Nutrient, fatty acid, amino acid and mineral analysis of natural prey of the Hawaiian monk seal, Monachus schauinslandi

Proximate nutrients, gross energy content, mineral, amino acid and fatty ac id composition were determined for teleost, cephalopod and crustacean prey of the Hawaiian monk seal. Crude protein was highest in the octopus, Octopu s cyanea (80.0%), crude fat was highest in the Muraenid teleost, Gymnothora x eurostus (14.1%), whereas crude ash was highest in the lobster, Panulirus marginatus (11.6%). Gross energies ranged from 4.0 +/- 0.01 kcal g(-1) in the Labrid teleost Bodianus bilulunatus to 6.0 +/- 0.12 kcal g(-1) in the m oray eel, Gymnothorax undulatus. Essential amino acids occurred in lower co ncentrations as a percentage of the total amino acids (35.8 +/- 2.6%) than non-essential amino acids (64.2 +/- 2.6%), but the ratio of individual amin o acids to total amino acid concentrations were similar to those required b y some monogastric terrestrial species and fingerling salmon. The fatty aci d concentrations varied widely among species (range = 1.2-16.5 mg 100 mg(-1 )); however, the teleosts had higher total fatty acids than the non-teleost s. This study indicates that, from a nutritional standpoint, some prey may be more beneficial to the Hawaiian monk seal; however, these prey are not n ecessarily the most abundant or available to some populations of the monk s eal. (C) 1999 Elsevier Science Inc. All rights reserved.