Name: Blue Gudgeon Dartfish - Ptereleotris heteroptera
Brand: TSA Fish
SKU: GOBYxBlueGudg
Price: 52.99 USD
Availability: InStock

Blue Gudgeon Dartfish - Ptereleotris heteroptera

$52.99

Blue Gudgeon Dartfish - Ptereleotris heteroptera

Goby Reef Safe Schooling

$52.99

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Goes well with:

Diet

Pellets Mysis Finely Chopped Seafood

Min Tank Size 40 gallons

Temperament Peaceful

Reef Safe Yes

Care & Diet Feeding, nutrition, and best practices.

Diet Type: Carnivore

The Blue Gudgeon Dartfish is carnivorous and requires a varied diet to maintain optimal health. Feed them a combination of high-quality frozen or live foods such as brine shrimp, mysis shrimp, and finely chopped seafood. Supplement their diet with marine-specific pellets or flakes to ensure they receive all necessary nutrients. Feed them small amounts 2-3 times a day, ensuring all food is consumed within a few minutes to prevent water quality issues. Observing their feeding behavior is important to ensure they are eating adequately, as they can be shy feeders.

Pellets Mysis Finely Chopped Seafood

Behavior Temperament, activity level, and interactions.

Temperament: Peaceful

Blue Gudgeon Dartfish exhibit agile swimming in mid-water, forming small groups for safety. They are peaceful, showing minimal aggression, and prefer to inhabit reef crevices. While not overtly territorial, they defend their immediate area when threatened. They coexist well with other non-aggressive species but may be shy around larger, boisterous fish. Their social nature makes them suitable for community aquariums, provided tank mates are calm and similar in size.

Tank & Aquascape Tank requirements and aquascaping tips.

Min Tank Size: 40 gallons
Max Size: 5.5 inches
Care Level: Easy
Origin: Fiji

Compatibility Tank mates, aggression, and introduction order.

Temperament: Peaceful
Reef Safe: Yes

Dartfish Reef Safe Carnivore Jumper

Reef & Health Reef safety, common issues, and prevention.

Reef Safe: Yes
Care Level: Easy

FAQs Answers to the most common questions.

Can Blue Gudgeon Dartfish be kept singly, or do they need to be in pairs or groups, and how does this affect their behavior and aggression?

Blue Gudgeon Dartfish do best in stable pairs or small, well-matched groups introduced at the same time. A single fish can live comfortably but will be more timid and spend more time hiding. A pair, ideally a bonded duo obtained together, will be bolder and display natural hovering and darting behavior. Groups of three or more are possible in larger tanks (4 feet/75+ gallons) with multiple caves and line-of-sight breaks, but extra care is needed: conspecific aggression can occur, especially as they mature. Never mix newly added individuals with an established single that has claimed territory, as it may harass or injure newcomers. When in doubt, start with a single or a known pair instead of building a group piecemeal.

How strong should the water flow be for Blue Gudgeon Dartfish, and where in the tank should powerheads be placed so they feel comfortable swimming?

Blue Gudgeon Dartfish prefer moderate, laminar flow with calmer pockets near the substrate and rockwork. Aim powerheads toward the top or along the back glass to create a broad current that they can swim into without being blown around, avoiding direct jets at their preferred midwater or near-bottom areas. They like to hover in gentle current near their burrow entrance, so set up rockwork and caves in areas where the flow has slowed after bouncing off glass or rock. If they are pinned against rock, constantly hugging the sand, or struggling to stay in place, flow is too strong; if they appear listless and debris settles everywhere, flow is too weak. Adjust until you see them calmly hovering and darting rather than fighting the current.

What specific tank-cover precautions are necessary for Blue Gudgeon Dartfish, and what behaviors signal a high risk of jumping?

Blue Gudgeon Dartfish are extreme jumpers and will exploit any opening larger than about 1 cm. Use a tight-fitting lid or mesh screen with all gaps sealed, including around plumbing, cords, overflows, and auto-feeders. Standard canopies or glass lids with open cutouts are often unsafe without extra blocking. Jumping risk spikes during the first weeks after introduction, after sudden lights on/off, during storms or loud noises near the tank, and when chased by tankmates. Signs of impending jumps include frantic laps along the top edge, sudden rushes straight up when startled, and repeated attempts to wedge into corners near the surface. Minimize sudden light changes with ramping or room lights on before tank lights, and avoid startling movements near the glass.

What feeding strategy works best to ensure a Blue Gudgeon Dartfish gets enough food when kept with faster or more aggressive eaters?

Feed small, frequent meals and target the area where the Blue Gudgeon hovers. Use a turkey baster or feeding tube to gently release finely chopped meaty foods (mysis shrimp, enriched brine, finely minced seafood, quality marine pellets) slightly upstream of its position so food drifts past its face. Turn down or briefly pause powerful pumps to slow food movement and give it time to grab each bite. Feed more aggressive eaters first in one part of the tank, then feed the Blue Gudgeon on the opposite side near its cave. If it is shy, stand back from the glass after placing the food. Consistent feeding 2–3 times daily, with at least one targeted session, helps keep it plump; a sunken belly or prominent backbone means it is losing out to other fish and needs more focused feeding.

How should the aquascape and substrate be arranged specifically for Blue Gudgeon Dartfish to support their burrowing and hiding habits?

