Flora & Fauna

Delicate, jointed branching coralline algae with alternating calcified segments and flexible joints — looks like tiny white-pink antlers. Forms low tufts on rockwork. A living indicator of good calcium and alkalinity levels. Grazed by urchins but otherwise grows without intervention in a mature reef.

Spongy, dark green dichotomously branched macroalgae with a velvety, foam-like texture. Attaches to rock and can grow quite large. In temperate reef tanks it is a natural part of the fauna; in tropical tanks it can become invasive. Slugs (nudibranchs) and sea hares may graze it.

Calcified encrusting algae that paints live rock, glass, and equipment in shades of pink, purple, and white — the hallmark of a mature, healthy reef. Requires stable calcium (400–450 ppm) and alkalinity (8–9 dKH). Does not need dedicated lighting but benefits from reef-level light. Spreads naturally from live rock and purchased plugs.

Brilliant scarlet-red, blade-shaped macroalgae — one of the most visually striking species for display refugia. Provides excellent colour contrast and nutrient export. More delicate than Chaeto; requires moderate flow and consistent light. Popular with collectors and stunning under reef lighting.

Bushy, branching red-to-purple macroalgae with cylindrical, succulent-looking branches. Common in intertidal zones worldwide. Used as a food source by certain nudibranchs and sea hares. Adds colour to refugia and is a moderate nutrient exporter. More compact and ornamental than Gracilaria.

Vivid blue-green turf-like tufts of very fine filaments — a common sight on Indo-Pacific reefs. In captivity it can spread across rockwork quickly. Produces terpene compounds that deter most grazers. Interesting as a biotope element but can become a nuisance if left unchecked.

Elegant fan-shaped calcified macroalgae on a slender white stalk. Grows in sandy areas near reefs and seagrass beds. A beautiful decorative species for low-flow areas of the display tank. Like Penicillus, it anchors in deep sand and has a natural lifespan of several months.

One of the most extraordinary organisms in biology — a single giant cell shaped like a wine glass on a slender stalk. Each 'plant' is a single cell that can grow to 10 cm. Famous in cell biology research. In aquariums it anchors in sand and is a remarkable conversation piece. Prefers cooler, calcium-rich water.

Tiny, elegant calcified algae with a barrel-shaped body ringed with white calcium bands at the tip. Short-lived (weeks to months) but reproduces readily in stable reef tanks. An interesting hitchhiker and occasional deliberate addition. Fish tend to leave it alone due to calcification.

Fan-shaped brown-grey macroalgae with distinctive concentric rings and a lightly calcified surface. Grows on rock in moderate flow zones. Not commonly traded but attractive in display refugia. Tolerates a wide range of temperatures — found from Mediterranean rock pools to tropical reefs.

Rare and coveted — clusters of translucent, deep-red spherical bladders like bunches of miniature grapes. A showpiece macroalgae that attaches to live rock. Slow-growing and sensitive; requires stable, high-quality water. Highly sought after for display refugia and naturally deters herbivorous fish.

The iconic free-floating brown macroalgae of the open ocean — forms dense golden-brown mats in the Sargasso Sea. In aquariums it anchors to rock or tumbles freely. Hosts an entire ecosystem of cryptic animals (pipefish, frogfish, shrimp) in the wild. Challenging to keep long-term but impressive in large displays.

Unmistakable calcified macroalgae resembling an old-fashioned shaving brush — white stalk topped with a tuft of fine green filaments. Anchors in sandbed. Relatively short-lived (months to a year); when it dies it releases calcium into the water. An endearing curiosity for Caribbean reef displays.