Common name: Green Spoonworm

General Information

The Green Spoonworm, scientifically known as Bonellia viridis, is a fascinating marine worm that belongs to the Echiura group. It is renowned for its vibrant green color and unique sexual dimorphism, where males are significantly smaller and live inside the female's body. The females are about 10 cm but their spoon-shaped proboscis can extend up to a meter. This species is primarily found in the Mediterranean Sea and along the Atlantic coasts of Europe.

The Green Spoonworm plays a crucial role in marine ecosystems, particularly in nutrient cycling and sediment turnover. Its presence in the hobbyist trade is minimal due to its specialized habitat requirements and unique biological characteristics, which make it more of a scientific curiosity than a common aquarium resident.

Care

Caring for Bonellia viridis in captivity is challenging due to its specific habitat needs. It thrives in environments that mimic its natural sandy or muddy seabed habitats, with stable water conditions and a rich supply of organic matter. This species is best suited for advanced aquarists or researchers with access to specialized marine setups.

Diet and Feeding

Bonellia viridis is a detritivore, feeding primarily on detritus and organic matter found in the sediment. In captivity, providing a diet that includes fine particulate organic material and ensuring a steady supply of detritus is crucial for its survival.

Behavior and Compatibility

The Green Spoonworm is a solitary species with a unique reproductive strategy. The tiny males live inside the female's body, making them dependent on the female for survival. This species is non-aggressive and poses no threat to other marine life, making it compatible with a range of peaceful tank mates, provided its specific habitat needs are met.

Reproduction

The reproductive strategy of Bonellia viridis is highly unusual. The males are only about 3 mm and live inside the female's body, where they fertilize the eggs internally. This form of sexual dimorphism is rare and intriguing, making the species a subject of interest in marine biology.

Health and Common Issues

In captivity, maintaining the health of Bonellia viridis requires careful attention to water quality and substrate conditions. Due to its specialized habitat needs, it is prone to stress if conditions deviate significantly from its natural environment. Regular monitoring and adjustments to its living conditions are essential for its well-being.

Habitat

Bonellia viridis is native to the Mediterranean Sea and the eastern Atlantic Ocean. It inhabits sandy and muddy substrates in shallow waters, where it can burrow and access detritus for feeding. Replicating these conditions in captivity is crucial for its survival.