Colonization patterns of the date mussel Lithophaga lithophaga (L., 1758) on limestone breakwater boulders of a marina

Background and Purpose: The European date mussel (Lithophaga lithophaga) is widespread along the whole Mediterranean rocky coastline where it is frequently but illegally harvested. It is well known that the growth of the date mussel is very slow; however, patterns of recolonization of exploited surfaces have been scarcely investigated. The objective of this study is to assess colonization patterns of the date mussel on limestone boulders which have been in the sea for 19 years. These results could be useful in predicting the reconstitution of natural populations of the date mussel after harvesting. Materials and Methods: Limestone breakwater boulders were placed along the dike of the Marina of Rovinj (northern Adriatic, Istrian peninsula, Croatia) in 1984. Sampling was carried out in summer 2003 by SCUBA diving from six habitats of different inclination and topography: horizontal, inclined, vertical, sheltered, vaults, and whole stones. The abundance and biomass of L. lithophaga at the Marina were compared with those in natural control locations. Results: At the Marina, no date mussels were found on the horizontal and inclined sides of the boulders, and very few date mussels were found on the vertical side. On the contrary, sheltered and vault sides of boulders and whole stones were intensively colonized by L. lithophaga. In vaults, the abundance was similar to that in nature. In these habitats, L. lithophaga biomasswas generally lower than in nature. However, large date mussels, of lengths from 50 to 70 mm, were already present on boulders of theMarina. They amounted to 35% in the sheltered habitat, 24% in vaults, and 3% of the total number in whole stones. Conclusions: An unexpected high colonization rate and growth of date mussels was detected in certain unexposed rocky habitats at the boulders of the Marina. However, on the natural rocky Istrian coast, the date mussel was mostly collected on exposed inclined and vertical rocky surfaces where repopulation after harvesting may require very long periods

Dodatne informacije o plavom trkaču, Caranx crysos (Mitchill, 1815), u sjevernom Jadranu: meristička i molekularna karakterizacija

In October 2014, a blue runner (Caranx crysos) was caught by a professional fisherman in waters off St. Eufemija Point (west Istrian Coast, northern Adriatic Sea, Croatia). This is the second recorded blue runner in the northern Adriatic Sea, which represents the northernmost biogeographic sector of the Mediterranean Sea. Recently, blue runners were recorded in the southern and central Adriatic Sea, suggesting that the central Mediterranean C. crysos is expanding its area of distribution throughout the Adriatic Sea. As a point of interest, this most recent specimen presented an unusual meristic feature: the number of spines of its first dorsal fin was VI, whereas it is generally recognised that the number of such spines characteristic for this species is VIII. Species identity of the specimen was confirmed by DNA sequence analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene. In addition, we provided the first report of C. crysos mitochondrial 16S ribosomal RNA (16S rRNA) partial sequence.U listopadu 2014. godine, ribu plavi trkač (Caranx crysos) je ulovio profesionalni ribar nekoliko stotina metara van rta Sv. Eufemija (zapadna obala Istre, sjeverni Jadran, Hrvatska). Ovo je drugi po redu nalaz ribe plavi trkač koja je ulovljena u sjevernom Jadranu, što predstavlja najsjevernije biogeografsko područje sredozemnog mora. Nedavno ova vrsta je zabilježena u južnom i srednjem Jadranu što ukazuje da se populacija C. crysos iz središnjeg Sredozemnog mora proširuje u Jadranskom moru. Razmatrani primjerak je pokazao neobičnu merističku značajku: broj bodlji u prvoj leđnoj peraji je VI, dok je općenito za ovu vrstu prihvaćeno (priznato) VIII bodlji. Identitet vrste potvrđen je analizom mitohondrijske DNA sekvence za pod-jedinicu I gena citokrom c oksidaze (COI). U ovom radu također je po prvi put analiziran dio mitohondrijske DNA sekvence odgovorne za kodiranje 16S ribosomske RNA (16S rDNA) kod vrste C. crysos

Chapter Lagoon scenarios for the Bassa Friulana plain: a flooding archipelago

The paper first focuses on morphological history of a landscape unit, consisting of biological deserts and wrecks of the endangered landscape. Secondly, it analyzes and elaborates hydrological scenarios to explore and discuss potential design strategies. Water margin continuity could be recovered through development of flooding strategies. In conclusion, form of the archipelago emerges as a specificity of the landscape unit. More than a metaphor but as a conceptual and programmatic dispositive, archipelago can inform on dynamic structure of the Bassa Friulana complex system within an ecological framework