Merluccius senegalensis Cadenat, 1950

González-Lorenzo, J. Gustavo, Triay-Portella, Raül, González-Jiménez, José F., Martín-Sosa, Pablo, Jiménez, Sebastián & González, José A., 2020, Merluccius polli and M. senegalensis (Merlucciidae) as first records from the Canary Islands (north-eastern Atlantic), with morphology data, Cybium 44 (1), pp. 57-60 : 59

Merluccius senegalensis Cadenat, 1950

Material examined. – TFMCBM-VP/01449 , one adult, 804 mm TL, 756 mm SL, East of Roque del Este, North-East of Lanzarote , 29°16’N -13°20’W, 295 m, 12 Dec. 2004, handline.

Morphology data. – Morphometrics, selected body proportions, meristics and other distinguishing features of the Canary specimen of M. senegalensis studied are shown in Table II, and compared with data from the literature ( Svetovidov, 1986; Cohen et al., 1990; Lloris et al., 2005, 2016). Body proportions, meristic data and other specific features of this specimen agree in all respects with those in the literature (Tab. II). In particular, the morphometric proportion of snout length in %HL is slightly extended upward, while eye diameter and inter-orbital width in %HL are slightly extended downwards (Tab. II). The presently studied material slightly extends the range of upper gill rakers on the first arch (3-4 in lit., this study, 5) (Tab. II). Radiographs corroborate six cervical vertebrae with four ribs on each, which is in agreement with Svetovidov (1986), Cohen et al. (1990) and Lloris et al. (2005) ( Fig. 3 ; Tab. II).

When fresh, the studied specimen exhibited a characteristic olive green blotch (dark at its proximal end) at the base of pectoral fins. A fishing captain informed us that this colour feature was widely used on board the Spanish trawler fleet operating in the region, to separate M. senegalensis from M. polli . Lloris et al. (2005) earlier pointed out the difficulty encountered by the fishing industry to separate the two species within catches. Surprisingly, such a distinguishing chromatic character does not appear in any specialized scientific text.

Remarks. – A benthic to bathypelagic species, ranging from 15 to 1055 m depth, usually at 100-600 m, found close to mud or muddy sand bottoms ( Cohen et al., 1990; Lloris et al., 2005, 2016; Manchih et al., 2018). It is an Eastern Atlantic species, distributed along the Western North Africa shelf and slope, from Cape Cantin, Atlantic Morocco as far as Cape Roxo, the border between Senegal and Guinea-Bissau, including the Cape Verde Islands ( Maurin, 1990; Wirtz et al., 2013), ranging 33°N- 12°N, 19° W-8 °W ( Cohen et al., 1990; Lloris et al., 2005, 2016). This species undergoes seasonal latitudinal migrations ( Martos and Peralta, 1995), moving southwards between October and March during the spawning season ( López Abellán and Ariz Tellería, 1993).

Figures

Figure 3. – Radiographs of M. senegalensis from the Canary Islands (TFMCBM- VP/01449, adult, 804 mm TL). Insert: Detail of five cervical vertebrae.