Garra napata, Moritz & Straube & Neumann, 2019

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 : 317-319

Garra napata , new species

( Figs 8-9 , Tabs II-III)

Garra sp. nov. “flathead” Neumann et al., 2016

Material

Holotype. – ZSM 47244 (ex ZSM 39815 , # 3 ), 39.9 mm SL, Sudan: Nile : rapids and riffles at small northern island opposite of Tarag main island, close to Takar village, north-east of Merowe (N18.59° E31.97°), coll. T. Moritz, D. Neumann & N. Pöllath, 10 Apr. 2008.

Paratypes. – ZSM 39815 (6 now 3), 26.3-38.5 mm SL, same data as holotype ; DMM IE/15073 (2) (ex ZSM 39815 ), 26.7-38.5 mm SL, same data as holotype ; MRAC 1983-030 - P-00887-0088 (2), 69.7-70.3 mm SL, Egypt: Nile at Elephantine Island , Aswan (N24.08° E32.88°), coll. W. van Neer & R. Lauwers, Sep. 1983 ; ZSM 39814 (3), 25.5-40.8 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 ; ZSM 39816 (2), 18.8-23.8 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 39817 (5), 36.0- 38.2 mm SL, same data as ZSM 39816; ZSM 39818 (6 now 2), 18.3-36.0 mm SL, same data as ZSM 39816; AMNH 267145 (2) (ex ZSM 39818 ), 21.5-26.6 mm SL, same data as ZSM 39816; BMNH 2018.9.3.1-2 (2) (ex ZSM 39818 ), 21.5-29.8 mm SL, same data as ZSM 39816; ZSM 39820 (2), 13.5-21.9 mm SL, same data as ZSM 39814.

Diagnosis

Garra napata differs from all other African Garra species, except G. jamila and G. ethelwynnae , in a scaleless area on the dorsal body area clearly exceeding beyond dorsal fin origin ( Fig. 6B ) and thus in an incomplete count of only 1 to 2.5 (vs. 3 or more) scale rows between the origin of the dorsal fin and lateral line series and dorsal fin. It is distinguished from G. ethelwynnae from the Damas River basin ( Eritrea) by its intermediate [type B] developed disc and only minute free posterior flap (vs. prominent disc [type C] with well-developed posterior flap) and an asquamate postpelvic area (vs. squamate). G. napata is distinguished from G. jamila of the Atbara (Main Nile basin) by its intermediate [type B] developed disc with a very small free posterior flap (vs. prominent disc [type C] with well-developed posterior flap), a smooth upper lip (vs. crenate) and, in live specimens, by an uncoloured anal fin (vs. red anal fin); dark humeral spot large and nearly twice as big as red postopercular spot (vs. equally sized small humeral and postopercular spots); fixed specimens usually display a pronounced lateral band and pale back (vs. dark back strongly and contrasting light belly). It is distinguished from G. vinciguerrae and G. sannarensis by its narrow disc (width much smaller than mouth vs. as large as mouth width), virtually absent lateroposteri- or flap of the disc (vs. clearly developed) ( Fig. 5B ), and a relatively broad head, i.e. cheeks visible when viewed from dorsal (vs. cheeks not visible); from G. vinciguerrae by its prominent dark colour markings in the centre of the dorsal-fin membrane near its base (vs. no such pattern) ( Fig. 6B ); from G. sp. “White Nile” by its visible cheeks when viewed from dorsal (vs. not visible from above) and by its short barbels barely reaching margin of lower-lip pad (vs. almost reaching each other).

