Haplochromis pardus, Vranken & Steenberge & Heylen & Decru & Snoeks, 2022

Vranken, Nathan, Steenberge, Maarten Van, Heylen, Annelies, Decru, Eva & Snoeks, Jos, 2022, From a pair to a dozen: the piscivorous species of Haplochromis (Cichlidae) from the Lake Edward system, European Journal of Taxonomy 815, pp. 1-94 : 58-62

Haplochromis pardus sp. nov.

urn:lsid:zoobank.org:act:8DDACAC6-C993-4750-BE1B-1BF4C0312DB7

Figs 1–2 , 32–34 ; Table 1

Differential diagnosis

Species with a piscivorous morphology; adult size small (max. known size 96 mm SL); outer oral teeth many and small [UOT 39–56 (median 58)]; dominant males speckled to uniformly black.

Amongst piscivorous species from the Lake Edward system, H. pardus sp. nov. differs from all by the combination of a smaller adult size (max. 96 vs 109–211 mm SL) and colour pattern of small specimens (<100 mm SL) speckled to uniformly black vs light coloured.

It further differs from H. latifrons sp. nov., H. mentatus , H. glaucus sp. nov., H. kimondo sp. nov., and H. squamipinnis by the combination of a shallower cheek [ChD 20.8–24.4 (mean 22.5) vs 23.8–36.0 (26.4– 30.9) % HL] and a narrower interorbital area [IOW 39.3–48.4 (44.6) vs 48.6–63.3 (51.9–60.0) % HW].

It further differs from H. rex sp. nov., H. simba sp. nov., and H. aquila sp. nov. by the combination of a shallower cheek [ChD 20.8–24.4 (22.5) vs 26.8–33.5 (28.3–31.1) % HL], smaller outer oral teeth, and a larger number of outer upper jaw teeth [UOT 39–51 (45) vs 22–37 (27–31)].

It further differs from H. falcatus sp. nov. by the combination of by weakly recurved vs strongly recurved outer jaw teeth, a shallower cheek [ChD 20.8–24.4 (22.5) vs 25.1–28.0 (exceptionally 23.3 in one specimen) (mean 26.0) % HL], and a shorter pre-dorsal distance [PrD 34.1–37.8 (36.0) vs 38.2–41.1 (exceptionally 36.9 in one specimen) (mean 39.5) % SL].

It further differs from H. curvidens sp. nov. by the combination of a longer anal-fin base [AFB 19.2–22.2 (20.5) vs 17.9–18.6 (18.3) % SL] and a slightly narrower interorbital area [IOW 39.3–48.4 (44.6) vs 46.4–52.5 (49.1) % HW].

It further differs from H. quasimodo sp. nov. by the combination of a shallower cheek [ChD 20.8–24.4 (22.5) vs 23.7–32.9 (27.5) % HL] and a smaller number of caudal peduncle scales (CPS 16, rarely 17 vs 17–20, rarely 16).

Etymology

Specific name from the Latin ‘ pardus ’ for ‘leopard’; referring to nearly uniform black to yellow-pink flanks with clear black blotches, i.e., interrupted horizontal and vertical stripes.

Material examined

Holotype UGANDA • ♂, 89.2 mm SL; Lake Edward, Mukutu Kihinga, rocky offshore of Mweya ; 0°11′31.2″ S, 29°52′26.4″ E; 23 Oct. 2016; HIPE1 exped. leg.; RMCA 2016.035.P.0202 .

