Platypharodon extremus explained

Platypharodon extremus is a species of cyprinid fish endemic to the upper Yellow River basin in the Qinghai–Tibet Plateau of China.^{[1] [2]} It is the only member of its genus, but is related to other schizothoracines (snowtrout and allies) like Aspiorhynchus, Chuanchia, Gymnocypris, Oxygymnocypris, Ptychobarbus, Schizopyge, Schizopygopsis and Schizothorax.^{[3] [4]}

P. extremus reaches up to in length and in weight. Similar to Schizopygopsis, P. extremus has a horny sheath on the lower jaw and spoon-shaped teeth that it uses to scrape off periphyton and algae from stones, but it will also eat benthic invertebrates.^{[3] [5]}

An important food fish,^[6] P. extremus has seriously declined and is now listed as vulnerable on China's Red List.^[1] The species has been bred and raised in captivity,^[1] and individuals are released back into the wild from two purposely built stations in an attempt of countering its threatened status.^[5]

Notes and References

1. Zhang, Y.P.; Z.Y. Lou; J.H. Su; W.L. Jiai; T. Wang; X.F. Gong; S.H. Qi; J.P. Wu; and Y.M. Wei (2010–2011). Artificial propagation of Platypharodon extremus. Journal of Fisheries of China.
2. Su, J.; W. Ji; Y. Zhang; D.M. Gleeson; Z. Lou; J. Ren; and Y. Wei (2015). Genetic diversity and demographic history of the endangered and endemic fish (Platypharodon extremus): implications for stock enhancement in Qinghai Tibetan Plateau. Environ Biol Fish 98(3): 763–774.
3. Tang, Y.; C. Li; K. Wanghe; C. Feng; C. Tong; F. Tian; and K. Zhao (2019). Convergent evolution misled taxonomy in schizothoracine fishes (Cypriniformes: Cyprinidae). Molecular Phylogenetics and Evolution 134: 323–337
4. Qi, D.; Y. Chao; Y. Zhao; M. Xia; and R. Wu (2018). Molecular evolution of myoglobin in the Tibetan Plateau endemic schizothoracine fish (Cyprinidae, Teleostei) and tissue-specific expression changes under hypoxia. Fish Physiology and Biochemistry 44(2): 557–571. .
5. Qi, D. (2016). Fish of the Upper Yellow River. Pp. 233–252 in: G.J. Brierley et al. (eds.). Landscape and Ecosystem Diversity, Dynamics and Management in the Yellow River Source Zone. Springer Geography.
6. Walker, K.F.; and H.Z. Yang (1999). Fish and Fisheries if China. Food and Agriculture Organization. Retrieved 10 May 2019.