2019. Hidden diversity under morphology-based identifications of widespread invasive species: the case of the 'well-known' hydromedusa Craspedacusta sowerbii Lankester 1880. Animal Biodiversity and Conservation, Doi: https://doi. AbstractHidden diversity under morphology-based identifications of widespread invasive species: the case of the 'wellknown' hydromedusa Craspedacusta sowerbii Lankester 1880. A relatively scarce number of morphological features available for delimiting closely related species and an increasingly worrisome scenario on Global Climate Change causing the rapid dispersion of invasive alien species can lead to the rapid spread of reports of a given species around the world. Craspedacusta sowerbii Lankester, 1880 is considered the most widespread freshwater jellyfish species and has been reported in numerous locations on all continents except Antarctica. Recently, a few medusae attributed to C. sowerbii were collected from a water reservoir (Bin El Ouidan) in Morocco, this being the first confirmed record of the species from North Africa. The morphology of these newly collected specimens agrees well with previous descriptions, but mitochondrial (Cox1 and 16S) and nuclear ITS (ITS1-5,8S-ITS2) molecular data lead to a discussion of a more complex general view concerning the number of species, synonyms and nomenclatural problems hidden behind the reports of Craspedacusta sowerbii. ResumenLa diversidad oculta en las identificaciones basadas en la morfología de especies invasoras de amplia distribución: el caso de la "bien conocida" hidromedusa Craspedacusta sowerbii Lankester 1880. El número relativamente escaso de características morfológicas utilizadas para delimitar especies estrechamente relacionadas y el panorama cada vez más preocupante en el que el cambio climático global provoca la rápida dispersión de especies exóticas invasoras pueden conducir a la difusión precipitada por todo el mundo de informes sobre una especie determinada. Craspedacusta sowerbii Lankester, 1880, que se considera la especie de medusa de agua dulce más extendida, ha sido observada en numerosos lugares en todos los continentes, excepto en la Antártida. Recientemente, se recogieron algunas medusas atribuidas a C. sowerbii en un embalse artificial (Bin El Ouidan) en Marruecos, que representaron el primer registro confirmado de la especie en el norte de África. La morfología de estos especímenes recién recolectados concuerda con las descripciones anteriores, pero los datos moleculares mitocondriales (Cox1 y 16S) y nucleares ITS (ITS1-5,8S-ITS2) suscitan un debate general más complejo con respecto al número de especies, las sinonimias y los problemas nomenclaturales ocultos tras los informes de Craspedacusta sowerbii.Hidden diversity under morphology-based identifications of widespread invasive species: the case of the 'well-known' hydromedusa Craspedacusta sowerbii Lankester 1880

This work describes the first isolation of Streptococcus iniae in red porgy, Pagrus pagrus (L.), and the first European isolation of this pathogen in gilthead seabream, Sparus aurata (L.). In both farmed fish species, infection resulted in lethargy, anorexia, abnormal swimming, exophthalmia and sudden death, with mortality rates of over 25% in red porgy and 10% in gilthead seabream. Beta-haemolytic Gram-positive cocci, catalase negative and oxidase negative, were isolated in pure culture from internal organs. Conventional and rapid identification systems, and 16S rRNA gene partial sequencing were used to identify the causative agent of the natural disease. LD50 trials were carried out to show the virulence of this isolated strain in these species, with values of 1.7 × 104 CFU per fish in red porgy and 1.32 × 105 CFU per fish in gilthead seabream. The most prominent lesions were meningoencephalitis and multifocal infiltration of macrophage cells in the kidney and spleen.

No abstract

No abstract

No abstract