Nutrient and energy consumption of captive mature dugong (Dugong dugon) consuming eelgrass at the Toba Aquarium

Digestive efficiency and nutrient and energy consumption of the dugong (Dugong dugon) were determined during 1 year, using one male and one female captive animals fed eelgrass (Zostera marina) at the Toba Aquarium. The quantity of urine excreted was also estimated to evaluate ingestion of metabolic energy (ME), by measuring creatinine concentration of spot samples taken from the female. Estimated consumption rate of eelgrass was low at 0.82–0.99% dry matter (DM) of bodyweight, which was closely associated with its high nutritive value and digestibility as shown by 74% total digestible nutrients and 14.6% digestible crude protein on a DM basis. Consumption of gross energy and digestible energy averaged 10.4 Mcal per day and 9.6 Mcal per day, respectively. The female individual consumed 8.64 Mcal per day ME, calculated from urination of 26.2 l per day and estimated from urinary creatinine concentration and an equation for urinary creatinine excretion and bodyweight.

Keywords

• dugong,
• consumption rate,
• digestive efficiency,
• energy,
• eelgrass,
• Dugong dugong