How many Scissortail Dartfish can I keep together, and what tank size and aquascape best support a small group without them fighting or jumping out?

Scissortail Dartfish (Ptereleotris evides) do best in small groups of 3–5 individuals, but only if the tank is large enough and they are introduced at the same time. For a pair, a 40-gallon long tank is the bare minimum; for a small group, 55–75 gallons with a 4-foot length is strongly recommended. Provide a sandy substrate with multiple rock “spurs” and caves where each fish can claim a visual territory, plus open water in the front and mid-water column for swimming. Use a tightly fitting lid or mesh screen (¼" or smaller openings) because they are notorious jumpers, especially in the first few weeks. Multiple hideouts and line-of-sight breaks reduce chasing and stress, allowing a small group to establish a stable hierarchy with minimal aggression.

My Scissortail Dartfish hides constantly and barely eats in my mixed reef. What specific environmental adjustments can I make to help it feel secure and start feeding?

Scissortails are shy, midwater planktivores that often shut down in bright, exposed setups. To help: (1) Reduce light intensity or provide shaded areas using overhangs, caves, and tall branching rock; they feel safer with “ceilings” above them. (2) Add at least 2–3 bolt-holes per fish—small caves or crevices they can dart into instantly. (3) Ensure lower to moderate flow in their preferred swimming area; strong laminar flow can keep them pinned to hiding spots. (4) Feed small, moving foods like enriched brine shrimp, copepods, mysis “shavings,” and high-quality marine pellets in the water column, not just sinking foods. Start feeding with pumps off or on a reduced setting so food lingers midwater, and offer small amounts 2–3 times daily. (5) Avoid sudden movements near the glass for the first couple of weeks and keep tank mates calm and non-bullying. With these changes, most Scissortails begin coming out reliably within 1–3 weeks.

What tank mates are most likely to cause problems specifically for Scissortail Dartfish, even if they are considered “reef-safe” or “peaceful”?

Scissortails are easily intimidated by assertive or fast-feeding tank mates. Fish that often cause issues include: (1) Boisterous wrasses (e.g., some Halichoeres, Thalassoma, large fairy wrasses) that constantly patrol midwater; they can outcompete Scissortails for food and keep them hiding. (2) Larger, active tangs or surgeonfish that zoom through the midwater column and create constant traffic. (3) Semi-aggressive dwarf angels that may chase them away from feeding zones. (4) Territorial dottybacks, hawkfish, and some damsels that can harass them when they approach rockwork or perches. (5) Larger predators such as groupers, lionfish, or big hawkfish that see slim, darting fish as potential prey. Ideal companions are small, peaceful planktivores like chromis, other non-aggressive dartfish species, peaceful gobies, and small reef-safe wrasses known for mild behavior (many smaller fairy and flasher wrasses), ensuring the Scissortail has a low-stress midwater niche.

How should I acclimate a newly purchased Scissortail Dartfish to minimize the risk of shock, jumping, and refusal to eat during the first week?

After temperature-floating the bag for 15–20 minutes, use a drip acclimation over 45–60 minutes, especially if store salinity differs from your tank (many shops run low salinity around 1.018–1.020). Aim to transition to your display’s salinity slowly to avoid osmotic shock. Dim or turn off tank lights during introduction and for several hours afterward. Release the fish near rockwork or a cave, not out in the open, and keep a tight lid in place before opening the bag; Scissortails can bolt on first contact with new surroundings. For the first week, feed small amounts of live or frozen foods (e.g., enriched brine, mysis, copepods) several times daily, ideally with pumps turned down or off so the fish can pick food from gently drifting currents. Avoid major aquascape changes, loud room activity, or adding new fish during this period. Patience and low stress in the first 3–7 days greatly increase long-term survival and feeding confidence.

What are early warning signs that my Scissortail Dartfish is not adapting well, and what targeted steps should I take before it crashes?

