Glossogobius hanisii, Zarei & Sithole & Schliewen & Bills & Chakona, 2025

Zarei, Fatah, Sithole, Yonela, Schliewen, Ulrich, Bills, Roger & Chakona, Albert, 2025, Integrative systematics of the taxonomically complex gobiid genus Glossogobius Gill, 1859 (Teleostei: Gobiidae) from the south-western Indian Ocean, with a description of a new species, Zoological Journal of the Linnean Society 203 (4) : -

Glossogobius hanisii sp. nov. Zarei, Chakona & Schliewen

( Figs 8F–J, 12–14)

Glossogobius callidus (non Smith)—Tweddle 2007: 89; Marshall 2010: 266; Maake et al. 2013 in part (Lineage 2); Fricke et al. 2018: 331 (listed).

Holotype: SAIAB 246227 , male, 78.2 mm SL, Lake Shengeza , South Africa, –27.025416, 32.7827, collected by P. Maake, E. R. Swartz, and B. Kramer, 26 October 2009 (GenBank: COI: PQ761175; Cytb: PQ768043 ).

Paratypes (N = 12): SAIAB 88624 , 12 specimens , 41.5– 72.2 mm SL, same locality information and collectors as holotype (GenBank: COI: PQ761174, PQ761176 ) .

Additional materials included in the description and analyses (N = 29): SAIAB 67656 , 2 males , 50.7–54.5 mm SL, Mussapa River near Zomba, Buzi System, Mozambique, –19.92611122, 33.3411102295, collected by R. Bills, S. Chimela , and A. Chivindzi, 27 September 2002 ; SAIAB 67668 , 1 male , 34.2 mm SL, Dombe Pontoon , Lucite River, Buzi System, Mozambique, –19.97750091, 33.3927764893, collected by R. Bills, S. Chimela , and A. Chivindzi, 28 September 2002 (GenBank: COI: PQ761181 ) ; SAIAB 78703 , 4 males, 1 female , Groot Letaba River at bridge near Letsitele , Groot Letaba River, Limpopo System, South Africa, –23.68583, 30.61138, collected by R. Bills , L. da Costa, and J. Matlala, 21 September 2006 (GenBank: COI: PQ761179 ) ; SAIAB 82223 , 1 specimen , 60 mm SL, Dunbrody 3 Wite confluence, Sundays River, South Africa, –33.469016, 25.547716, 5 December 2008 (GenBank: PQ761158 ) ; SAIAB 97295 , 1 male , 61.9 mm SL, Tete near Mbenga , Muarazi, Zambezi, Mozambique, –16.3075, 33.73388889, collected by R. Bills and W. Aken, 22 August 2010 (GenBank: COI: PQ761182 ) ; SAIAB 97550 , 1 female , 72.5 mm SL, North Ambinanibe Lagoon , Anosy, Madagascar, –25.06203, 46.92775, collected by P.C. Heemstra, 4 May 2010 (GenBank: COI: PQ761183; Cytb: PQ768044 ) ; SAIAB 98235 , 2 males , 33.9–80.7 mm SL, Olifants gorge, Letaba, Olifants, Limpopo, South Africa, –23.990361, 31.82580556, collected by R. Bills , 21 October 2010 (GenBank: COI: PQ761178 ) ; SAIAB 190678 , 5 males , 22.0– 67.7 mm SL, Pan Mbukwini , Mofolozi, St Lucia, South Africa, –28.38561, 32.038527 , R. Bills and M. Riddin, 26 May 2013 (GenBank: COI: PQ761171 ) ; SAIAB 203852 , 1 male , 80.7mm SL, Antholista , Sabie, Nkomati, South Africa, -24.967027, 31.75005, collected by R. Bills, P.H. Skelton , V. Bills, and R. Peterson , 25 August 2016 (GenBank: COI: PQ761177 ) ; SAIAB 210318 , 1 male, 2 females , 27.0–38.3, Muzi Pan in eNhlangano, Mkuze, KZN, South Africa, –27.6454, 32.40061, collected by A. Chakona, N. Mazungula, and B. Motshegoa, 5 September 2015 (GenBank: COI: PQ761172 ) ; SAIAB 210324 , 1 male , 40.5 mm SL, Msenyeni Pan , Phongola, KZN, South Africa, –27.2178, 32.2067, collected by A. Chakona, N. Mazungula, and B. Motshegoa, 6 September 2015 (GenBank: COI: PQ761173 ) ; SAIAB 235956 , 3 females , 40.0– 41.8 mm SL, small stream on the road to Lower Mdloti , Mdloti, South Africa, –29.63893312, 31.10085619, M. Magoro, L. Mofu, A. Chakona, and W. Kadye, 29 November 2022 (GenBank: COI: PQ761170 ) ; SAIAB 236055 , 1 female , 32.7 mm SL, Noordgrens Landgoed , Limpopo River, South Africa, –22.15816219, 29.60671247, collected by A. Chakona and W. Kadye, 27 January 2023 (GenBank: COI: PQ761180 ) ; SAIAB 246100 , 4 males , 56.9–89.3 mm SL, Mpophomeni River , Eswatini, collected by G . R. Ithala , 14 July 2010 .

