Dolabella Sea Hare

Dolabella Sea Hares are highly effective algae grazers valued in the saltwater aquarium hobby for their ability to consume large amounts of nuisance algae. Also known as the Wedge Sea Hare or Blunt-End Sea Hare, Dolabella auricularia is a large herbivorous marine gastropod with a mottled brown, tan, green, or algae-like appearance that helps it blend into rockwork and algae-covered surfaces. These sea hares can be extremely useful in mature aquariums experiencing heavy algae growth, but they should only be added to systems that can provide a consistent food source and stable water quality. Once available algae is depleted, supplemental feeding or rehoming may be necessary to prevent starvation.

Introduction to Dolabella Sea Hare (Powerful Algae Grazer & Nuisance Algae Specialist)

Dolabella Sea Hares (Dolabella auricularia) are large, peaceful herbivores known for their unusual body shape, soft texture, and strong appetite for algae. In the wild, they are found in shallow Indo-Pacific habitats such as intertidal zones, seagrass beds, seaweed areas, and algae-rich coastal environments. This natural behavior gives important insight into their care: they are constant grazers that require abundant algae or supplemental vegetable-based foods to thrive.

Unlike snails or hermit crabs, Dolabella Sea Hares are soft-bodied and more vulnerable to injury. They move slowly across rockwork, glass, and substrate while grazing, making them excellent algae-control animals in the right aquarium. However, they are not ideal for small, new, or overly clean systems.

Care Requirements

Care Level: Moderate to Expert – Best for mature, algae-rich aquariums
Minimum Tank Size: 100+ gallons for long-term adult care
Aquarium Setup: Requires established rockwork, abundant algae growth, hiding areas, stable parameters, and protected pump intakes

Dolabella Sea Hares should be placed in mature saltwater aquariums with significant natural algae growth. They are best used in systems with persistent nuisance algae problems rather than clean, low-nutrient aquariums. Because they can grow very large and consume algae quickly, smaller systems may not provide enough food for long-term success.

Powerheads, overflows, and pump intakes should be covered or guarded to prevent injury. Sea Hares are soft-bodied and can be seriously harmed if pulled into equipment.

Diet & Nutrition

Dolabella Sea Hares are herbivorous grazers that feed primarily on algae.

Diet: Herbivorous – Prefers nuisance algae, filamentous algae, macroalgae, and vegetable-based foods
Recommended Foods:
Naturally occurring nuisance algae
Hair algae and filamentous algae
Macroalgae such as chaeto or other safe marine algae
Dried seaweed or nori
Vegetable-based pellets or algae wafers if accepted

Dolabella Sea Hares require a constant food source. They are excellent for reducing algae outbreaks, but once the algae is gone, they may starve quickly without supplemental feeding. If the aquarium becomes too clean, offer dried seaweed, macroalgae, or algae-based foods, or consider relocating the sea hare to another suitable algae-rich system.

Lifespan & Growth Rate

Lifespan: Often short-lived compared to many reef invertebrates, with lifespan varying by age, condition, and food availability
Growth Rate: Moderate to Fast when well fed – Can grow very large, with some references listing adult sizes near 12 inches or more

Dolabella Sea Hares are often sold as smaller specimens, but they should be housed with adult size and food demand in mind. Their large size makes them very effective algae consumers, but it also means they require far more available food than standard cleanup crew snails.

Temperament & Compatibility

Temperament: Peaceful – Does not bother fish, corals, or most peaceful invertebrates
Reef Safe? Yes, with caution – Does not eat corals, but may release ink if severely stressed or injured

Dolabella Sea Hares are peaceful algae grazers and generally safe with corals and reef fish. However, they should not be kept with aggressive or predatory tankmates that may bite, pick at, or injure them. Avoid triggers, puffers, large wrasses, large crabs, aggressive shrimp, and other animals that may harass soft-bodied invertebrates.

Common Challenges & Considerations

Requires Constant Algae: Dolabella Sea Hares need abundant algae or supplemental feeding to avoid starvation.
Not for Clean Tanks: They are best used in mature aquariums with active algae growth, not new or sterile systems.
Can Release Ink: If startled, injured, or severely stressed, they may release a purple dye into the water. Running carbon and performing a water change can help remove it.
Protect Pump Intakes: Their soft body can be damaged by powerheads, overflows, or uncovered intakes.
Large Adult Size: They can become much larger than many customers expect and require enough space to graze.
Sensitive to Copper: Like most marine invertebrates, they should never be exposed to copper-based medications.
Sensitive to Poor Water Quality: Sudden changes in salinity, temperature, pH, or alkalinity can cause stress.

To prevent issues, only add a Dolabella Sea Hare to a mature aquarium with abundant algae, acclimate carefully, cover pump intakes, avoid aggressive tankmates, and have a feeding or rehoming plan once algae levels decline.

Water Conditions

Temperature: 72-78°F
dKH Alkalinity: 8-12
pH: 8.1-8.4
Specific Gravity: 1.023-1.025

Sea Hares are a popular choice among reef-aquarists for eliminating a wide variety of algae species from the home aquarium. These delicate animals are closely related to nudibranchs and share many of the same features, including a large muscular foot for locomotion, small rasping teeth for scraping algae, and the lack of an external shell. Sea hares can be quite voracious, removing large swaths of nuisance algae from rock and glasswork in a matter of days, depending on tank size. Unfortunately, sea hares can sometimes be TOO efficient at clearing the algae out of an aquarium and starve themselves unless supplemented with offerings of various dried seaweed species anchored to a surface for easy access. In extremely rare instances of stress, sea hares can produce an ink-like substance as a defense mechanism; This ink is toxic to many other reef inhabitants and if observed, should be removed immediately via a large water change.