Negative signs include: (1) Staying hidden all day for more than a week, only emerging briefly at dawn/dusk. (2) Rapid, shallow breathing even when resting, indicating stress or poor water quality. (3) Hanging at the surface or near a powerhead, suggesting low oxygen or bullying. (4) Weight loss along the body line—visible pinching behind the head—even if it occasionally snaps at food. (5) Frayed fins or white patches from harassment or injury. Respond by: (a) Testing and correcting water parameters immediately (ammonia and nitrite at zero, nitrate under ~20 ppm, stable temperature and salinity). (b) Increasing aeration and surface agitation. (c) Providing more cover—extra caves, PVC sections, or rock rubble near its preferred area. (d) Temporarily reducing food competition: target-feed with a turkey baster or pipette near its hideout with pumps off. (e) If bullying is confirmed, use an acclimation box for the aggressor or relocate the aggressor. Addressing these issues quickly often reverses decline before the fish becomes too weak to recover.

Scissortail Dartfish

Ptereleotris evides

Dartfish Reef Safe Carnivore Jumper

Care Level

Easy

Temperament

Peaceful

Reef Safe

Yes

Max Size

6 inches

Min Tank

30 gallons

Origin

Philippines

Diet

Carnivore

Food

Pellets, Mysis, Finely Chopped Seafood

Overview:
The Scissortail Dartfish, known for its striking appearance and active swimming behavior, thrives in a well-maintained marine aquarium. Ideally, it requires a tank of at least 30 gallons, with plenty of open swimming space and secure rock formations for hiding. Water conditions should be stable, with a temperature range of 72-78°F, a pH of 8.1-8.4, and specific gravity between 1.020-1.025. Proper filtration and regular water changes are essential to maintain water quality and mimic its natural reef habitat.

Compatibility:
Scissortail Dartfish are generally peaceful and can coexist with a variety of other non-aggressive fish species. They do well in community tanks with species like clownfish, gobies, and other dartfish. However, they can be timid and may become stressed if housed with aggressive or overly boisterous tankmates. Providing ample hiding spots and maintaining a peaceful environment is crucial to prevent stress and encourage natural behavior. It is advisable to keep them in small groups of their own kind to promote social interaction and reduce shyness.

Health and Quarantine:
To ensure the health of Scissortail Dartfish, it is important to quarantine new arrivals for at least two weeks before introducing them to the main tank. This helps prevent the spread of diseases and allows time to observe for any signs of illness. Common health issues include marine ich and bacterial infections, which can be mitigated by maintaining excellent water quality and a balanced diet. Regularly monitor for signs of stress or disease, such as changes in appetite, color, or behavior. If any health issues arise, consult with a marine veterinarian for appropriate treatment. Regular maintenance, including water testing and equipment checks, is vital for preventing health problems and ensuring a thriving environment for the Scissortail Dartfish.

Pellets Mysis Finely Chopped Seafood

Scissortail Dartfish are agile swimmers, often darting quickly in the water column. They prefer to stay in small groups, showing peaceful social behavior and seldom displaying aggression. Territoriality is minimal, making them suitable for community tanks. They are compatible with other non-aggressive species, thriving in environments with ample hiding spots. Their swimming habits include mid to upper water levels, where they actively explore and feed. These fish are known for their jumping ability, so a secure aquarium lid is recommended to prevent escape.

Recommended Products

Premium Fish Food - Pellets - Reef Genetics

$11.99

FAQ

Frequently Asked Questions

About the Scissortail Dartfish

How many Scissortail Dartfish can I keep together, and what tank size and aquascape best support a small group without them fighting or jumping out?

Scissortail Dartfish (Ptereleotris evides) do best in small groups of 3–5 individuals, but only if the tank is large enough and they are introduced at the same time. For a pair, a 40-gallon long tank is the bare minimum; for a small group, 55–75 gallons with a 4-foot length is strongly recommended. Provide a sandy substrate with multiple rock “spurs” and caves where each fish can claim a visual territory, plus open water in the front and mid-water column for swimming. Use a tightly fitting lid or mesh screen (¼" or smaller openings) because they are notorious jumpers, especially in the first few weeks. Multiple hideouts and line-of-sight breaks reduce chasing and stress, allowing a small group to establish a stable hierarchy with minimal aggression.
My Scissortail Dartfish hides constantly and barely eats in my mixed reef. What specific environmental adjustments can I make to help it feel secure and start feeding?

