The term “bass” is commonly used to describe various species of fish, leading to confusion about where these fish live. While many people associate the word exclusively with freshwater sport fishing, the ocean is home to a diverse group of marine fish also referred to as bass. These saltwater species represent distinct evolutionary lineages adapted to the high-salinity environment of the sea. Understanding this difference requires looking past the common name to the scientific families that define their biological relationships.
The Taxonomic Divide: Freshwater vs. Marine Bass
The shared name “bass” is a source of taxonomic confusion, grouping together fish that are not closely related. Most popular freshwater black basses, such as Largemouth and Smallmouth bass, belong to the sunfish family (Centrarchidae). These species are not true basses and are confined to inland lakes and rivers.
In contrast, fish called sea bass and temperate bass are saltwater creatures belonging to different families within the order Perciformes (perch-like fish). True sea bass, including the Black Sea Bass and groupers, fall within the marine family Serranidae. Temperate bass, which includes the Striped Bass, belongs to the Moronidae family. This linguistic overlap arose because these different species share a similar, robust body shape and predatory behavior, not a recent common ancestor.
Prominent Species of Ocean Bass and Their Habitats
The Striped Bass (Morone saxatilis) is a widely recognized temperate bass, identified by seven or eight dark, unbroken horizontal lines along its silvery body. This species is anadromous, spending most of its adult life in the saltwater of the Atlantic Ocean and coastal estuaries but migrating to freshwater rivers to spawn. Striped Bass are found along the Atlantic coast of North America.
The Black Sea Bass (Centropristis striata) is a true sea bass species inhabiting the western Atlantic Ocean, ranging from the Gulf of Maine to the Florida Keys. They are found in shallower coastal waters, preferring rough bottom areas like wrecks, rock piles, and artificial reefs. These fish are dark brown or black, reaching an average length of about one foot, and are commercially and recreationally important.
The European Sea Bass (Dicentrarchus labrax), often marketed as Branzino, is another commercially significant species. This temperate bass is distributed across the temperate waters of the eastern Atlantic Ocean and the Mediterranean Sea. They have an elongated, silver body and a distinct spiny dorsal fin, commonly inhabiting coastal areas and river mouths.
Many other marine species carry the “bass” name, including numerous Grouper species, which are also part of the Serranidae family. Groupers, such as the Goliath Grouper, are large, often sedentary fish that prefer tropical and subtropical coral reefs and rocky bottoms.
Unique Adaptations for Saltwater Survival
Marine bass thrive in the ocean through osmoregulation, a physiological process that manages the balance of water and salt within their bodies. The ocean’s high salinity causes water to constantly leave the fish’s body through the gills via osmosis, requiring marine fish to continually counteract this dehydrating effect. They actively drink large quantities of seawater to replace lost water.
The ingested seawater introduces excess salt, which must be expelled. Specialized structures in the gills, known as chloride cells, actively pump the excess sodium chloride back into the surrounding ocean water. This process requires energy to move the salt against its concentration gradient. The kidneys of marine bass are adapted to conserve water, producing only a small amount of highly concentrated urine that primarily removes divalent ions like magnesium and sulfate.