Molly Miller Blenny for Your Reef: Vet Guide 2025 🐠🩺

By Dr Duncan Houston BVSc – The Molly Miller Blenny (*Scartella cristata*) is a rugged, reef-compatible fish valued for algae cleanup and sometimes Aiptasia control. Ideal for marine aquaria ≥30 gal, this 2025 vet-reviewed guide covers identification, benefits, behavior, and best care practices to ensure your blenny thrives.

📌 At-a-Glance Species Profile

• Scientific name: *Scartella cristata*
• Max size: ≈10 cm (4″) :contentReference[oaicite:3]{index=3}
• Temperament: Peaceful but can show semi-territorial behavior among blennies :contentReference[oaicite:4]{index=4}
• Tank size: Minimum 30 gal/100 L :contentReference[oaicite:5]{index=5}
• Water conditions: 72–78 °F (22–26 °C), SG 1.020–1.025, pH 8.1–8.4 :contentReference[oaicite:6]{index=6}
• Diet: Omnivore—grazes on algae, meaty frozen/brine shrimp, seaweed sheets :contentReference[oaicite:7]{index=7}

💪 Why Aquarists Love Them

• Hardy pioneer fish: Excellent for early cycling due to resilience in fluctuating water :contentReference[oaicite:8]{index=8}
• Algae & detritus control: Eats nuisance algae, cyanobacteria, and detritus off live-rock surfaces :contentReference[oaicite:9]{index=9}
• Aiptasia helper: Observed nibbling small glass anemones; effectiveness varies but promising :contentReference[oaicite:10]{index=10}
• Engaging behavior: Energetic, curious, and personable—often dubbed a "utility pet" :contentReference[oaicite:11]{index=11}

🐟 Behavior & Compatibility

• Tankmates: Generally peaceful with fish, inverts, and corals; may be territorial with other blennies :contentReference[oaicite:12]{index=12}
• Personality: Constantly patrols rockwork, grazes throughout tank—entertaining and lively :contentReference[oaicite:13]{index=13}
• Dietary behavior: Requires varied diet—seaweed, pelleted foods, meaty frozen feeds to stay healthy :contentReference[oaicite:14]{index=14}
• Potential issues: Some hobbyists find wild-caught specimens finicky or slow to eat; captive-bred are preferred :contentReference[oaicite:15]{index=15}

🏝 Tank Setup & Care Tips

1. Tank size: ≥30 gal with varied live rock structures for grazing and hiding :contentReference[oaicite:16]{index=16}
2. Decor: Crevices, caves, horizontal surfaces—they mimic natural habitat and support grazing.
3. Filtration: Moderate flow with biological and mechanical filtration; stable water parameters are key.
4. Diet:
   • Algae and biofilm from rockwork
   • Dried seaweed sheets (e.g., nori or kelp pellets)
   • Frozen mysis/brine shrimp and quality marine pellets :contentReference[oaicite:17]{index=17}
5. Feeding frequency: Daily grazing supplemented 3–4× weekly.
6. Compatibility caution: Watch for aggression toward similar species. Avoid overcrowding with congeneric blennies :contentReference[oaicite:18]{index=18}
7. Quarantine practice: Use a separate QT tank, especially for wild-caught specimens vulnerable to parasites :contentReference[oaicite:19]{index=19}

🍽 Aiptasia & Pest Control

The Molly Miller has gained a reputation among reefers for helping control small infestations:

• Reports indicate they help suppress or consume small Aiptasia anemones :contentReference[oaicite:20]{index=20}
• One hobbyist shared: "…demolished a small group of aiptasia in just over a week" :contentReference[oaicite:21]{index=21}
• Caution: results vary—smaller Aiptasia are more likely targeted; theater case studies vary :contentReference[oaicite:22]{index=22}
• May work best in concert with Peppermint shrimp or Aiptasia-eater nudibranchs for complete control.

⚠ Vet-Approved Tips & Warnings

• Choose captive-bred individuals to ensure disease resistance and consistent behavior :contentReference[oaicite:23]{index=23}
• Monitor body condition: Underfed or wild-caught fish may become skinny; offer varied diet and track weight gain :contentReference[oaicite:24]{index=24}
• Watch reef impact: Generally reef-safe, but some claim they nibbled flower polyps—monitor your tank during first weeks :contentReference[oaicite:25]{index=25}
• Prevent aggression: One per tank unless large tank with ample territory to avoid conflict :contentReference[oaicite:26]{index=26}
• Use Ask A Vet telehealth: Send photos/videos of behavior, feeding habits, tank setup for personalized guidance.

🩺 Ask A Vet Support

The Ask A Vet app offers dedicated aquatic vet support for Molly Millers—get help with:

• Behavior assessments (aggression, grazing)
• Body-condition tracking (address malnutrition early)
• Algae/Aiptasia control strategies
• Reef compatibility advice
• Quarantine protocols and treatment plans

Pair with AquaCare’s marine blends like live-food supplements, reef conditioners, and quarantine care packs. Download now to start 2025 with a healthy, happy Molly Miller on your team! 📱💙