# Some Hematological and Physiological Indicators of Health in Triploid Tambaqui (Colossoma macropomum): A Preliminary Study

## TL;DR

This study shows that triploid tambaqui fish have normal health and can efficiently transport oxygen, making triploidy a safe option for aquaculture.

## Contribution

The study provides the first comprehensive physiological evaluation of triploid tambaqui and confirms their health and metabolic stability.

## Key findings

- Triploid tambaqui have larger erythrocytes with higher MCV and MCH, compensating for lower erythrocyte counts.
- No significant differences were found in biochemical parameters between triploid and diploid fish.
- Triploid fish maintain efficient oxygen transport and respiratory capacity similar to diploids.

## Abstract

This study provides the first comprehensive hematological and biochemical evaluation of triploid tambaqui, demonstrating that triploidy does not compromise physiological health or metabolic stability. By showing that triploid fish exhibit compensatory adjustments in erythrocyte structure that preserve oxygen transport and overall respiratory capacity, the work establishes a physiological basis for the safe and sustainable application of triploidy in tambaqui aquaculture. These findings support the use of triploidization as both a production-enhancing and biosafety strategy, contributing valuable evidence for its broader adoption in tropical aquaculture systems.

This study evaluated the physiological condition and health status of triploid tambaqui (Colossoma macropomum) using hematological and biochemical indicators. Hematocrit, hemoglobin concentration, erythrocyte count, glucose, and plasma protein levels (albumin, globulin and albumin/globulin ratio) were assessed in triploid and diploid fish, and mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were calculated. Triploid fish exhibited larger erythrocytes, reduced erythrocyte counts, and slightly lower hemoglobin and hematocrit values compared with diploids. Correspondingly, MCV and MCH were significantly higher in triploids, indicating increased hemoglobin content per erythrocyte. In contrast, MCHC values did not differ between ploidy groups, suggesting that hemoglobin concentration within erythrocytes remained unaffected. No significant differences were observed in the evaluated biochemical parameters. These findings indicate that triploid tambaqui undergo compensatory physiological adjustments associated with increased nuclear DNA content in erythrocytes, enabling the maintenance of efficient oxygen transport and respiratory capacity. Overall, triploid fish displayed normal physiological performance, comparable to that of diploids. The results support the use of triploidy as a viable and sustainable strategy in tambaqui aquaculture.