Original scientific paper
https://doi.org/10.2478/cjf-2018-0017
DIET COMPOSITION AND TROPHIC LEVEL OF GREATER FORKBEARD Phycis blennoides (GADIFORM: PHYCIDAE) FROM THE ALGERIAN COAST
Zakia Alioua
orcid.org/0000-0003-4868-5080
; Fisheries laboratory, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene Algiers, Algeria
Soumia Amira
orcid.org/0000-0001-8377-8763
; Fisheries laboratory, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene Algiers, Algeria
Farid Derbal
; Marine Bioresources Laboratory, University Badji-Mokhtar-Annaba, Algeria
Mounira Rachedi
; Fisheries laboratory, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene Algiers, Algeria
Lamia Bahbah
; Fisheries laboratory, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene Algiers, Algeria
Billel Bensari
; Fisheries laboratory, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene Algiers, Algeria
Fatiha Zerouali-Khodja
; Fisheries laboratory, Faculty of Biological Sciences, University of Sciences and Technology Houari Boumediene Algiers, Algeria
Abstract
The diet of the greater forkbeard Phycis blennoides (Brünnich, 1768) of the Algerian coast was studied between December 2013 and June 2015, providing information on its ecology for a better understanding of the feeding strategy. A total of 956 individuals, whose total length (TL) varied between 9.7 and 54.5 cm and weight (W) between 2.80 and 1334.11 g, were examined. The index of relative importance (%IRI), combining the three main descriptors of the presence of different ingested prey (%F, %N, %W), was used to characterize the relative importance of different food taxa. Qualitative and quantitative variations in diet were studied according to sex, size and seasons. The average annual digestive vacuity index (%V) was 5.51. It did not vary between seasons (χ²cal = 5.43, χ²th = 7.82, α = 5%) and size (χ²cal = 2.08, χ²th = 5.99, α = 5%), but was different between male (%V = 4.94) and female (%V= 12.78). Qualitative analysis of stomach contents reveals a fairly diverse range of predation with 1342 preys counted for a total weight of 462.84 g, which corresponds to an average number (AN) and weight (AW) of 3.03 and 1.04 g, respectively. This species feeds on benthic preys, composed mainly of natantia crustaceans (%IRI = 44.84) and teleost fish (%IRI = 2.61) with intraspecific preys (%IRI = 6.15). This cannibalism was frequent in specimens with a TL that exceeds 20 cm; it was even more frequent in females as well as in winter. Significant differences in feeding habits of P. blennoides occurred according to sex, fish size and between seasons. The trophic level (TROPH) was high (3.66 < TROPH < 3.97), corresponding to carnivorous character.
Keywords
Feeding; Phycis blennoides; Cannibalism; Trophic level; Algerian coast
Hrčak ID:
213216
URI
Publication date:
18.12.2018.
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