Discognathus vinciguerrae Boulenger, 1901

Moritz, Timo, Straube, Nicolas & Neumann, Dirk, 2019, The Garra species (Cyprinidae) of the Main Nile basin with description of three new species, Cybium 43 (4), pp. 311-329 : 314-317

Discognathus vinciguerrae Boulenger, 1901

non Garra dembeensis (Rüppell, 1835) after Menon, 1964;

Lévêque and Daget, 1984 non Garra blanfordii ( Boulenger, 1901) after Stiassny and

Getahun, 2007

Material

Syntypes. – BMNH 1907.12.2.1175-1179 (5), 25.0- 26.9 mm SL, Sudan: about 3 miles north of Kermah , coll. Mr. Loat, Apr. 1900. One syntype apparently missing as Boulenger (1907: 185) reports six specimens from this collection .

Other material. – DMM IE/15077 (2), 51.2-57.3 mm SL,

Sudan: Nile at rapids at small island north of Tarag Island close to Takar village , north-east of Merowe (N18.59° E31.97°), coll. T. Moritz, D. Neumann & N. Pöllath, 10 Apr. 2008 ; MRAC 1983-030 -P-0082-0086 (5), 86.9-119.2 mm SL , Egypt: Nile at Elephantine Island , Aswan (N24.08° E32.88°), coll. W. van Neer & R. Lauwers, Sep. 1983 ; MRAC 1984-006 -P-0097 (1), 122.3 mm SL , Egypt: Nile at Elephantine Island , Aswan (N24.08° E32.88°), coll. W. van Neer & R. Lauwers, 26 Feb.-11 Mar. 1984 ; ZSM 39819 (1), 29.4 mm SL , Sudan: Nile at small rapid at right bank of Tarag main island, close to Takar village (N18.58° E31.94°), coll. T. Moritz, D. Neumann & N. Pöllath, 9 Apr. 2008 ; ZSM 39821 (2), 23.0- 24.5 mm SL , Sudan: Nile upstream of Merowe dam at Dar el-Arab village (raising water level and already impoundment conditions) (N18.83° E32.07°), coll. T. Moritz, D. Neumann & N. Pöllath, 12 Apr. 2008 ; ZSM 39822 (2), 32.2-33.2 mm SL, same data as ZSM 39819; ZSM 39823 (3), 35.8-62.8 mm SL; same data as ZSM 39819; ZSM 39824 (2), 15.5-71.4 mm SL , Sudan: Nile at rapids of small island north of Tarag Island close to Takar village , north-east of Merowe (N18.59° E31.97°), coll. T. Moritz, D. Neumann & N. Pöllath, 10 Apr. 2008 ; ZSM 39825 (2), 17.9- 20.6 mm SL; same data as ZSM 39824; ZSM 39827 (4), 49.6-63.7 mm SL; same data as ZSM 39824; ZSM 39828 (8), 18.4-57.7 mm SL , Sudan: Nile at a smaller island close to Tarag Island opposite Takar village , north-east of Merowe (N18.57° E31.96°), coll. T. Moritz, D. Neumann & N. Pöllath, 9 Apr. 2008 .

Diagnosis

Garra vinciguerrae is distinguished from other African garras by its well-developed sucking disc of type C (vs. A or B in G. aethiopica , G. allostoma , G. dembecha , G. dembeensis , G. duobarbis , G. lancrenonensis , G. regressus , G. tana , G. sp. nov. napata and G. sp. nov. sannarensis ), by its partly scaled predorsal area (vs. fully scaled in G. aethiopica , G. blanfordii , G. chebera , G. congoensis , G. hindii , G. ignestii , G. makiensis and G. quadrimaculata ; or vs. predorsal scales absent in G. duobarbis , G. ethelwynnae , G. sp. nov. napata , G. sp. nov. sannarensis , G. sp. nov. jamila and G. sp. White Nile). Garra vinciguerrae is distinguished from G. geba by its scaled postpelvic area (vs. asquamate), from G. ornata by its asquamate belly (vs. scaled), from G. trewavasae by only 3-3.5 scales between lateral line and pelvic fin (vs. 4.5), and from G. waterloti from the upper Niger and upper Senegal rivers by the absence of a marked dark lateral band along the flank (vs. present). Inside the entire Nile basin, overall similar to G. dembeensis and G. blanfordii , but distinguished from G. dembeensis by the scaled postpelvic area (vs. asquamate) and by an increased number of predorsal scales (5-9 vs. 0-4); from G. blanfordii by having a large scaleless predorsal area (vs. fully scaled, corresponding to 15 predorsal scales) and in the densely rior flap (vs. medial enlarged posteriorly pointing flap); pad round (vs. quadrangular); and from G. sp. “White Nile” by the presence of only minute posterior barbels not reaching pad of disc when folded medially (vs. almost reaching each other when flexed inwards).