Additional materials not included in the description and analyses but eoamined and confirmed morphologically to map the overall geographic range of the species: SAIAB 43359 , 4 specimens, 27.4–35.2 mm SL, Pinda Island , Mozambique, –14.21666622, 40.7666664124, collected by J.L.B. Smith and M. Smith, 20 September 1956 ; SAIAB 44597 , 1 specimen, 17.0 mm SL, Marico Oog , Limpopo System, South Africa, –25.79166603, 26.3666667938, collected by E. Skelton and V. Twentyman-Jones , March 1994 ; SAIAB 55894 , 1 specimen, 43.4 mm SL, Murugulu River , Moebase System, Mozambique, –16.88689994, 38.6018981934, collected by R. Bills , 20 July 1997 ; SAIAB 60745 , 2 specimens, 45.1–51.5 mm SL, upstream of Marromeu , Zambezi River, Zambezi System, Mozambique, –18.28083419, 35.6105537415, collected by R. Bills, N. Loureiro , and P. Yose, 28 July 1999 ; SAIAB 61480 , 12 specimens, 25.6–57.7 mm SL, sugar factory jety, Zambezi River , Zambezi System, Mozambique, –18.28583335, 35.9480552673, collected by R. Bills, N. Louriero , and P. Yose, 11 August 1999 ; SAIAB 68058 , 3 specimens, 48.6–61.5 mm SL, Upstream from Namakgale , Selati River, Olifants System, South Africa, –23.98166656, 31.0236110687, collected by J. Rall, 10 September 2001 ; SAIAB 70123 , 12 specimens, 20.6–37.4 mm SL, Lavumisa , Jozini Dam, Phongolo System, Swaziland, –27.31694412, 31.9297218323, collected by R. C. Boycot, J. Msibi, M. Fakudze, and N. Khumalo, 2 April 2003 ; SAIAB 81932 , 3 specimens, 45–65 mm SL, Amanzi Farm , Coega River, South Africa, –33.7138, 25.52194, collected by A.H. Bok, 26 May 2008 ; SAIAB 82790 , 1 specimen, 41.7 mm SL, Mangoro River at Pontoon crossing near coast, Nosivolo , Mangoro River, Mangoro System, Madagascar, –19.947, 48.694, collected by R. Bills and T. Raminosoa , 30 May 2007 ; SAIAB 83472 , 8 specimens, 32–50 mm SL, Mapanda uncua dam site, about 60 km upstream of Tete, Zambezi River, Mozambique, –15.795, 33.155, collected by B.E. Marshall, February 2001 ; SAIAB 83609 , 2 specimens, 56.0– 57.8 mm SL, Zotsha River Estuary, South Africa, –30.78099, 30.42329, collected by H.K. Larson, 19 November 2005 ; SAIAB 88759 , 1 specimen 46 mm SL, below the confluence of the Moatize with the Revuboe rivers, Revuboe, Mozambique, –16.10214, 33.68349, collected by W. Aken, 23 September 2008 ; SAIAB 120312 , 4 specimens, 31–81 mm SL, Lower Lundi , Zimbabwe, –21.416, 32.3, collected by R.A. Jubb , 15 May 1958 ; SAIAB 121056 , 27 specimens, 28–55 mm SL, Beitbridge dam, Limpopo, Zimbabwe, –22.25, 29.96, collected by B.G. Donnelly, 25 January 1972 ; SAIAB 123855 , 2 specimens, 57–73 mm SL, Mutale and Levuvhe River junction, Levuvhe, Limpopo, South Africa, –22.45, 31.06, collected by M.E. van Tonder, 14 May 1963 . SAIAB 124590 , 16 specimens, 19–50 mm SL, Sterkstroom , Spekboom , Steelpoort, Olifants, Limpopo, South Africa, –24.8, 30.383, collected by I. Gaigher, 13 June 1968 ; SAIAB 134522 , 2 specimens, 39–50 mm SL, Upstream Mnini dam, Mgababa, South Africa, -30.1475, 30.795, collected by R. Karssing , 17 May 2006 ; SAIAB 201903 , 2 specimens, 52–54 mm SL, Gumbwa lagoon 5 km upstream from Chikwawa, Lower Shire, Lower Zambezi, Malawi, –15.992916, 34.805083, collectedbyD.TweddleandT. B.Davies, 6 November 2015 ; SAIAB 203327 , 1 specimen, 37 mm SL, Tabina River at Zangoma, Limpopo, South Africa, –23.910805, 30.3365, collected by A. Chakona and L. Dlamini, 25 March 2016 .

