Dichotomyctere biocellatus, previously known as Tetraodon biocellatus and commonly referred to as the Figure of Eight Puffer, is a small and uniquely patterned species of freshwater pufferfish. Native to Southeast Asia, specifically the coastal and brackish waters of Thailand and Malaysia, this species is part of the Tetraodontidae family, renowned for its members' ability to inflate their bodies as a defense mechanism. The Figure of Eight Puffer is particularly appreciated in the aquarium hobby for its manageable size, distinctive appearance, and engaging personality, making it a fascinating addition to appropriately set up aquariums.

Characterized by its light green to yellowish body adorned with dark spots and a distinctive "figure of eight" or "double eye" pattern near the tail, Dichotomyctere biocellatus is a visually striking species. This pattern not only contributes to its common name but also serves as a unique identifier among freshwater puffers. Typically reaching a modest size in captivity, the Figure of Eight Puffer is suitable for smaller aquarium setups compared to some of its larger relatives, provided its specific care needs are met.

Creating an optimal environment for Dichotomyctere biocellatus involves simulating the brackish conditions of its natural habitat. This includes maintaining a specific gravity of around 1.005 to 1.008, achievable through the careful addition of marine salt to freshwater. The aquarium should feature a soft, sandy substrate, along with various hiding spots and territories created by rocks, driftwood, and hardy plants that can tolerate brackish conditions. While the Figure of Eight Puffer can adapt to fully freshwater setups, replicating brackish conditions can contribute to their overall health and longevity.

The diet of the Figure of Eight Puffer is carnivorous, with a strong preference for hard-shelled invertebrates, which are crucial for wearing down their continuously growing teeth. In captivity, their dietary needs can be met with a variety of foods, including snails, shrimp, clams, and mussel meat. Providing a diet that includes shellfish can help maintain the puffer's beak-like teeth at a manageable length, preventing overgrowth that could impede eating.

Breeding Dichotomyctere biocellatus in captivity is challenging, with few successful reports. Like many pufferfish, specific environmental conditions and triggers for spawning are not well understood, making breeding efforts a topic of interest but limited practical application for most hobbyists.

Caring for the Figure of Eight Puffer requires diligent attention to water quality, as pufferfish are sensitive to poor conditions and can be susceptible to common aquatic diseases. Regular water changes, effective filtration, and careful monitoring of water parameters are essential for maintaining a healthy environment. Due to their territorial and sometimes aggressive behavior, careful consideration should be given to tank mates, with a preference for species that can thrive in similar brackish conditions and have a peaceful disposition.

In summary, Dichotomyctere biocellatus, or the Figure of Eight Puffer, offers aquarists the opportunity to care for a unique and engaging species known for its intriguing behaviors and distinctive appearance. While the care of the Figure of Eight Puffer demands a commitment to specific dietary, environmental, and social needs, the rewards include the enjoyment of their personality and the captivating presence they bring to the home aquarium.