Vladimir Onofri

Calycophorae (Siphonophora) in the open waters of the central and southern Adriatic Sea during spring 2002.

Twenty species of calycophoran siphonophores were identified from the central and south Adriatic Sea in spring 2002. Highest abundance and species diversity were noted at the deepest stations in the south Adriatic. Highest total abundance was found in the upper 100 m. The dominant species above 100 m were Lensia subtilis , Eudoxoides spiralis and Sphaeronectes gracilis , none of which showed diel migration. The first two species correlated significantly with the vertical abundance of microzooplankton, and the last with that of copepods. The most abundant species in the 100-400 m layer was Lensia meteori , whereas Lensia conoidea and Chlausophyes ovata were most abundant below 400 m.

The spawning, embryonic and early larval development of the green wrasse Labrus viridis (Linnaeus, 1758)(Labridae) in controlled conditions

Green wrasse, Labrus viridis (Linnaeus, 1758), is an endangered species in the southern Adriatic Sea, but it is also of interest for potential rearing in polyculture with other commercial species for the repopulation of areas where it is endangered or as a new aquaculture species. A parental stock of the green wrasse was kept in aquaria for six years. The spawning, embryonic and early larval development maintained under controlled laboratory conditions are described and illustrated. The average diameter of newly spawned eggs was 1.01±0.03 mm. Mature and fertilized eggs were attached to the tank bottom by mucus. Hatching started after 127 h at a mean temperature of 14.4±0.8°C. The average total length of newly hatched larvae was 4.80±0.22 mm. Absorption of the yolk-sac was completed after the 5th day when larvae reached 5.87±0.28 mm. Larvae were fed with the rotifers Brachionus plicatilis. The pigmentation of L. viridis larvae is similar to that of Labrus merula and Labrus bergylta, but the main differences between these species are in the size of larvae and the development time of the melanophores on the anal fin-fold (five days later than with L. merula) and on top of the head (nine days earlier than with L. merula).