Yellow and blueback fusilier (Caesio teres)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Eupercaria incertae sedis · Family: Caesionidae · Genus: Caesio.

Accepted name: Caesio teres · Authority: Seale, 1906 · Taxonomic status: accepted · AphiaID: 219996.

Synonyms and superseded combinations recorded for this taxon: Caesio pulcherrima Smith & Smith, 1963; Caesio pulcherrimus Smith & Smith, 1963; Caesio terus Seale, 1906.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=219996 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (FishBase)

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

Maximum length: 40 cm · Common length: 26.600000381469727 cm · Depth range: 5–60 m · Habitat zone: reef-associated · Body shape: fusiform / normal · Vulnerability index: 30 of 100 · Fishery importance: minor commercial · Aquarium trade: never/rarely.

FishBase notes: Adults are found primarily around coral reefs, with a preference for coralline lagoons. They feed on zooplankton in large midwater groups and form schools with other caesionids. Mature adults migrate to select areas around the reef to spawn near the surface in the entrances of deep channels during outgoing tides on a lunar cycle. They are oviparous, with numerous, small pelagic eggs (Ref. 402). Are caught with drive-in nets. Maximum depth reported taken from Ref. 128797.

Source: FishBase species summary (SpecCode 923) — https://www.fishbase.se/summary/Caesio-teres.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

3,294 georeferenced occurrence records for Caesio teres are published through GBIF from 45 countries or marine areas. The map above plots 314 distinct locations from a sample of 3,000 records, omitting 18 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: Australia (594); American Samoa (549); United States Minor Outlying Islands (511); Northern Mariana Islands (328); Indonesia (242).

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

Source: GBIF Occurrence Search (taxonKey 2374798) — https://www.gbif.org/occurrence/search?taxon_key=2374798&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=219996 (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 Caesio teres Seale, 1906 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 20250059) — https://www.iucnredlist.org/species/20250059/0; GBIF IUCN Red List category endpoint (taxonKey 2374798) — https://api.gbif.org/v1/species/2374798/iucnRedListCategory. Accessed 2026-09-23.

Description and natural history (Wikipedia)

Caesio teres was first formally described in 1906 by the American ichthyologist Alvin Seale with the type locality given as Shortland Island in the Solomon Islands. This species has been placed in the subgenus Flavicaesio. The specific name teres means "cylindrical", a reference to the cylindrical cross-section of the body compared to C. lunaris.

Caesio teres has a moderately deep, fusiform and laterally compressed body. The dorsal fin has 10 spines and 14–16, typically 15, soft rays while the anal fin contains 3 spines and 12–13 soft rays. The pectoral fins contain 20–22, typically 21 rays. This species attains a maximum total length of 40 cm, although 26.6 cm is more typical. The upper back and the rear part of the dorsal fin are bright yellow with the remainder of the body being bright blue on the upper body and white ventrally. The pectoral fin is white with a black upper base, the pelvic and anal fins are white.

Caesio teres has a wide tropical Indo-West Pacific distribution. It is found from the East African coast between Somalia and South Africa east into the Pacific as far as the Line and Tuamotu Islands, north to southern Japan south to the Great Barrier Reef. It is absent from the Red Sea and the Persian Gulf. In Australian waters this species is found at Rowley Shoals in Western Australia, at the Ashmore Reef in the Timor Sea, and from the northern Great Barrier Reef to Escape Reef, Queensland. It is also found at Christmas Island and the Cocos (Keeling) Islands. This species is found on coral reefs at depths between 5 and 60 m.

Caesio teres feeds on zooplankton. It is diurnal, and lives in groups and forms schools with other species of fusiliers such as Caesio xanthonota.The adults migrate to defined areas in The vicinity of the reef where they spawn close to the surface over and in the openings of deep channels during ebbing tides, the timing being governed by lunar cycles. It is an oviparous species which lays large numbers of small, pelagic eggs.

Caesio teres is targeted by fisheries in some parts of its distribution and frequently drive-in nets are used to catch it.

Source: Wikipedia: Caesio teres — https://en.wikipedia.org/wiki/Caesio_teres (CC BY-SA 4.0). Accessed 2026-09-23.