Lotic regions of Belize and their aquatic byrrhoid Coleoptera (Dryopidae, Elmidae, Lutrochidae, Psephenidae, Ptilodactylidae)

摘要

A survey of the streams of Belize showed that the country has at least 23 species of aquatic byrrhoid Coleoptera and four major lotic regions. Lotic regions were defined using regional geomorphology and stream characteristics. The highest number of taxa per region and highest mean number of taxa per stream both occur in Region 3, which is associated with the great topographic relief of the Maya Mountains. Belize is a small country on the Caribbean coast of Central America, south of Mexico and east ofGuatemala. It is 320 km long and 120 km wide (Graham 1990) and includes 22,700 km~2 (Glassman 1991), approximately the size of the USA state of Massachusetts (Mallan 1991). There are four major highways in the country (Fig. 1). The Western Highway bisects the country, leaving Belize City and traveling southwestward toward Tikal, Guatemala. The area north of the Western Highway is a southward extension of the karstic Yucatan Peninsula of Mexico. The area south of the Western Highway is dominated by theMaya Mountains which contain the highest point in Belize at 1120 m. The physiography of Belize is discussed by Boomsma & Dunkle, 1996.