River whale (SciiFii)

The river whale (Flumeniacetus lacupinnulas) is a species of cetothere whale that originally did not exist, but has since been created by SciiFii and introduced throughout the large lakes and rivers across North America and South America to help boost biodiversity, making it the only known species of baleen whale naturally found in the freshwater habitats. The river whale is one of the smallest known baleen whales, reaching lengths of about 2 meters (6.5 feet) long and can reach a weight of up to 900 kilograms (2,000 lbs). The river whale is a shy filter feeder that feeds only on small fish and schooling crustaceans. Like the humpback whales, river whales use bubbles to catch prey. They are known for breaching and other distinctive surface behaviors, making it popular with many people who are visiting or swimming in the lakes and rivers where the river whales live in. Males produce a complex song typically lasting 4 to 33 minutes. Mating and breeding take place during the winter months. Females go through estrus while males reach peak testosterone and sperm levels. River whales are promiscuous, with both sexes having multiple partners. Males will frequently trail both lone females and cow-calf pairs. These are known as "escorts", and the male that is closest to the female is known as the "principal escort", who fights off the other suitors known as "challengers". Other following males that are not directly competing to be next to the female are called "secondary escorts". Aggressive behavior between males includes tail slashing, ramming, and head-butting. Gestation in the species is around 4 months, short even for baleen whales, due to their small sizes, and females reproduce every year. River whale births have been commonly observed. Birthing mostly takes place in early-to-mid-spring, usually to a single calf, but twins can occur (although it is uncommon for twins to occur naturally). Calves suckle for up to almost a year but can feed independently by six months. River reach sexual maturity at 2–5 years, depending on the population. The length at maturity is around 1.6 meters (5.2 feet). The average lifespan of the river whale is around 70 and 80 years, despite its small size among baleen whales. Crocodilians and freshwater sharks (including bull sharks) are the main natural predators of river whales. The conservation status of the river whale is Least Concern due to successful conservation efforts, the river whale's wide range and its tolerance to many of the human activities.