Hepatoxylon trichiuri (Cestoda: Trypanorhyncha) plerocercoids in cage-reared northern bluefin tuna, Thunnus thynnus (Osteichthyes: Scombridae)
Northern bluefin tuna (Thunnus thynnus) were caught by purse seine boats and brought to a farm for a rearing cycle of 1.5 years. Mortalities occurred in the first weeks of acclimatization at the facility. Parasitological examination revealed plerocercoids of the cestode Hepatoxylon trichiuri embedded in the stomach mucosa. The larvae were found in 28.4% of the fish and the mean abundance was 3.12 per fish. Histopathology revealed disseminated erosion at the site of attachment, atrophy of fundic glands, lymphocytic migration, and hyperplasia of connective tissue in the lamina propria. These symptoms, however, together with the parasite abundance, could not have triggered the mortalities. This is the first record of this parasite in northern bluefin tuna.
HELMINTOS PARÁSITOS DE Dosidicus gigas “POTA” EVISCERADA EN AREQUIPA, PERÚ
El “calamar gigante” o “pota” Dosidicus gigas (D’Orbigny 1835), ha sido catalogado dentro de las especies de mayor importancia en los ecosistemas marinos pelagicos. Se cuantifico la fauna helmintologica parasitaria con enfasis en aquellos de importancia zoonotica y sanitaria de 254 individuos (D. gigas) frescos y eviscerados capturados en aguas oceanicas del Pacifico Sur de Peru, y desembarcados en Puerto Lomas, Arequipa (15o26´ S a 75o03´ L) durante el ano 2009. En cada pota se determino su Longitud Dorsal del Manto (LDM) en cm y su Peso Estandar del Manto (PEM) en kg. Se encontraron cinco taxones larvales de helmintos: Didimozoidea sp. no identificada (Abundancia media de infeccion (AM):0,0039; prevalencia:0,39%), dos cestodos: Hepatoxylon trichiuri (Holten 1802) (AM:0,04; prevalencia:0,78%) y Tentacularia coryphaenae (Bosc 1797) (AM:1,68; prevalencia:56,29%), y dos nematodos Anisakis simplex o Tipo I (Dujardin 1845) (AM:0,23; prevalencia:15,74%), A. physeteris o Tipo II (Baylis 1923) (AM:1,11; prevalencia: 50%). Se encontro el 57% de calamares (D. gigas) infestados por el nematodo zoonotico Anisakis. Los tres parasitos con mayor importancia especifica fueron: T. coryphaenae, A. physeteris y A. simplex. Se encontro una relacion lineal con la LDM del hospedero y la prevalencia media de T. coryphaenae. Se observo una relacion lineal con el PEM y la prevalencia media de A. simplex. Los estimadores no parametricos indicaron que se requiere un incremento en el esfuerzo de colecta y senalaron que deberian encontrarse hasta seis especie helminticas en D. gigas. La comparacion de la LDM entre las potas parasitadas y no parasitadas por A. simplex, A. physeteris y T. coryphaenae no mostro diferencias significativas. Finalmente, se realizo un analisis comparativo de los parasitos de D. gigas entre los anos 1981-1989, 2003-2004, 2008-2009 y 2009
Study of External Parasites Infesting Carcharhinus Melanopterus Fish From The Red Sea In Jeddah, Saudi Arabia
Parasitic diseases are harmful and limiting factors in breeding and rearing ornamental fish industry, such as the Monogenea ( Dactylogyrus sp and Erpocotyletiburonis ) and copepod ( Pandarus sinuatus  and Anchistrotostangi ). The copepod and the monogenean are gill parasites found on the shark; CarcharhinusMelanopterus . The primary purpose of this study was to determine the parasitic infections of sharks in red sea in Jeddah. For this purpose, 19 female C. Melanopterus and 14 male C. Melanopterus were first examined for ectoparasites using wet mount under a light microscope. All male sharks had Monogenea and/or copepod in their gill and only 3 females haven’t infections. Then, we aimed to find a combination of copepod and monogenea infection in C. Melanopterus gills. 50% of male and 42% of female were infected by copepod and monogenea. Our findings revealed that the protozoan infections are very common among sharks. Although, no gross pathology was observed among infected shark, but it is likely that in case of any changes in the environment, then parasitic infections could be harmful.