Mudskipper (Periophthalmus Gracilis )

Mudskipper — The Fish That Walks on Land

Prehistoric, fascinating, and unlike anything else in the aquarium hobby, the Mudskipper (Periophthalmus gracilis) is one of nature’s most extraordinary creatures. A true amphibious fish, the Mudskipper is equally at home on land as it is in water — using its powerful pectoral fins to "walk" and even climb, breathing through its skin and the lining of its mouth when out of water. Keeping Mudskippers is less like keeping a fish and more like keeping a miniature prehistoric creature — an experience unlike any other in the hobby.

With their bulging, independently mobile eyes, expressive faces, and bold territorial personalities, Mudskippers are endlessly entertaining and interactive. They will learn to recognize their keeper and often display and "perform" at feeding time.

Care at a Glance

• Common Name: Graceful Mudskipper
• Scientific Name: Periophthalmus gracilis
• Origin: Indo-Pacific (mangrove estuaries and mudflats)
• Adult Size: Up to 9 cm (3.5 inches)
• pH: 7.0 – 8.0
• General Hardness (GH): 8 – 20
• Carbonate Hardness (KH): 2 – 3
• TDS: 100 – 300
• Temperature: 25 – 26°C (77 – 78°F)
• Nitrite (NO₂): 0 ppm — must be zero at all times
• Nitrate (NO₃): 15 ppm or lower
• Water Type: Freshwater when young; transitions to brackish water as they mature
• Difficulty: Moderate to Advanced

⚠️ Important: Brackish Water & Land Space Requirements

Mudskippers have unique long-term care requirements that set them apart from standard aquarium fish:

• Water transition: Juveniles can be kept in freshwater for approximately 1–2 years, but must be gradually acclimated to brackish water as they mature. Plan ahead for this transition.
• Land access is essential: Mudskippers are amphibious and must have access to a dry land area at all times. A paludarium or vivarium setup with a sloped substrate, mudflat, or platform above the waterline is required for their long-term health and wellbeing.
• Humidity: The land area must remain humid to allow them to breathe through their skin. Mist regularly.

Tank & Setup Tips

A paludarium (part aquatic, part terrestrial) is the ideal setup — with a shallow water area and a sloped substrate or platform that allows easy access to a dry land zone. Mangrove roots, smooth rocks, and driftwood create a naturalistic environment that replicates their mangrove mudflat habitat. A tight-fitting, ventilated lid is essential — Mudskippers are skilled climbers and escape artists.

Feeding

Carnivorous predators. Currently eating bloodworms. Also accept live and frozen foods: crickets, mealworms, small earthworms, brine shrimp, and other meaty invertebrates. They prefer to feed on land or at the water’s edge. Hand-feeding is possible once they are comfortable with their keeper.

Compatible Tank Mates

Best kept as a species-only setup or with other mudskippers of similar size. They are territorial and may fight with conspecifics — provide ample space and land territory for each individual. Avoid housing with fish that require fully aquatic conditions.

📸 Photos are for reference only. Actual fish may vary slightly in appearance — each one is uniquely characterful!