Description

Based on holotype ( Fig. 8 ) and 24 paratypes. A small Garra species with a maximum recorded size 70.3 mm SL (84.0 mm TL). Counts and proportional measurements are given in tables II and III. Head and anterior body region dorsoventrally flattened; posterior half of body laterally compressed. Body dorsoventrally compressed, thinner than most other Garra species in the Main Nile. Head relatively flat and broad, cheeks visible when viewed from dorsal. Disc intermediate (type B), with very small lateroposterior flap without papillae; central callus of disc smaller than mouth and usually longer than wide ( Fig. 5B ). Rostral cap poorly developed, its margin being only weakly fringed if fringed at all. Two well-developed pairs of maxillary barbels. Dorsal fin originates midway on body, its distal margin slightly convex or straight with one large and one smaller simple ray, often supported by an additional minute small ray deeply embedded in the anterior dorsal fin tissue and visible only in X-ray images; unbranched rays followed by 7 branched. Pectoral fins inserting ventrally low on body; pelvic fins reaching beyond vent, but ending in front of base of anal fin. Anal fin with one large and one small simple ray, often supported by additional minute rays deeply embedded into the anterior fin tissue and visible only in X-ray images; 5 branched rays, distal fin membrane straight. Caudal fin emarginated, upper and lower lobe rounded. Body covered with large scales, except for chest, belly and postpelvic area; predorsal area naked, asquamate area expands laterally onto body flanks ( Fig. 6B ) consequently reducing the number of scale rows between the dorsal fin origin and lateral line series to 2.5.

Colouration. – Head and flanks in life deeply olive-green, body sides gradually getting darker towards mid-dorsal line, lower third of flanks and belly whitish ( Fig. 9 ). Flank scales with dark anterior centres and light distal part resulting in reticulate pattern on flanks, towards tail additional, usually 7 irregular, vertically merged dark green to blackish blotches. Caudal peduncle with prominent and broad, slightly rectangular marking, contrasting the flank colouration. Iris orange. Prominent red spot at posterior dorsal corner of opercle merges with dark-green humeral spot, nearly twice as large as blotch on the first lateral line series scale. Pectoral, pelvic and anal fins hyaline to slightly orange with few scattered melanophores along fin rays. Caudal fin membrane hyaline, rays bordered by dark grey melanophores in proximal twothirds, often fused to a dark spot at the base of the inner-most caudal rays; distal third of caudal fin membrane slightly orange, border of ventral and dorsal lobes orange. Dorsal-fin base with four prominent dark spots at branched rays 3 to 6; middle of fin membrane with horizontal dark band with very dark to black zone in anterior half ( Fig. 7B ); distal third of dorsal fin membrane orange or slightly orange.

Preserved specimens dark brown on flanks and dorsum; lower third of flanks and ventral side pale whitish. Posterior half of flanks darker; faint dark band along lateral line occa- sionally visible in specimens, the irregular colour pattern on tail faintly recognisable. First scale of lateral line series with dark blotch. Dark bar at end of caudal peduncle and innermost caudal rays with dark spots at insertion. Pectoral pelvic and anal fin whitish-hyaline with single melanophore along rays, dark dorsal fin markings also visible in preserved specimens.

Distribution

Known from the area around Elephantine Island at the 1 st cataract and Tarag Island below the (former) 4 th cataract ( Figs 1 , 10 ).

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 5. – Underside of head show- ing the different types of sucking-discs. A: Garra vinciguerrae; B: G. napa- ta; C: G. sannarensis; D: G. jamila, holotype; E: G. jamila, large speci- men; F: G. sp. “White Nile”. Scale bars = 5 mm.

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.

Figure 8. – Garra napata sp. nov., holotype, ZSM 47244 (ex ZSM 39815#3), 39.9 mm SL, Sudan: Nile: Tarag Island, 10 Apr. 2008. Scale bar = 10 mm.

Figure 9. – Live specimens of Garra napata sp. nov. All from the area of Tarag Island, 4th cataract, Nile, Sudan. A-B: ~38 mm SL, 9 Apr. 2008; C: ~50 mm SL, 10 Apr. 2008.

Figure 10. – Small rapid at right bank of Tarag main island (13 Apr. 2008), type locality of G. napata.