus occurs in shallow water on coral reefs and rocky habitats. Can also occur in inner coastal and lagoon reefs, including brackish-water regions. Depth distribution 5-25 meters.  From Myers (1989) and Heemstra and Randall (1993). Feeds on crabs, shrimps, octopi and fishes (Craig 2007). This species is a protogynous hermaphrodite, which means the fish start out as females and transition to males later on in their life. Females mature around 3 years old and 19 cm (TL). Males are older and larger, with an average age of 9 years and average length of 29 cm (TL) (Ohta and Ebisawa 2016). Max life span is 20 years (Craig 2007; Ohta and Ebisawa 2016). 

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)

Craig, M.T. 2007. Preliminary observations on the life history of the white-streaked grouper, Epinephelus ongus, from Okinawa, Japan. Ichthyology Research 54:81-84.

Heemstra, P. C. and J. E. Randall.  1993.  Groupers of the World.  FAO Species Catalogue.  Food and Agriculture Organization of the United Nations, Rome.

Myers, R. F.  1989.  Micronesian Reef Fishes.  A Practical Guide to the Identification of the Coral Reef Fishes of the Tropical Central and Western Pacific.  Coral Graphics, Guam.

Ohta, I. and A. Ebisawa. 2016. Age-based demography and sexual pattern of the white-streaked grouper, Epinephelus ongus in Okinawa. Environmental Biology of Fishes 99:741-751.

Randall, J. E., G. R. Allen and R. C. Steene.  Fishes of the Great Barrier Reef and Coral Sea.  University of Hawai'i Press, Honolulu.

Other Resources:
FishBase Summary

Author: Schofield, P.J.

Revision Date: 9/16/2019

Peer Review Date: 9/1/2010

Citation Information:
Schofield, P.J., 2024, Epinephelus ongus (Bloch, 1790): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=2822, Revision Date: 9/16/2019, Peer Review Date: 9/1/2010, Access Date: 7/17/2024

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/17/2024].

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