Physiculus caboverdensis, González & Triay-Portella & Biscoito, 2018

González, José A., Triay-Portella, Raül & Biscoito, Manuel, 2018, A new species of Physiculus (Teleostei: Moridae) from the Cape Verde Islands (Eastern Central Atlantic), Zootaxa 4461 (2), pp. 286-292 : 287-292

Physiculus caboverdensis n. sp.

(Capeverdean codling; PT, Abrótea de Cabo Verde)

Tables 1–2, Figs. 1–4

Material examined (10 specimens, SL 83–168 mm, Cruise “ Camarão 1”, R/ V Prof. Ignacio Lozano, semi-floating shrimp traps, rocky bottom). Holotype: MMF 42537, SL 167 mm, East of Cidade Velha , 15° 14’N, 23° 34’W, St. 14D2, 108 – 111 m, 25 Nov. 2011. Paratypes: BMNH 2013.5 .10.1, SL 142 mm, same collection data as holotype; MMF 43122, SL 165 mm, Ponta Covinha , 15° 09.6’N, 23° 43.8’W, St. 10, 260 – 270 m, 21 Nov. 2011; MMF 43123, SL 153 mm, MMF 43124, SL 168 mm, TFMCBMVP/01955, SL 154 mm, MNHN 2013-0648 , SL 150 mm, Ponta Água Doce , 15° 09’N, 23° 47’ W, St. 4, 220 – 258 m, 19 Nov. 2011; MMF 43127, SL 83 mm, MMF 43128, SL 132 mm, USNM 440407 , SL 144 mm, Ribeira da Barca , 15° 07’N, 23°47’ W, St. 9, 225– 238 m, 20 Nov. 2011. Additional 67 specimens, not included in the type series, were caught and are being studied for its biology.

Diagnosis. A species of Physiculus , as defined by Paulin (1989) and Shcherbachev (1993), with the following combination of characters: teeth in upper jaw in two series, the outer one with large inward-curved canine teeth interspaced with small canine-like teeth, and the inner one a narrow band with small canine-like teeth identical to the smaller teeth on outer row, irregularly distributed; teeth in lower jaw in one series, with large straight canine teeth, interspaced with small canine-like teeth; scales in longitudinal series ca. 111–128; scale rows between base of first dorsal fin and lateral line 8–9; D 11–12, 57–67; A 63–69; P 26–28; V 7; C 25–28; vertebrae: 52–55 ( Tab. 1).

Description. Body moderately elongate, laterally compressed posteriorly; greatest body depth at level of the origin of first dorsal fin, slightly less than four times into SL (17.3%–24.3%); head moderately conical; eye large (21.7%–28.9% HL); snout short (24.1%–28.5% HL), blunt at tip; mouth terminal, slightly oblique, upper jaw reaching to vertical from posterior rim of orbit; jaw teeth unequal ( Fig. 2 ), distributed as above; upper jaw symphyseal separation wide; chin barbel very small (7.0%–9.6% HL); outer gill rakers on first gill arch small, varying from spinous tubercles to small clubs, spinous initially at tips and progressively more spinous towards the angle on lower branch and spinous at tips on upper branch ( Fig. 3 ); abdominal cavity reaching the 15th pterygiophore of anal fin.

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Scales moderately large, ca. 111–128 in longitudinal series; 8–9 scale rows between base of first dorsal fin and lateral line; scales present on head and gular region; no scales penetrating into vertical fin membranes; lateral line starting above upper angle of opercle; continuous tube of lateral line reaching at least to mid second dorsal fin; discontinuous tubes of lateral line reaching caudal peduncle.

First dorsal fin higher than second, 5th ray longest, a very small gap separating first from second dorsal fins; second dorsal fin origin at level of vertical through 6th anal-fin ray; anal fin base slightly larger than second dorsal fin base, both fins not indented, their rear tips rounded; pectoral fins symmetrical, their origin almost at level of vertical through origin of first dorsal fin and extending to below 4th to 6th second-dorsal fin rays; pelvic fins small, the first two rays elongate, reaching at least the 5th anal-fin ray; caudal peduncle narrow (2.1–2.4% SL), caudal fin rounded and well separated from second dorsal and anal fins.

Light organ small, its diameter ranging from 6.8% to 13.3% InV-af and behind interventral line (20.0–26.3% InV-af), distance from posterior margin of light organ to anterior margin of anus 18.2% to 27.8% InV-af.

Otoliths sagitiform. Sulcus acusticus heterosacoidal positioned in the longitudinal line of the otolith with well differentiated tail and ostium. Ostium smaller than the tail, long and elliptical, ending close to the anterior margin. Tail funnel-shaped and slightly convex. Anterior region slightly pointed. Posterior region very sharp, with postrostrum long, narrow and pointed and antipostrostrum short, narrow and pointed. Excisura caudalis with a deep and sharp notch ( Fig. 4 , Table 2).

Vertebrae: 13–16+38–40=52–55.

Colouration. In recently caught specimens, overall body reddish-brown, bluish silvery on belly and golden reflections on cheeks, opercles, and dorsum above lateral line. Fins reddish. Pectorals with dark bluish mark at base, first dorsal fin ray with a dark mark distally, second dorsal and anal fins with dark bluish margins. Interior of mouth pale.

Comparative remarks. Taking into account that Physiculus species have fairly restricted geographical distributions ( Paulin 1989) and that up to the present there are no known species occurring in more than one ocean basin ( Froese & Pauly 2017), P. caboverdensis is only compared with their Atlantic Ocean congeners.

P. caboverdensis can be distinguished from all other nine Atlantic Physiculus species by the dentition, being the only one to have large fang-like teeth, interspaced with smaller canine teeth in both jaws.

In comparison with the other 33 or 32 species from the Indian and Pacific oceans, only Physiculus cynodon Sazonov, 1986 from the Emperor Seamount chain, in the North Pacific, has a similar dentition. However, it differs from this species by several characters, namely, the number of fin rays in first dorsal fin (11–12 vs 9–10), second dorsal fin (57–67 vs 72–79), anal fin (63–69 vs 78–85), pectoral fin (26–28 vs 24–25), the number of scales in longitudinal series (111–128 vs ca. 200) and number of vertebrae (52–55 vs 54–59) ( Sazonov 1986). Moreover, the present species has a shorter abdominal cavity than P. cynodon (extending to the 15th pterygiophore of the anal fin vs 24th to 26th) ( Sazonov 1986).

Distribution. At present, P. caboverdensis is only known from the Cape Verde archipelago, where it has been found off the islands of Santa Luzia, São Vicente, Santiago and Sal, at depths between 104 m and 339 m, over rocky bottoms. Its collection in semi-floating traps, and not on benthic ones, seems to indicate that it is epibenthic.

Etymology. P. caboverdensis is named for the Cape Verde Islands, the type locality of the species.

Figures

FIGURE 1. Physiculus caboverdensis n. sp., holotype, MMF 42537, SL 167 mm, East of Cidade Velha, 108–111 m of depth. Scale bar 10 mm.

FIGURE 2. Upper and lower jaws of Physiculus caboverdensis n.sp., showing distinct unequal teeth.

FIGURE 3. Gill rakers on first gill arch of Physiculus caboverdensis n. sp. Upper insert showing rakers near angle. Lower insert showing rakers 2–4 on lower branch.

FIGURE 4. Inner side of right sagittal otolith of Physiculus caboverdensis n. sp., showing the major anatomical features (D = dorsal margin; P = posterior margin; A = anterior margin; V = ventral margin; sulcus acusticus limited by a discontinuous line). Scale bar 2 mm.