Provide a sand bed of at least 2–3 cm (3–5 cm is better) made of fine to medium aragonite so they can dig shallow burrows. Avoid sharp or very coarse substrates that can irritate them. Build stable rock structures that rest directly on the tank bottom or on solid supports, not on top of loose sand, so their digging does not cause collapses. Create multiple caves and overhangs with small entrances near the sand line; they often adopt a cave and gently excavate under it. Position some caves in lower-flow areas and some in moderate flow so they can choose their preferred spot. Leave open swimming space in front of the rockwork so they can hover a short distance from their refuge; if forced into tight rock mazes with no clear “front yard,” they tend to stay hidden and show less.

Blue Gudgeon Dartfish – Ptereleotris heteroptera

The Blue Gudgeon Dartfish is an elegant saltwater fish with a slender, streamlined body washed in pearly blue to pale blue-gray. Iridescent markings accent the head and gill covers, while a prominent black blotch on the tail creates the contrast behind its alternate names, Blacktail Goby and Tailspot Dartgoby. Its graceful hovering behavior and vivid coloration make it especially attractive in peaceful marine displays.

Native across the tropical Indo-Pacific, Ptereleotris heteroptera ranges from the Red Sea and East Africa to Hawaii and other central Pacific islands, north to the Ryukyu Islands and south to Australia and Lord Howe Island. It inhabits lagoons, bays, reef passes, and outer reef slopes, typically remaining near sandy or rubble patches at the base of the reef. Adults commonly form monogamous pairs and share a retreat beneath coral rubble or rock.

Reaching approximately 5.5 inches, this peaceful marine aquarium fish is well suited to mature reef aquariums and calm fish-only aquariums. It spends much of the day hovering above its shelter to capture drifting plankton before quickly retreating when startled. A secure aquarium cover, suitable hiding places, and non-aggressive tankmates are essential for long-term success.

Quick Care Guide

Care Level: Easy to Moderate
Minimum Tank Size: 40 gallons
Temperament: Peaceful
Diet: Planktivore / Carnivore
Reef Safe: Yes
Region: Indo-Pacific
Scientific Name: Ptereleotris heteroptera

Adults reach approximately 14 cm, or 5.5 inches, and naturally feed on current-borne zooplankton above the reef substrate.

Tank Requirements

Provide a mature aquarium with open midwater swimming space and live rock arranged into caves, narrow passages, overhangs, and secure retreats. Adults naturally shelter beneath coral slabs or pieces of rubble, so the aquascape should include several low openings near the base of the rockwork. Preformed caves or short sections of aquarium-safe tubing concealed beneath the rocks can provide additional security.

A fine- to medium-grain sand substrate with scattered rubble creates a natural setting, although the fish should not be expected to excavate a complete burrow for itself. Keep major rock structures stable and ensure that shelter entrances cannot collapse or become blocked.

Moderate, well-distributed water movement helps suspend appropriately sized foods in the water column. Include calmer areas close to the fish’s retreat so it can rest without fighting strong flow. A tightly fitted lid or fine mesh cover is mandatory because dartfish are accomplished jumpers, especially when newly introduced, startled, or pursued.

Diet and Feeding

The Blue Gudgeon Dartfish is a planktivore that naturally rises above its shelter to capture zooplankton carried by the current. In captivity, offer small foods that drift slowly through the water column rather than relying entirely on food that sinks immediately to the substrate.

Suitable foods include mysis shrimp, enriched brine shrimp, copepods, calanus, finely chopped krill or shrimp, small frozen marine blends, and appropriately sized slow-sinking carnivore pellets. Live or frozen enriched brine shrimp may help encourage a hesitant new arrival to begin feeding.

Feed two or three small portions daily, particularly during acclimation. Allow food to drift near the fish’s shelter and confirm that it receives enough before faster tankmates consume everything. A mature aquarium containing copepods and other natural plankton can provide useful supplemental nutrition but should not replace regular feeding.

Temperament and Tankmates

This species is peaceful, shy, and best housed with calm community fish. Suitable tankmates include clownfish, cardinalfish, firefish, peaceful gobies, blennies, assessors, smaller fairy wrasses, and other non-predatory species that will not intimidate it or dominate feeding time.

Adults naturally occur in pairs and often share the same retreat. A single specimen can be maintained successfully, but a compatible pair may display more confident and natural behavior. Small groups can be considered in a substantially larger aquarium with multiple shelters, although individuals should be introduced together and watched for social conflict. Juveniles may form very large groups in nature, while adults typically settle into pairs.

Avoid aggressive dottybacks, large hawkfish, predatory wrasses, groupers, triggers, and highly territorial fish. Persistent harassment can cause a Blue Gudgeon Dartfish to remain hidden, stop feeding, or jump from the aquarium.

Reef Compatibility

The Blue Gudgeon Dartfish is reef safe. It does not normally damage stony corals, soft corals, zoanthids, anemones, clams, snails, crabs, or established ornamental shrimp. Its feeding activity takes place primarily in the water column, where it captures small planktonic prey.

Copepods, amphipods, larval crustaceans, and other tiny planktonic animals may be consumed as part of its natural diet. This feeding behavior does not typically present a risk to mature ornamental invertebrates or established coral colonies.

Water Parameters

Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Maintain consistent salinity, good oxygenation, and stable water quality. Stability is more important than repeatedly adjusting the aquarium to reach one exact measurement. The species naturally occupies tropical reef habitats across a broad Indo-Pacific range.

Common Considerations

Use a secure cover: This dartfish may jump through very small openings when startled.
Provide ready-made shelters: It relies on existing crevices and burrows rather than consistently excavating its own.
Choose peaceful tankmates: Aggressive or fast-feeding fish may cause it to hide and lose body condition.
Feed several small meals: Its natural plankton-feeding behavior is best supported by food drifting through the water column.
Allow time for acclimation: Newly introduced specimens may remain hidden until they feel secure and establish a regular feeding response.