Enteromius niggie, Scheepers & Bragança & Chakona, 2024

Scheepers, Martinus, Bragança, Pedro H. N. & Chakona, Albert, 2024, Naming the other cousin: A new goldie barb (Cyprinidae: Smiliogastrininae) from the northeast escarpment in South Africa, with proposed taxonomic rearrangement of the goldie barb group in southern Africa, Journal of Fish Biology 105 (4), pp. 1137-1150 : 1140-1147

Enteromius niggie sp. nov.

[niggie: ‘n ᶕᶍ i] (g/ch from Afrikaans/Dutch) is pronounced with a hard guttural sound, made at the back of the throat.

urn:lsid:zoobank.org:act:.

(Figures 5 and 6; Table 3).

3.4 | Proposed common names

Southern sidespot barb; Suidelike sykol ghieliemientjie (Afrikaans).

3.5 | Holotype

SAIAB 236359 , field number: NPEJ21-B080, male, 41.10 mm SL, Steelpoort River , Limpopo River system , 24.80238, 30.11740, collected by Hoffman A., May 2021 (Figures 5b and 6b) .

3.6 | Paratypes

SAIAB 236360 , nine unsexed, 33.35–42.21 mm SL, same collector and locality as holotype. SAIAB 186470 , five unsexed, 35.76– 44.36 mm SL, Steelpoort River , Limpopo River system , 24.72907, 30.18468, collected by Palmer R., May 14, 2012 .

3.7 | Additional material

SAIAB 26620, 1 unsexed, 48.00 mm SL, Mohlapitse River, Limpopo River System , 24.04999, 30.03333, collected by J. Engelbrecht, April 1, 1986. SAIAB 27269, 1 unsexed, 39.15 mm SL, Letaba River, Limpopo River system, collected by D. Curle, September 22, 1986. SAIAB 49504, 6 unsexed, 35.40–45.10 mm SL, tributary of the Levuvhu River, Limpopo River system, 23.06667, 30.25000, collected by M. Angliss, April 6, 1995. SAIAB 61031, 20 unsexed, 20.00– 39.10 mm SL, Mutale River, Limpopo River system, 22.73444, 30.65861, collected by R. Bills, D. Naran, B. Van der Waal, November 13, 1999. SAIAB 61044, 1 unsexed, 28.10 mm SL, Mutale River, Limpopo River system, 22.70000, 30.64305, collected by R. Bills, D. Naran, B. Van der Waal, 13 November 1999. SAIAB 63443, 4 unsexed, 40.70–48.40 mm SL, Wyliespoort, tributary of Mutamba River, Limpopo River system, 22.91670, 29.92811, collected by J. Engelbrecht, September 20, 2000. SAIAB 190517, 44 unsexed, 27.50–41.2 mm SL, Orighstad River, Limpopo River system, 24.89027, 30.58833, collected by E. Swartz, L. da Costa, October 22, 2005. SAIAB 190556, 10 unsexed, 20.60–35.70 mm SL, Sterkspruit River, Limpopo River system, 25.156944, 30.558611, collected by E. Swartz, L. da Costa, October 23, 2005. SAIAB 203320, 1 unsexed, 31.00 mm SL, Thabina River, Limpopo River system, 24.02706, 30.18103, collected by A. Chakona, L. Dlamini, March 25, 2016. SAIAB 76348, 29 unsexed, 27.3–40.7 mm SL, Buffelskloofspruit, tributary of Crocodile River, Incomati River system, 25.40833, 30.46917, collected by R. Bills, J. Engelbrecht, May 19, 2005. SAIAB 27262, 2 unsexed, 33.00– 40.12 mm SL, Mlumati River, Incomati River system, 25.79999, 31.10000, collected by D. Curle, July 29, 1986. SAIAB 70742, 3 unsexed, 34.70–57.10 mm SL, Houtbosloop, tributary of Crocodile River, Incomati River system, 25.42222, 30.74333, collected by R. Boycott, R. Bills, J. Engelbrecht, April 29, 2003. SAIAB 67330, 1 unsexed, 33.50 mm SL, tributary of Mkhondvo River, Maputo River system, 26.96861, 31.02139, collected by J. Msibi, M. Fakudze, R. Boycott, N. Khumalo, November 6, 2002. SAIAB 76071, 1 unsexed, 27 mm SL, Besterspruit, Mfolozi River system, 27.75056, 30.83222, collected by B. Grant, August 6, 2005. SAIAB 76077, 3 unsexed, 35.00–45.00 mm SL, tributary of Lenjane River, Mfolozi River system, 27.90083, 31.07472, collected by B. Grant, June 8, 2005.

