The Rectangular Trigger, Rhinecanthus rectangulus, also known as the Rectangulus Trigger, features a distinct body shape and a thick dorsal spine. It has a beautiful cream-colored face with a brown and black band across their body and a black triangle on their tail fin. The Rectangular Trigger will use its unique body shape to wedge itself into crevasses in the rock for protection. Their rough scales make them difficult to handle in nets so use caution while netting.  As an active fish, it will spend most of its time searching for food, including small inverts, so tank mates should be chose carefully and they should not be housed in a reef setup. Growing up to 12 inches they require a tank of at least 120 gallons with lots of filtration to keep up with their meaty diet and high waste load. Feed them 1-2 times a day a diet of clams, shrimp, krill, and squid to help keep their teeth trimmed. The Rectangular Trigger Fish In Your Aquarium The Rectangular Triggerfish (Rhinecanthus rectangulus) is a distinctive and captivating addition to your saltwater marine aquarium. In this comprehensive product description, we'll provide essential information for hobbyists and potential buyers about keeping the Rectangular Triggerfish. This includes details on its habitat, reef compatibility, size, lifespan, diet in captivity, aquaculture availability, compatibility with other marine life, sexual dimorphism, coloration changes from juvenile to adult, temperament, tank requirements, and ideal water conditions. We'll also cover common names for this species, list compatible tank mates, and explain why people should consider purchasing the Rectangular Triggerfish from Saltwaterfish.com. Habitat of the Rectangular Triggerfish The Rectangular Triggerfish is commonly found in the Indo-Pacific and Hawaiian regions, inhabiting coral reefs, rocky substrates, and areas with ample hiding spots. To ensure their well-being in captivity, it's crucial to replicate a similar environment within your aquarium. Reef Compatibility of the Rectangular Triggerfish The Rectangular Triggerfish is generally not considered reef-safe due to its natural foraging behavior. These fish may disturb corals and invertebrates, making them better suited for fish-only or fish-only-with-live-rock (FOWLR) setups. Size and Lifespan of the Rectangular Triggerfish In captivity, Rectangular Triggerfish can grow to a length of up to 12 inches (30 cm). They have a relatively long lifespan, typically ranging from 8 to 12 years with proper care. Diet of the Rectangular Triggerfish in Captivity These triggerfish are omnivorous and have diverse dietary preferences. They readily accept high-quality marine pellets, frozen foods, and live or frozen seafood. Maintaining a balanced diet is essential to ensure their health and vibrancy. Aquaculture and Availability of the Rectangular Triggerfish Rectangular Triggerfish are not aquacultured, but they are often available to hobbyists through reputable suppliers and online retailers like Saltwaterfish.com as wild-caught specimens. Compatibility with Other Fish and Invertebrates Rectangular Triggerfish can be territorial and occasionally aggressive, especially when they feel threatened or while establishing their territory. Selecting compatible tankmates is essential to minimize potential conflicts. Suitable tankmates may include Foxface Rabbitfish, Clownfish, large angelfish, and certain tang species. Sexual Dimorphism of the Rectangular Triggerfish Rectangular Triggerfish do not exhibit significant sexual dimorphism, making it challenging to visually distinguish between males and females based on their external characteristics. Coloration Changes from Juvenile to Adult in Rectangular Triggerfish Juvenile Rectangular Triggerfish typically display vibrant colors with striking patterns. As they mature into adults, their coloration tends to become more subdued, with a less prominent patterning and a more solid appearance. Temperament of the Rectangular Triggerfish The Rectangular Triggerfish is known for its territorial and sometimes aggressive nature. Providing sufficient hiding spots and territories within the aquarium can help mitigate aggression, creating a more balanced environment. Tank Requirements for the Rectangular Triggerfish To ensure the well-being of your Rectangular Triggerfish, you will need an aquarium with a minimum capacity of 120 gallons. These fish require ample swimming space, hiding spots, and the freedom to establish territories. Water Conditions for the Rectangular Triggerfish Maintaining stable water conditions is vital for the health of your Rectangular Triggerfish. Here are the recommended parameters: pH: 8.1 to 8.4 Salinity: 1.020 to 1.025 Water Temperature: 76 to 82°F (24 to 28°C) Water Flow: Moderate to strong, replicating the natural c…