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A charophyte assemblage from lower Holocene sediments in ces,mealti (Izmir Gulf, Turkey) is described and illustrated for the first time here. This assemblage is composed of well-preserved gyrogonites and oospores of Lamprothamnium papulosum, which occur in association with seeds of Ruppia cf. maritima and up to eight ostracod species and 22 benthic foraminiferal taxa. The fossil assemblage was extracted from five clay intervals of the SK-2 borehole. The presence of monospecific assemblages of L. papulosum indicates that very shallow (up to 1 m deep), brackish, alkaline, and oligotrophic waters prevailed in the gulf under strong seasonality (marked cyclical changes in humidity and/or temperature). The dominance of germinated gyrogonites suggests that the water salinity of the lagoon decreased during the humid season, reaching at least 10 parts per thousand. The associated ostracod fauna supports the palaeoenvironmental conditions inferred from the flora. Despite the gulf receiving considerable freshwater input, it remained semiconnected to the sea, as indicated by the diverse foraminifera assemblage. The availability of freshwater in the Izmir Gulf during the early Holocene Climatic Optimum, between-9000 and 5000 years BP, might have played an important role for the first human settlements in the area dating back 5500 years BP. Project TUBITAK, 2214-A International Research Fellowship Program (The Scientific and Technological Research Council of Turkey) [1059B142100601]; Spanish Research Agency (AEI) [PID2020 - 113912 GB -100]; European Regional Development Fund (ERDF) [PID2020 - 113912 GB -100] This study was funded by the project TUBITAK, 2214-A International Research Fellowship Program 1059B142100601 Fellowship Number (The Scientific and Technological Research Council of Turkey) . This work is a contribution of the project IBERINSULA (PID2020 - 113912 GB -100/AEI/10.13039/501100011033) of the Spanish Research Agency (AEI) and the European Regional Development Fund (ERDF) . The authors thank the Yumun Engineering Limited Company who performed the borehole campaigns and provided the studied samples. The editor Dr. Elisabeth Gross and two anonymous reviewers greatly improved the manuscript. The English text was cor- rected by Michael Maudsley (Serveis linguistics , University of Barcelona) .

For aquatic and riparian plants, the important role of fish in seed dispersal is increasingly recognised. While the propensity of seeds to disperse is known to be a function of morphological, physical and chemical traits of the seed, in the case of fish-mediated seed dispersal (ichthyochory), it is largely unknown how seed traits modulate the potential for seed ingestion and their subsequent survival through the gut. Furthermore, which seed traits are important may vary among fish species. To evaluate the role of both seed and fish traits in ichthyochory, we fed seeds of 19 aquatic and riparian plant species to fish with differing feeding mechanisms. Cyprinus carpio (common carp) has a pharyngeal ‘mill’, which it uses physically to crush hard food, while Oreochromis mossambicus (Mozambique tilapia) has only tiny oral and pharyngeal teeth and instead relies more on chemical digestion. A number of seed traits, including hardness, size and shape, were important determinants of the potential of seeds for ichthyochory. Certain traits (e.g. seed dimensions) were more important during ingestion, whereas other traits were more important for seed survival and subsequent germination (e.g. seed hardness, mucilaginous coat). Compared to controls, germination of retrieved seeds in carp was lower in 10 and higher in two plant species, whereas for tilapia, it was lower in seven and higher in three species. Overlap between these plant species was low, indicating clear difference between the fish studied in their potential for seed dispersal. Carp increased in size during the experiment and concomitant decreases in seed survival and retrieval were found, suggesting that body size and the correlated bite force is an important fish trait in ichthyochory. Overall, seed hardness, size and shape appear crucial for the survival of seeds passing through the guts of carp and tilapia. Beyond this general pattern, a greater complexity of trait-performance relationships appeared: different seed traits are involved during each of the stages of ichthyochory. Moreover, the importance of seed traits differed between carp and tilapia, with some traits having interactive and contrasting effects in both fish species. Aquatic plants with floating seeds adapted to hydrochorous dispersal were less likely to be dispersed by tilapia than plants with non-floating seeds, suggesting a dispersal trade-off between ichthyochory and hydrochory. Thus, depending on their seed characteristics, fish may offer an additional dispersal route to aquatic and riparian plants.