Anubias gigantea

The Giant Anubias is a large and striking plant from West Africa, perfect for bigger aquariums. It's known for its toughness, making it a great choice if you're worried about fish nibbling on your plants. While it's quite hardy, it's considered moderately difficult mainly because of its large size and specific planting needs.

One of the most important things to know is that you should never bury its thick, horizontal stem (called a rhizome) under gravel or sand. Doing so will cause the plant to rot and die. Instead, you should attach it to a piece of driftwood or a rock using super glue gel or fishing line. The roots will eventually anchor themselves to the hardscape.

This plant doesn't need much to thrive. It's happy in low-light tanks and doesn't require any extra CO2, making it ideal for simple, low-tech setups. In fact, too much light can cause ugly algae to grow on its leaves because the plant grows so slowly. You can expect a new leaf to appear only every month or two. Its impressive height makes it a perfect 'background' plant to fill in the back of your tank, and its broad, tough leaves provide excellent shelter for shy fish or fry. It's very adaptable and can handle a wide range of water conditions, as long as they are kept stable.

Anubias gigantea, commonly known as the Giant Anubias, is a robust and visually impressive species hailing from the riverbanks of West Africa. Its 'medium' difficulty rating stems not from chemical sensitivity, but from its slow growth and specific physical requirements. Morphologically, it is distinguished by its large, leathery, dark green leaves that can be spear or arrowhead-shaped (hastate). These impressive leaves sit atop long, sturdy petioles that emerge from a thick, creeping rhizome. Due to its potential to reach a substantial height, it is best suited for large aquaria of 75 gallons or more, where it serves as an excellent background specimen to conceal hardware or create a dense, structural focal point.

Proper placement is critical for the long-term health of A. gigantea. The rhizome must remain above the substrate to prevent rot. Attaching the plant to hardscape like driftwood or porous rock using cyanoacrylate gel glue, thread, or zip ties is the recommended method. Over time, its strong, white roots will wrap around and firmly anchor the plant. While it tolerates a broad range of pH and water hardness, it thrives in stable conditions and prefers gentle water movement to avoid damaging its large leaves.

This species is a quintessential 'low-tech' plant. Its adaptation to shaded forest streams means it performs best under low to medium lighting. High-intensity lighting, combined with its extremely slow growth rate and low nutrient uptake, makes it a magnet for algae, particularly Green Spot Algae (GSA) and Black Beard Algae (BBA). To mitigate this, place it in shaded areas of the tank or use floating plants to diffuse overhead light. While CO2 injection and comprehensive fertilization are not required, they can promote more robust health and deeper coloration, though they will not significantly increase its growth rate. Propagation is straightforward: using a sterile blade, the rhizome can be cut into sections, ensuring each piece has at least 3-4 leaves and some roots. Its tough, calcium oxalate-laced leaves make it an excellent choice for cichlid tanks or aquariums with otherwise destructive herbivores.

Anubias gigantea is a flowering plant belonging to the Araceae family, a group well-known for its semi-aquatic and rheophytic members. Native to West Africa, its natural ecology is primarily along the margins of fast-flowing, shaded forest rivers and streams. There, it grows in an emergent or semi-emergent fashion, with its rhizome and roots anchored to rocks or fallen logs in the splash zone, while its foliage reaches for the light. Its IUCN status of 'Least Concern' reflects its stable and widespread population in its native habitat.

The morphology of A. gigantea is well-adapted to this environment. It features a thick, creeping rhizome that stores nutrients and provides a firm anchor against water currents. From this rhizome arise long, durable petioles supporting large, hastate or sagittate leaf blades. This plant's physiological processes are characterized by a very slow metabolic rate. Its low rates of photosynthesis, corresponding low oxygen output, and minimal nutrient absorption are classic traits of a shade-adapted K-strategist plant, prioritizing durability over rapid growth. This slow metabolism explains its minimal demand for CO2 and its ability to thrive in low-light, oligotrophic conditions typical of a blackwater river under a dense canopy.

Reproduction in situ occurs both vegetatively through rhizome fragmentation and sexually. When grown emersed, A. gigantea can produce a characteristic aroid inflorescence, consisting of a spathe and spadix, though this is rare in submersed aquarium conditions. In horticulture, propagation is exclusively vegetative via rhizome division. A key biochemical characteristic of the genus Anubias, including A. gigantea, is the presence of idioblasts containing sharp calcium oxalate crystals (raphides). This serves as a highly effective anti-herbivory defense mechanism, rendering the plant unpalatable to most fish and invertebrates—a trait that makes it uniquely valuable in aquariums housing phytophagous species.