White cachama (Piaractus brachypomus), an option for Latin American aquaculture. Methodology for confirming intramuscular spines in early stages of development

Abstract

The fish production from aquaculture in Colombia has been increasing year by year, growing from 102,460 tons per year in 2013 to 202,956 tons in 2023, with the most cultivated species being tilapia, trout, pirapitinga, and shrimp. The white pacu (Piaractus brachypomus), native to the Orinoco and Amazon River basins and their tributaries, is the main native species produced in Colombia. Despite this, its consumption and commercialization are limited due to the presence of intramuscular bones (IMB). Some authors have reported individuals of White pacu without intramuscular bones from production batches in the southeast region of Colombia, whose diagnosis was confirmed based on ultrasounds, X-rays, and computed tomography (CT) scans. Others have reported the presence of black pacu (Colossoma macropomum) in north region from Brazil without intramuscular bones confirming this particularity through X-ray and ultrasound imaging. This project aims to monitor White pacu juveniles from 3 g to the identification of intramuscular bones using ultrasound and X-rays, and it is currently under development. For this purpose, ultrasounds and X-rays have been performed on 100 individuals, periodically tracking their growth at 3, 15, 30, and 50 grams of weight. It was found that IMBs can be observed in individuals weighing 15 g via ultrasound, and in individuals weighing 50 g, they could be identified through X-rays (however, the project will continue periodic monitoring in individuals weighing 100, 200, 300, and 600 grams). It is concluded thus far that ultrasound is a tool that can identify the presence of intramuscular bones earlier than X-rays (15 g vs. 50 g), and since more evidence is needed, both types of imaging will continue to be performed on individuals at different weights.