The Sulawesi Shrimp

The Caridina dennerli, commonly known as the Cardinal or Sulawesi Shrimp, is a small, vibrant freshwater shrimp species from Sulawesi, Indonesia. Discovered in 2007, it quickly gained popularity in the aquarium trade for its striking appearance and is considered a treasure among aquarists. Despite its small size, growing up to just 2.5 centimeters, this species is renowned for its bright red color with distinctive white spots, making it a standout in any aquarium.

Females of the species are slightly larger than the males and have a deeper carapace. They carry relatively large eggs for their size under their abdomen, a unique aspect of their breeding. Native to Lake Matano in Sulawesi, these shrimp inhabit waters that range from shallow areas to depths of up to 10 meters. Lake Matano is known for being ultra-oligotrophic, meaning it's extremely nutrient-poor with very little organic matter. This unique habitat contributes to the clear waters with visibility estimated around 20 meters, and conditions that include temperatures between 27–31°C, a pH of 7.4, and a conductivity of 224 μS/cm.

In their natural environment, Caridina dennerli is believed to feed primarily on detritus. In captivity, they require a specific set of conditions to thrive. Their care demands an understanding of their natural habitat, as they are sensitive to water parameter fluctuations. They feed on small animals in a planted aquarium, and maintaining stable water conditions is crucial for their well-being. To replicate their natural environment, aquarists need to provide a habitat with the right temperature, pH levels, and water hardness.

Cardinal Sulawesi Shrimp have a lifespan of about two years in optimal conditions. They are considered one of the most attractive species in the Caridina genus, but their care is challenging due to the need for specific water conditions, which are difficult to replicate. They are recommended for experienced aquarists for this reason. Their breeding in captivity is also possible but requires careful maintenance of water quality and feeding.

Unfortunately, this species faces significant threats in the wild, primarily due to pollution from nickel mining, human activities, and introduced species such as the flowerhorn cichlid. Hydro-electric power plants on the southern shore of Lake Matano also pose a threat. As a result, no Caridina dennerli have been recorded in the wild since 2013, and they may possibly be extinct in their natural habitat. They are now listed as critically endangered on the IUCN Red List.

In summary, the Caridina dennerli is a species that encapsulates the beauty and fragility of aquatic life. Its vibrant appearance and unique habitat requirements make it a fascinating subject for aquarists, yet its precarious conservation status highlights the importance of responsible breeding and habitat conservation efforts.