3.8 | Diagnosis

E. niggie sp. nov. belongs to the goldie barb group in southern Africa, which is characterized by species with a soft primary dorsal-fin ray, a relatively short compact body (< 70 mm SL), the presence of two pairs of well-developed barbels, 24–30 lateral line scales, and a bright golden breeding colouration in males. Along with E. niggie the goldie barb group includes the species E. pallidus (Smith 1841) , E. brevipinnis (Jubb 1966) , E. neefi s.s. ( Greenwood, 1962), E. thamalakanensis (Fowler 1935) , E. greenwoodi ( Poll, 1967) , E. lineomaculatus “ Malawi ” (Boulenger 1903), and E. viviparus (Weber 1897) . E. niggie and E. neefi can be readily distinguished from all the aforementioned species by the presence of distinctive pigmentation along the margins of flank scales that are expressed as wavy parallel lines (Figure 4a,b). Further, E. niggie can be distinguished from E. neefi by the lack of wavy parallel lines below the lateral line (Figure 4c) and by the lack of dark bold and rounded spots on the dorsal midline of the body (Figure 4d).

3.9 | Description

Proportional measurements and meristic characters are presented in Table 3.

Body fusiform, moderately compressed laterally. Dorsal profile convex from tip of snout to origin of dorsal fin; body depth greatest between dorsal-fin and pelvic-fin origins, tapering from posterior margin of dorsal-fin base to base of caudal fin. Ventral profile slightly concave from tip of snout to anal-fin origin, slightly convex from posterior end of anal-fin base to base of caudal fin.

Head relatively small, head length equal to body depth. Eye relatively large and round, located dorsolaterally, closer to tip of snout than distal margin of operculum. Snout slightly rounded, shorter than post-orbital length; equal to or less than eye diameter; nuptial tubercles absent. Mouth inferior with two pairs of barbels; rostral (anterior) barbels relatively long, extending past the anterior end of eye, length similar to eye diameter; maxillary (posterior) barbels 2.0 times longer than rostral barbels, reaching posterior edge of eye.

Dorsal fin with three unbranched and eight branched rays, last unbranched ray flexible; distal margin almost straight; origin centered vertically with origin of pelvic fins. Pectoral fin with 1 unbranched and 11 branched rays; posterior edge gently rounded, not reaching pelvic-fin origin. Pelvic fin with 1 unbranched and 7 branched rays; posterior edge gently rounded, almost reaching anus; origin closer to anal-fin origin than pectoral-fin origin. Anal fin with three unbranched and five branched rays; distal margin almost straight; origin inserted midway between origin of pelvic fin and base of caudal fin. Caudal fin bifurcate; with one unbranched ray and eight branched rays on each lobe.

Scales moderately large, radiately striated. Lateral line complete, with 27–30 (mode 28) perforated scales in lateral scale series; 5 scale rows between dorsal-fin origin and lateral line; 3 scale rows between pelvic-fin origin and lateral line; 3 scale rows between lateral line and anal-fin origin; 12 circumpeduncular scale rows; 11–12 (mode 12) predorsal scale rows.

3.10 | Colouration

Alcohol preserved colouration (Figure 5). Dorsal and upper half of flank grayish brown, whitish below lateral line scales onto abdomen. Characteristic markings more apparent upon preservation and include a dark spot at the bases of the anal and caudal fins, variable number of rounded dark spots, not exceeding size of single scale along the midline in some specimens. Dark background pigmentation band running along the mid-lateral flank from caudal fin toward but not reaching the head. Wavy parallel lines along scale margins of flank, darker above lateral line to dorsal fin, not present below the lateral line scales. Dorsal portion of head dark gray. Preoperculum off-white. Operculum off-white with small scattered pigmentation markings. Fins uniform white.

Live colouration (Figure 6). Body olive green on dorsal surface and upper flanks, gold around the midline and silver toward and on the belly. Males turn bright golden during breeding season. Characteristic spots on flank inconspicuous. Three wavy parallel lines visible on dorsal surface extending from nape to caudal fin. Dorsal surface of head olive green, preoperculum silver, operculum iridescent gold. Fins are pale olive.

3.11 | Distribution

E. niggie is known from escarpment streams of northeastern South Africa and Eswatini, notably in the headwaters of the Limpopo, Incomati, Maputo, and Mfolozi River systems (Figure 7).

3.12 | Etymology

When describing the species E. neefi, Greenwood (1962) used the Afrikaans word neef, which means “male cousin,” a humorous acknowledgment to Graham Bell-Cross (1927–1998) who collected the types of E. neefi and often called Greenwood by the Afrikaans word oom which means “uncle” (Paul Skelton, personal communication). Therefore, in keeping with Afrikaans familial terms, the use of nig [ ‘n ᶕᶍ] to name the new species, which means “female cousin,” is a symbolic representation of the historical association between these two species, which were considered to represent disjunct populations of the same species.

3.13 | Conservation

The southern sidespot barb was listed as “near threatened” in the most recent IUCN assessment ( Roux & Hoffman, 2017). Threats to the survival of this species are mainly associated with farming and logging activities and the presence of alien predatory fish. Agricultural and timber production cause habitat degradation through a combination of water regulation and extraction, which results in sedimentation. Pollution resulting from these industries further increases habitat degradation. Alien predatory fish, specifically largemouth bass Micropterus salmoides (Lacepède 1802) , and to some extent trout Oncorhynchus mykiss (Walbaum 1792) , are present in much of the catchments within the distribution range of E. niggie . Studies will be required to assess the viability of constructing barriers, which could establish refugia where habitat degradation and the presence of alien predators are limited.