Thalassia as a Food Source: Importance and Potential in the Marine and Terrestrial Environments

Abstract

The chemical composition of Thalassia leaves is described. Of the leaf-dry matter, 40.6% consists of soluble nutrients: crude protein, lipids, soluble carbohydrates and ash. Crude protein content was 17% (R = 15.8-18.1%). Essential nutritive minerals were found in considerable quantities: calcium, 1.32% (R = 1.21-1.47%); phosphorus, .21% (R = .19-.23%); potassium, 3.0% (R = 2.47%-3.30%) and magnesium, 1.26% (R = 1.09%-1.38%). The cell wall or neutral-detergent fiber fraction was 59.4% (R = 46.1-64.6%), of which 19.1% consisted of hemicellulose. The lignin content varied from 22.9% (KMnO₄) to 9.1% (H₂SO₄) depending on whether KMnO₄ or H₂SO₄ was used as an oxidizing agent. The importance of Thalassia leaves as a food source for the seagrass community is described by five major food chains hereby proposed: the large herbivore, the fish herbivore, the gastropod herbivore, the urchin herbivore and the detrital food chains. The potential value of Thalassia as a food source for domestic animals is evaluated on the basis of comparison with forage crops.