Banded Archerfish, Toxotes jaculatrix
The Banded Archerfish (Toxotes jaculatrix) is a brackish water perciform fish of the archerfish genus Toxotes. Its coloration is silvery and has a dorsal fin towards the posterior end. It has distinctive and semi-triangular markings located along its side. It is best known for its ability to spit a jet of water to “shoot down” its prey. Larger specimens might be able to hit their prey 6 feet 7 inches to 9 feet 10 inches away. The archerfish might reach the displaced prey within 50 milliseconds of it hitting the water.
The name is in reference to Sagittarius the archer, because of the unusual method that the banded archerfish uses to capture its prey. They can be found in the Indo-Pacific and Oceanian waters, usually in the mouths of rivers and mangrove estuaries. They move between fresh, brackish, and salt water over the course of their lifetime, though not to breed. Because of their markings and their silvery color, these archerfish are occasionally kept as aquarium fish, though they are hard to care for and aren’t recommended for most home aquaria.
These fish were originally described by Peter Simon Pallas in 1767. Since then, several synonyms and misspellings have come into use.
Toxotes is Greek for “bowman” or “archer” and specifically refers to Sagittarius. The species name jaculatrix is related to the English jaculate and means “thrower” or “caster”. Both the common name and the binomial name are in reference to the banded archerfish’s habit of catching their prey via shooting “arrows” of water through its mouth.
These fish have 4 dorsal spines, 11 to 13 dorsal soft rays, 3 anal spines, and 15 to 17 soft rays. The first spine is always the shortest one; the rays become shorter towards to posterior end. There are about 23 scales between the first dorsal spine and the posterior nostrils. Particular areas of the body are tinged with green. The back of the fish is an olive-green or brown color. The dorsal fin is a yellowish-green and can be found towards the posterior end, and its base is shorter than that of the anal fin. The caudal fin is a “dirty green” color and about the same height until the point of attachment, where it becomes shallower. The anal fin is silver colored.
The body is oblong shaped and raised on the posterior side. It is generally white-silver in coloration, though it can vary, such as yellow. 4 to 6 broad black bars might be present on the dorsal side. The first bar is found anterior to the operculum, the bony plate covering the gills, and the second is found behind the operculum. The third bar is found below the origin of the dorsal fin, and the fourth is found below the soft dorsal, the fifth being found on the area between the anal fin and the caudal fin. These bars become shorter as the fish gets older. The lateral line curves upwards at the area between the fourth and the ninth lateral scales. The archerfish can achieve a maximum length of 30 centimeters; however, the average length is about 20 centimeters.
The fish have large eyes, which, unlike many other fishes, are positioned for binocular vision. The head is slightly shorter than the body, with a distinctively pointed snout. The juveniles might be a yellow-green to brown color on the dorsal side and silvery on the ventral side. The juvenile’s flanks are a grey-green color and some of these fish have irregular yellow colored patches between their bands.
They are omnivorous. During the day, they come to the surface to feed on the floating matter. Their diet contains plant matter and insects, which they are able to “shoot down”. They are also capable of capturing prey by jumping out of the water and seizing it from low overhanging branches. Young fish create small schools while learning aim, increasing the chance that at least one shot will hit the target. Their diet also includes underwater prey, including crustaceans and small fish.
The breeding habits aren’t well known. They first begin breeding when they are about 3.9 inches long and they reproduce by spawning. There are reports that these fish go to saltwater reefs to spawn, but these haven’t been confirmed. They lay 20,000 to 150,000 eggs at a time and they rarely breed in captivity.
Image Caption: Banded archerfish. Credit: Chrumps/Wikipedia (CC BY-SA 3.0)