Gobies are popular in marine aquariums because of their diversity in size, colour and behaviour. They are from the family Gobiidae and occur on coral reefs all over the world. Gobies vary in size and temperament and can be introduced into most marine aquariums. Always consult your OATA retailer before purchasing any gobies to ensure they will mix with current tank mates.
Thanks to Maidenhead Aquatics for the use of this photo
Water requirements
Gobies are usually undemanding of water chemistry and their suggested parameters are shown below. These parameters are a general guide for this group of fish, so it is important to check with your OATA retailer for any species-specific requirements before purchasing. Please also note that if keeping these fish in a reef aquarium, some parameters will need to be altered to accommodate more sensitive species.
- Salinity: Between 1.020-1.025
- Temperature: Between 24-26°C
- pH: 7.9-8.3
- Ammonia: Zero mg per litre
- Nitrite: Zero mg per litre
- Nitrate: Not to exceed 50 mg per litre
- Carbonate hardness: Hard (8-12°dkH)
- Calcium: Between 380-450 ppm
- Magnesium: Between 1250-1350 ppm
Biology
Gobies differ from similar-looking species, such as blennies, by having fused pelvic fins that form a ‘suction disc’ on which they perch.
Gobies are a very diverse group and can behave in a variety of different ways. Some species live in coral heads, others cling onto larger fish to eat parasites, and some sift the gravel for food items. There are some species which have a symbiotic relationship with shrimp and live together in burrows. However, they will all generally live near the sand bed or rock and few, if any, swim in the open.
Size can vary greatly. Species such as the yellow coral goby (Gobiodon okinawae) only reach about 4cm, while the yellow sleeper goby (Valenciennea strigata) grows up to 20cm. Several species of gobies, such as the yellow watchman (Cryptocentrus cinctus) and the neon goby (Elacatinus oceanops) are bred commercially, and tank-bred individuals are often available. Due to their diversity, different goby species can be mixed, however it is usually best to avoid members of the same or similar looking species to avoid any disputes. Sometimes male and female pairs are available, and these can be kept together. Some species can tolerate small groups if there is enough space. Always consult your OATA retailer before introducing a goby to your aquarium. Regardless of size, gobies can live for many years in a well-matured set-up with good water quality.
Sexing gobies depends on the species involved: some species will have no differences whereas others will have differences in finnage or colour.
Aquarium requirements
As a general rule, you should within reason, buy an aquarium as large as possible. It is recommended that an aquarium of at least 40 litres is used for an individual of the smaller species (under 7-8cm). For larger species, an aquarium of at least 120 litres is recommended. Aquariums will need to be even larger if you wish to keep gobies with other fish species. A larger aquarium will also provide more stability to environmental conditions such as temperature and water quality. Whatever the size, a filter is essential. For marine set-ups, this can be in the form of live rock with sufficient water flow, an internal or external filter, or a sump-based filter. A protein skimmer can also be beneficial for maintaining water quality as it will help to remove dissolved organic waste before it can break down into more harmful substances.
Due to their natural behaviour, live or artificial rockwork is essential for gobies and should be arranged to provide crevices, overhangs and outcrops to allow them to find cover as required. Additionally, many species will require a thick sand bed to allow them to filter through their gills to feed or to construct a burrow. This should be at least 4cm, but perhaps deeper for some species, and comprised of a fine coral gravel (grains under 3mm) that can easily be moved or filtered. Some gobies may move the sand around and this can undermine rock structures, so it is important to ensure that rock touches the bottom glass to prevent any falling down and causing damage. There should be a moderate water flow to provide good surface movement and to ensure detritus does not accumulate. A lid or cover is essential as these fish can jump, especially if startled.
A heater is required to maintain a suitable temperature all year round. To minimise fluctuations in water temperature, the aquarium should not be situated near any draughts or heat sources. It should also be out of direct sunlight and away from loud noises, vibrations and sudden movements. Overhead tank lighting is recommended to maintain a correct day-night cycle. This will not need to be particularly bright for gobies alone but may need to be brighter if keeping with coral species – see our coral care sheets for more information.
Water testing kits are essential so that water quality can be checked on a regular basis (once a week) to ensure it does not slip below the water requirements stated earlier.
Introducing your fish
Before adding any fish, seek advice from your OATA retailer to make sure that your aquarium is an appropriate size for the goby you would like to keep. Check that the water quality in your aquarium is suitable i.e. levels of ammonia and nitrite are zero. Only increase the number of fish you have in your aquarium slowly as the population of beneficial bacteria established when maturing your aquarium filter need to increase every time more fish are added and feeding increases. Overstocking or stocking your aquarium too quickly can result in ‘new tank syndrome’. This occurs when there are not enough nitrifying bacteria to cope with the increased waste from the fish, leading to unhealthy levels of ammonia and nitrite, which may cause fish to become ill or die.
