Dispersal of Artemia franciscana Kellogg (Crustacea; Anostraca) populations in the coastal saltworks of Rio Grande do Norte, northeastern Brazil

摘要

In spite of the presence of Artemia franciscana Kellogg in several saltworks in the State of Rio Grande do Norte (RN) (northeastern Brazil) that were colonized from inoculations made in Macau (RN) in April 1977 with cysts from a San Francisco Bay (California, U.S.A.) stock, there is no recent data on the degree of regional dispersal of this anostracan. For 12 months (July 1996 – June 1997), 55 saltworks located in the municipalities of Areia Branca, Grossos, Galinhos, Guamaré and Macau in RN were visited and sampled for the presence of Artemia franciscana and the occurrence of its cysts. Populations of Artemia franciscana were found in all 55 saltworks, although significant amounts of cysts were only found in six sites. The presence of Artemia franciscana in all visited sites brings further evidence to the ample dispersal of this anostracan throughout the saltwork region of RN. However, the relatively low incidence of cysts suggests that most of these populations are reproducing ovoviviparously.