Blue Spot Jawfish Care: Tank Setup, Diet, Tank Mates, Diseases & More!

Blue Spot Jawfish, also known as Opistognathus rosenblatti, are strikingly beautiful creatures with their vibrant blue spots and yellow accents. As a fish enthusiast, I’ve always been fascinated by their unique behavior, making them a captivating addition to any saltwater aquarium.

Blue Spot Jawfish care involves providing a suitable aquarium environment, proper diet, and regular maintenance. These small, colorful fish require a well-oxygenated tank with plenty of hiding places and open swimming space. They need a varied diet of meaty foods, including crustaceans and mollusks. Blue Spot Jawfish are known for their burrowing behavior, so a sandy substrate is necessary. Regular water changes and maintenance are also important for their health and well-being.

When I first got my Blue Spot Jawfish, it was amazing to watch them construct their burrows in the sand. These quirky fish are known for being skilled engineers, creating intricate tunnels to serve as a safe haven. This exceptional trait has quickly made them one of my all-time favorites.

With proper care, Blue Spot Jawfish can thrive in a home aquarium. They require a well-established tank, plenty of sand for burrowing, and pristine water conditions. By paying close attention to these needs, you can help ensure a happy, healthy life for your jawfish.

Blue Spot Jawfish 2

Species Summary


The Blue Spot Jawfish, known scientifically as Opistognathus rosenblatti, is native to the Eastern Pacific Ocean. Specifically, they can be found off the coast of Baja California and the Revillagigedo Islands in Mexico.


In the wild, Blue Spot Jawfish typically have a lifespan of about 5-6 years. With proper care and attention in captivity, they may live up to 8 years, but it varies significantly depending on the individual.


These fascinating creatures have a striking appearance with their vibrant blue spots on a pale yellow background. They also have large eyes and a distinctive, large mouth – perfect for collecting and moving sand or gravel when building their burrows.


Blue Spot Jawfish typically reach sizes of 4-5 inches (10-12.5 cm) in length as adults.

Growth Rate

The growth rate of Blue Spot Jawfish varies but generally, they grow moderately fast, especially in their first year. You may see about 1-2 inches of growth during this time, slowing down as they reach adulthood.

Behavior & Temperament

Blue Spot Jawfish are known for their shy temperament. They enjoy spending most of their time within their burrow. They’re also known to be territorial, and it’s essential to give them enough space to establish their territory. Interestingly, they may even spit sand at invaders or tank mates that encroach on their space.

Male vs Female

Sexual dimorphism in Blue Spot Jawfish is not easily distinguishable. Males are sometimes slightly larger and may have slightly more vibrant coloration. However, to accurately determine the sex, one would likely need to observe their behavior during spawning times.

Personal anecdote: I remember when I first added a Blue Spot Jawfish to my aquarium. It was fascinating to watch its unique burrowing habits. It quickly became one of my favorite fish, not only for its stunning appearance but also for its quirky personality.

Tank Setup

Tank Size

A Blue Spot Jawfish requires a minimum tank size of 30 gallons. I once made the mistake of using a smaller tank, and my Jawfish weren’t as active or happy as they could have been.


Moderate lighting is preferred, as these fish like to have some shaded areas to hide in. While LED lighting is common, any kind can be used.

Filtration & Aeration

Using a high-quality filter is crucial to maintaining a clean environment. For proper aeration, ensure you have a good water flow and an air stone.


Keep your tank temperature between 72-78°F. Monitor and adjust your heater to maintain a stable temperature for your fish.


Jawfish tend to dig, so a soft, sandy substrate is ideal for their burrows. About 2-4 inches deep is perfect.


Include live rock in the tank to provide shelter and hiding spots. Mixing in some PVC pipes encourages jawfish to burrow.


Adding sea grass and other marine-based plants will make jawfish feel more at home, as well as increasing water quality. Just be sure they’re compatible with the species.

Water Quality

Water Temperature

The Blue Spot Jawfish likes a stable and warm environment. Aim to keep their tank within the range of 74-80°F (23-27°C). I once noticed my own jawfish becoming more reclusive when the temperature fluctuated too much.