Healthy fish have clear bright eyes, undamaged fins, intact scales, no ulcerations or bumps, appropriate swimming behaviour and steady breathing. Do not purchase a seemingly healthy fish if sickly fish are present in the tank with it. Signs of disease can include clamped fins, flicking against gravel or décor and shimmying (shaking). Diseases can be easily carried by fish that do not show any clinical signs. If in doubt, ask your OATA retailer for advice as they will have in-depth knowledge and experience.
Your OATA retailer will usually sell your fish to you in a plastic bag, try not to keep them in this for too long. Once purchased, take your new fish home as quickly as possible because fish are easily stressed by bright lights, extreme temperatures, noise and movement.
Once home, your fish will need to acclimatise to their new environment and a common method of doing this is known as the ‘floating bag’ method. Switch off the aquarium lights and take the bag containing your new fish out of its outer wrappings carefully, avoiding exposure to bright light. Float the bag in the water of your tank to ensure the temperature in the bag is the same as the aquarium water. After 10 minutes, slowly introduce small amounts of aquarium water into the bag containing the fish for up to 30 minutes. Once complete, carefully release the fish into the aquarium whilst introducing as little bag water into the aquarium as possible. This is especially important if keeping fish with any invertebrate species as some retailers run copper in their systems, which is toxic to invertebrates. After this, dispose of the bag and any excess water appropriately.
For sensitive species or to ensure retailer water does not enter your aquarium, a better method might be the use of drip acclimation. This could be achieved by keeping the fish in the container in which it is sold and a small airline siphon started to drip water into the container, slowly changing the water parameters to that of the aquarium. Ensure that the temperature does not fall too low during this procedure. Once conditions match, carefully net the fish from the container into the aquarium. Dispose of the water in the transport container appropriately. Monitor your new fish carefully for the first week, paying particular attention to water quality. If in doubt, contact your OATA retailer for advice.
If possible, quarantining new livestock in a separate aquarium for at least a week before they enter the main tank can help reduce any risk of disease spread from new inhabitants. Ask your OATA retailer for advice on this topic.
Maintenance
At least once every week, a partial water change of 25% is strongly recommended (a siphon device is useful to remove solid waste from the gravel). Filters should be well maintained, with regular checking and cleaning to prevent blockages. If the filter needs cleaning, do not run it under the tap because any chlorine or chloramine present may kill the beneficial bacterial population that has established in the media. Instead, it should be rinsed lightly in the tank water which is removed during a partial water change as this reduces the amount of bacteria which are lost. Protein skimmers should be regularly cleaned to maintain their performance.
Good husbandry is essential as gobies can be stressed by even the smallest amounts of ammonia and nitrite which may then cause them to develop various diseases. Test the water to monitor the ammonia, nitrite and nitrate levels, together with pH and carbonate hardness every week, especially during initial set-up and after adding extra fish. It is also important to regularly monitor salinity and use reverse osmosis water to replace any water lost through evaporation.
What to watch out for
All fish will have slight variations in their behaviour or appearance, but keeping an eye on any changes in the following will help to identify any potential problems before they become a real health issue:
- swimming behaviour – hanging at the surface, sitting on the bottom or erratic swimming
- colour – turning a darker or paler colour than normal
- temperament – changes in level of aggression or hiding more than normal
- breathing – gill covers moving at a slower or faster rate than normal
- appearance – development of white spots or fluffy growths, loss of fins or scales
- condition – increase or decrease in body weight and condition
- feeding – reduced intake or lack of interest in food
If you are concerned about the health of any of your livestock, then test your water quality and contact your OATA retailer for further guidance.
Feeding
Most gobies are omnivorous and will require a varied diet. Generally, frozen meaty items are accepted well but should be sized according to the species being fed. Larger species will appreciate krill, mysis shrimp or enriched brine shrimp. Smaller species will require frozen copepods or finely chopped krill or mysis shrimp. In addition, many species will eat prepared diets, but granules or flakes should be of an appropriate size.
Some species will sift through the sand to obtain invertebrate food items, therefore the sand bed should be mature so that there is a large population of these prey items. In addition, these may need to be supplemented with cultured or shop-bought live copepods, small frozen meaty foods or sinking pellets.
