Contribution to the knowledge on supralittoral macroinvertebrates of the northwestern Black Sea

A checklist of the northwestern Black Sea supralittoral fauna is presented. It includes 18 species: Ophelia bicornis, Namanereis pontica, Cryptorchestia cf. garbinii, Deshayesorchestia deshayesii, Orchestia montagui, Orchestia gammarellus, Orchestia montagui, Armadilloniscus ellipticus, Halophiloscia cf. couchii, Ligia italica, Tylos ponticus, Chthamalus stellatus, Microeuraphia depressa, Thalassomyia frauenfeldi, Donacilla cornea, Myosotella myosotis, Truncatella subcylindrica, and Melarhaphe neritoides. This paper provides distribution maps for this species in the northwestern Black Sea, based on field studies. The changes that occurred in species composition are discussed. The regional IUCN categories are proposed.

Bivalent Metal-Chelating Properties of Harzianic Acid Produced by Trichoderma pleuroticola Associated to the Gastropod Melarhaphe neritoides

Harzianic acid is a secondary metabolite of Trichoderma, structurally belonging to the dienyltetramic acid subgroup of the tetramic acids. Biological activities of harzianic acid are of great interest for its antimicrobial and plant growth-promoting activities, which might be related to its chelating properties. In the present work harzianic acid, isolated from cultures of a strain of Trichoderma pleuroticola associated to the gastropod Melarhaphe neritoides, was studied as a complexant agent of a number of biologically relevant transition metals (i.e., Zn2+, Fe2+, Cu2+, and Mn2+), using UV-VIS, potentiometry, MS and NMR techniques. Our findings show the coordination capacity of harzianic acid toward the above cations through the formation of neutral or charged complexes in a variable ratio depending on the metal and pH conditions.

Morphometric variation in two intertidal littorinid gastropods

Here we investigate spatial variation in shell shape of Littorina saxatilis, an ovoviviparous species, and Melarhaphe neritoides, a species with planktonic eggs and larvae. Populations of both species were sampled in 6 sites located along the west coast of the Iberian Peninsula. Shell shape was studied using landmarkbased morphometric methods. Landmark data was used to estimate individual size and to describe shell shape. Prior to statistical analysis specimens were aligned using Generalised Procrustes Analysis (GPA). Ordinations based on GPA of landmark data and using Principal Components Analysis (PCA), revealed a clear spatial segregation of sites for both species, although this was more evident for L. saxatilis than M. neritoides. Statistical analysis revealed significant multivariate variation in shape among sites and a significant effect of allometry on shape for both species. In contrast to this last result, there was no significant linear relationship between any of the first three PC axes and size in L. saxatilis but highly significant associations between the first and third PC axes and size for M. neritoides. Spatial variation in the shape of both species was primarily related to variation in the height of the apical whorls and in the width of the aperture for L. saxatilis. Further variation in shape was related to the shape of the last whorl in L. saxatilis and shell elongation and a change in aperture shape in M. neritoides.