Water pH

Jawfish prefer a slightly alkaline environment. To keep them healthy and active, maintain a pH level between 8.1-8.4. You can use commercial solutions or natural materials to help balance the pH.

Water Hardness

Balancing water hardness is crucial for the jawfish’s well-being. Aim for a dKH range of 7-12, which you can maintain with commercial additives or natural water conditioners.

Water Changes

  • Regularly changing a portion of the tank water is essential.
  • Perform weekly 10-15% water changes.
  • Make sure water changes maintain the proper pH, temperature, and hardness levels.

Doing that for my own Blue Spot Jawfish, I’ve noticed it to be more outgoing and thriving in its habitat!

Tank Maintenance

To maintain a healthy environment for your Blue Spot Jawfish, regular tank maintenance is crucial. I remember when I set up my first Jawfish tank, I quickly realized how important cleanliness and stability were to their well-being.

One essential aspect is water testing. Ensure your tank’s pH levels, ammonia, nitrite, and nitrate levels are within acceptable ranges. Frequent water testing allows you to identify and rectify imbalances early on.

Partial water changes are vital for reducing nitrate levels and replenishing minerals. Replace 10-20% of the tank water weekly, keeping a close eye on the overall condition of your Jawfish throughout this process.

The filtration system plays a significant role in keeping your tank water clean. Invest in a high-quality filter and ensure it functions efficiently by regularly cleaning the media and filter components. This will help prevent harmful bacteria and parasites from blooming.

Substrate cleaning is equally crucial given the Blue Spot Jawfish’s burrowing behavior. Gently siphon the top layer of sand or crushed coral once a week to remove detritus and uneaten food. Be mindful of your Jawfish’s burrows during this process.

Lastly, keeping tank decorations clean promotes the overall health of both the aquarium and its occupants. While scrubbing algae off rocks and structures, be careful not to disturb the Jawfish’s burrows.

Remember, proper tank maintenance provides a stable and clean environment, allowing your Blue Spot Jawfish to thrive. Good luck, and enjoy the fascinating world of Jawfish care!

Tank Mates

Compatible Fish Species

Blue Spot Jawfish are generally peaceful and can cohabit with other reef-safe fish species that won’t outcompete them for food or space. Some ideal tank mates include:

  • Clownfish: They occupy different regions in the tank, preventing territorial disputes.
  • Firefish: Their similar size and nature makes them compatible.
  • Gobies: Many gobies are also burrowers like the Blue Spot Jawfish, and they usually don’t bother each other.

One time, I added a Royal Gramma to my Blue Spot Jawfish tank, and they got along well as they have their distinct territories.

Incompatible Fish Species

Some fish species are not suitable as tank mates for Blue Spot Jawfish due to their aggressive behavior, size, or feeding habits. Here are a few examples:

  • Lionfish and Angelfish: They can prey upon smaller, more vulnerable species like the Blue Spot Jawfish.
  • Triggerfish and Large Wrasses: These fish can be territorial and may become aggressive towards smaller tank mates.
  • Damsels and Chromis: While some damsels are reef-safe, many can be territorial and aggressive, leading to stress for your Blue Spot Jawfish.


What To Feed

As a Blue Spot Jawfish owner, I’ve found that a varied diet is essential for their health and well-being. Offer meaty foods such as:

  • Mysis shrimp
  • Brine shrimp
  • Finely chopped marine fish
  • Squid
  • Clam

Occasionally, it’s a good idea to include vitamin-enriched pellets.


Feeding Blue Spot Jawfish 2-3 times per day is ideal. This ensures they receive enough nutrients and maintains their vibrant colors.


Here are some helpful tips for feeding your Blue Spot Jawfish:

  1. Feed small portions: Blue Spot Jawfish have small mouths, so feed them bite-sized pieces.
  2. Use a feeding stick: This helps place food directly in front of their burrows, ensuring they receive their share.
  3. Monitor intake: Keep an eye on how much your fish eats to prevent uneaten food from polluting the tank.
  4. Turn off pumps: Temporarily switching off water movement can make it easier for the fish to catch their food.

