Full-Length Transcriptome Sequencing From the Longest-Lived Freshwater Bony Fish of the World: Bigmouth Buffalo (Ictiobus Cyprinellus)

Abstract

BACKGROUNDBigmouth buffalo (Ictiobus cyprinellus) belongs to the family Catostomidae. It is one of the largest freshwater fish endemics in North America, with a body length of more than 1.25 m and a body weight of more than 36 kg (Eddy and Underhill, 1974). Bigmouth buffalo is characterized by good meat quality and taste, a large size, rapid growth, strong disease resistance, relatively early maturity, and high reproductive ability. Due to its important economic value, it is highly valued among more than 30 species of Catostomidae that are abundant in America. Bigmouth buffalo has been a commercially important fish in the United States since the 19th century (Hoffbeck, 2001). In the 21st century, the value of its fisheries in the upper Mississippi River basin alone has exceeded US$1 million per year (Great Lakes Mississippi River Interbasin Study (GLMRIS), 2012). In 1971, the area of intensive bigmouth buffalo breeding in Arkansas, USA, reached 136 hm 2 . As an important economic fish, bigmouth buffalo has been successfully introduced for breeding and popularized in many countries. Bigmouth buffalo was introduced from the United States into Russia and Ukraine (from the former Soviet Union) in 1971, and it has since been widely farmed in reservoirs and ponds. In 1993 and 1994, China successively introduced bigmouth buffalo yolk sac fry and 3-5 cm fry from the United States in four batches, including more than 20,000 tails. After careful breeding and domestication, these bigmouth buffalo reached sexual maturity in 1996, and artificial induction and hatching success were achieved (Wang et al., 1997).A 112-year-old bigmouth buffalo was found in 2019, making it the longest-lived species identified among the ∼12,000 freshwater bony fish known globally (Lackmann et al., 2019). Recently published research shows that bigmouth buffalo exhibit negligible senescence in multiple physiological systems despite living for nearly a century (Sauer et al., 2021). At present, studies about bigmouth buffalo mainly focus on hybridization and breeding promotion (