Caulerpa cupressoides (Cactus / Zipper Caulerpa)
A succulent on your window sill? A succulent in your aquarium!
What You Get
Caulerpa cupressoides—often called Cactus Caulerpa or Zipper Caulerpa— is a sculptural green macroalga with long, upright stems lined in tight, notched segments. Its repeating “zipper” pattern gives it a cactus-like silhouette that adds bold vertical texture to both display tanks and refugiums.
We encounter this species most often in shallow seagrass beds and sandy flats from the shoreline down to about 10 ft, though healthy colonies also appear on deeper dives around 40 ft. In the aquarium it’s hardy and steady-growing, yet considerably less invasive than many other Caulerpa species. It prefers sandy or silty substrate where it can be gently buried if desired, but will also anchor to rocks and coral fragments over time.
Flow and habitat shape this species in beautiful ways. In high-flow areas, it develops a compact, upright “cactus” form with a single sturdy stalk and tightly grouped fronds. In calmer grass beds and sandy flats, it grows a longer, more relaxed “zipper” morph with multiple uprights spaced along the rhizome. Both forms behave the same in aquariums—they simply reflect the conditions in which they were collected. Because its firm blades are not very palatable to most herbivores, it tends to maintain its arrival morphology, making it a standout macroalga for aquascapers looking for structure, texture, and natural nutrient uptake.
Why It Is Algaesome
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Highlights: Distinct “cactus” or “zipper” growth forms that bring vertical structure and character to your scape.
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Behavior: Less invasive than many other Caulerpa species, with steady, manageable growth.
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Palatability: Firm blades are usually ignored by most herbivores, helping it keep its tidy form.
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Habitat-inspired: Morphology shifts with flow and depth, giving each specimen a unique, habitat-driven look.
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Role: Provides moderate nutrient uptake while serving as a strong visual focal point.
Sizing & Availability
Each order includes a specimen (or combined specimens) of Cactus/Zipper Caulerpa totaling approximately 12" in length with about 5–6 uprights. Exact shape and form will vary by collection site and natural growth pattern, ranging from compact cactus-like clusters to more elongated, zipper-style runners. Availability may fluctuate with season, tides, and weather conditions.
Traits
Color Bright–medium green
Ease Hardy & undemanding
Classification Green macroalgae (Caulerpa)
Nutrient Uptake Moderate
Availability Seasonal (Warm Months)
Use Display & refugium
Lighting Moderate–high
Flow Moderate; form varies with flow
A Note from the Collectors:
Every macroalga we offer is hand-collected, acclimated, and observed by our team before shipping. While we carefully try to remove other algae, sponges, and tiny hitchhikers, it’s possible that a few “goodies” from the reef may tag along. It's a natural part of receiving genuine wild-collected specimens!
Many species may arrive paler or whitish in color. This is completely normal. Macroalgae shift their pigments inward during transport to protect from light and stress; color returns within a few days under good aquarium lighting and flow.
We ship via 2-Day service on Mondays and Tuesdays only to ensure specimens arrive healthy. You’ll receive a notification with tracking information as soon as your order ships.
