Seriolella porosa (Silver warehou) is an important fish resource in the Argentine Sea. No previous studies have been carried out to date on its parasite fauna. The present study aims to (i) identify the digenean trematodes that parasitize Silver warehou, (ii) estimate parasite frequency and abundance, and (iii) establish their relationship with fish size and sex. A total of 100 specimens of S. porosa from San Matías Gulf, Argentina were examined between September and October 2006. Host size and sex were determined. Parasites extracted from the stomach lumen were fixed, conserved in 5% formalin, and stained with Langeron's hydrochloric carmine. The following parameters were also determined: dispersion coefficient, prevalence, intensity, and parasite abundance. Differences in parasitism were assessed using non-parametric tests. Four adult digenean species were found in the stomach, namely Lecithocladium cristatum, Aponurus laguncula, Elytrophalloides oatesi and Gonocerca cf. phycidis. L. cristatum was not only dominant but also the most prevalent and abundant species. None of the digeneans showed interspecific association with each other and therefore they might follow different patterns of colonization (i.e., different intermediate hosts, seasonal and/or spatial distribution of the infective stages). Significant differences were observed among the digeneans analyzed in respect to the sex of the host. Results from this study show that Silver warehou plays a key role as a final host of a significant number of digeneans in the ecosystem. This study is the first step in an attempt to further determine the larval stages in intermediate hosts in San Matías Gulf.
162 SummaryLarvae of tetraphyllidean cestodes have been recorded in several species of marine teleosts. However, little is known on parasite-host interactions. In view of this, the present study aims at i) determining the localization sites of a larval type, belonging to the Scolex group, in the digestive tract mucose; ii) describing the anatomo-pathological features of the larval lesions produced; and iii) evaluating the potential effect of parasite intensity on the body condition of the host. Our findings reveal that parasitic charges were more intense in the second portion of the digestive tract. In the area of contact between the parasite and the epithelium a compressive atrophy of the cells was observed with a marked lowering and disappearance of the epithelial layer. The condition factor of the samples analyzed was significantly affected by infection intensity, thus revealing an adverse effect on the growth and physical condition of the host.
Hasta el momento no se llevaron a cabo estudios sobre aspectos de los ensambles de helmintos de Seriolella porosa. El presente estudio se propone analizar el ensamble de metazoos parásitos de S. porosa y establecer las interrelaciones entre variaciones en la estructura parasitaria y el sexo y tamaño del hospedador. Se examinó un total de 101 especímenes de S. porosa capturados entre septiembre y octubre de 2006 en el Golfo San Matías, Argentina. Trece especies y un total de 3366 parásitos fueron registrados. La especie más prevalente, dominante y abundante fue Lecithocladium cristatum. La riqueza específica fue de 3.2 ± 1.20. La equitatividad mostró una correlación inversa con el número total de parásitos y no reveló diferencias entre sexos. Ninguna de las especies parásitas mostró asociación interespecífica con otras especies del ensamble. La riqueza promedio de la infracomunidad fue significativamente menor que aquella del componente comunitario. La comunidad de helmintos del savorín mostró poca diversidad con varias especies satélites y solo dos especies centrales (core) (Anisakis sp. and L. cristatum). El presente podría constituir la base para identificar stocks poblacionales, empleando parásitos, parademostrar si la población del Golfo San Matías es un conjunto reproductivo que penetra estacionalmente al Golfo en invierno, o si se trata de un stock propio del Golfo y separado física y reproductivamente de los savorines de la Plataforma Continental Argentina.
A pesar de la ubicuidad de Cucullanus spp. en los ecosistemas acuáticos de todo el mundo, su desarrollo embionario y post-embrionario, así como los patrones de transmisión, siguen siendo poco conocidos y, en algunos casos, controvertidos. En el presente estudio se proporcionan datos comparativos y embriológicos de Cucullanus pinnai pinnai (Travassos, Artigas & Pereira, 1928). Los nematodes adultos provenientes de Rhamdia quelen (Quoy & Gaimard, 1824) (Heptapteridae) se describen e ilustran mediante microfotografía electrónica de barrido. Se obtuvieron huevos de hembras grávidas y se siguió el desarrollo embrionario y larvario in vitro. Las etapas L y L se describen e ilustran por primera vez. El 2 3 desarrollo embrionario de C. pinnai pinnai es muy rápido a 20-22°C. En cinco días tiene lugar la eclosión y las L libres permanecen vivas menos de dos semanas. Se plantea la hipótesis de un patrón de transmisión 2 heteroxeno que involucra a R. quelen como hospedador definitivo y Bryconamericus iheringii (Boulenger, 1887) (Characidae) como hospedador intermediario.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.