Paratypes UGANDA – Lake Edward • 1 ♀, 84.9 mm SL; Mukutu Kihinga, rocky offshore of Mweya ; 0°11′31.2″ S, 29°52′26.4″ E; 23 Oct. 2016; HIPE1 exped. leg.; RMCA 2016.035.P.0203 • 2 ♂♂, 2 ♀♀, 83.6–96.1 mm SL; mouth of Kazinga Channel ; 0°12′32.4″ S, 29°53′06.0″ E; 24 Oct. 2016; HIPE1 exped. leg.; RMCA 2016.035.P.0204 to 0207 • 1 ♀, 1 ♂, 75.9, 84.7 mm SL; Rwenshama rocky shore; 0°24′05.7″ S, 29°46′35.1″ E; 26 Mar. 2017; HIPE2 exped. leg.; RMCA 2017.006.P.0342 to 0343 • 3 ♀♀, 67.4– 70.5 mm SL; Kayanja offshore; 0°05′34.8″ S, 29°45′28.8″ E; 30 Mar. 2017; HIPE2 exped. leg.; RMCA 2017.006.P.0346 to 0348 • 1 ♀, 1 ♂, 67.7, 78.1 mm SL; Kayanja offshore; 0°05′34.8″ S, 29°45′28.8″ E; 30 Mar. 2017; HIPE2 exped. leg.; RMCA 2017.006.P.0344 to 0345 • 1 ♀, 92.4 mm SL; islands near Katwe ; 0°10′04.9″ S, 29°52′27.4″ E; 19 Jan. 2018; HIPE3 exped. leg.; RMCA 2018.008.P.0331 • 1 ♀, 1 ♂, 72.3, 81.7 mm SL; Rwenshama rocky shore; 0°24′05.7″ S, 29°46′35.1″ E; 24 Jan. 2018; HIPE3 exped. leg.; RMCA 2018.008.P.0332 to 0333 • 2 ♀♀, 2 ♂♂, 71.0– 84.9 mm SL; Rwenshama rocky shore; 0°24′05.7″ S, 29°46′35.1″ E; 26 Mar. 2017; HIPE2 exped. leg.; IRSNB 920 to 922 .

Description

Based on 20 specimens (67.4–96.1 mm SL); body shallow ( Table 1 ) and oval to slightly rhomboid ( Fig. 32 ). Head narrow, shallow, and with a straight dorsal outline with a concavity above eye; eye average in size in comparison to generalised H. elegans (but large for a piscivorous species); interorbital area very narrow; cheek shallow; lacrimal average in depth. Snout average in length, very acute, and slopes gently at 30–40°; premaxillary pedicel long and prominent. Jaws iso- to slightly prognathous, average in length, narrow, and rounded in dorsal view; gape large and slopes gently at 15–25°; maxilla extends to between verticals through anterior margins of orbit and pupil. Lower jaw shallow and with straight ventral outline in lateral view, mental prominence absent, and lower jaw side nearly flat with an inclination of 15–30° to horizontal in anterior view. Upper jaw weakly expanded anteriorly and ventrally. Lips and oral mucosa large. Neurocranium average in depth, ethmo-vomerine block decurved, preorbital region very shallow (18–22% NL), orbital region average in depth (30–33% NL), and supraoccipital crest shallow and wedge-shaped ( Fig. 33b ).

Outer oral teeth numerous, small, and weakly embedded in oral mucosa. Necks stout, cylindrical, and straight; crowns weakly recurved, unicuspid in large specimens (<80 mm), bicuspid with posteriorly some weakly tricuspid teeth in small specimens (> 70 mm), and acutely pointed in all specimens. Dental arcades rounded and with anterior half weakly expanded laterally. Outer teeth closely and regularly set with neck-distances of ½ neck-width; lateral outer teeth implanted slightly labially. In upper jaw, 1–3 posteriormost teeth enlarged. Inner teeth small, recurved, unicuspid in large specimens (> 80 mm), tricuspid in small specimens (<70 mm), and acutely pointed in all specimens. Tooth bands very slender crescent-shaped with 2 (rarely 3) rows of inner teeth, and narrow posteriorly until only outer row remains past ⅔ length of tooth band. Inner rows closely and regularly set on 1 neck-width from outer row in lower jaw, on 1–2 neck-widths from outer row in upper jaw; implantation erect in first row and recumbent in subsequent rows; size uniform throughout tooth band.

Lower pharyngeal bone average in length, narrow, slim, and shallow over entire length ( Fig. 34 ). Pharyngeal teeth small and slender; major cusps acutely pointed; cusp gaps nearly straight; minor cusps and cusp protuberances small. Teeth in two median longitudinal rows equal in size and form to lateral teeth, 11–12 in each row. Posterior transverse row with 22 teeth, implanted erectly with a slight lateral inclination; major cusps weakly recurved, bluntly pointed, and laterally compressed; minor cusps mostly present.

Chest scales small; transition to larger flank scales gradual. Minute scales on proximal half of caudal fin. Caudal fin emarginate; dorsal and anal fins reach to between verticals through one scale anterior and one scale posterior to caudal-fin base. Pectoral and pelvic fins reach to genital opening; pelvic fin reaches to first anal-fin spine in males; first branched pelvic-fin ray not elongated.

Ceratobranchial gill rakers in outer row of first gill arch short, stout, and simple; posteriormost rakers mostly weakly bifid. Epibranchial gill rakers relatively slender and simple.

