Reproductive performance of three Artemia franciscana Kellogg (Crustacea, Anostraca) populations in north-eastern Brazil pond culture conditions MARCOS R. CAMARA*, LIGIA G. REIS and MARCOS F. COSTA Departamento de Oceanografia e Limnologia, Universidade Federal do Rio Grande do Norte, Natal, RN 59078-900 Brasil Abstract Artemia franciscana Kellogg (Crustacea, Anostraca) is found on a year-round and permanent basis in the State of Rio Grande do Norte (RN) in north-eastern Brazil as a result of inoculations made in Macau saltworks in 1977 with cysts from San Francisco Bay (California, USA). Inoculation of Artemia in the saltworks of RN was initially followed by high cyst yields. However, recent data indicate that these feral brine shrimp populations reproduce predominantly ovoviviparously. In the present study, the reproductive performance of three populations from Macau (5° 06' S; 36° 38' W), Areia Branca (4° 57' S; 37° 08' W), and Grossos (4° 58' S; 37° 09' W) in RN was examined under similar pond culture conditions. A higher incidence of ovoviviparous than oviparous females for all experimental populations was found throughout ten culture cycles carried out in ponds of 0.72 ha. Furthermore, no significant variability in reproductive mode (ovoviviparity versus oviparity) or in fecundity (brood size) was observed (p > 0.05). These results presumably reflect the homogeneity of local populations and are consistent with the suspected decrease of genotypic diversity of feral Artemia franciscana in the saltworks of RN in north-eastern Brazil.   < back .