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Blue-spotted jawfish

Opistognathus rosenblatti

Also known as Blue Dot Jawfish, Bluespot Jawfish, Blue Spot Jawfish

SaltwaterFish

Blue-spotted jawfish (Opistognathus rosenblatti)

Care at a glance

Temperature
70–77°F
21–25°C
pH
8.1–8.4
Adult size
3.9 in
10 cm
Minimum tank
30 gal
115 L
Temperament
Peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Medium
Breeding
Hard
Rarity
Rare
Reef safe
Reef safe
Family
Opistognathidae
Origin
Endemic to the Gulf of California, also called the Sea of Cortez, in cooler sandy bays at depths of about 9 to 27 m.

Overview

The blue-spotted jawfish is a peaceful burrowing fish for a reef tank with room to dig. It is best kept by someone with a little experience.

Did you know

Keeping the blue-spotted jawfish too warm shortens its life. It is one of the few popular marine fish that genuinely prefers a cooler tank.

Caring for the blue-spotted jawfish

Give the blue-spotted jawfish at least 30 gal (115 L), with a sand and rubble bed at least 8 cm deep for burrowing. It jumps, so fit a very tight lid.

Keep the water on the cool side, at 70 to 77°F (21 to 25°C), with a pH of 8.1 to 8.4. It needs lower temperatures than most reef fish, so use a chiller if the room runs warm. Feed mysis, enriched brine shrimp and other small meaty foods.

It is peaceful and reef safe, but choose its tank mates with caution. It does fine alone or in a group, though males spar over burrows, so give each fish its own space.

Like other jawfish, the male holds the egg mass in his mouth until the young hatch. Breeding it is rated hard.

Good to know

Opistognathus rosenblatti is a jawfish in the family Opistognathidae. It has a tan body covered in electric blue spots. It is collected only seasonally, which keeps it scarce and pricey. The trade also calls it the blue dot, bluespot or blue spot jawfish.

In the wild

The blue-spotted jawfish lives only in the Gulf of California, also called the Sea of Cortez. It keeps to cooler sandy bays about 9 to 27 m deep, in loose colonies with burrows spaced across the sand. Each fish digs a vertical burrow in sand and rubble and hovers just above the entrance, dropping back tail first when startled.

Common questions

What size tank does a blue-spotted jawfish need?

A blue-spotted jawfish needs at least 30 gal (115 L). It spends most of its time in the bottom.

What temperature and pH does a blue-spotted jawfish need?

A blue-spotted jawfish is comfortable at 70–77°F (21–25°C) with a pH of 8.1–8.4.

What does a blue-spotted jawfish eat?

A blue-spotted jawfish eats mysis, enriched brine shrimp and other small meaty foods.

How big does a blue-spotted jawfish get?

An adult blue-spotted jawfish reaches about 3.9 in (10 cm).

How does a blue-spotted jawfish breed?

Blue-spotted jawfish are hard to breed. Like other jawfish, the male holds the egg mass in his mouth until the young hatch.

Related species