La sardina monterrey Sardinops sagax (Jenyns, 1842) representa uno de los recursos pesqueros más importantes del país. Los hábitos alimentarios de la sardina (filtro-alimentador) hacen que sea un hospedero adecuado para diferentes helmintos parásitos. Objetivos. El propósito de esta investigación fue determinar la carga helmintológica de la sardina monterrey S. sagax de las costas de Baja California. Métodos. Se analizaron muestras de S. sagax desembarcadas por la flota sardinera del puerto El Sauzal, en Ensenada, Baja California, durante dos temporadas: inviernoprimavera y verano-otoño. Resultados. Se encontraron tres especies de trematodos: Miosaccium ecaude, Parahemiurus merus (= P. noblei) y Bucephalus sp.; dos especies de nematodos: Anisakis sp. y Hysterothylacium sp., así como cestodos pertenecientes a la familia Tetraphyllidea. Durante las dos temporadas de muestreo la prevalencia más alta correspondió a los trematodos (100%). La prevalencia e intensidad de la carga helmintológica fue mayor en la temporada de inviernoprimavera. Conclusiones. Las metacercarias del trematodo Bucephalus sp. representan un riesgo potencial de parasitosis para los atunes, mientras que los nematodos Anisakis sp. e Hysterothylacium sp., además de transmitirse al atún, pueden provocar zoonosis. Estos hallazgos constituyen la primera información parasitológica de la sardina monterrey en México y el primer registro de Bucephalussp. en S. sagax. La información obtenida conforma la línea base para estudios patológicos y epidemiológicos sobre esta especie de importancia comercial, ya que es crucial para la industria pesquera y acuícola.

The aim of the present study is to analyze the synergy of antimicrobial elements, such as Ga, Ag and Cl by incorporating them in ZnO nanorods and measuring their antimicrobial and photocatalytic activity under visible light irradiation for water treatment. AgGa-doped ZnO nanorods and AgGaCl-doped ZnO nanorods on polyethylene substrate were prepared by a simple and fast microwave assisted synthesis. HCl was used in order to lower the pH of the precursor solution and favor Ga and Cl incorporation in the ZnO nanorods. The synthesized undoped and doped ZnO nanorods were analyzed with SEM, EDX, XRD and CL. The photocatalytic properties of the nanorods were evaluated via methylene blue degradation under visible light irradiation. Antimicrobial activity of the nanorods was measured via growth kinetics of Vibrio parahaemolyticus. It was found that AgGaCl-doped ZnO nanorods improve the methylene blue photo-degradation and above all, the antimicrobial activity of the AgGaCl tri-doped ZnO nanorods showed a lethal effect on the bacteria’s growth. This work shows that AgGaCl NRs are an excellent alternative for the development of sustainable water treatment devices and antimicrobial applications.

Totoaba macdonaldi is an endangered species of croaker endemic to the Gulf of California, Mexico. This species has been cultured for the repopulation of wild stocks and commercialization at the Wildlife Management and Conservation Unit for the culture of T. macdonaldi at the Universidad Autónoma de Baja California, Mexico. A mortality episode was observed in 50 day-old juveniles, that coincided with an increase of temperature from 16 to 25.5˚C that affected the aquaculture facility. Histopathological and bacteriological analysis of survivor fishes were conducted to investigate the possible causes of mortality. Gill damage including severe congestion in gill filaments, necrosis, and epithelial dissociation of lamellae were observed. Moreover, epidermal, hypodermic necrosis, as well as diffuse bacterial colonization of the dermis was detected. Severe congestion and hemolysis were detected in the heart’s atrium and hepatic portal vessels. From the skin lesions, eight colonies of bacteria were isolated, these corresponded to four species of genus Vibrio, tentatively identified by partial sequence of the 16S rRNA gene as Vibrio harveyi, V. rotiferianus, V. brasilensis and V. shilonii. From them, V. harveyi corresponded to 4 of the 8 isolates and was found in all moribund fishes. Characteristics of the tissue alterations related with these opportunistic Vibrio spp. suggest an acute mortality event favoured by a temperature increase. This is the first record of the histopathology of T. macdonaldi juveniles that suffered an unusual mortality event under an increase of temperature in cultured conditions associated with Vibrio spp.

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