Diagnosis: Head and body pigmented, eyes present (vs. head and body unpigmented, eyes absent in G. ankaranensis ). Predorsal midline naked or with up to seven scales, not extending over opercle; sides of predorsal area scaled to mid-opercle or behind it (vs. predorsal area fully scaled to above preopercular margin in G. tenuiformis , and fully scaled to behind eyes in G. giuris clade B, with a distinct naked patch usually present). All suborbital papillae lines (7–11) and those underside of head (12–13) single rows (vs. Lines 9–10 and 13 double or triple in G. giuris clade B). Anterior half of papillae Line 5 below eye double, single row posteriorely (vs. single row in G. tenuiformis and G. giuris clade B). Distinct predorsal blotch present (vs. absent in G. tenuiformis and G. giuris clade B). Blotch on caudal-fin base double and round, with the posterior blotch being slightly larger (vs. triangular in G. tenuiformis and G. giuris clade B, with a distinct unpigmented gap posteriorly in the former species). Glossogobius hanisii sp. nov. differs from G. callidus s.s. in pectoral-fin rays count (18–20, usually 18–19 vs. 14–17, usually 16), having lighter coloration on the head and body, and fewer midlateral blotches (5–6, usually 5 vs. 5–8, usually 6–7).

General morphology: Body proportions are given in Table 2. All morphometric values in the text are presented as holotype first and other materials, if different, in parentheses. Body moderately elongate, its depth at pelvic-fin origin 18.5% (16.0%–19.4%) SL, at anal-fin origin 17.4% (14.6%–18.0%) SL, laterally compressed posteriorly, with caudal peduncle shallow, caudal–peduncle depth 0.34 (0.32–0.42) times caudal–peduncle length. Head large, its length 29.2% (28.3%–33.3%) SL, width 66.7% (56.3%–68.7%) head length, its depth 62.6% (49.2%–66.8%) head length and 0.88 (0.86–1.03) times head width. Postorbital profile nearly straight/slightly convex. Snout short, oblique, convex, longer than eye, its length 1.33 (0.99–1.75) times eye diameter, 35.0% (28.4%–36.2%) head length. Anterior nostril a short, erect flared tube, rim posteriorly elevated; posterior nostril pore-like, the rim anteriorly elevated. Eyes dorsolateral, more lateral than dorsal, large, eye diameter is 22.6% (20.7%–29.0%) head length, orbit elevated. Interorbital area narrow to wide, width 68.0% (21.5%–72.5%) eye diameter. Mouth directed obliquely upwards, lower jaw projecting, upper lip usually widened in front of lateral preorbital area and swollen, angle of jaws in front of pupil. Cheek moderately deep, 0.43 (0.36–0.57) times head depth at eye. Both jaws with conical teeth in outermost and innermost rows, irregular rows of smaller teeth in-between; teeth in lower jaw more numerous and more obvious. Gill opening broad, reaching forward to just anterior to posterior margin of preoperculum.

Fins: D1 VI; D2 I/8–I/9 (holotype I/9; other materials: I/8:4, I/9:37); A I/8–I/9 (holotype I/8; other materials: I/8:37,

I/9:4); P 18–20 (holotype: 19; other materials: 18:21, 19:17, 20:2), V I/5 + 5/I. Morphometric characters are given in Table 2. D 1 dorsal profile triangular; 1st to 2nd spines of D1 become progressively longer, 3rd to 6th spines become progressively shorter, 6th spine length 0.68 (0.59–0.73) times 1st spine length. D1 1st spine length 0.96 (0.85–1.01) times D2 spine length. D1 and D2 not connected by interdorsal membrane, interdorsal space between D1 VI and D2 I narrow, usually one scale long or shorter. D2 originates slightly behind vertical to anus. Anal fin originates below 1st to 2nd branched rays of D2. Anal fin with last ray below D2 penultimate ray or slightly further. D2 and A rays usually not reaching backwards to the base of uppermost and lowermost caudal-fin rays, except for some large specimens. C lanceolate, 1.26 (0.81–1.39) times head length. P more or less lanceolate, reaches vertical of D2 origin or slightly beyond. P rays all branched, the uppermost rays not free from the membrane. V disc complete, oval, originates below P and significantly anterior of vertical through D1 origin, length 1.16 (0.81–1.39) times V origin to anus, usually not reaching or rarely extending almost to A origin. V with well-developed pelvic frenum; pelvic frenum with straight edge.

