Belted sandfish
A small, synchronous hermaphrodite sea bass of the western Atlantic.
The belted sandfish (Serranus subligarius), also called the dwarf sea bass or stubby sea bass, is a type of marine ray-finned fish in the sea bass subfamily Serraninae, part of the family Serranidae (which includes groupers and anthias). It lives in the western Atlantic Ocean and is also sold for home aquariums.
This fish has a long, flattened body and a short, pointed snout. Its gill cover has three visible spines, with the middle one straight, and the edge of the preopercle is serrated. The dorsal fin has 10 spines and 12 to 14 soft rays, while the anal fin has 3 spines and 7 soft rays. The tail fin is blunt. The head and body are reddish-brown, with lines formed by dark spots on the scales. A dark stripe runs through the eye and extends to the front part of the body. The rear part of the body has four dark bars that continue onto the dorsal fin; the frontmost bar is the most obvious and becomes a black blotch on the front of the dorsal fin’s soft rays. Just in front of that bar, on the lower body, is a clear white bar. The dorsal, anal, and tail fins have wavy dark bars, and some fish have two large black blotches at the base of the tail fin. The pelvic fins are black with white leading edges. The belted sandfish reaches a maximum total length of 10 centimeters (3.9 inches).
Its range in the western Atlantic goes north to North Carolina, then south along the U.S. east coast into the Gulf of Mexico. There, it extends from northwestern Cuba and the Florida Keys north and west along the Gulf coast to the U.S.-Mexico border, and along Mexico’s coast from Veracruz and Madagascar Reef on the Campeche Banks. In the Caribbean, it is found along Cuba’s southern coast.
This fish lives in silty waters with a mix of rubble and sand, often near jetties, rocky outcrops, and artificial reefs. It can be found from the water’s edge down to 18 meters (59 feet). It is a predator: fish smaller than 40 millimeters (1.6 inches) eat small crustaceans like amphipods, gammarids, and shrimp; larger fish also eat amphipods but prey on crabs, fish, and shrimp. They are solitary and hunt close to the bottom, usually at dusk. They capture prey by opening their large mouth to create suction, drawing the prey in and swallowing it whole.
Quick Facts
- Taxon
- Serranus subligarius
Facts from the source article.
Lore & Background
The belted sandfish was first formally described as Centropristis subligarius in 1870 by the American paleontologist and zoologist Edward Drinker Cope, with the type locality given as Pensacola in Florida. It has a laterally compressed elongate body with a short, pointed snout, three spines on the gill cover, and serrated preopercle margins. The dorsal fin has 10 spines and 12-14 soft rays, the anal fin 3 spines and 7 soft rays, and the caudal fin is truncate. Its head and body are reddish-brown with lines created by dark spots on the scales; a dark stripe runs through the eye to the anterior body, and the posterior body has four dark bars that extend onto the dorsal fin, the most forward bar being the most obvious and extending as a black blotch. A clear white bar sits on the lower body in front of that bar. Wavy dark bars appear on the dorsal, anal, and caudal fins, and some fish have two large black blotches at the caudal fin base. The pelvic fins are black with white leading edges.
Reader's Guide
The belted sandfish is a small predatory species found in silty waters with mixed rubble and sand substrate, often near jetties, rocky outcrops, and artificial reefs, from the water's edge down to 18 meters. It is solitary and hunts close to the substrate, typically at sunset, capturing prey by drawing it into its large mouth via suction and swallowing it whole. Smaller fish (under 40 mm) eat small crustaceans such as amphipods, gammarids, and shrimp; larger fish also eat crabs, fishes, and shrimp. Notably, the belted sandfish is a synchronous hermaphrodite, possessing both male and female functional gonads, making self-fertilization theoretically possible. It exhibits three mating strategies: some fish behave as females, others as courting males (like gonochoristic species), and still others as opportunistic 'streaker' males. Fish under 7.5 cm are most often females, while larger fish breed more often as courting males; streaker males tend to be smaller but can be any size. The species is also found in the aquarium trade.
Did You Know?
- The belted sandfish is a synchronous hermaphrodite, meaning each individual has both male and female functional gonads.
- It captures prey by creating a powerful suction as its mouth opens and swallowing the prey whole.
- The species was first described in 1870 by Edward Drinker Cope from a specimen collected at Pensacola, Florida.
- Its maximum recorded total length is only 10 centimeters (3.9 inches).
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