Skeletal Anomalies of Pacu, Piaractus mesopotamicus, Larvae from a Wild‐caught Broodstock

Abstract

AbstractSkeletal anomalies in fish are frequent, representing a major problem for the aquaculture industry. The anomalies usually arise in the larval phase and worsen, persist, or recover over the ensuing stages of development. In addition to impairing larval quality, they compromise the growth, health, and food conversion of fish, lowering their economic value. This study evaluated the occurrence of skeletal anomalies in pacu larvae during the first 30 d of development. The newly hatched larvae of six breeding pairs taken from the Paranapanema River (offspring A, B, C, D, E, and F) and subjected to induced spawning were reared separately for 30 d, feeding on live prey (Artemia nauplii). Nearly 20 larvae from each breeding pair were killed and stored 1, 2, 4, 6, 8, 10, 13, 16, 19, 22, 25, and 30 days post‐hatching. The larvae were stained to differentiate cartilage and bones and examined under a stereo microscope. A total of 1310 larvae were checked for the presence (1) or absence (0) of anomalies in the head, vertebral column, and fins. Associations between growth parameters (total length [TL] vs. standard length [SL]; SL vs. vertebral column length [VL]) were obtained by regression. Correspondence analysis was used to correlate data on the different parameters evaluated. On completion of observation, larvae from pair E had the highest SL, whereas offspring F were the shortest. All types of skeletal anomalies were detected in the larvae irrespective of the offspring, affecting the normal growth of pacu larvae obtained from wild‐caught breeders.