Scissortails are shy, midwater planktivores that often shut down in bright, exposed setups. To help: (1) Reduce light intensity or provide shaded areas using overhangs, caves, and tall branching rock; they feel safer with “ceilings” above them. (2) Add at least 2–3 bolt-holes per fish—small caves or crevices they can dart into instantly. (3) Ensure lower to moderate flow in their preferred swimming area; strong laminar flow can keep them pinned to hiding spots. (4) Feed small, moving foods like enriched brine shrimp, copepods, mysis “shavings,” and high-quality marine pellets in the water column, not just sinking foods. Start feeding with pumps off or on a reduced setting so food lingers midwater, and offer small amounts 2–3 times daily. (5) Avoid sudden movements near the glass for the first couple of weeks and keep tank mates calm and non-bullying. With these changes, most Scissortails begin coming out reliably within 1–3 weeks.
What tank mates are most likely to cause problems specifically for Scissortail Dartfish, even if they are considered “reef-safe” or “peaceful”?

Scissortails are easily intimidated by assertive or fast-feeding tank mates. Fish that often cause issues include: (1) Boisterous wrasses (e.g., some Halichoeres, Thalassoma, large fairy wrasses) that constantly patrol midwater; they can outcompete Scissortails for food and keep them hiding. (2) Larger, active tangs or surgeonfish that zoom through the midwater column and create constant traffic. (3) Semi-aggressive dwarf angels that may chase them away from feeding zones. (4) Territorial dottybacks, hawkfish, and some damsels that can harass them when they approach rockwork or perches. (5) Larger predators such as groupers, lionfish, or big hawkfish that see slim, darting fish as potential prey. Ideal companions are small, peaceful planktivores like chromis, other non-aggressive dartfish species, peaceful gobies, and small reef-safe wrasses known for mild behavior (many smaller fairy and flasher wrasses), ensuring the Scissortail has a low-stress midwater niche.
How should I acclimate a newly purchased Scissortail Dartfish to minimize the risk of shock, jumping, and refusal to eat during the first week?

After temperature-floating the bag for 15–20 minutes, use a drip acclimation over 45–60 minutes, especially if store salinity differs from your tank (many shops run low salinity around 1.018–1.020). Aim to transition to your display’s salinity slowly to avoid osmotic shock. Dim or turn off tank lights during introduction and for several hours afterward. Release the fish near rockwork or a cave, not out in the open, and keep a tight lid in place before opening the bag; Scissortails can bolt on first contact with new surroundings. For the first week, feed small amounts of live or frozen foods (e.g., enriched brine, mysis, copepods) several times daily, ideally with pumps turned down or off so the fish can pick food from gently drifting currents. Avoid major aquascape changes, loud room activity, or adding new fish during this period. Patience and low stress in the first 3–7 days greatly increase long-term survival and feeding confidence.
What are early warning signs that my Scissortail Dartfish is not adapting well, and what targeted steps should I take before it crashes?

Negative signs include: (1) Staying hidden all day for more than a week, only emerging briefly at dawn/dusk. (2) Rapid, shallow breathing even when resting, indicating stress or poor water quality. (3) Hanging at the surface or near a powerhead, suggesting low oxygen or bullying. (4) Weight loss along the body line—visible pinching behind the head—even if it occasionally snaps at food. (5) Frayed fins or white patches from harassment or injury. Respond by: (a) Testing and correcting water parameters immediately (ammonia and nitrite at zero, nitrate under ~20 ppm, stable temperature and salinity). (b) Increasing aeration and surface agitation. (c) Providing more cover—extra caves, PVC sections, or rock rubble near its preferred area. (d) Temporarily reducing food competition: target-feed with a turkey baster or pipette near its hideout with pumps off. (e) If bullying is confirmed, use an acclimation box for the aggressor or relocate the aggressor. Addressing these issues quickly often reverses decline before the fish becomes too weak to recover.

Read

Account

Your cart is empty

Account

Recommended Products

Frequently Asked Questions

Related Reading

Rabbitfish Care Guide: Reef-Safe Algae Eaters for Serious Hobbyists

Wrasse Care Guide: Reef-Safe Wrasses For Modern Reef Tanks