No abstract

It is well known that parameters relating to physical condition and reproduction of fish provide essential data for estimating the productivity of exploited populations, as is the case with the European hake (Merluccius merluccius) in the northwestern Mediterranean Sea. Although parasitism might affect these parameters, research in this area is very scarce (and in the case of the Mediterranean almost non-existent). This study evaluates for the first time the potential link between parasitism, condition and reproduction of the European hake. Indicators of fish energy reserves (total lipid content in liver and gonads) and reproductive capacity (fecundity, egg quality and atresia) were evaluated, as were the prevalence and intensity of infection by metazoan parasites. The results indicate that the impact of anisakid nematodes is mostly negative and occurs mainly when hake are allocating their energy reserves to gonadal development. Although the results reveal a link between parasitism, condition and reproduction, we concluded that the northwestern Mediterranean hake population is in equilibrium with its metazoan parasites, which are not causing severe impairment to their physical condition or reproductive capacity.

SUMMARY: Scorpaena notata (Teleostei: Scorpaenidae) is an oviparous species with external fertilisation that shows some unusual features in its gonadal morphology and gametogenesis. In this work we analyse the annual reproductive cycle and the fecundity of this species by studying the monthly histological changes in the gonads and of various indices related to reproduction. Sexual dimorphism does not occur in the population we studied, which is clearly dominated by males. Multiple spawning takes place between July and October, consisting of between 6,000 and 33,000 eggs per female, each of about 500 µm in diameter. The fecundity of the species is determined by the size and weight of the individuals.Keywords: scorpionfish, reproduction, annual cycle, fecundity.RESUMEN: CICLO REPRODUCTIVO ANUAL Y FECUNDIDAD DE SCORPAENA NOTATA (TELEOSTEI: SCORPAENIDAE). -Scorpaena notata (Teleostei: Scorpaenidae) es una especie ovípara de fertilización externa que presenta algunas características peculiares en su morfología gonadal y gametogénesis. En este trabajo se analiza el ciclo reproductivo anual y la fecundidad de dicha especie, mediante el estudio de los cambios histológicos mensuales que muestran las gónadas a lo largo del ciclo anual así como de diversos índices relacionados con la reproducción. La población analizada no presenta dimorfismo sexual, aunque el número de machos es muy superior al de hembras. La puesta múltiple ocurre entre los meses de Julio y Octubre y consiste de entre 6000 y 33000 huevos por hembra, de unos 500 µm de diámetro. La fecundidad de la especie viene determinada por el tamaño y el peso de los especimenes.Palabras clave: escórpora, reproducción, ciclo anual, fecundidad.

Cyclolipopeptides derived from the antimicrobial peptide c(Lys-Lys-Leu-Lys-Lys-Phe-Lys-Lys-Leu-Gln) (BPC194) were prepared on solid-phase and screened against four plant pathogens. The incorporation at Lys5 of fatty acids of 4 to 9 carbon atoms led to active cyclolipopeptides. The influence on the antimicrobial activity of the Lys residue that is derivatized was also evaluated. In general, acylation of Lys1, Lys2 or Lys5 rendered the sequences with the highest activity. Incorporation of a D-amino acid maintained the antimicrobial activity while significantly reduced the hemolysis. Replacement of Phe with a His also yielded cyclolipopeptides with low hemolytic activity. Derivatives exhibiting low phytotoxicity in tobacco leaves were also found. Interestingly, sequences with or without significant activity against phytopathogenic bacteria and fungi, but with differential hemolysis and phytotoxicity were identified. Therefore, this study represents an approach to the development of bioactive peptides with selective activity against microbial, plant and animal cell targets. These selective cyclolipopeptides are candidates useful not only to combat plant pathogens but also to be applied in other fields.

Cyclic peptidotriazoles derived from the antimicrobial cyclic peptide c(Lys‐Lys‐Leu‐Lys‐Lys‐Phe‐Lys‐Lys‐Leu‐Gln) (BPC194) were prepared by incorporating a triazolyl amino acid at the 3‐position. The synthesis was accomplished on solid‐phase and involved as the key step a copper‐catalyzed cycloaddition reaction between a resin‐bound alkyne or a resin‐bound azide and a range of azides or alkynes in solution, respectively. This methodology was also applied to the synthesis of a conjugated peptide containing a cyclic and a linear peptidyl sequence linked through a triazolyl ring. Cyclic peptidotriazoles were obtained in excellent purities starting either from an alkynyl or an azido peptidyl resin. These compounds were screened in vitro for their growth inhibition of bacterial phytopathogens and for their cytotoxic effects on eukaryotic cells. Peptide sequences with high antibacterial activity and low hemolysis were identified, constituting good candidates for the design of new antimicrobial agents.