Common Diseases


As a Blue Spot Jawfish owner, I’ve found that they are quite hardy, but can still suffer from a few common diseases. Some of these are:

  1. Ich (White Spot Disease): Caused by the parasite Ichthyophthirius multifiliis, this is a common fish disease.
  2. Marine Velvet: This is a parasitic infection caused by Amyloodinium ocellatum, which affects marine fish.


Identifying symptoms is essential to ensuring your Blue Spot Jawfish stays healthy. Here are some common signs:

  • Ich: Tiny white spots covering the fish’s body, gills, and fins.
  • Marine Velvet: A velvety or powdery appearance on the skin, rapid breathing, and loss of appetite.


Act quickly if you notice any symptoms, as timely treatment can make a difference. Here’s what I would do:

  • Ich: Increase water temperature by 2-3°F for three days and treat the tank with copper-based or malachite green medications.
  • Marine Velvet: Use a copper-based medication following the manufacturer’s instructions.


Preventing diseases is key to keeping your Blue Spot Jawfish healthy. Some tips include:

  • Quarantine new fish for 2-4 weeks.
  • Maintain good water quality.
  • Monitor ammonia, nitrite, and nitrate levels regularly.
  • Feed a varied and balanced diet.

Following these steps, your Blue Spot Jawfish will be well-equipped to fight off common diseases.

Signs of a Healthy Fish

Blue Spot Jawfish

Identifying a healthy Blue Spot Jawfish is crucial for ensuring its proper care. In my experience, vibrant coloration is one key indicator that the fish is in good health.

Additionally, an active and alert Jawfish often signals well-being. They should be swimming without difficulty and showing interest in their surroundings.

When it comes to feeding, a healthy Jawfish will display a good appetite. I once tried offering a new type of food, and my Blue Spot Jawfish immediately started eating it— a great sign of a healthy fish!

Lastly, check for intact fins and scales. These physical features should appear full, without any damages or abnormalities.

Signs Your Fish is Sick

One day, I noticed my Blue Spot Jawfish acting a little off, and that’s when I realized how crucial it is to identify the signs of a sick fish. Here are a few indicators that your fish may be unwell:

  1. Loss of Appetite: If your fish isn’t as enthusiastic about eating as usual, it could be a sign of illness.
  2. Lethargy: A healthy fish should be active and swim with energy. Lethargy and listlessness may indicate a problem.
  3. Changes in Color: If your fish’s colors become pale, faded, or change drastically, it is a cause for concern.
  4. Bloated Appearance: A swollen or bloated body could indicate an internal issue, like parasites or infection.
  5. Labored Breathing: Gasping at the surface or rapid gill movement is a sign of respiratory distress.
  6. Erratic Swimming: Unusual swimming patterns, like swimming upside down or in circles, suggest neurological or physical issues.
  7. Visible Signs of Infection: Look for redness, inflammation, open sores, or a white cottony growth on the fish’s body.

Remember, always act quickly if you notice any of these symptoms in your Blue Spot Jawfish. Consult a fish care expert or veterinarian for proper diagnosis and treatment. It’s better to be safe than sorry!


Breeding Setup

To successfully breed Blue Spot Jawfish, I had to create a cozy environment for them. First, I placed a fine sand layer of about 3-4 inches in the tank, as they love to create burrows in the sand. Then, I added PVC pipes and small rocks to provide ideal hiding spots.

How To Breed

I had to choose mature, healthy Blue Spot Jawfish by looking for vibrant colors and good appetites. Pairing is easy, just place a male and female together in the tank. To stimulate breeding, I made sure the tank conditions were optimal:

  • Temperature: 72-78°F
  • pH: 8.1-8.4
  • Specific Gravity: 1.020–1.025

Feeding them with a varied diet of live and frozen foods like mysis shrimp, brine shrimp, and even chopped fish helped condition them and triggered spawning.


When eggs are laid, I noticed the male Jawfish take care of them by oxygenating them with his fins. He was very protective, so no intervention was needed.

After about 10 days, the eggs hatched. It’s crucial to have a proper setup for the juveniles:

  • Separate breeding tank or partition in the main tank
  • Fine mesh to prevent escape
  • Freshly-hatched Artemia nauplii (baby brine shrimp) as their first food.

