The intense reddish orange body and bright, electric blue bands make the Catalina Goby a great eye catcher for cooler water tanks that are no higher than 71˚F!
The Catalina or Bluebanded Goby is a serious POP of red to reddish orange, although it is found in a very small package! Their fins are clear with rays being the same color as the body. The tail fin can be yellow to yellowish orange. The black eyes are surrounded with bright blue irregular bars that can form interesting patterns on the face and head. Behind the blue band located behind the eyes, are 4 to 5 more bright blue vertical bands that may or may not extend the entire depth of the body. The first set of dorsal fins have elongated rays that are about 3 times longer than the second dorsal fin rays in males. Males barely make it past 1.25,” however they may grow larger in captivity, up to 2.”. They live for for 2 years, similar to the Neon Goby. They are best kept by intermediate aquarists.
A study of these little gobies showed that they are found in smaller sizes in the wild, which is probably due to predation. One study cited that of the harems they studied, the females were just under 3/4” to barely over 1,” and the males only slightly bigger. They only live 2 years, so it is possible the stated size on most websites of “up to 2” may indicate the ultimate size they can obtain if they are not eaten first! Catalina Gobies are found in harems of one male and several females. These little gobies are quite fearful, quickly diving into holes and crevices. In a pinch, they will even hide within the spines of the Long Spined Urchin (Centrostephanus coronatus)! I think most fish would avoid trying to get them out of there! Years ago, when these gobies were new to the hobby, they died quickly in the typical reef aquarium and where thought to be delicate. It was discovered they are actually quite hardy when kept at the appropriate temperatures. Sadly, higher temperatures are still being recommended.
These fish are easy to feed, but their care would be labeled as “moderately hardy” since they need tank water to be from the mid 50’s to the mid 60’s. The aquarist would need to have a knowledge of cold water marine systems to be successful. Although in the wild they may be FOUND at warmer temperatures, the Catalina Goby will not stay there and will move into deeper, colder waters in the summer. The reason why they are recorded at such a wide range of water depths, is because they dive deeper in the summer and shallower in the winter. They may visit warmer waters, but will not stay there. Kind of like being in Las Vegas when it is 110˚F! You will not stay outside too long when it is that hot, because it would eventually kill you. Experience has shown that water that is warmer than 71˚F will result in a much shorter life span than they already have. The fact is, colder water yields higher oxygen levels, so warmer water, with less oxygen, messes up the Catalina Goby’s respiration and lowers their oxygen levels, causing disease to develop and premature death.
The Catalina Goby is peaceful as long as there are no other substrate dwellers competing for space. They will share their space with the Zebra Goby (L. zebra), a slightly harder to keep species. A small tank that is 20 gallons can house a pair and 40 gallons can easily house a small grouping of 3. When adding multiple Catalina Gobies to one tank, add small individuals that are under 1” at the same time. One will change to male and the others will remain the female part of the harem. Do not house with fish that will eat these small beauties. Do not house with aggressive fish. Other fish that make good candidates are the Blue Spotted Jawfish that shares similar temperatures and the Oldwife, which is a cold water fish, but temperature tolerances do cross.
One goby can be housed in a nano tank that is at least 10 gallons, but the water should be 58˚F to 71˚F. The Monterey Bay Aquarium and the Steinhart Aquarium, both in California, keep their Catalina Gobies at 58˚F to 60˚F, although most people are successful keeping them at 68˚F or less. Optimal would be 64˚F if your chiller can swing it! Provide vertical “walls” with crevices in the live rock for them to hide in. Larger abandoned shells are also appreciated. You will probably need a chiller unless you live in the far northern reaches of the continental USA! Any light is acceptable, just be sure to provide areas where they can get out of the light if they want. Normal water flow, stable salinity and clean water are required.
For more Information on keeping this fish see:
Guide to a Happy, Healthy Marine Aquarium
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Perciformes
- Family: Gobiidae
- Genus: Lythrypnus
- Species: dalli
Habitat: Distribution / Background
The Catalina Goby, Lythrypnus dalli, was first described by Gilbert in 1890. The two common names they are known for are the Bluebanded Goby and the Catalina Goby. Those names give away their coloring and location!
Distribution – Habitat:
The Catalina Goby is found only in the Eastern Pacific from the Gulf of California to Ecuador and then south the northern coast of Peru. They are found on exposed surfaces of rock, however, they stay very close to holes and crevices, yet will hide within the spines of sea urchins when threatened. They can be found from 3 feet to 249 feet (0 to 76 m), where they feed on planktonic crustaceans and other planktonic inverts as well as amphipods, copepods, tiny mollusks, and small polychaete worms.
