Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 528 species
Roule's abyssal cusk
Barathronus roulei
Barathronus roulei is a deep-sea bythitid/brotula-type fish from the Northeast Atlantic, recorded from deep water (e.g., ~1349 m). It is extremely rarely encountered and not an aquarium species due to collection and decompression/pressure constraints.
Roule's smooth-head
Rouleina livida
Rouleina livida is a deep-sea slickhead (family Alepocephalidae) that lives way down in the bathypelagic zone, not something you will ever see in the aquarium trade. It tops out around 34 cm standard length and has those classic deep-sea vibes like huge eyes plus little light organs (photophores) around the head and jaw.
Roundel batfish
Zalieutes elater
Zalieutes elater is a weird little "walking" batfish that lives on sand and mud bottoms and basically scoots around like a tiny sea creature robot. The coolest giveaway is the pair of orange-and-black eye-spots (ocelli) on its back, plus it has a short anglerfish-style lure it uses to ambush small crustaceans and fish.
Round stingray
Urobatis halleri
A neat California-to-Ecuador coastal ray that spends a lot of time buried in sand with just the eyes showing. It fans the bottom to pop up shrimp and crabs, and once it trusts you it will cruise over for hand-fed seafood. Cool-water marine fish that needs a deep soft sand bed and a big, wide tank to turn comfortably.
Roundtail duckbill
Bembrops greyi
The roundtail duckbill (Bembrops greyae) has the classic duckbill appearance with its broad, flattened head and a mouth designed for catching prey. Its natural home is way down on the slope, so its care is basically "public-aquarium only" rather than something that realistically fits a normal home setup.
Royal codling
Urophycis mystacea
This is a deepwater hake from the Southwest Atlantic, hanging over muddy and sandy bottoms a couple hundred meters down. It maxes out around two feet and snacks on shrimps, crabs, and squid, so it is a public-aquarium fish at best. Super cool chin barbel and classic codling look, but way too big and cold for home tanks.
Royal gramma
Gramma loreto
Royal grammas are that classic purple-to-yellow Caribbean basslet that likes to claim a cave and hover around it (sometimes totally upside-down under a ledge). They're usually chill with tankmates, but they can get spicy with other grammas/basslets/dottybacks if space is tight-give them rockwork and a "home" cave and they settle right in.
Saddle wrasse
Thalassoma duperrey
This is the Hawaiian saddle wrasse - an always-on, cruise-the-rockwork kind of wrasse that constantly hunts little critters. Juveniles will sometimes do cleaner-fish behavior, then as they grow they turn into bold, fast, snack-hunters that can rearrange your clean-up crew.
SAIAB goatfish
Upeneus saiab
Upeneus saiab is a small demersal goatfish from northern Mozambique that cruises sandy bottoms and uses its chin barbels to hunt little critters. In fresh colors it has a subtle pale lateral stripe and a really eye-catching tail pattern (red oblique bars on the upper lobe and a mostly red lower lobe with a dark tip). This one is basically a wild marine fish from deeper water, so its more of a research/taxonomy fish than a realistic home-aquarium species.
Saikai grenadier (rattail)
Ventrifossa saikaiensis
This is a deepwater grenadier (rattail) from the western Pacific - the kind of fish that lives way down on the slope where its "aquarium" is basically cold, dark, and high pressure. It tops out around 25 cm and has that classic rattail look with a chin barbel, plus a ventral light organ. Cool animal, but realistically its not an aquarium species at all unless youre talking public-aquarium level coldwater deep-sea systems.
Sailfin cardinalfish
Quinca mirifica
This is a chunky, almost jet-black cardinalfish with a crisp white tail and an absurdly tall second dorsal fin - it looks like it belongs in a comic book villain lair. It hides in caves and crevices by day and comes out to hunt at night, and the males mouthbrood the eggs (with a wild courtship color change to bright silvery-white). It is a super range-restricted Western Australia species, so you do not see it often in the hobby.
Samoan surf sardine
Iso nesiotes
Iso nesiotes (Samoan surf sardine) is a very small surf-zone marine fish (family Isonidae) reported from places such as American Samoa and Pitcairn Island, inhabiting surf and waves around rocky headlands and reefs. Maximum reported size is about 4 cm TL; detailed life-history and aquarium husbandry information is limited.