A fire has destroyed the main building at the Texas facilities of struggling US land-based shrimp producer NaturalShrimp.

The building housed the company's nursery, grow-out tanks and electrocoagulation machinery, but offices, greenhouse and maintenance buildings were unaffected.

CEO Gerald Easterling described the fire as "a blow in already uncertain times," in a note to shareholders, but said the future of the company "remains very bright," with insurance proceeds available to reconstruct a "newer, state of the art building" to house tanks and equipment.