Ngazidja has two volcanoes, 1. Harthala (active), 2. La Grille (dormant) and lack of good harbors. Mwali, with its capital at Fomboni, is the smallest of the fourmajor islands. Nzwani, whose capital is Mutsumuduhas a distinctive triangular shape caused by three mountain chains, Sima, Nioumakele, and Jimilime, emanating from a central peakn Ntringi, 5,170 ft.
The islands of Comoros Archipelagowere formed by volcanic activity. Mount karthala, an active volcano located on Ngadijda is the country's highest point, 7,748 ft., contains the largest patch of its disappearing rainforest. Karthala is one of the most active volcanoes of the World, with a minor eruption in 2006, and previous eruptions were on 2005 and 1991.
Comoros constitute an ecoregion in their own right , Comoros forest
Fresh water Habitat: Moheli possess streams and other water bodies, including lakes. The Island Grande Comore and Anjouan possess few fresh water habitat but possess highland rain forest of the island. Between ten to fifteen species of fishfrequent in the rivers and lakes.