A 180‐d trial was done to evaluate the effect of stocking different ratios of Nile Tilapia Oreochromis niloticus, Striped Mullet Mugil cephalus, and Thinlip Grey Mullet Liza ramada on production and economic return in brackish‐water ponds. The trial was conducted in twelve 3,000‐m2 earthen ponds with four treatments (3 ponds/treatment): Nile Tilapia alone (100% Nile Tilapia, monoculture group [MG]); 75% Nile Tilapia and 25% Thinlip Grey Mullet (polyculture group 1 [PG1]); 75% Nile Tilapia, 12.5% Thinlip Grey Mullet, and 12.5% Striped Mullet (PG2); and 75% Nile Tilapia and 25% Striped Mullet (PG3). Fish were fed a commercial diet containing 25% crude protein twice per day. The efficiency of feed utilization was determined in terms of feed conversion ratio (FCR; feed intake/weight gain). Polyculture group 3 had the best FCR, whereas the FCR results did not differ significantly among the MG, PG1, and PG2 treatments. In addition, PG3 had the highest total yield (3,350.3 kg/pond), followed in descending order by PG2 (3,234.4 kg/pond), PG1 (3,078.4 kg/pond), and MG (2,856.3 kg/pond). The PG3 treatment achieved the highest net financial return, followed by PG2, PG1, and MG. This study indicates that tilapia–mullet polyculture may improve the efficiency with which natural food resources are used within the system, resulting in better environmental quality, system sustainability, feed utilization, and net financial return.

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Objective: Our study aims to analyze the epidemiological, clinical, radiological, and etiological aspects of this disease. Methods: We reviewed data from patients who consulted the same seigneur for hearing loss and in whom the otoscopic examination was normal with a conductive hearing loss objectively confirmed on tonal audiometry, for a period of one year (from October 2018 to October 2019). Epidemiological, clinical and paraclinical data were collected and recorded onfarm records. Results: The average age is 36 years. The M/F sex ratio was 1.5 in favor of the men. None of our patients reported a personal otologic history. Three patients reported a notion of head trauma and a similar case in the family was found in four patients. Hearing loss is the most frequent reason for consultation. Otoscopic examination shows a normal tympanic membrane without perforation in all patients. CT scan of the temporal bone was performed in all patients (100%); it was normal in 4 cases (17%), which required surgical exploration. However, he showed images of otosclerosis in 15 cases (65%), an image of congenital cholesteatoma in a single patient, tympanic glomus in a single patient, an incudo-malleolar dislocation in a single patient (4.5%), and an incudo-stapedial dislocation in a single patient (4.5%). Conclusion: Conductive hearing loss (CHL) is a diagnostic challenge for the physician that requires a schematic approach. The diagnosis is based on a combination of clinical and paraclinical arguments.