Squamation: Body covered with ctenoid scales, cycloid on predorsal area, posterior part of breast, and abdomen. Head, including nape, cheek, and opercle naked. Base of pectoral fin naked. Predorsal area on top naked or scaled with up to seven cycloid scales (holotype: 2; other materials: 0:9, 1:5, 2:9, 3:14, 4:3, 6:3, 7:1), ending posterior to or at predorsal blotch above upper pectoral-fin base ( Fig. 9A). Sides of predorsal area scaled to mid-opercle or behind it. LSS 30–33 (holotype: 32; other materials: 30:3, 31:13, 32:22, 33:3). TR 9.

Cephalic sensory system: Head pores ( Fig. 15): Anterior oculoscapular canal with pores B′, C, D, E, F, G, and H′. Posterior oculoscapular canal with pores K′ and L′. Preopercular canal with pores M′, N, and O′. All except C and D paired. Sensory papillae ( Fig. 15): Line 1a with single row of papillae, 1b with 1–3 papillae. Line 2a as cluster, usually not continuous across snout, rarely connected via a single row. Line 2b composed of a single papilla lateral of pore B′. Line 5 below eye, double anteriorly, single posteriorly. Line 6 short, anteriorly starts at row 5 behind mid-eye. Five suborbital longitudinal lines (7–11), all in single rows of papillae. Line 7 composed of slender papillae posteriorly, becoming larger and oval anteriorly, axes of papillae aligned with papilla line. Line 8 composed of larger oval papillae, axes vertical and perpendicular to papilla line. Lines 9 and 10 with single rows of large papillae, axes in line with axis of papilla line. Line 11 in single row, composed of small to medium sized oval papillae, axes vertical and perpendicular to papilla line. Line 12 in single row and continuous. Line 13 in single row and continuous, tripled anteriorly. Line 20 transverse single row of papillae. Line 21 longitudinal and curved single row. Line 22 short longitudinal single row. Chin with two clusters of papillae; mental frenum papillae free. Line 14 short single row behind eye. Line 15 single row from eye to pore K′. A short single row between lines 14 and 15. Line 17 in single row between pore H′ and pore K′. Lines 16 and 18 in single rows, parallel to each other behind pore L′, Line 16 starts at pore L′ or slightly anterior to pore L′. Line 19 in single transverse row, dorsally starting behind pore G′ downwards to just behind or above pore M′.

Osteology (N = 28): Total vertebrae 27–28 (holotype: 27; other materials: 27:27, 28:1), precaudal vertebrae 10, caudal vertebrae 17–18 (holotype: 17; other materials: 17:27, 18:1). D1 pterygiophore insertion patern: 3-22110. Number of anal pterygiophores anterior to the first haemal spine: 3.

Coloration: No sexual dichromatism. In fesh specimens (see Fig. 14, based on three photographs from Mozambique and Madagascar): head and body golden to yellowish brown; paler ventrally. Body with 5–6 main midlateral blotches, forming X-shaped structures; rearmost blotch on caudal-fin base darkest, double, rounded, and posterior one slightly larger and rarely triangular posteriorly. Upper body with irregular brown spots. Dark-brown oblique stripe from eye to upper lip, another dark-brown oblique stripe from below eye to jaw. Preoperculum and opercle golden to yellowish brown with varying-sized brown spots. Pectoral-fin base with a dorsal brown spot extending onto pectoral-fin ray basally. D1 with a horizontal band (not obvious in all specimens), darker and broader posteriorly (more obvious in the Madagascar specimen). D2 with 2–6 oblique rows of small brown spots. C with up to 12 vertical bands. In preservative (see Figs 8F–J, 12, 13, based on all examined materials): head and body yellowish brown, body paler ventrally. Body with 5–6 (usually 5) dark-brown midlateral blotches comprising chevrons or X-shaped structures; the rearmost blotch on the caudal-fin base darkest and double, with both blotches rounde and the posterior one being larger. Upper body with greyish to brown motling pattern and irregular blotches. A distinct dark blotch in front of DI above upper pectoral-fin base. Interorbital area and snout occasionally darker than body. A dark-brown oblique stripe from front of eye to upper lip. Dark-brown oblique stripe from below eye to jaw. Preoperculum and opercle greyish to brown, with irregular blotches of different sizes. Pectoral-fin base with a distinct brown spot dorsally, extending onto the origin of pectoral rays. Mental frenum usually loosely pigmented with tiny brown spots. Ventral surface of head, and breast usually unpigmented or loosely pigmented. D1 with a distinct horizontal band on proximal part, usually darker and broader in the posterior half; outer part of D1 usually with diffuse tiny brown spots on interspinous membranes. D2 usually with three (sometimes four and rarely more than four) oblique rows of small brown spots. C with 6 to 12 vertical bands. P rays usually greyish. P and A rays and membranes grey to white.

