Lamprologus teugelsi, SCHELLY & STIASSNY, 2004

SCHELLY, ROBERT C. & STIASSNY, MELANIE L. J., 2004, Revision of the Congo River Lamprologus Schilthuis, 1891 (Teleostei: Cichlidae), with Descriptions of Two New Species, American Museum Novitates 3451, pp. 1-40 : 29-32

Lamprologus teugelsi , new species

Figures 24–27 , Table 7, Plate 2c

HOLOTYPE: AMNH 233611 , Kinshasa region, 04 ° 06 ̍ S, 15 ° 15 ̍ E // 04 ° 20 ̍ S, 15 ° 23 ̍ E, 1993, M. Smith.

PARATYPES: AMNH 233612 (n = 3, 1 specimen c&s), Kinshasa region, 04 ° 06 ̍ S, 15 ° 15 ̍ E // 04 ° 20 ̍ S, 15 ° 23 ̍ E, 1993, M. Smith; MCZ 50549 (n = 24), Congo River mainstream near Inga dam , 5 ° 31 ̍ S, 13 ° 37 ̍ E, 4/8/ 1973, T.R. Roberts and D.J. Stewart; MRAC 96029.0001 –0002, Kinshasa region, 04 ° 18 ̍ S, 15 ° 18 ̍ E, 4/12/1996, W. van der Elst.

MATERIAL EXAMINED: 31 specimens of the type series.

DIFFERENTIAL DIAGNOSIS: Lamprologus teugelsi , n.sp., is distinguished from L. lethops and L. symoensi by its regularly imbricating, large, uniformly sized flank scales, and from L. mocquardi by its uniformly dark pigment around the exposed margin of flank scales, giving the appearance of chain mail. A shallow supraoccipital crest distinguishes L. teugelsi , n.sp., from L. congoensis and L. tumbanus , and pelvic fins never reaching the anus distinguish L. teugelsi , n.sp., from L. congoensis , L. tumbanus , and L. tigripictilis , n.sp. A larger value for BD as a percentage of SL (21.9–28.6% vs. 17.3–20.3%) and almost always fewer vertebrae (30–32 vs. 31– 33) and lateral line scales (32–34 vs. 34–37) differentiates L. teugelsi , n.sp., from L. werneri .

DESCRIPTION: Counts and measurements for holotype and eight paratypes are given in table 7. Because most of the MCZ paratypes are under 20 mm SL, only eight paratypes were included for most measurements. Relatively stout, deep­bodied species, especially as adults (BD 21.9–28.6%, mean 25.2% of SL). Greatest body depth at about base of third or fourth dorsal fin spine. Head length 31.0–33.8%, mean 32.8% SL. Dorsal head profile rises straight at about 40 ° angle, curving gently behind eye to become almost horizontal. Dorsal body profile slightly convex, with steepest angle curving ventrally at base of caudal peduncle. Ventral body profile also slightly convex, curving upward just anterior to caudal peduncle. Sexual dimorphism not apparent in limited material available.

Fins: Dorsal fin XVII–XIX (mode XVIII) 8–9 (mode 9). Anal fin V–VI (mode VI) 6– 7 (mode 6). Spines in both fins gradually increasing in length posteriorly. Filamentous extensions of dorsal and anal fins extending beyond caudal fin base, to as far as middle of caudal fin in largest specimens. Caudal fin moderately large and rounded rather than paddle shaped, never appearing subacuminate, with 14 branched rays. Pectoral fins short, not reaching vertical through anus. Second pelvic fin ray is longest in fin in both sexes, but not reaching vertical through anus.

Teeth: (fig. 25a): Jaws isognathous, but with lower lip sometimes protruding slightly; both outer and inner row teeth unicuspid and sharply pointed. Single series of 6–8 greatly enlarged, recurved, procumbent canines situated anteriorly on premaxilla, with 6 such canines on dentary; lateral­most canines considerably larger than those at symphysis. Inner teeth in about 5 poorly defined rows of tightly packed, small, recurved caniniform teeth anteriorly; outmost row medium sized. Inner teeth thinning posteriorly to single row of medium sized caniniform teeth, extending almost entire length of both dentary and premaxilla.

