Cnidaria, Hydrozoa: latitudinal distribution of hydroids along the fjords region of southern Chile, with notes on the world distribution of some species

The coast of continental Chile extends over almost 4,200 km and covers a large part of the southeast Pacific. While the coastline between Arica (18°20' S) and Chiloe Island (ca. 41°30' S) is more or less straight, the region between Puerto Montt (ca. 41°30' S) and Cape Horn (ca. 56° S) is highly structured and presents a large number of islands, channels and fjords. This extension is formed by two parallel mountain ranges, the high Andes on Chile’s eastern border, and the coastal mountains along its western edge which, in the area of Puerto Montt, drop into the ocean with their summits, forming the western channels and islands, while the Andes mountain range constitutes the continental fjords. The Chilean oceanographic institute SHOA calculated that the thousands of islands, channels and fjords enlarge the coast of this region to a length of almost 90,000 km (map scale). During the last three decades, an important number of papers dealt with the biogeography of Chilean benthic invertebrates. While most studies treated a single taxon (e.g. Moyano 1991; Desqueyroux-Faundez 1994; Ojeda et al. 2000; Haussermann and Forsterra 2005; Montiel et al. 2005; Haussermann 2006), some summarize