The life history of the freshwater shrimp Palaemonetes antennarius (H. Milne Edwards, 1837) was investigated from April 1993 to November 2002 at 13 sites in the delta of the Neretva River, Croatia. The sex ratio (males vs. females) was in favour of females throughout the study year ð AE SD ¼ 0:70 AE 0:12Þ. The breeding period lasts from April to August with a peak of 75% of the ovigerous female in June. The maximum number of eggs carried by ovigerous females was 73, and there was a positive significant linear correlation between fecundity (number of early embryonic stage eggs per female) and female body size (carapace length) (R 2 ¼ 0:698, po0:01). The breeding period was longer in limnocrenes and lakes with oligohaline-limnic water than in other habitat types because the water is more rapidly warmed in spring and cooled more slowly in autumn in these habitats. Larvae were present from June to October, with a peak reaching 19.4% of the total population in June. The shrimps follow a synchronic univoltine life cycle with a short egg-laying period and a new summer generation. Their larvae, apparently having no ecological flexibility, did not appear in any environment with high oscillations of salinity.

In order to gain better insight into the distribution of white-clawed crayfish (Austropotamobius pallipes) in Croatia, we pooled together all of the available historical and recent data. The historical data on distribution were compiled from literature and the Croatian Natural History Museum collection. Fieldwork, to evaluate the current distribution of crayfish, took place between 1995 and 2003. The distribution of Austropotamobius pallipes is restricted to the limestone region and therefore the species is found spread in rivers belonging to the Adriatic Sea basin (from NW to SE of Croatia). Those waters are mainly unpolluted and the substrate consists of rocks and stones and crayfish were found near banks. We also occasionally found crayfish in subterranean habitats but as they appear to have no troglomorphic adaptations they are probably of epigean origin. According to data taken from literature, both A. pallipes and A. torrentium live in the coastal rivers. But to date, we have not yet recorded presence of A. torrentium there, while we did record the presence of Astacus astacus. While studying the data from the literature, we were frequently confronted with contradictory findings, therefore, in the near future we are planning to do intensive field research within the coastal region in order to get a clearer picture of the detailed distribution of freshwater crayfish in this part of Croatia.In addition, individuals from four different geographical areas were compared using two morphometric and two meristic characteristics and the results are discussed. Key-words:Austropotamobius pallipes, Croatia, geographical distribution, morphological characteristics. DISTRIBUTION D'AUSTROPOTAMOBIUS PALLIPES EN CROATIE ET NOTES SUR SA MORPHOLOGIE RÉSUMÉPour améliorer notre connaissance sur la distribution des écrevisses à pattes blanches (Austropotamobius pallipes) en Croatie, nous avons rassemblé toutes les données historiques disponibles et les résultats de notre recherche. Les données historiques sont issues de la littérature et de la collection du Muséum d'Histoire Naturelle de Croatie. Nous avons étudié la distribution actuelle sur le terrain depuis 1995. La distribution d'A. pallipes est limitée à la région karstique de la Croatie, donc aux fleuves du drainage Adriatique (du Nord-Est au Sud-Ouest de la Croatie). Ces fleuves sont principalement de bonne qualité -58 -chimique avec des fonds rocheux et caillouteux et les écrevisses peuvent être trouvées à proximité des rives. Pendant notre recherche nous avons enregistré la présence de spécimens d'A. pallipes dans les habitats souterrains. Toutefois, les animaux n'ont pas d'adaptation troglomorphiques et sont en conséquence probablement d'origine épigée. Selon la littérature, dans les fleuves côtiers est présente également A. torrentium. Nous n'avons pas trouvé cette espèce mais nous avons trouvé Astacus astacus. Dans la littérature, nous avons fréquemment été confrontés à des contradictions. La recherche sur la distribution des écrevisses dans cette région de l...

A new species of the freshwater subterranean amphipod genus Niphargus Schiödte, 1849 (Crustacea Amphipoda, fam. Niphargidae), N. echion, n. sp., is described and figured from the cave PliÓkoviƒeva jama near Ò ikuti village, Istra (Croatia), and its taxonomic position within the genus Niphargus is discussed.