Garden Hassi

Garden Hassi Eel (Heteroconger hassi)

Also known as the Spotted Garden Eel or Hass’s Garden Eel, Heteroconger hassi is a mesmerizing, highly specialized marine eel prized for its unique, swaying colony behavior.

• Physical Appearance: They have slender, worm-like bodies that typically grow up to 14 to 16 inches in captivity. Their bodies feature a white-to-cream or pale gray base densely peppered with small black spots, distinguished by three prominent dark black patches (one near the gill opening, one mid-body, and one near the anus). They also feature large, expressive yellow eyes and an upturned mouth adapted for catching drifting food.

• Behavior: Garden eels are permanent burrow-dwellers. Rather than swimming actively around the tank, they anchor their tails securely into vertical sand burrows they construct themselves, extending the upper third to half of their bodies into the water column to sway synchronously with the current. They are peaceful, incredibly shy, and will quickly retreat completely into their burrows if startled by sudden movements or aggressive tankmates.

Aquarium Tank Care Requirements

Because of their specialized habitat needs, garden eels are classified as expert-only animals that thrive best in dedicated or carefully planned setups:

• Tank Size & Setup: A minimum of a 40-gallon aquarium is required for a single specimen, but a larger footprint (125+ gallons) is strongly recommended if you intend to keep a social colony. The central area of the tank must remain an open, unobstructed expanse of deep sand.

• Substrate (Deep Sand Bed): They require a very fine-to-medium sand bed that is at least 6 to 8 inches deep so they can safely construct and maintain their permanent vertical burrows without risk of collapse.

• Water Flow: They require a gentle, consistent laminar flow (roughly 10x to 15x turnover per hour). The current should be aimed slightly above the sand bed to act as a conveyor belt for food, avoiding harsh, turbulent wavemakers that can stress the eels or scour away their burrows.

• Water Parameters:

  • Temperature: 74°F – 78°F (23°C – 26°C)

  • Salinity (Specific Gravity): 1.024 – 1.026 (kept stable with reliable ATO systems)

  • pH: 8.1 – 8.4

• Tank Mates & Safety: Must be kept exclusively with small, peaceful, slow-swimming fish (such as small gobies, dartfish, or peaceful cardinals). Fast or aggressive fish will outcompete them for food or keep them permanently hidden in their burrows, leading to starvation. They are 100% reef-safe regarding corals, but a tightly secured mesh lid is mandatory to prevent accidental escape.

Diet & Feeding Requirements

Feeding is often the most challenging aspect of long-term garden eel care because they will not actively hunt food across the tank floor:

• Natural Diet: In the wild, they are micro-carnivores that feed continuously on tiny zooplankton drifting past their burrows.

• Captive Feeding Schedule: They require frequent, small feedings multiple times a day. Utilizing an automatic feeder paired with gentle circulation pumps can help keep a continuous, slow stream of food drifting past their heads.

• Preferred Foods: Offer vitamin-enriched, tiny meaty foods such as cyclops, baby brine shrimp, finely chopped frozen mysis shrimp, rotifers, and specialized liquid or powdered planktonic coral foods.

Why Choose a Quarantined Eel?

A properly quarantined Eel is a healthier, acclimated specimen that has been observed, treated, and conditioned for aquarium life. Our quarantine protocol includes 4–6 weeks minimum observation, preventative parasite treatment, dietary conditioning to frozen foods, feeding behavior verification, and secure housing to prevent escape.