Length-weight relationships of ornamental fish from floodplain lakes in the Solimões River basin (Iranduba, Amazonas, Brazil)

This research reports the LWR of ornamental fish from floodplain lakes of the Solimoes River basin. The fish were caught in the Paciencia island (a fluvial island) in two lakes Sacambu and Cacau using purse seine 7 m × 4 m and mesh size = 3 mm, once during the flood in June 2017 and dry in January 2018. The specimens captured were anesthetized using eugenol 15 mg · L–1, fixed formalin 10% and stored ethanol 70% after 10 days. This study provides the LWR parameters for the species Anablepsoides micropus, Anchoviella jamesi, Cichlasoma amazonarum, Heros efasciatus, Ctenobrycon hauxwellianus, Copella nattereri and Hemigrammus levis. The parameter a ranged from 0.0092 to 0.0229, b ranged from 2.78 to 3.50 and the R2 ranged from 0.985 to 0.998. The results represent new information about ornamental fish from floodplain lakes, with new LWR for five species that are not present in FishBase data set and probably are new for science. This study is preliminary and much work needs to be done especially in the Solimoes River floodplain areas and with our research we hope to encourage new studies in the region.