Distribution and habitat: Glossogobius hanisii sp. nov., comprising two mitochondrial DNA sublineages, I and II, is found in marine habitats, coastal lakes, estuaries, the lower and middle reaches of numerous rivers along the south and east coasts of southern Africa, from Coega River in the Eastern Cape province of South Africa north to Malawi and Pinda Island in Mozambique ( Figs 2, 11). Te small Glossogobius specimen (17.0 mm SL; see Greenwood 1994) found in the buccopharynx of a cichlid in March 1994 at Marico Oog, a major source of the Limpopo River system located 1500 km from the river’s mouth, also pertains to this species. Tis suggests that the species inhabits the upper reaches of the Limpopo system; however, further sampling and examination of material from this area are needed for confirmation. Te species has also been documented in south-eastern and eastern Madagascar, extending from Ambinanibe Lagoon north to Mangoro River system. Sublineage I of G. hanisii is found from Coega River in South Africa north to the middle reaches of Limpopo at the South Africa / Zimbabwe border, whereas records of this species in the Buzi and Zambezi systems in Mozambique, Malawi (Lower Zambezi), and Madagascar belong to sublineage II. Te presence of sublineage I in southern Mozambique, specifically in the Limpopo and Incomati river systems, is also anticipated. Te overall distribution range of G. callidus overlaps with the southern range of G. hanisii sublineage I, and their sympatric occurrence has been documented in the Zotsha and Keiskamma rivers.

Seoual dimorphism: Males possess a conical urogenital papilla with a pointed posterior edge, while females have a wider, trapezoid papilla with a fringed posterior edge. Males reach a larger size (up to 122.2 mm TL) compared to females (max 94.3 mm TL). Morphometric and meristic traits are similar between sexes.

Etymology: The species is named in honour of Mr Vuyani Hanisi in recognition of his long-standing and exceptional contributions to the NRF-SAIAB National Fish Collection. For over 17 years, Vuyani has played an important role in caring for the collection through day-to-day hands-on activities associated with the general curation. This honour is unique as, traditionally, this has mainly been given to scientists or collectors of specimens, but hands-on caring for one of the largest fish collections in the southern hemisphere is a substantial contribution.

Similarity with Glossogobius minutus Geevarghese and John, 1983 fom India: Glossogobius minutus , described from a set of 10 specimens from the Kerala coast of India, shows significant morphological similarities with G. hanisii sp. nov.. Key aspects include the squamation of the predorsal area (naked or minimally scaled), the structure of papillae Line 5 (double anteriorly), the number of pectoral-fin rays (18–19 vs. 18–20), and the colour patern (5–6 X-shaped midlateral blotches). However, G. minutus differs from G. hanisii sp. nov. in having deep reddish orange spots when fresh over the antero-dorsal region, especially over the nape and snout, the dorsal half of body, and the caudal fin and peduncle (vs. absence of reddish orange spots over the head and body), and lacking of a distinct predorsal blotch (vs. present) [morphological data for G. minutus is sourced from Geevarghese and John (1983)].

Comparison with other Glossogobius species from Africa and Madagascar

Glossogobius callidus and G. hanisii sp. nov. differ from G. ankaranensis , a blind cave-adapted species endemic to a subterranean river in the Ankarana massif of northern Madagascar, in the following characters. (i) Head and body pigmented and eyes present (vs. head and body devoid of pigment and eyes lost, the only traces of eyes are two small spots of dark pigment deeply embedded in the tissues just lateral to the supraorbital narrowing of the frontals). (ii) Dorsal profile of head more or less convex (vs. concave and shovel-like). (iii) Head pores present (vs. absent). (iv) Sensory papillae Line 5 present (vs. absent); Line 2a patchy (vs. single row). (v) Scales in lateral series 29–33 (vs. 25–26). (vi) Head length 28.3%–36.1% SL (vs. 37.3%–38.5% SL). (vii) First dorsal-fin spine 14.1%–21.1% SL (vs. 11.5%–11.8% SL). (viii) Second dorsal-fin base 19.2%–24.3% SL (vs. 15.6%–15.7% SL). (ix) Caudal–peduncle length 21.8%–30.2% SL (vs. 19.6%–19.8% SL). (x) Snout to pelvic-fin origin 26.6%–34.7% SL (vs. 35.4%–37.3% SL). (xi) Pelvic-fin elements I/5 + 5/I (vs. I/4 + 4/I).