Colouration in life

Dominant males: body speckled to uniformly black with a blue sheen; dorsum and dorsal part of head pink to speckled black; chest white; belly, caudal peduncle, operculum, lower jaw, and lips black; cheek, lacrimal, and snout speckled to uniformly black, cheek with yellow sheen; eye with grey to dark outer ring and silver to dark inner ring ( Fig. 33c ). Flank with dorsal-lateral and mid-lateral bands and 5–6 vertical stripes, all black, broad, well-defined, but interrupted, hereby body seemingly blotched. Nostril, interorbital, supraorbital, lacrimal, vertical preopercular stripes, nape band, mental blotch, and black posterior margin of operculum well-defined. Pectoral, dorsal, and anal fins dusky; lappets, bases, and posterior parts of anal and dorsal fins black; anal fin with faint crimson flush and 1–3 small orange eggspots with dusky rings. Pelvic and caudal fins black; caudal fin with dusky distal part and a faint crimson flush.

Females and juveniles: body yellowish with a dusky sheen; dorsum and dorsal part of head pink; belly, chest, operculum, and cheek, white; lacrimal speckled black; snout dusky to black; eye with grey to dark outer ring and silver to dark inner ring ( Fig. 33d ). Flank with dorsal-lateral and mid-lateral bands and 5–6 vertical stripes, all faint and interrupted. Nostril and interorbital stripes faint; supraorbital, lacrimal, vertical preopercular stripes, mental blotch, and nape band well-defined. Pectoral, pelvic, and dorsal fins dusky; anal and caudal fins dusky with yellow sheen; dorsal and anal fins with black lappets and posterodistal part; caudal fin with black base and 1–2 small spots resembling egg-spots.

Preserved colouration

In all specimens, dorsal part of body dark brown to speckled black; ventral part of body dark brown to uniformly black; belly black; chest whitish ( Fig. 33a ). Flank with faint to well-defined, broad, but interrupted mid-lateral, dorsal-lateral, and dorsal-medial bands and 5–6 vertical stripes. Snout dusky; lips dusky with well-defined black spots; cheek yellowish to black; operculum black. Nostril, interorbital, supraorbital, lacrimal, vertical preopercular stripes, nape band, mental blotch, and black posterior margin of operculum well-defined. Pectoral, dorsal, and anal fins dusky; lappets, bases, and posterior parts of anal and dorsal fins black; anal fin with 1–3 egg-spots. Pelvic and caudal fins dusky to black; caudal fin with blackish distal part.

Distribution and ecology

Only known from Lake Edward; found in inshore areas. Based on its morphology, most probably a piscivorous species.

Figures

Fig. 1. The Lake Edward system, consisting of Lakes Edward and George that are connected through the Kazinga Channel. The catch localities of all examined specimens are indicated: Haplochromis sp. ‘latifrons’ (), H. mentatus Regan, 1925 (), H. sp. ‘rex’ (), H. sp. ‘simba’ (▼), H. sp. ‘glaucus’ (), H. sp. ‘aquila’ (), H. sp. ‘kimondo’ (●), H. sp. ‘falcatus’ (), H. sp. ‘curvidens’ (), H. sp. ‘pardus’ (), H. sp. ‘quasimodo’ (▲), and H. squamipinnis Regan, 1921 (█). The type localities of H. mentatus and H. squamipinnis are not shown as the exact locations are unknown.

Fig. 2. a. Differences in total number of outer teeth and premaxillary dentition between the macro- and microdontic groups of piscivores from the Lake Edward system.b. Schematic presentation of the dominant male colour patterns in life, in the various groups studied. For H. sp. ‘latifrons’ the female and for H. sp. ‘curvidens’ the non-dominant colour patterns are shown, as those of dominant males are unknown.

Fig. 32. Haplochromis pardus sp. nov., holotype, ♂, 89.2 mm SL (RMCA 2016.035.P.0202). Drawn by N. Vranken.

Fig. 33. Haplochromis pardus sp. nov. a. Photograph of preserved holotype (RMCA 2016.035.P.0202; 89.2 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2017.006.P (HP1463); 81.4 mm SL). d. Female (RMCA 2017.006.P.0342; 75.9 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 34. Haplochromis pardus sp. nov. (RMCA 2016.035.P.0207; 96.1 mm SL). a. Dorsal view of the lower pharyngeal jaw. b. Lateral view of the lower pharyngeal jaw.