Blue Spot Jawfish - Opistognathus rosenblatti

 

The Blue Spot Jawfish (Opistognathus rosenblatti) is a captivating species known for its vibrant blue spots and unique behavior. This species is a favorite among aquarists who enjoy observing interesting tank inhabitants and providing a dynamic environment. Its characteristic burrowing habits and striking coloration make it an excellent addition to a reef or sandy-bottomed tank.

Description:

• Common Name: Blue Spot Jawfish

• Scientific Name: Opistognathus rosenblatti

• Family: Opistognathidae

• Size: Grows to about 4-5 inches (10-12 cm) in length.

• Coloration: The Blue Spot Jawfish features a yellowish body with vibrant blue spots scattered across its body and fins. The blue spots are especially visible on the dorsal region, and the fish’s pectoral fins often have a yellowish tint.

• Lifespan: In captivity, the Blue Spot Jawfish can live for about 5-7 years when kept in optimal conditions.

Native Region:

The Blue Spot Jawfish is native to the western Atlantic, specifically in the Caribbean Sea, where it is commonly found around reefs and sandy substrates. It is typically seen at depths ranging from 20 to 100 feet (6 to 30 meters).

Aquarium Setup:

• Tank Size: A minimum of 30 gallons (114 liters) is recommended. Due to its burrowing behavior, it is important to provide sufficient space and substrate for the Blue Spot Jawfish to create its tunnels.

• Aquascaping: The Blue Spot Jawfish requires a sandy substrate to burrow, so a deep layer of fine sand is essential. It also enjoys having rock structures to help build its burrow, but make sure the rocks are stable to prevent collapse. A well-aquascaped tank with hiding spots and crevices is ideal.

• Water Flow: Prefers moderate to low water flow. Gentle flow allows it to feel secure and not be swept away, while also mimicking its natural habitat of calmer reef zones.

Water Parameters:

• Temperature: 74-78°F (23-26°C)

• pH: 8.1-8.4

• Salinity: 1.020-1.025 specific gravity

• Alkalinity: 8-12 dKH

• Nitrate: Below 10 ppm

• Phosphate: Below 0.03 ppm

Care Level:

• Difficulty: Moderate. The Blue Spot Jawfish requires a stable environment and may be sensitive to changes in water parameters or tank mates. It is essential to ensure that the substrate is deep enough for burrowing and that the tank provides adequate hiding places.

• Diet: The Blue Spot Jawfish is primarily carnivorous and scavenges for small invertebrates, plankton, and detritus in the wild. In captivity, it can be fed mysis shrimp, brine shrimp, frozen or live food, and other small meaty foods. It may also scavenge food from the substrate or rocks.

• Behavior: This species is known for its burrowing behavior. It digs tunnels and uses its mouth to carry sand, creating intricate burrows for shelter. The Blue Spot Jawfish is generally peaceful, though it can become territorial when establishing its burrow.

• Activity Level: Moderate. The Blue Spot Jawfish spends a lot of time either in its burrow or emerging from it to forage. It may occasionally retreat into its burrow if it feels threatened.

Reef Compatibility:

• Reef-Safe: Yes, the Blue Spot Jawfish is considered reef-safe. It does not typically harm corals or other invertebrates but may disturb the sandbed and rockwork while creating its burrow.

• Tank Mates: This fish is peaceful but can become territorial, especially when it establishes a burrow. It is best kept with peaceful fish that will not disturb its burrow. Avoid aggressive or overly curious fish that may harass the jawfish.

• Avoid: Larger, more aggressive fish may pose a threat to the Blue Spot Jawfish. Similarly, overly active fish or fish that disrupt the substrate could disturb its burrow.

Tank Maintenance:

• Feeding: The Blue Spot Jawfish feeds on small meaty foods and may require supplemental feeding of frozen or live foods. Providing a stable, regular feeding schedule ensures the fish receives the nutrients it needs.

• Water Quality: Regular water changes and high-quality filtration are essential to maintain good water quality. The Blue Spot Jawfish is sensitive to poor water conditions, so maintaining a stable environment is critical for its health.

• Substrate: A deep sandy substrate is crucial for the Blue Spot Jawfish to burrow comfortably. The sandbed should be at least 3-4 inches (7.5-10 cm) deep to allow the fish to dig and feel secure.

Breeding:

Breeding the Blue Spot Jawfish in captivity is rare, as it requires specific conditions, including a stable tank environment and the presence of suitable burrow sites. Little is known about its breeding habits in the aquarium, but it is believed to be a pelagic spawner, with eggs released into the water column.

Additional Tips:

• Acclimation: Acclimate the Blue Spot Jawfish slowly to minimize stress, as it is sensitive to changes in water parameters. Use a drip acclimation method when introducing it to a new tank.

• Burrow Collapse: Ensure that the rockwork is stable, as the Blue Spot Jawfish will burrow around the base of rocks. An unstable rock structure can collapse, potentially harming the fish.