Glossogobius callidus and G. hanisii sp. nov. differ from G. giuris clade B ( Fig. 16A, B) in the following characters. (i) Squamation of the predorsal area ( Fig. 9): predorsal on top naked or with up to eight scales, ending at or behind the predorsal blotch above upper pectoral-fin base; sides of predorsal area scaled to mid-opercle or usually to behind it (vs. predorsal area fully scaled with up to 28 scales to behind eye, with a distinct naked patch usually present). (ii) Scales in transverse series 9 (vs. 10). (iii) Sensory papillae patern ( Figs 10, 15, 17): Line 5 double (vs. single row); suborbital longitudinal lines (i.e. Lines 7–11), and lines underside of head (i.e. Lines 12, 13) all in single rows (vs. Lines 9, 10, and 13 double or triple); Line 1a on snout in single row (vs. double); Line 2a patchy (vs. single row); a short longitudinal line between Lines 14 and 15 present (vs. absent); chin partly covered with two clusters of papillae (vs. fully covered with proliferated papillae). (iv) Colour patern: distinct predorsal blotch present (vs. absent) ( Fig. 9); body with 5–8 midlateral blotches comprising narrow chevrons or X-shaped structures, with rearmost blotch on caudal-fin base double, both rounded and the posterior one slightly larger (vs. five large grey brown saddles on back, alternating with five diffuse oval grey-brown midlateral blotches, with rearmost blotch on caudal-fin base triangular; colour patern is less pronounced in preserved specimens; Figs 16A, B, 18); proximal part of first dorsal-fin spine and membrane without a distinct dark brown spot (vs. a distinct dark brown spot present). (v) Horizontal eye diameter 19.9%–30.4% head length (vs. 14.7%–17.2% head length). (vi) Postorbital length 42.4%–50.4% head length (vs. 51.1%– 56.9% head length).

Glossogobius callidus and G. hanisii sp. nov. differ from G. tenuiformis ( Fig. 16C, D) in the following characters. (i) Squamation of the predorsal region ( Fig. 9): predorsal on top naked or with up to eight scales, ending at or behind the predorsal blotch above upper pectoral-fin base; sides of predorsal area scaled to mid-opercle or usually to behind it (vs. predorsal area fully scaled to above preopercular margin). (ii) Sensory papillae patern: Line 5 double (vs. single row); Line 2a patchy (vs. single row); a short longitudinal line between Lines 14 and 15 present (vs. absent); chin partly covered with two clusters of papillae (vs. fully covered with proliferated papillae) [see Al Jufaili et al. (2022) for an illustration of the sensory papillae patern in G. tenuiformis ]. (iii) Colour patern: distinct predorsal blotch present (vs. absent) ( Fig. 9); 5–8 midlateral blotches, rearmost blotch on caudal-fin base double, with both blotches rounded and the posterior one being slightly larger (vs. 5 midlateral blotches, the rearmost blotch on caudal-fin base triangular with a distinct unpigmented gap posteriorly; Figs 16C, D, 18).

A KEY TO THE RECOGNIZED SPECIES OF GLOSSOGOBIUS IN AFRICA AND MADAGASCAR

1a. Head and body unpigmented; eyes vestigial (two small dark spots embedded in tissue); head pores absent.............................. .................................................................................................................................................................................................. G. ankaranensis

1b. Head and body pigmented; normal eyes present; head pores present................................................................................................2

2a. Predorsal area fully scaled to behind eyes, with a distinct naked patch usually present; suborbital papillae Lines 9–10, Line 13 on underside of head, and Line 1a on snout all double or triple.......................................................................... G. giuris clade B

2b. Predorsal area naked or fully/partially scaled to above opercle/preopercle posterior margins; suborbital papillae lines, lines on underside of head, and Line 1a on snout all single ............................................................................................................................3

3a. Predorsal area fully scaled to above preopercular margin; papillae Line 5 below eye single; predorsal blotch absent; blotch on caudal-fin base triangular, with a distinct unpigmented gap posteriorly................................................................. G. tenuiformis

3b. Predorsal area naked in midline or with up to eight scales, ending at or behind a distinct predorsal blotch above upper pectoral-fin base; sides of predorsal area scaled forward to mid-opercle or usually to behind it; papillae Line 5 below eye double anterior to the midpoint of the eye, and single row posteriorly; blotch on caudal-fin base double, both blotches rounded and the posterior one slightly larger...........................................................................................................................................4

4a. Pectoral-fin rays 14–17; body with 5–8 (usually 6–7) midlateral blotches........................................................................ G. callidus

4b. Pectoral-fin rays 18–20; body with 5–6 (usually 5) midlateral blotches................................................................ G. hanisii sp. nov.

