Frequently Asked Questions
The most-asked questions about wrasses and gobies.
What are wrasses and gobies?
Wrasses (family Labridae) and gobies (family Gobiidae) are two large, species-rich families of primarily tropical marine fish. Wrasses tend to be more colorful and diverse in body shape, while gobies are usually smaller, flatter, and spend much of their time on the substrate.
What's the main physical difference between the two families?
Wrasses typically have a single dorsal fin and a more robust, laterally compressed body, whereas gobies usually carry two separate dorsal fins and lack a swim bladder, using their fused, rounded pelvic fins to perch like little legs. Wrasses also span a far wider size range, from a few centimeters to over a meter in the case of the humphead.
Which species are the most popular among reef hobbyists?
The cleaner wrasse (Labroides dimidiatus), the clown goby (Tigrigobius saarinus), the mandarinfish, and the sixline wrasse are consistently among the most requested. Firefish gobies and various dwarf wrasses also enjoy a huge following in nano-reef circles.
What should a beginner prioritize when choosing a wrasse or goby?
Hardiness and feeding requirements matter more than color; species like the sixline wrasse or the clown goby tolerate new-tank conditions well and accept a range of meaty foods. Avoid species that are strict live-feeders or require very specific parameters until you have a stable system.
How much tank space do they actually need?
Dwarf wrasses and small gobies can do well in 20-gallon nano reefs, but most mid-sized species are happiest in 40- to 75-gallon setups with plenty of rockwork for hiding and foraging. Larger wrasses, such as certain parrotfish-adjacent species, demand significantly more open swimming volume.
Why are they considered near-essential in a reef tank?
Many species act as natural pest control, grazing on nuisance algae, small snails, and other invertebrates that would otherwise overgrow a display. They also add constant visual interest through vivid coloration, acrobatic swimming, and (in gobies) nonstop substrate activity.
What's the most common mistake new keepers make with them?
Underfeeding or offering only flake food is the top culprit of loss; many wrasses and gobies are obligate carnivores that need frequent, varied meaty items or they will slowly starve. A second frequent error is adding them to a bare or sparsely decorated tank, which causes chronic stress and hiding.
Are they aggressive or do they get along with other tankmates?
Most are peaceful, but some wrasses can be territorial over a patch of rock, and cleaner wrasses are well known for nipping at the fins of larger, slower fish. Gobies are generally docile but will vigorously defend a small burrow or anemone if another goby crowds them.
What behaviors do fans love to watch?
Cleaner wrasses set up recognizable "stations" and meticulously pick parasites off passing fish, while clown gobies perform elaborate courtship dances and build small pebble nests. Many gobies also do headstands or perch on anemone tentacles, and wrasses are famous for sudden color shifts and barrel rolls.
Where can newcomers find reliable information and community support?
Dedicated reef-keeping forums, species-specific Facebook or Discord groups, and local aquarium societies are the most active places to ask questions and share photos. Supplementing those with a good marine-fish identification guide and care videos from experienced hobbyists fills in practical details that general references often skip.