Garra sp.

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 : 324-325

Garra sp. “ White Nile ”

( Fig. 17 , Tabs II, V)

Material

BMNH 1907.12 .2.1180, 23.7 mm SL, “ Sudan ” [now in the Republic of South Sudan]: White Nile at Kaka, coll. Mr. Loat, 17 Apr. 1901. One specimen apparently missing, as Boulenger (1907: 185) refers to two specimens from this collection .

Diagnosis

Garra sp. “ White Nile ” differs from all other African Garra species, except of G. napata , G. sannarensis and G. geba by having only 2.5 scale rows between lateral line and origin of pelvic fin. It is distinguished from G. geba by the absence of predorsal scales (vs. 5-9) and only 3 scale rows between lateral line and origin of dorsal fin (vs. 4.5- 5.5). From other Garra species of the Main Nile basin, G. sp. “ White Nile ” is distinguished by its long barbels nearly touching each other when folded inwards (vs. not reaching the disc-pad or being hardly perceivable at all); from G. vinciguerrae by the lack of predorsal scales (vs. presence of at least single scales) and a bare naked belly and postpelvic area (vs. scaled belly); from G. napata by cheeks being not visible when viewed from above (vs. visible cheeks) and from G. sannarensis by an asquamate predorsal area that exceeds slightly beyond the dorsal-fin origin (vs. scaleless area terminating at dorsal fin origin) and absence of a sucking disc (vs. clearly developed sucker with free posterior margin).

Description

Based on a single specimen with only 23.7 mm SL in very poor condition ( Fig. 17 ). Measurements are given in table II and V. 37 scales in lateral line, 3 scale rows between lateral line and dorsal-fin origin, 2.5 scale rows between lateral line and pelvic-fin origin. Head and anterior body region cylindrical, laterally posterior body increasingly compressed. Cheeks not visible when viewed from dorsal. Sucking disc not developed and apparently absent or not (yet?) developed ( Fig. 5F ). Rostral flap indicated and slightly fringed, two large and well-developed pairs of maxillary barbels: anterior barbels originates at the end of rostral cap and reach the corner of the mouth gap; posterior barbels originate at corners of the mouth opening and almost touch each other when flexed inwards. Dorsal fin originates at about midway on body; with one small and one large unbranched ray, followed by 7 branched rays. Pectoral fin inserts low on body, with 14 rays. Pelvic fin with one simple and 7 branched rays, fin reaches caudally beyond anus but terminates in front of anal fin. Anal fin with 2 simple and 5 branched rays. Caudal fin 9 principal caudal rays in each lobe and usually with 9 upper and 6 lower procurrent rays. Entire body covered with large scales, chest, belly and postpelvic area without scales; naked predorsal area expands caudally slightly beyond dorsal fin origin.

Colouration. – Pigmentation and colouration patterns in the only available specimen hardly perceivable ( Fig. 17 ): pale brown body colouration, seemingly darker on back and paler on belly and lower half of head. Dark humeral spot behind operculum at beginning of lateral line series; presence or absence of a dark bar on caudal peduncle not detectable. Dark pattern in middle of dorsal fin membrane, but exact extension and shape not traceable; distinct dark spots at base of branched rays.

Distribution

The single species record originates from Kaka (N10.58° E32.15°) at the White Nile ( Fig. 1 ) .

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 17. – Garra sp. “White Nile”, BMNH 1907.12.2.1180, 23.7 mm SL, White Nile at Kaka, 1 Oct. 1905. Scale bar = 10 mm.