The vast waters of our planet are home to a stunning variety of fish, each with a story to tell. This category focuses on the letter J, from the glittering, iridescent scales of the Jewel Cichlid to the raw, muscular power of the saltwater Jack.
There’s the John Dory, a fish steeped in biblical myth; the Jack Dempsey, a cichlid whose name is a warning of its pugnacious attitude; and the Jawfish, whose title perfectly describes its role as a master of the seafloor. This article unpacks the unique abilities and surprising histories that give these fish their famous name.
Common Fish Names That Start With J
This section features fish recognized by their common names that perfectly capture their most remarkable traits.
John Dory (Zeus faber)
Habitat: Demersal (bottom-dwelling) on the coasts of the eastern Atlantic Ocean, Mediterranean Sea, and the Indo-Pacific.
Size: Typically grows up to 2 feet long.
Conservation Status: Not formally evaluated by the IUCN, but it is a popular food fish and subject to fishing pressure.
The John Dory is a master of stealth, possessing an extremely thin, laterally compressed body that makes it almost invisible when viewed head-on. Its most famous feature is the large, dark eyespot on its flank, often called the “thumbprint of St. Peter,” which it flashes to startle prey or confuse predators. This combination of stealth and deception makes it a highly effective ambush predator.
Despite its bony and unusual appearance, it is a highly prized gourmet fish. It hunts by sneaking up on small fish before rapidly extending its huge, tube-like mouth to create a powerful suction that inhales the victim. For protection, the first dorsal fin is composed of long, sharp spines that can be erected for defense against larger predators.
Jack Dempsey Cichlid (Rocio octofasciata)
Habitat: Slow-moving freshwater bodies like canals and swamps in Central America.
Size: Can grow up to 10 inches in length.
Conservation Status: Not formally evaluated, but it is widespread in the aquarium trade.
This fish is famously named after the 1920s heavyweight boxing champion, Jack Dempsey, a title earned for its strong facial features and notoriously aggressive, territorial behavior. It is renowned for its stunning iridescent scales, which shimmer with brilliant blue, gold, and pink spots on a dark background. This coloration becomes much more intense and vibrant when the fish is excited, breeding, or feeling aggressive.
Despite their pugnacious reputation, they are remarkably dedicated parents, with both the male and female working together to guard the eggs and fry from any perceived threats. They are also known to be intelligent fish that can learn to recognize their owners and will often interact with them through the aquarium glass, showcasing a personality as bold as their namesake.
Scientific Fish Names That Start With J
In this section, we focus on species or genera where the scientific name is particularly significant.
Julidochromis (Julies)
Habitat: The rocky shorelines of Lake Tanganyika in Africa, one of the African Great Lakes.
Size: Small, typically ranging from 3 to 5 inches in length.
Conservation Status: Most species are listed as Least Concern (LC), but they are endemic to a single lake, making them vulnerable to localized threats.
The genus Julidochromis, affectionately known as “Julies” by hobbyists, is famous for its slender, torpedo-shaped body. This form is a perfect adaptation for life in the rocky shorelines of Lake Tanganyika, allowing them to navigate the narrowest crevices with ease. Their most unique trait is their rock-hugging swimming style, where they stay in constant contact with surfaces, often swimming upside down or vertically to follow the contours of their environment.
These cichlids are known to form monogamous pair bonds that can last for their entire lives, a rare trait in the fish world. The pair works together to defend a shared territory and raise their young as substrate spawners, laying their eggs in the safety of tight caves or crevices. Their diet consists of scraping algae and picking out tiny invertebrates from the rocky surfaces they constantly patrol.
Jordanella (Flagfish)
Habitat: Vegetated freshwater ponds, lakes, and slow-moving streams in Florida, USA.
Size: A small fish, reaching up to 2.5 inches in length.
Conservation Status: Least Concern (LC) by the IUCN.
The genus Jordanella is named in honor of David Starr Jordan, one of the most influential ichthyologists in American history. Its common name, Flagfish, comes from the male’s brilliant breeding coloration, which features reddish stripes and a dark blue spot that resembles the American flag. This makes it a visually striking, though often feisty, addition to an aquarium.
Belonging to the same family as pupfish and killifish, they are known for their hardiness and resilience. Uniquely, the Flagfish is one of the few known fish species that is a true omnivore with a strong preference for hair algae, making it a useful and popular choice for aquarists looking for natural algae control. Males can be quite territorial and will establish and defend a small area, especially when ready to spawn.
Other Fish Species That Start with J
- Jack (Genus Caranx)
- Jaguar Catfish (Liosomadoras oncinus)
- Japanese Amberjack (Seriola quinqueradiata)
- Japanese Anglerfish (Lophius litulon)
- Japanese Armorhead (Pentaceros japonicus)
- Japanese Bluefish (Scombrops boops)
- Japanese Bullhead Shark (Heterodontus japonicus)
- Japanese Butterfish (Psenopsis anomala)
- Japanese Chub Mackerel (Scomber japonicus)
- Japanese Dragonet (Callionymus japonicus)
- Japanese Eel (Anguilla japonica)
- Japanese Goby (Tridentiger spp.)
- Japanese Grenadier Anchovy (Coilia nasus)
- Japanese Herring (Clupea pallasii)
- Japanese Icefish (Family Salangidae)
- Japanese Loach (Misgurnus anguillicaudatus)
- Japanese Pilchard (Sardinops melanostictus)
- Japanese Pufferfish (Takifugu rubripes)
- Japanese Roughshark (Oxynotus japonicus)
- Japanese Sardine (Sardinops melanostictus)
- Japanese Sawshark (Pristiophorus japonicus)
- Japanese Snapper (Paracaesio caerulea)
- Japanese Stingfish (Inimicus japonicus)
- Japanese Topshark (Hemitriakis japanica)
- Japanese Turbot (Verasper moseri)
- Japanese Velvetfish (Paraploactis obbesi)
- Japanese Whiting (Sillago japonica)
- Japanese Wobbegong (Orectolobus japonicus)
- Jawfish (Family Opistognathidae)
- Jellybean Tetra (Paracheirodon simulans hybrid)
- Jellynose Fish (Family Ateleopodidae)
- Jewel Cichlid (Hemichromis bimaculatus)
- Jewfish (Goliath Grouper, Epinephelus itajara)
- Jolthead Porgy (Calamus bajonado)
- Jumping Halfbeak (Hemirhamphodon pogonognathus)
- Jungle Perch (Kuhlia rupestris)
- Juniper Catfish (Megalodoras uranoscopus)
FAQs
What are some popular aquarium fish that start with ‘J’?
The Jack Dempsey Cichlid is famous among keepers of large, aggressive tanks. For smaller community tanks, the Jewel Cichlid is known for its brilliant red color, and various species of Julidochromis (“Julies”) are popular choices for African cichlid enthusiasts with rock-based aquariums.
What is a ‘Jawfish’ and what makes it unique?
A Jawfish is a small saltwater fish famous for two things. First, it uses its enormous mouth like a shovel to construct elaborate burrows in the sand, which it lives in. Second, it is a paternal mouthbrooder, meaning the male carries the fertilized eggs in his mouth for protection until they are ready to hatch.
Are there any dangerous fish that start with ‘J’?
While not typically aggressive towards humans, the Japanese Pufferfish is one of the most poisonous fish in the world to eat. Its organs contain a deadly neurotoxin, and it can only be prepared by specially licensed chefs in Japan. The term Jewfish, an outdated name for the Goliath Grouper, refers to a fish large enough to be potentially dangerous due to its sheer size.
