Abudefduf vaigiensis
A widespread damselfish found across the Indo-Pacific and possibly the Mediterranean.
The Indo-Pacific sergeant (Abudefduf vaigiensis) belongs to the damselfish family, Pomacentridae. It is sometimes called the Sergeant major, but that name typically refers to its close relative Abudefduf saxatilis. Another similar species, Abudefduf caudobimaculatus, was once thought to be the same fish, and some experts still consider them identical.
This fish lives across the Indo-Pacific region, including the Red Sea. In the Indian Ocean, it appears from the Red Sea and Gulf of Aden to Arabia, the Persian Gulf, the Arabian Sea, the Maldives, eastern Africa, Tanzania, Madagascar, the Seychelles, Sri Lanka, the Andaman Sea, Indonesia, Malaysia, and Australia. In the Pacific, it is found in the Gulf of Thailand, Malaysia, Indonesia, the Philippines, Taiwan, Japan, the Yellow Sea, the Great Barrier Reef around Australia, New Zealand, and Pacific islands as far as Hawaii. It may have entered the Mediterranean through the Suez Canal, but its range there is unclear because it can be confused with Abudefduf saxatilis and Abudefduf troschelii.
The Indo-Pacific sergeant is whitish-blue with a yellow top. It has a black spot near its dorsal fin and yellow eyes. Its dorsal fin has 13 spines and 11 to 14 soft rays, while the anal fin has 2 spines and 11 to 13 soft rays. The largest recorded size is 20 centimeters (7.9 inches), and juveniles mature at 12 centimeters (4.7 inches). Males turn more blue during spawning. Many people mistake this fish for Abudefduf saxatilis, a close relative from the Atlantic.
These fish eat zooplankton, benthic algae, and small invertebrates. Adults live in coral reefs, tide pools, and rocky reefs, while larvae drift in the open sea. They are found in tropical and subtropical waters at depths of 1 to 15 meters (3.3 to 49.2 feet). They form large groups, where individuals either feed in midwater or tend their nests. This species is also sold in the aquarium trade. There have been reports of ciguatera poisoning from eating this fish.
Larvae hatch and drift into the pelagic zone, growing until they settle on a reef. During breeding, males turn more bluish and build nests on rocks or coral ledges. Females lay eggs in the nests, and males fertilize them. Males then guard and aerate the eggs until they hatch.
Quick Facts
- Taxon
- Abudefduf vaigiensis
Facts from the source article.
Lore & Background
The Indo-Pacific sergeant is white bluish with a yellow top, has a black spot around its dorsal fin, and yellow eyes. Its dorsal fin has 13 dorsal spines and 11 to 14 dorsal soft rays, while the anal fin has 2 anal spines and 11 to 13 anal soft rays. Males turn more blue during spawning. Many people confuse this fish for Abudefduf saxatilis, a closely related species found in the Atlantic Ocean.
This species is found in the Indo-Pacific including the Red Sea. Indian Ocean populations occur from the Red Sea and eastern Africa to Australia, and Pacific populations range from the Gulf of Thailand to Hawaii. It was likely introduced via the Suez Canal in the Mediterranean Sea, where its distribution remains unclear due to possible confusion with Abudefduf saxatilis and Abudefduf troschelii.
Adults live in coral reefs, tide pools, and rocky reefs, while larvae live in the open sea. It is found in tropical and subtropical waters at depths of 1 to 15 metres. These fish form large aggregations, where individuals either feed in the midwater or tend their nests. They feed on zooplankton, benthic algae, and small invertebrates.
Reader's Guide
The Indo-Pacific sergeant is notable for its broad distribution across the Indo-Pacific, including the Red Sea, Indian Ocean, and Pacific Ocean as far as Hawaii. Its likely introduction via the Suez Canal into the Mediterranean Sea adds to its significance, though its presence there remains uncertain due to possible confusion with similar species. The species is also found in the aquarium trade. There have been reports of ciguatera poisoning from this fish, indicating a potential hazard to humans. Its life cycle involves larvae hatching and drifting into the pelagic zone before settling on reefs. Males build nests on rocks or coral ledges, females lay eggs, and males guard and aerate the eggs until they hatch. The species' ability to form large aggregations and its role in reef ecosystems, along with its taxonomic history—where Abudefduf caudobimaculatus was formerly considered synonymous—underscore its ecological and scientific interest.
Did You Know?
- The Indo-Pacific sergeant may also be known as the Sergeant major, though that name is usually reserved for Abudefduf saxatilis.
- It has been reported to cause ciguatera poisoning in humans.
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