Gobius xoriguer, a new offshore Mediterranean goby (Gobiidae), and phylogenetic relationships within the genus Gobius

Gobius xoriguer sp. nov., a new ofshore species of goby (Teleostei: Gobiidae: Gobiinae) is described based on three specimens collected in 2010, 2012 and 2018 in the western Mediterranean, off Menorca (Spain), in the Gulf of Lion and off Corsica (France), at 51-104 m depth on coralline algae sea bed. It is easily distinguishable from its Atlantic-Mediterranean congeners by the combination of the following characters: large eyes, similar to 27-28% of head length; anterior nostril with a small triangular process; 14 soft rays on D2, 13 soft rays on A; enlarged first dorsal fin rays (adult males), with third D1 spine the longest, 23-27 % SL; uppermost P fin rays not free from membrane; long V-shape pelvic fins with vestigial frenum; 50-51 scales on LL; head oculoscapular canal with pores sigma, lambda, kappa, omega, alpha, beta, rho, rho 1, rho 2, and preopercular canal with pores gamma, delta, epsilon present; row x1 ending anteriorly behind pore beta; a groove section between pore rho and rho 1; suborbital row d discontinuous with large gap below suborbital rows 3 and 4; rows o separated; seven enlarged orange blotches on body side; white dotes on cheek and opercle on an orange background. With a known maximum size of 64 mm TL, it is among the smaller species of Gobius. Bayesian inference and Maximum likelihood phylogenetic tree topologies based on mitochondrial DNA COI sequences (barcoding region), including most Atlantic-Mediterranean Gobius species, support Gobius gasteveni Miller 1974 as the closest relative to Gobius xoriguer sp. nov. These sister species exhibit a high genetic divergence of 9.5% (uncorrected p-distance).