They are often found with the Zebra Goby (Lythrypnus zebra), and are found in pairs or harems with 1 male and 2 to 7 females. The Catalina Goby is on the IUCN Red List for Least Concern and a stable population trend.
Species Variations and Similar Species:
Zebra Goby (Lythrypnus zebra): The Zebra Goby has more evenly pattered vertical blue bars that extend the entire length of the body, instead of the Catalina Goby’s irregular head bands and vertical bands that are only found on the front 2/3rds of the body.
The Catalina Goby is an elongated, thin fish which red to reddish orange in color. They have the same color in their fin rays but the area between is clear. The tail fin can be yellow to pale orange. The eyes are black with bright blue irregular lines that run in front and behind them. The top of the head has a band across the top and a horizontal bright blue dash on the nose. The body has 4-5 vertical bright blue thin bands after the eye band and the bands can be partial or extend fully from top to bottom. They have 2 dorsal fins, with the front section being a little longer than the second dorsal fin’s rays, which are much shorter and even. The pelvic fins act as their support as they perch, and like most gobies they lack a swim bladder so they are usually found resting on a surface. The Catalina Goby male will develop very long front dorsal rays that are 2 to 3 times longer than the back dorsal fin. When changing sexes, the pattern on their body remains the same. Color fades when the water is too warm for them. The average male can get to or a little under 2” and females grow to 23 to 30 mm or just under 1” to 1.18,” and they only live 2 years.
Fish Keeping Difficulty
Catalina Gobies are moderately hardy if kept in a properly cooled marine tank. Warmer waters lower the oxygen levels, taxing their breathing, which will eventually cause disease and parasites to overtake them. The tank can be as small as 10 gallons, and even larger tanks should not house aggressive fish or fish that are large enough to swallow your goby whole. They are quite easy to feed, accepting any carnivorous foods. They are very skittish and will hide at the slightest movement when first introduced. Allow them time to acclimate before adding other peaceful tank mates. Avoid rock anemones, since they would easily take this little fish down!
Foods and Feeding
The Catalina Goby is a carnivore. They eat planktonic and benthic crustaceans and small polychaete worms. Feed them food that are designed for carnivores, but lean toward foods with mysis, brine and other small crustaceous foods that will sink to the bottom. They will also eat copepods and amphipods found the in system. Feed them twice a day.
- Nano/Small tanks up to 40 gallons, perform 5% water changes weekly.
- Medium sized up to 90 gallons, perform 15% bi-weekly.
- Large Tanks 100 gallons and over, once water is aged and stable can be changed 10% bi-weekly to 20% monthly, depending on bioload.
Fish only tanks:
- Nano/Small tanks up to 40 gallons, perform 15% water changes bi-weekly.
- Medium sized up to 90 gallons, perform 20% to 30% monthly depending on bioload.
- Large Tanks 100 gallons and over, once water is aged and stable can be changed 20% to 30% every 6 weeks depending on bioload.
For more information on maintaining a saltwater aquarium see: Saltwater Aquarium Basics: Maintenance. A reef tank will require specialized filtration and lighting equipment. Learn more about reef keeping see: Mini Reef Aquarium Basics.
The Catalina Goby is a great candidate for a 10 gallon nano tank! They seem to prefer vertical rock faces, so structure your live rock vertically with lot of little crevices and little caves that they can shoot into. If there isn’t enough room for such an aquascape, they will still be happy with flat surfaces that have crevices and caves nearby. Even a large empty shell that they can hide in is appreciated. Sand is the preferred substrate and any lighting is okay, as long as you provide an over hang for them if they wish to escape the brightness. Although older textbooks state that they can be kept in tropical temperatures, they do best at 58˚F to 60˚F, however, a temperature range is 64˚F to 71˚F (16 to 21˚C) is acceptable. Catalina Gobies need the normal salinity of 1.023 to 1.025 and calmer water movement at the bottom where they live. You can keep them as pairs or in groups since one will turn male and the others will remain female. House in a tank that is 40 gallons or more if you want to do a small group of 3 or 4.
Catalina Gobies are peaceful, however, they are still territorial toward their own kind and need 10 gallons for one, 20 for a pair; 40 gallons for 3 and so on. They can be kept in groups of 1 to 7 if they are added at the same time and they are all under 1” in size. One will turn male and the other will remain in the harem as females. Females are slightly smaller than males, only growing up to about 1.25,” however if the male dies, the dominant female will become male in 2 weeks, as seen by the growth of their front dorsal rays.