Gill Rakers: (fig. 25b): Moderately elongate and non­denticulate. Eight to 11 (mode 9) gill rakers along outer row of first gill arch. No rakers present on hypobranchial, 5– 6 (mode 6) rakers along ceratobranchial, 1 raker in angle of arch, and 2–4 (mode 3) rakers along epibranchial.

Lower Pharyngeal Jaw (fig. 25c): Wider than long, and straight or slightly interdigitating along ventral suture. Usually 20–24 teeth in most posterior tooth row. Posterior median teeth somewhat more robust, even slightly molariform; lateral teeth slender and either beveled or bluntly hooked.

Scales: Flank scales large, ctenoid, and regularly imbricating. Pored lateral line scales 32–34; upper and lower branches not overlapping. Cheek and chest naked, belly with small scales. Nape predominantly scaleless to dorsal fin origin, though a few embedded scales may be present anterior to dorsal fin origin; transition to small scales above first 6 or so scales of upper lateral line. A few scattered scales on opercle and subopercle. Dorsal and anal fins scaleless. Small scales over proximal half of caudal fin.

Vertebrae: 30–32; 14 + 16 (6), 14 + 17 (10), 14 + 18 (4).

Additional Osteology (fig. 26): Infraorbital series comprised of broad, platelike lachrymal with 5 large sensory canal pores and 2– 4 tubular infraorbitals adjacent to lachrymal. Dermosphenotic absent. Supraneural present in 4 of 10 specimens. Supraoccipital crest low, frontal ridge present and extends anteriorly to median coronal pore (NLF0).

Coloration: In a photograph of a live aquarium specimen from Kinshasa (Seegers, in litt.), base body coloration is light gray, with six wide, irregular, dark bars on flanks separated by thinner, whitish blotches. Dorsal, anal, and caudal fins are darkly pigmented, lacking obvious maculae. Dorsal fin with light yellow margin, caudal fin with reddish margin restricted to dorsal edge. Preserved specimens yellowish brown, with darker dorsal, anal, and pelvic fins and head. Scaleless, dark opercular spot present. About five dark vertical bars present on flanks. Individual flank scales with dark pigment distributed uniformly along exposed posterior margin, creating intersecting rows of thin, oblique bands of pigment that present the appearance of a chain­link fence or chain mail.

DIET: Unknown; the larger specimens in the type series were kept in aquaria prior to preservation, so gut contents analysis was not possible.

DISTRIBUTION (fig. 27): Known from Malebo Pool and the lower Congo River rapids near Inga.

ETYMOLOGY: Named in memory of our friend and colleague Guy Teugels. Guy’s leadership in the field of African ichthyology and his commitment to the training and support of African ichthyologists were an inspiration. He will be sorely missed.

REMARKS: An examination of the voucher specimens identified as Lamprologus mocquardi in the analysis of Sturmbauer et al. (1994) reveals that they are L. teugelsi , n.sp., and two of these specimens have been included herein as paratypes.

Figures

Plate 2. (a) Lamprologus symoensi, paratype, MRAC 79001.6284–85, female, 46 mm SL; (b) Lamprologus lethops, holotype, MCZ 50248, male, 26 mm SL; (c) Lamprologus teugelsi, n.sp., holotype, AMNH 233611, female, 60 mm SL; (d) Lamprologus tigripictilis, n.sp., holotype, AMNH 233609, male, 62 mm SL.

Fig. 24. Lamprologus teugelsi, n.sp., holotype, AMNH 233611, female, 60 mm SL, drawn by Ian Hart.

Fig. 25. Lamprologus teugelsi, n.sp., AMNH 233612: (a) premaxilla; (b) first gill arch; (c) lower pharyngeal jaw dorsal view; (d) lower pharyngeal jaw ventral view.

Fig. 26. Lamprologus teugelsi, n.sp., AMNH 233612: (a) neurocranium and first vertebra; (b) lachrymal and adjacent infraorbitals.

Fig. 27. Collection localities of Lamprologus teugelsi, n.sp.