Host-Parasite Relationship Octopus Tehuelchus - Aggregata Valdessensis in Patagonian Coast, Southwestern Atlantic Ocean

VÁZQUEZ, NURIA; GLASINOVICH, NATUSHA; ORTÍZ, NICOLAS; GESTAL, CAMINO; PONTONES, JULIÁN; GILARDONI, CARMEN; CREMONTE, FLORENCIA

SSRN Electronic Journal

Academic Press Inc

Año: 2023

Histolopathology associated with the apicomplexan Aggregata valdessensis on wildpopulation of Octopus tehuelchus was studied. Moreover, to analyze the impact of theprevalence and infection intensity on the size, sex, maturity stages, condition index andtotal hemocyte counts on wild O. tehuelchus, Generalized Linear Models (GLMs) wereapplied. Kruskal–Wallis (KW) test was used to compare growth parameter (RNA/DNAratios) in infected and no infected octopuses. Lesions including hypertrophy of host celland destruction of the tissue organ architecture as well as the replacement of host tissue byparasites were associated with infection. The infection caused an inflammatory defensiveresponse in form of hemocytic infiltration and encapsulation. Prevalence of apicomplexanincreased with octopus size (GLM, t = 2.68; p = 0.007). Infection intensity was significant higher in males octopus (GLM, t = 2.69; p = 0.009) and decreased at higher temperaturesin both sex (GLM, t = -2.42; p = 0.018). The digestive gland condition index did not significantly vary with infection intensity, and no significant relationship between totalhemocyte counts and coccidian infection was found (Lineal Model, t = 0.46; p = 0.64). Theacid nucleic ratio was significantly lower in octopuses infected by A. valdessensis (KruskalWallis test, H = 4.8; p = 0.02), suggesting a detrimental effect on O. tehuelchus growthcaused by the coccidian.