Remember to maintain optimal water parameters and provide a stable environment for your Blue Spot Jawfish to thrive during the breeding process.

Product recommendations for Blue Spot Jawfish:

  1. Hikari Marine S Pellets: This fish food is specially formulated for marine fish, including Blue Spot Jawfish, and provides a balanced diet for optimal health.
  2. Seachem Stability: This product helps to establish a healthy biological filter in your aquarium, which is important for maintaining good water quality for Blue Spot Jawfish.
  3. Fluval Sea Protein Skimmer: This protein skimmer helps to remove organic waste from your aquarium water, which can be harmful to Blue Spot Jawfish.
  4. Hydor Koralia Nano Aquarium Circulation Pump: This circulation pump helps to create a natural water flow in your aquarium, which is important for the well-being of Blue Spot Jawfish.
  5. Instant Ocean Sea Salt: This sea salt mix is perfect for creating a healthy marine environment for Blue Spot Jawfish and other saltwater fish.
  6. API Aquarium Salt: This product helps to promote healthy gill function and reduce stress in fish, including Blue Spot Jawfish.
  7. Seachem Prime: This water conditioner helps to detoxify ammonia, nitrite, and nitrate in aquarium water, which can be harmful to Blue Spot Jawfish.
  8. Coralife BioCube 16 Gallon LED Aquarium Kit: This aquarium kit is perfect for keeping Blue Spot Jawfish in a small space, and comes with a powerful filtration system.
  9. Marina Floating Thermometer: This thermometer helps you to monitor the temperature of your aquarium water, which is important for keeping Blue Spot Jawfish healthy.


In caring for Blue Spot Jawfish, I had a fascinating experience observing their unique behavior. Remember that attention to water parameters and adequate tank setup are crucial. By creating a suitable habitat with mixed substrate, hiding places, and a lid, your active burrower will be well-accommodated.

  • Water temperature: 72-76°F
  • pH levels: 8.1-8.4
  • Salinity: 1.023-1.025

Feeding them a varied diet is essential to their health. Offer a mix of live and frozen foods like brine shrimp, mysis shrimp, and other marine crustaceans.

They tend to be shy, so it’s best to avoid housing them with aggressive tank mates. Instead, opt for peaceful, reef-safe species. With the proper care, your Blue Spot Jawfish can be a thriving and engaging member of your aquarium for a long time.


What size tank does a Blue Spot Jawfish need?

Blue Spot Jawfish require at least a 30-gallon tank due to their territorial nature. A larger tank is preferable if you plan to add more fish.

What type of filtration system is best for Blue Spot Jawfish?

A high-quality filtration system, such as a canister filter, is important to maintain clean water and remove toxins. Regular water testing and changes are also necessary.

What should I feed my Blue Spot Jawfish?

Blue Spot Jawfish are carnivorous and enjoy a varied diet. Frozen or live foods like brine shrimp, mysis shrimp, and small fish are ideal. Avoid overfeeding; once daily is sufficient.

What kind of substrate should I use?

A soft, sandy substrate is preferred, as Jawfish love to burrow. Ensure the sand is at least 4 inches deep for proper burrowing.

Can Blue Spot Jawfish be kept with other fish?

Yes, they can coexist with other peaceful, community fish. However, be cautious with other bottom dwellers or aggressive fish, as this may cause territorial conflicts.

How do I know my Blue Spot Jawfish is healthy?

A healthy Jawfish will be active, display vibrant colors, and have a good appetite. Keep an eye out for any signs of injury or disease, like sluggishness or discoloration. If I notice any concerning behavior, I personally consult with a local fish expert or veterinarian.

Remember, your Blue Spot Jawfish wants to feel safe and comfortable in its environment, so make sure to maintain good water quality, provide appropriate hiding spots, and interact with it regularly. A happy Jawfish is a healthy Jawfish!

Reference: Wikipedia.


Hi there! My name is Jacob, and I'm the founder of this Pet people blog that talks all about aquarium and fishkeeping. I've been passionate about fish and aquatic life since I was a kid, and I've spent countless hours learning about different species, their habitats, and how to create the perfect environment for them to thrive in.

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