Journal of Fish Biology (2017) doi:10.1111/jfb.13484, available online at wileyonlinelibrary.com Population biology of the little gulper shark Centrophorus uyato in Lebanese waters M. Lteif*†‡§, R. Mouawad‖, G. Khalaf*, P. Lenfant†‡¶, B. Seret** and M. Verdoit-Jarraya†‡¶ *Lebanese National Council for Scientifc Research – National Centre for Marine Sciences (CNRS-L/CNSM), Batroun, Lebanon, †Université de Perpignan Via Domitia, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR 5110, 52 Avenue Paul Alduy, 66860 Perpignan, France, ‡CNRS, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR 5110, 52 Avenue Paul Alduy, 66860 Perpignan, France, ‖Lebanese University – Faculty of Sciences II, Lebanon, ¶Centre de Recherche sur les Ecosystèmes Marins (CREM), impasse du solarium, 66420 Port-Barcarès, France and **IchtyoConsult, 6 bis rue du Centre, 91430, Igny, France (Received 8 March 2017, Accepted 11 September 2017) A total of 38 individuals of the heavily exploited little gulper shark Centrophorus uyato were collected from Lebanese coastal waters using bottom longlines and trammel nets of different meshes at depths ranging from 115 to 600 m between May 2013 and February 2014. Their total lengths were between 45 and 94 cm and their total mass was from 870 to 6700 g. The sex ratio was not signifcantly different from 1:1, with 20 males and 18 females, but bathymetric sexual segregation occurred. Catch per net setting (CNS) was used as a relative abundance index to detect spatial distribution; trammel nets showed largest CNS ranging from 4·9 to 5·45 kg per unit effort in the north and south, at depths from 120 to 200 m, during spring and summer. The mass–length relationships demonstrated negative allometric growth (b < 3) (males: M T = 0.3585L T 2·071 , r 2 = 0·94; females: M T = 0.0239L T 2·735 , r 2 = 0·64). The condition factor as well as the gonado-somatic and hepato-somatic indices of C. uyato in the study area were also calculated. The results are discussed in relation to the distribution, growth and reproduction as well as the management of C. uyato. © 2017 The Fisheries Society of the British Isles Key words: by-catch; Centrophoridae; Chondrichthyes; distribution; fsheries management; reproduc- tion. INTRODUCTION The Mediterranean Sea is considered one of the seven Chondrichthyan biodiversity hotspots and one of the three main hotspots where the biodiversity of sharks and rays is seriously threatened (Dulvy et al., 2014). Among the 80 species of cartilaginous fsh known in the Mediterranean Sea (45 sharks, 34 batoids and one chimaera), 71 were assessed in the frame of the International Union for Conservation of Nature (IUCN) red list and >40% (34 species) are threatened and face an elevated risk of extinction §Author to whom correspondence should be addressed. Tel.: +961 3198277; email: myriamlteif@hotmail.com 1 © 2017 The Fisheries Society of the British Isles