Living Ostracod Species From Permanent and Semi-Permanent Ponds of Bardenas Reales De Navarra (Northern Spain) With Remarks on Their Ecological Requirements

Abstract

Abstract. Ostracod species living in 13 ponds (25 sample points) in Bardenas Reales de Navarra Natural Park and World Biosphere Reserve are studied for the first time. Nineteen species were identified, nine of them being the most abundant. According to statistical analyses (cluster and Correspondence Analysis), the distribution of ostracod species in this semi-arid area is mainly controlled by water conductivity and pH. The hydroperiod, sediment type, dissolved oxygen, altitude and vegetation cover play a secondary role. Thus, in semi-permanent waters with conductivity between 4.5 and 5.4 mS/cm and pH from 7.95 to 8.73 the most abundant species is Sarscypridopsis aculeata (Costa). In ponds with water conductivity from 0.3 to 2 mS/cm, pH between 7.1 and 7.78 and dissolved oxygen from 0.1 to 7.95 mg/l, Cypridopsis vidua (Muller) s the most abundant species. When the vegetation cover increases in this type of ponds, Limnocythere inopinata (Baird) and Potamocypris villosa (Jurine) appear as more abundant. Fin...