Characterization of Three Populations of Phallocryptus Spinosa (Branchiopoda, Crustacea) from North-East of Algeria

Abstract

Phallocryptus spinosa (Thamnocephalidae), which was long considered as Branchinella spinosa, lives in saline lakes of America, Africa, and occidental Asia. There are very few data on its biology and ecology. It has been recently found in the Eastern Hauts Plateaux of Algeria and co-occurs with Artemia sauna in Sebkha Ez-Zemoul. Three populations have been studied focusing on their biometrics and reproduction. During the sampling period in April 2005, only adults (more than 90%) and some pre-adults were found. Adults are short (16.14 +/- 1.1-17.84 +/- 2.65 mm) compared to Mediterranean populations. No differences were found between the total lengths of males and females. The latter are oviparous and begin to reproduce when they reach the length of at least 11.5 mm. They are not very fertile (15.6 +/- 8.45-27.65 +/- 14.49 cyst/brood) and produce cysts of a mean diameter range of 276.28 +/- 18.79 to 292.18 +/- 21.81 mu m, according to the studied population. Edwards 1840. Rogers (2006) gave a new description of the species and classified it as Phallocryptus Biraben 1951. Studies on this species are very scarce (Ketmaier et al. 2008). P. spinosa is known in Algeria in five biotopes (Samraoui et al. 2006). It co-occurs with Artemia sauna in the Sebkha Ez-Zemoul hypersaline lake (35 degrees 53 N, 6 degrees 30 E), where relatively large (40 mm) dead individuals were sampled in January 2003. This study is a first characterization of three populations in the northeastern part of Algeria. Data on biometrics and reproduction are presented.