Gobies should only be fed what they can eat within a few minutes, twice a day. Take care not to overfeed as this can lead to a build-up of uneaten food which breaks down releasing toxic waste into the water. If in doubt, ask your OATA retailer for advice on appropriate feeding levels.
Compatibility
Gobies will generally mix well with other fish species. Some species such as yellow gobies are small and shouldn’t be kept with any predatory species. Others such as the high fin clown goby (Stonogobiops yasha) can be timid and won’t do well in aquariums with boisterous species. However, some of the larger species such as the yellow watchman goby are more confident and can be mixed with more active fish. Some species may eat small invertebrates such as shrimp if they can fit them in their mouths. In addition, species that sift through the sand can deposit piles of sand in unwelcome places so be careful if mixing these species with corals that live on or near the bottom of the aquarium.
Breeding
Some gobies have been bred in captivity and may spawn in the home aquarium. The exact process varies depending on species, but generally the female deposits hundreds of eggs in a cave or on a hard surface, which are tended to by the male. After approximately a week, these hatch and hundreds of larvae are produced. These are too delicate to survive in a home aquarium as they are likely to get sucked into filters and pumps or eaten by other aquarium inhabitants. They also require specific live feeds and so a specialist set-up is required to raise them to adulthood.
Checklist
Before purchase make sure:
- You have the appropriate equipment and position for the aquarium.
- You have researched all the species in which you are interested and your final choices are all compatible.
- You are familiar with how to transport and release your fish.
- You are aware of the daily, weekly and monthly maintenance your aquarium will require.
- You are prepared to look after your fish properly for the duration of their life.
Shopping list
- Glass or acrylic aquarium
- Filter*
- Heater
- Lighting (required for live plants)*
- Gravel or sand
- Tap water conditioner/dechlorinator
- Gravel cleaner/siphon cleaning device (recommended)
- Aquarium salt and a hydrometer or refractometer
- Access to reverse osmosis water or a reverse osmosis unit
- Water testing kits (ideally ammonia, nitrite, nitrate, pH and water hardness)
- Live or artificial rock
- Protein skimmer* (optional but recommended)
- Ultraviolet steriliser (optional but recommended)
- Aquarium decorations and/or live plants
- Bucket for water changes
*may be included in branded aquarium sets but can be purchased separately.
Before purchase make sure:
- The aquarium is of a suitable size that ideally can accommodate the fish once they are fully grown.
- Water parameters are as advised in this leaflet.
- Aquarium is cycled and ready to receive fish.
Top tips
Always buy…
test kits and regularly check the water for ammonia, nitrite, nitrate and pH. This will allow you to make sure the water in your aquarium is not causing welfare problems for your fish.
Establish a routine…
for testing the water in your aquarium. Record your results to enable you to identify fluctuations quickly. Also check the temperature of the water.
Maintain…
the water in the aquarium within the accepted parameters highlighted above. You may need to do regular water changes to achieve this.
Always wash your hands…
making sure to rinse off all soap residues, before putting them into your aquarium, or use long sleeved rubber gloves. Wash your hands again afterwards and certainly before eating, drinking or smoking.
Never siphon by mouth…
A fish tank can harbour bacteria which can be harmful if swallowed. Buy a specially designed aquarium gravel cleaner which can be started or primed without the need to place the siphon in your mouth.
Five Welfare Needs Checklist:
The Animal Welfare Act 2006 states that all pet owners have a legal duty of care to their pets. Anyone who is cruel to an animal or is found not to be providing the five animal welfare needs, as listed below, can be prosecuted.
- A suitable environment e.g. appropriately sized tank (with water heater if tropical set up) within a suitable location in your home.
- A suitable diet which meets the needs of your chosen fish.
- Behaviour – Fish are able to exhibit their normal behaviour e.g. hiding places for timid fish, enough room for fish to swim freely.
- Companionship – Ensure you know whether your chosen fish need to be kept with, or apart from, other fish.
- Health – Protected from pain, injury, suffering & disease e.g. you are aware of the daily, weekly and monthly maintenance that your aquarium will need.
Remember...
Water quality test kits are a necessity not an optional extra.
You must be prepared to look after your fish properly for the duration of their life and provide an aquarium which can accommodate your fish when fully grown.
Never release your aquarium animals or plants into the wild. It is illegal and for most fish species this will lead to an untimely and possibly lingering death. Any animals or plants that do survive might be harmful to our native countryside. Take care to properly dispose of any soiled substrate (e.g. sand or gravel) water or decorations so that non-native organisms do not enter natural watercourses.