They are quite happy in tanks with other fish that are peaceful, and should not be housed with aggressive tank mates or other tank mates that occupy the bottom of the tank unless the tank is long and gives everyone plenty of space. Do not house with fish that are large enough to eat this small beauty. Even smaller hawkfish have large enough mouths to swallow your Catalina Goby whole. Any tank mates added should be able to tolerate the colder water that the goby needs. They may be okay with the Blue Spotted Jawfish if the tank is suited to their size and would work well with the Oldwife. Oldwife are from southern Australia, and while they are cold water fish, their temperature tolerances will cross with the Catalina Goby between 58˚ and 64.4˚F.
The Catalina Goby will not bother any corals, so if you have cold water corals, they will do great! Be aware that there are very few corals that can tolerate temperatures below 75˚F. Avoid housing with rock anemones. Although certain species do well with cold water, little fish like this gobies is on the menu!
Inverts are not bothered, in fact, obtaining a Long Spine Urchin would enable the aquarist to possibly witness the goby hiding in it’s spines! They will not bother any inverts, however will munch on a few copepods and amphipods here and there. Tigger Pods, as they are called, are great for cold water tanks and live much longer in these lower temperatures, making them a great snack when your goby is hungry. They will not decimate the population however.
Sex: Sexual differences
Males are slightly larger and have longer rays on their first dorsal fin.
Breeding / Reproduction
The Catalina Goby being a simultaneous hermaphrodite, where they are all born females and can become males as needed, but can change back! In a harem, there may be some that are pure female or females on the verge of change, and they stay in the harem until they are pure male. Scientists found that they can switch back to females or into males if needed, within 2 weeks! They are found in harems of one male and 1 to 7 females.
Females start to develop their eggs a few months early in preparation for spawning season from March to August. The male will jerk towards the female and nip at her tail. Both will wiggle their tails during the courtship until she is ready to lay her eggs. The female will lay her sticky, oblong eggs on the walls of the nesting area, or inside the walls of large empty shells, then the male will follow after her and fertilize the eggs. The male will protect the nest of eggs, until they hatch into larvae. The planktonic larvae drift in the ocean’s water column for 2 to 3 months when they reach about 9-11 mm. At that time, they settle into the reef and they grow very quickly, reaching maturity within one month of settling! This means from hatching to settling, they are ready to reproduce within 4 months. The Catalina Goby’s life span is said to be 2 years.
In captivity, 2 females added to the same tank will easily result in a male and female pair. The male will be the one with the elongated dorsal rays and larger size. These fish have been raised in captivity, however, sometimes the males will eat their first clutches.
See general breeding techniques on the Breeding Marine Fish page.
Catalina Gobies are quite hardy if kept in tanks with the appropriate max temperatures of 64 to 71˚F, however, the upper 50’s to mid 60’s are the most desirable levels. At higher temperatures, especially over 71˚F, they will develop illnesses since the oxygen level is too low, compromising their immune systems. Do not subject these fish to low salinity or low pH. They need their natural habitat as a guide, providing salinity levels at 1.025 and pH no lower than 8.1, preferably 8.2.
For information about saltwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.
These fish are often found online and they are not very expensive for marine fish.
Beautiful, Hardy In the Right Setting, But Subtropical, The Catalina Goby, Lythrypnus dalli
By Bob Fenner
The Biological Bulletin
Sex Reversal in Pairs of Lythrypnus dally: Behavioral and Morphological Changes
By Edmund W. Rogers, Shelia Drane and Matthew S. Grober
Copyright © 2014 by the Marine Biological Laboratory
Aquarium Fish: A Look at the Gobies
By James W. Fatherree, M.Sc.
Copyright © 2002-2014 by Pomacanthus Publications, LLC, all rights reserved.
Cold Water Catalina Gobies
By Felicia McCaulley
© 2017 Reefs.com
Novel Sexual Patterns in Two Simultaneously Hermaphroditic Gobies, Lythrypnus dalli & Lythrypnus zebra
By Colette M. St. Mary
©2000-2013 ITHAKA. All Rights Reserved
An initial description of alternative male reproductive phenotypes in the blue banded goby, Lythrypnus dally (Teleostei, Gobiidae)
By Cathleen C. Drilling & Matthew S. Grober