Anguilla anguilla

• Main Authors: Derbal, Farid, Hamdi, Sandra, Rouag-Laouira, Lydia, Chaoui, Lamya, Kara, Mohamed Hichem
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2022
• Subjects: Biodiversity; Taxonomy; Animalia; Chordata; Anguilliformes; Anguillidae; Anguilla; Anguilla anguilla
• Online Access: https://doi.org/10.5281/zenodo.10904648; http://treatment.plazi.org/id/1F4B8786B437FFC6D2CC0AD1FB60FCF0

RESULTS Figure 2 shows the evolution of the digestive vacuity of A. anguilla from Mellah lagoon and Wadi El Kebir, according to sampling seasons and silvering stage. The seasonal maximum and minimum values of the coefficient of digestive vacuity are higher in Mellah lagoon (72.2% and 31.3%) than in Wadi El Kebir (56.1% and 25.8%), with respective annual averages of 53.1% and 42.9%. Statistical analysis showed the existence of seasonal changes in the digestive vacuity in both sites (χ2 ML = 71.014; χ2 WEK = 37.803; P = 0.000). The digestive vacuity in yellow and intermediary eels are less than 50% while those of silver eels is almost 90% in Mellah lagoon and null in Wadi El-Kebir. In these two sites, digestive vacuity is significantly different between the three silvering stages (χ2 ML = 33.309, P = 0.000; χ2 WEK = 7.907, P = 0.019). Tables I and II summarize the composition of the diet of A. anguilla and the classification of taxa ingested in Mellah lagoon and Wadi El Kebir, respectively. Qualitative analysis of digestive contents shows poor diet diversity in both sites. In Mellah lagoon, A. anguilla feeds mainly on arthropods, bony fish, molluscs and macrophytes (Tab. I). According to IRI, arthropods are preferred foods (IRI = 89.98%), particularly decapod macrurans (IRI = 58.78%). Bony fish are secondary favourite preys (IRI = 9.59%) while shellfish and macrophytes were ingested accidentally (IRI <0.5%). Preys identified belong to 11 species attached to the following phylums: Arthropoda ( Palaemon adspersus , Penaeus kerathurus , Carcinus aestuarii , Microdeutopus gryllotalpa ), Chordata ( Aphanius fasciatus , Atherina lagunae , Gobius niger ), Mollusca ( Abra ovata , Cardium glaucum , Mytilus galloprovincialis ) and Macrophyta ( Ruppia sp.). We recognized a total of 462 preys for a total weight of 633 g, which represents approximately 1.6 preys for a weight of 2.16 g per digestive tract. In Wadi El Kebir, molluscs and nematods und. are only accidental preys in the eels feeding (Tab. II). Decapods ...