Comparative material

Glossogobius ankaranensis : Data from the original description by Banister (1994) based on two specimens, 51 mm SL (holotype: BMNH 1994.12.1.1) and 48 mm SL (paratype: BMNH 1994.12.1.2) .

Glossogobius tenuiformis : ANSP 60250 , holotype, 57 mm SL, St. Lucia Lake , South Africa ; SAIAB 34280 , 26 specimens, 24.46–49.61 mm SL, Richards Bay Sanctuary, South Africa, –28.81666755, 32.0166664124, collected by H. Mander and T. Pike, 4 July 1990 ; SAIAB 40657 , 6 specimens, 39.7– 59.5 mm SL, Tugela River mouth, South Africa, –29.22500038, 31.4916667938, collected by M. Coke and J. Dives, 30 June 1992 ; SAIAB 55749 , 25 specimens, 17.16–48.18 mm SL, Molocue Island , Mozambique, –17.03333282, 38.8333320618, collected by R. Bills and A.W. Paterson, 7 July 1997 ; SAIAB 55769 , 32 specimens, 30–56 mm SL, Molocue Pontoon Mangrove Bank , Molocue System, Mozambique, –17.03333282, 38.8333320618, collected by R. Bills and A. Paterson, 10 November 2000 ; SAIAB 58466 , 9 specimens, 39.7–54.3, Mgeni River , South Africa, –29.79999923, 30.0333328247, collected by T. Harrison, 10 September 1992 ; SAIAB 75883 , 2 specimens, 33.4–35.1 mm SL, Marracuene Lodge , Nkomati River, Mozambique, –25.77388954, 32.6852760315, collected by R. Bills and L. da Costa, 26 May 2005 (GenBank: COI: PQ761185 ) ; SAIAB 78404 , 2 specimens, above saltwater barrier ( John Ross Highway ), Mzingazi River, South Africa, -28.7743, 32.07255, collected by S. Weerts, 11 March 2002 ; SAIAB 83601 , 10 specimens, 26.86–39.60 mm SL, Umhlatuzi River , Richard’s Bay, South Africa, –28.826, 31.9872, collected by H.K. Larson, 15 November 2005 ; SAIAB 83612 , 12 specimens, 31–48 mm SL, Mzingazi Canal , Richards Bay, South Africa, –28.78031, 32.07282, collected by H.K. Larson, 15 November 2005 ; SAIAB 86904 , 14 specimens, 30.35–81.69 mm SL, at road bridge, Nangua , Mozambique, –13.00472, 40.38638, collected by R. Bills, 26 November 2009 (GenBank: COI: PQ761184; Cytb: PQ768045 ) ; SAIAB 97555 , 1 specimen, 74 mm SL, Anosy , Madagascar, –25.067, 46.9313, collected by E. Heemstra, 1 May 2010 ; SAIAB 203903 , 3 specimens, 28.4–37.5 mm SL, Bridge on R33 below the weir, Mzingazi , South Africa, –28.77475, 32.0705, collected by E . R. Swartz, P, Maake, and M. Ramoejane, 23 September 2011 ; SAIAB 236603 , 70 specimens, Mannivo mouth, Madagascar, collected by S. Weerts and F. Mackay, 10 July 2013 ; ZM-CBSU O001. Gt 101-Gt-121, 21 specimens, 52–75 mm SL, Salalah , Wadi Hasik at Hasik, Oman, 17.362641, 55.291497, collected by H . R Esmaeili, S.M. Al Jufaili, and A.H Masoumi, 4 January 2022 ; ZM-CBSU O002. Gt 126- Gt 143, 18 specimens, 22–39 mm SL, Wadi Shab, Sur in Al Sharqiyah, Oman, 22.833611, 59.238889, collected by H . R Esmaeili, S.M. Al Jufaili, and A.H Masoumi, 4 Janury 2022 .