Description

Based on 5 syntypes, 26

specimens from the 4 th cataract and 6 specimens from the 1 st cataract. A large Garra species that shares the typical body profile of most Garra with only slightly flattened head and moderately elongat-

ed body ( Figs 2-4 ). Maximum cave in specimens of about 60 mm SL and more; first large unbranched ray flanked by one or two anterior smaller simple rays and often by an additional very small ray embedded in soft tissue anterior of dorsal-fin insertion and visible only in X-ray images; unbranched rays followed by 7 branched rays. Pectoral fins inserting ventrally low on body with 2 unbranched and 12-14 branched rays. Pelvic fins with 9 branched rays, surpassing vent, but terminating in front of anal fin base. Contour of anal fin usually straight with 5 branched rays, supported by one large and one smaller simple ray and an additional minute ray in the tissue anterior of the anal fin insertion which is visible only in X-ray images. Caudal fin clearly emarginated with rounded upper and lower lobe. Body covered with large scales. Chest and belly without, postpelvic area with scales; predorsal area partly but not entirely covered with scales ( Fig. 6A ).

Colouration. – In life: head, back and body flanks olivegreenish, towards dorsum slightly darker; lower thirds of flanks and belly whitish. Flank scales with dark posterior margin. Dark vertically elongated blotch at end of caudal peduncle. Iris bright orange. Posterior dorsal corner of the opercle with one prominent red spot, merging with a dark-green blotch on adjacent first scale of lateral-line series. Anal fin hyaline with orange hue, and orange colouration being more prominent in paired fins. Caudal fin membrane hyaline, becoming slight orange in upper and lower margin of fin lobes; membrane near caudal fin base along rays densely covered with melanophores. Dorsal fin hyaline with four dark blotches at the bases of branched rays 3-6 ( Fig. 7A ); anterior distal part with orange hue; caudal margin with few irregular melanophores.

Preserved specimens usually dark brown on flanks and towards dorsal, rarely faint dark band along lateral line visible; lower third of flanks and ventral side pale whitish. First scale of lateral line darker, but not as dark as in G. napata . Dark bar at end of caudal peduncle poorly visible. All fins pale whitish; dark markings at dorsal fin bases visible.

Distribution

Known from the 1 st, 3 rd and 4 th cataract ( Fig. 1 ). Type locality: “a pond in the cataract country about 3 miles north of Kermeh” ( Boulenger, 1901: 160).

Figures

Figure 1. – Records of Garra species from the Main Nile basin (dotted line). Star – Garra vinciguerrae; diamond – G. napata; square – G. jamila; triangle – G. sannarensis; cross – G. sp. “White Nile”; numbers indicate the cataracts of the Nile river.

Figure 2. – Garra vinciguerrae, syntype, BMNH 1907.12.2.1175, 35.7 mm SL, 3 miles north of Kermah, Sudan. Scale bar = 10 mm.

Figure 3. – Garra vinciguerrae, MRAC 84-06-P-97, 122.3 mm SL, Nile at Elephantine Island,Aswan, Egypt. Scale bar = 20 mm.

Figure 4. – Live specimens of Garra vinciguerrae. All from the area of Tarag Island, below 4th cataract, Nile, Sudan. A: ~20 mm SL, 10 Apr. 2008; B: ~38 mm SL, 9 Apr. 2008; C: ~60 mm SL, 9 Apr. 2008.

Figure 6. – Scaled (dark) and unscaled (light grey) areas in dorsal view. A: Garra vinciguerrae; B: G. napata; C: G. jamila; D: G. sannarensis.

Figure 7. – Dorsal fin melanophore pattern. A: Garra vinciguerrae; B: G. napata; C: G. jamila; D: G. sannarensis.