Seagrasses exhibit vital ecological roles in the marine environment. Nevertheless, the genomic resources available for seagrasses are still scarce. In the present study, the transcriptome of Cymodocea nodosa was sequenced with a view to study the molecular mechanisms underlying abiotic stress responses. The sequenced transcriptome for the species was near-complete and a high percentage of the transcripts was computationally annotated. An experimental simulation of marine plant exposure to extreme temperature (34°C), salinity (50psu) and their combination was conducted. A dynamic transcriptome 24h response (short-term) from stress initialization was recorded. The most noteworthy alteration in gene expression was observed in heat-stressed plants. Transcripts associated with development, photosynthesis, osmotic balance and stress-response were differentially expressed, under the set experimental conditions. Results indicate a potential negative interaction of heat and osmotic stress on seagrasses transcriptome.

Monitoring of Delphinidae species population patterns in the Mediterranean Sea was carried out in a sequence of surveys employing different approaches. Data from seven-year surveys with small catamaran sailing boats were analyzed under model-based approaches. Density Surface Models were used to produce spatial distribution prediction of three Delphinidae species (Stenella coeruleoalba, Tursiops truncatus, and Delphinus delphis) in an extended study area covering much of the Mediterranean Sea. A classical distance sampling protocol was applied in order to calculate the detection probability of clusters. Static (depth, slope, distance from the coast, and distance from isobaths of 200 m) and nonstatic (sea surface temperature and chlorophyll) variables were used to predict the species distribution/abundance in a generalized additive model context. Stenella coeruleoalba was found to be the dominant species, with an extended distribution in the study area; its abundance was significantly affected by both depth and distance. Tursiops truncatus and Delphinus delphis illustrated a significant abundance correlation with depth and chlorophyll, respectively, while both species showed a robust longitude correlation. Our model pinpoints the significance of nondesigned transect line surveys, suggesting the importance of specific habitat areas for future monitoring and conservation aspects of marine mammals.

Common sole (Solea solea) aquaculture production is based mostly on wild-caught breeders. Recently, the successful reproduction of first-generation fish that were reared in captivity was accomplished. A consistent good quality and quantity of produced eggs throughout the year, and of next-generation broodstock, is important for reducing the overall cost of production.Hoxgenes play a pivotal role in normal embryonic development and alterations of their temporal expression level may be important for egg viability. Expression profile analysis of fivehoxgenes (hoxa1a,hoxa2a,hoxa2b,hoxb1aandhoxb1b) involved in early embryonic development and ofhoxa13a, which is involved in late stages, was carried out. Results revealed a premature and/or maternal expression ofhoxa13ain sole embryos, and the detection ofhoxa2aandhoxa2bgenes as members of paralog group 2. Principal Component Analysis ofhoxgene expression in 54 ± 6 hours post fertilization embryos coming from wild-caught broodstock and a first-generation one reared in the hatchery, unveiled that these broodstocks are clearly distinct. In addition, their pairwise comparison revealed significant differences in the expression levels ofhoxb1aandhoxb1bgenes.Hoxgene regulation during embryonic development could give valuable insight into rearing sole broodstocks with different origin in concert, and also into gaining a steady mass production of eggs, either in quality or quantity, all year round.

In sole aquaculture production, consistency in the quality of produced eggs throughout the year is unpredictable.Hoxgenes have a crucial role in controlling embryonic development and their genetic variation could alter the phenotype dramatically. In teleosts genome duplication led paraloghoxgenes to become diverged. Direct association of polymorphism inhoxa1a,hoxa2a&hoxa2bofSolea soleawith egg viability indicateshoxa2bas a potential genetic marker. High Resolution Melt (HRM) analysis was carried out in 52 viable and 61 non-viable eggs collected at 54±6 hours post fertilization (hpf). Allelic and genotypic frequencies of polymorphism were analyzed and results illustrated a significantly increased risk for non-viability for minor alleles and their homozygous genotypes. Haplotype analysis demonstrated a significant recessive effect on the risk of non-viability, by increasing the odds of disrupting embryonic development up to three-fold. Phylogenetic analysis showed that the paralog geneshoxa2aandhoxa2b, are separated distinctly in two clades and presented a significant ω variation, revealing their diverged evolutionary rate.