Glossogobius giuris clade B sensu Hammer et al. (2021): SAIAB 62495 , 3 specimens, 84.7–238 mm SL, Upper reaches— Larde Estuary, Mozambique, –16.46833419, 39.6577758789, collected by A.W. Paterson, 14 April 2000 ; SAIAB 68249 , 4 specimens, 45.4–98.3 mm SL, Nyetane Dam / Hatchery , Nyetane River, Usutu System, Swaziland, –26.63666725, 31.9572219849, collected by R. C. Boycot, D. Tweddle, N. Khumalo, J. Msibi, M. Fakudze, and P. Dlamini, 18 December 2002 ; SAIAB 68252 , 2 specimens, 57.4–95.4 mm SL, Nyetane Dam Wall , Swaziland, –26.63222312, 31.9544448853, collected by R. C. Boycot, D. Tweddle, N. Khumalo, J. Msibi, M. Fakudze, and P. Dlamini, 19 December 2002 ; SAIAB 70207 , 29 specimens, 27.8–118.2 mm SL, Ubombo , Sivunga Dam (east), Usuthu System, Swaziland, –26.66111183, 31.9861106873, collected by R.C. Boycot, 16 May 2003 ; SAIAB 73863 , 11 specimens, 42.36–91.1 mm SL, Mbatamila-Mussoma Road , Mussoma bridge, Lugenda River, Lugenda System, Mozambique, –12.43972206, 37.6711120605, collected by R. Bills, 16 August 2003 ; SAIAB 73940 , 16 specimens, 31.1– 102.0 mm SL, Chamba game-scout camp, Rovuma River, Mozambique, –12.59638881, 36.9355545044, collected by R. Bills, 19 August 2003 ; SAIAB 83636 , 6 specimens, 28–96 mm SL, below pump station weir, Mhlatuze River , South Africa, –28.80138, 31.95, collected by M. Coke, 24 May 2004 ; SAIAB 86902 , 1 specimen, at road bridge, Nangua , Cabo Delgado, Mozambique, –13.0047222222, 40.3863888889, collected by R. Bills, 26 November 2009 (GenBank: COI: PQ761189 ) ; SAIAB 86903 , 1 specimen, 45 mm SL, road bridge between Nampula and Lumbo , Monapo, Mozambique, –14.895, 40.307, collected by R. Bills, 29 November 2009 (GenBank: COI: PQ761190 ) ; SAIAB 97430 , 1 specimen, 155 mm SL, Douane Beach , Fort Dauphin, Anosy, Madagascar, –25.027516, 46.9956, collected by E. Heemstra, P.C. Heemstra, and T. Razafimanambina, 3 May 2010 (GenBank: COI: PQ761188 ) ; SAIAB 98367 , 1 specimen, 145 mm SL, North Ambinanibe Lagoon , Anosy, Madagascar, –25.06203, 46.92775, collected by P.C. Heemstra, 4 May 2010 ; SAIAB 203846 , 2 specimens, 103– 113 mm SL, Sabie gorge right on Mozambique border, Sabie, Nkomati, –25.18416, 32.028305, collected by P.H. Skelton , R. Peterson , R. Bills, and V. Bills, 24 August 2016 ; SAIAB 205125 , 1 specimen, 91 mm SL, Muteri Dam , Zimbabwe, collected by A. Chakona, W. Kadye , T. Bere, and M. Machingura, 19 December 2013 ; SAIAB 134149 , 7 specimens, 33–95 mm SL, below pump station weir, Mhlatuze , South Africa, below pump station weir, Mhlatuze, South Africa, –28.80138, 31.95, collected by M. Coke, 19 May 2002 ; SAIAB 236055 , 5 specimens, 44.04– 61.26 mm SL, Noordgrens Landgoed , Limpopo River, South Africa, -22.15816219, 29.60671247, collected by A. Chakona and W. Kadye, 27 January 2023 ; ZM-CBSU G1- MK, 1 specimen, 103 mm SL, Sarbaz River at Sarbaz, Iran, 26.634750, 61.259139, collected by H. Malekzehi ; ZM-CBSU N1060– N1061 and N1063–N1064, 4 specimens, 82.6–101.5 mm SL, Sarbaz River at Jakigur, Iran, 26.130861, 61.536944, collected by A. Elmi, 10 March 2013 ; ZM-CBSU S102-1–S102-5, 5 specimens, 102.1–123 mm SL, Sarbaz River at Rask, Iran, 26.234806, 61.391694, collected by M. Ghanbarifardi, 9 February 2022 ; ZM-CBSU S102-6–S102-10, 5 specimens, 112.6–180 mm SL, Sarbaz River at Pishin Dam, Iran, 26.030750, 61.689694, collected by M. Ghanbarifardi, 11 February 2022 .