Elasmobranchs of tropical marine ecosystems

Abstract

The marine ecosystems of the world are vast, with the total volume of water in the worlds’ oceans exceeding 1450 km3 (Briggs 1995), and habitat for marine organisms occurs from the surface to the deepest ocean trench, that is, the Challenger Deep in the Mariana Trench at 10,920 m (Gvirtzman and Stern 2004). This is reflected in the fact that 34 of the 37 recognized animal phyla are found in the marine environment (Nicol 1971). On a global scale, temperature is the primary factor that controls species distributions and the ocean’s surface can be divided into four major temperature zones: the tropical, the warm-temperate, the cold-temperate, and the polar zones (see Figure 55, Briggs 1995). These zones then can be subdivided by ocean basins and adjacent landmasses (Parenti 1991, Table 2.1 in Musick, Harbin, and Compagno 2004).