The best way to preserve a starfish depends on whether you want a dry specimen for display or a wet specimen stored in fluid. For most people looking to keep a starfish on a shelf or in a shadow box, the alcohol-soak-then-dry method produces the sturdiest, most attractive result. The entire process takes about two to three days.
Start With a Clean Specimen
If you found a dead starfish on the beach, rinse it thoroughly in fresh water to remove sand, salt, and any remaining tissue. A gentle scrub with a soft toothbrush helps clear debris from the textured surface and between the arms. If the starfish still has a strong odor, soaking it in fresh water for 30 minutes and repeating the rinse can help. You want to remove as much organic material as possible before moving to the preservation step, since leftover tissue is what causes smell and decay later.
Avoid collecting live starfish. Many coastal areas, including national wildlife refuges managed by the U.S. Fish and Wildlife Service, prohibit removing any living creatures from the beach. Some locations ban collecting anything at all, even empty shells. Florida, for example, specifically prohibits taking live marine organisms. Stick to specimens that are already dead and washed ashore.
The Alcohol Soak Method
Museum collections and naturalist guides consistently recommend soaking starfish in 70% ethanol (ethyl alcohol) as the first step, whether you plan to keep the specimen wet or dry it out. This concentration is high enough to fix the tissue and kill bacteria without making the specimen overly brittle. You can find 70% ethanol at pharmacy or lab supply stores. Isopropyl (rubbing) alcohol at the same concentration works as a substitute for home display purposes, though ethanol is the standard in professional settings.
Place the starfish in a shallow container and submerge it completely in the alcohol. Gently arrange the arms in the position you want, since the specimen will stiffen as it soaks. If you want the tube feet (the tiny projections on the underside) extended for a more natural look, one technique is to first place the starfish in a dilute solution of about 20% alcohol until the feet relax outward, then transfer it to the full 70% solution. Let it soak for 48 hours, flipping it once halfway through to ensure even penetration.
Drying for Display
After the alcohol soak, remove the starfish and pat it gently with paper towels. Place it on a drying rack or a piece of cardboard in a well-ventilated area, out of direct sunlight. Weight the arms down lightly with small objects if they start to curl. Some people place a flat board or heavy book on top (with a paper towel between the book and the starfish) to keep the specimen flat as it dries.
Drying typically takes one to three days depending on the size of the starfish and the humidity where you live. You’ll know it’s done when the body feels completely rigid and lightweight. A properly dried starfish has very little odor. If it still smells after drying, the tissue wasn’t fully fixed during the alcohol stage, and you may need to re-soak it.
Preserving Color
Color fading is the biggest cosmetic challenge. Most starfish lose some vibrancy during preservation, and there’s no way to fully prevent it. Alcohol fixation preserves more color than simply air-drying a raw specimen, which is one reason the soak step matters even for dry display pieces. Keeping the dried starfish out of direct sunlight slows further fading over time.
A light coat of clear acrylic spray or polyurethane after drying can add a subtle sheen and help lock in remaining pigment. Apply thin coats and let each one dry fully. This also adds a small layer of structural protection, which is useful for more fragile species. Don’t expect a coating to restore lost color, but it does help preserve what’s left and gives the surface a clean, finished look.
Wet Preservation in Fluid
If you’d rather keep the starfish in a jar of liquid (the classic natural history collection look), the process is different. The specimen is fixed in a 5% to 10% formaldehyde solution first, with larger starfish needing the higher concentration. After fixing for several days, the specimen is rinsed multiple times in plain water and then transferred to 70% ethanol for long-term storage. The ethanol needs to be topped off periodically since it evaporates, and the solution should be fully replaced roughly every two years.
Formaldehyde (sold as formalin) is a serious chemical hazard. It requires a well-ventilated workspace, ideally a fume hood. At minimum, wear chemical-resistant gloves, safety goggles, and work outdoors or with strong airflow. Prolonged exposure to formalin fumes irritates the eyes, nose, and lungs, and the liquid causes chemical burns on contact with skin. For most home projects, this method is overkill. It’s primarily used in laboratories and museum collections where specimens need to last decades and retain tissue for potential study.
One important note: formalin degrades specimens over very long periods if they’re left in it indefinitely. The standard practice is to use formalin only for the initial fixing stage, then switch to ethanol for permanent storage.
Handling Fragile Species
Not all starfish hold up equally well during preservation. The classic five-armed species you find on most beaches (like common sea stars and chocolate chip starfish) have relatively rigid, calcified bodies that dry well and resist breakage. Brittle stars are a different story. Their thin, flexible arms snap easily when handled, and they lack the suction-cup tube feet that give other species structural grip. If you’re preserving a brittle star, wet preservation in alcohol is safer than drying, and you should handle it as little as possible throughout the process.
Thicker, knobby species like red knob starfish tend to preserve beautifully because their dense bodies hold shape well. Thinner, flatter species may curl at the edges during drying and benefit from being weighted down more carefully.
Long-Term Care of Dried Specimens
A well-preserved dried starfish can last for years with minimal attention. Store or display it in a dry environment, since humidity encourages mold growth on any remaining organic material. Keep it away from windows where UV light will bleach the color further. If you’re displaying it in a shadow box or frame, a small silica gel packet tucked out of sight helps absorb ambient moisture.
The arms are the most vulnerable part. They can snap if the starfish is dropped or knocked off a shelf. If an arm does break, a small dot of clear epoxy on the break point reattaches it cleanly. For especially delicate specimens, mounting them on a backing board with a tiny amount of adhesive keeps them secure during display.