Haplochromis curvidens Vranken, Van Steenberge, Heylen, Decru & Snoeks, 2022

Family:  Cichlidae (Cichlids), subfamily: Pseudocrenilabrinae
Max. size:  11.2 cm SL (male/unsexed)
Environment:  pelagic; freshwater
Distribution:  Africa: Lake Edward (Ref. 126312).
Diagnosis:  Dorsal spines (total): 15-16; Dorsal soft rays (total): 8-10; Anal spines: 3-3; Anal soft rays: 8-9; Vertebrae: 29-31. Diagnosis: Species with a piscivorous morphology; outer oral teeth many, small, and (strongly) recurved, 45-60; non-dominant males dusky green with a blue sheen and 5-7, faint, vertical stripes (Ref. 126312). Amongst piscivorous species from the Lake Edward system, Haplochromis curvidens differs from H. latifrons, H. mentatus, H. rex, H. simba, H. glaucus, and H. aquila by small vs. large outer oral teeth and a larger number of outer upper jaw teeth, 45-60 vs; 22-47; further from H. latifrons, H. mentatus, H. rex, H. simba and H. glaucus by a shallower lacrimal, lacrimal depth 16.0-17.8% of head length vs. 18.0-23.0%; further from H. rex, H. simba, H. glaucus and H. aquila by a shallower cheek, cheek depth 22.4-24.9% of head length vs. 26.2-33.5% (Ref. 126312). It differs from H. kimondo, H. falcatus and H. quasimodo by the combination of a shallower cheek, cheek depth 22.4-24.9% of head length vs. 24.8-35.2%; and absence vs. presence of a well-defined mid-lateral band; further from H. kimondo by narrower jaws, lower jaw width 38.5-43.2% of lower jaw length vs. 44.7-53.3%; further from H. falcatus by a shorter pre-dorsal distance, 34.5-37.9% of standard length vs. 38.2-41.1%; further from H. quasimodo by a shallower body, body depth 29.0-32.0% of standard length vs. 33.5-41.7% (Ref. 126312).It differs from H. pardus by the combination of a shorter anal fin base, 17.9-18.6% of standard length vs. 19.2-22.2%; a slightly broader interorbital area, interorbital width 46.4-52.5% of head width vs. 39.3-48.4%; and all specimens faint yellow to dusky green vs. speckled to uniformly black (Ref. 126312). It differs from H. squamipinnis by the combination of a shallower body, body depth 29.0-32.0% of standard length vs. 32.4-39.3%; a shallower cheek, cheek depth 22.4-24.9% of head length vs. 24.9-36.0%; and absence vs. presence of minute scales on proximal parts of dorsal and anal fins (Ref. 126312).

Description: Body shallow and oval (Ref. 126312). Head long, narrow, and with a straight to very gently convex dorsal outline; eye and interorbital area average in width; cheek and lacrimal average in depth (Ref. 126312). Snout average in length, narrow, acute, and slopes gently at 35-45°; premaxillary pedicel long and strongly prominent; jaws isognathous to weakly prognathous, long, slim, very narrow, and rounded in dorsal view; gape large and slopes gently at 15-30°; maxilla (almost) extends to vertical through anterior point of pupil; lower jaw shallow and with a straight ventral outline in lateral view, mental prominence absent, and lower jaw side nearly flat with an inclination of 20-30° to horizontal in anterior view; upper jaw weakly expanded anteriorly; lips and oral mucosa thin (Ref. 126312). Neurocranium shallow, ethmo-vomerine block decurved, preorbital region very shallow, 19-21% of neurocranium length, orbital region shallow, 28-31% of neurocranium length, and supraoccipital crest shallow end wedge-shaped (Ref. 126312). Outer oral teeth numerous, unicuspid, and small; necks slender, cylindrical to conical, and weakly recurved; crowns recurved and acutely pointed; dental arcades rounded; outer teeth closely and regularly set with neck-distances of 1/2 neck-width; in upper jaw, 1-3 posteriormost teeth enlarged; inner teeth small, strongly recurved, unicuspid, and acutely pointed; tooth bands very slender crescent-shaped with 1-2 rows of inner teeth, and narrow posteriorly until only outer row remains past 2/3 lenghts of tooth bands; inner teeth closely and regularly set on 1/2-1 neck-width from outer row in lower jaw, on 1-2 neck-widths from outer row in upper jaw; implantation recumbent; size uniform throughout tooth band (Ref. 126312). Lower pharyngeal bone average in length, narrow, slim, and shallow with a slightly deeper keel; pharyngeal teeth relatively large and slender; major cusps acutely pointed; cusp gaps straight; minor cusps and cusp protuberances very small; teeth in two median longitudinal rows equal in size and form to lateral teeth, 10-11 in each row; posterior transverse row with 20-22 teeth, implanted erectly with a lateral inclination; major cusps weakly recurved, bluntly pointed, and laterally compressed; minor cusps mostly absent (Ref. 126312). Chest scales small; transition to larger flank scales gradual; minute scales on proximal half of caudal fin; scales on longitudinal line 31-34, scales on upper lateral line 20-23, scales on lower lateral line 8-11, scales between dorsal fin and upper lateral line 5-7, scales between upper lateral line and anal fin 10-11, scales around caudal peduncle 16-17, scales between pectoral and pelvic fins 5-6, infraorbital cheek scales 3-4, postorbital cheek scales 9-12 (Ref. 126312). Caudal fin emarginate; dorsal and anal fins reach to between verticals through caudal-fin base and two scales anterior to this vertical; pectoral and pelvic fins reach to anal opening, pelvic fin reaches to first anal-fin spine in males; first branched pelvic-fin ray elongated in all specimens (Ref. 126312). Ceratobranchial gill rakers in outer row of first gill arch short, stout, and simple; posteriormost rakers anvil-shaped, bi-, or trifid; epibranchial gill rakers slender and simple (Ref. 126312).

Colouration: Colouration in life of dominant males: colour pattern unknown (Ref. 126312). Colouration in life of non-dominant males: dorsal half of body dusky greenish; ventral half of body faint yellow; transition gradual; flank with blue sheen and 5-7 vertical stripes; belly, chest, and cheek whitish; operculum yellowish; snout dusky; eye with (dark) grey outer ring and silver inner ring; nostril and lacrimal stripes and nape band present; interorbital and supraorbital stripes faint; pectoral fin yellowish; pelvic fin black; dorsal fin dusky and with black lappets; anal fin faint orange and with 1-3 relatively large, yellow egg-spots with dusky rings; caudal fin dusky (Ref. 126312). Colouration in life of females and juveniles: body faint yellow with a greenish dorsum; belly and chest white; snout dusky; eye with (dark) grey outer ring and silver inner ring; nostril, interorbital, supraorbital, and lacrimal stripes and mental blotch faint; pectoral and pelvic fin yellowish; dorsal fin dusky and with black lappets; anal fin yellowish and with 2 spots resembling egg-spots; caudal fin dusky (Ref. 126312). Preserved colouration: body brown; dorsum dark brown; chest and belly white; cheek and operculum yellowish; snout dusky; flank with 5-7 faint vertical stripes; nostril and lacrimal stripes and mental blotch present; interorbital and supraorbital stripes faint; pectoral fin hyaline; pelvic fin yellowish with black first rays in females, black in males; dorsal and caudal fins dusky; dorsal fin with black lappets and posterior sooty part; caudal fin with maculated dorsal part; anal fin yellowish and with dusky distal margin and 1-3 relatively large egg-spots (Ref. 126312).

Biology:  Found over muddy substrates (Ref. 126312). Based on its morphology, most probably a piscivorous species (Ref. 126312).
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


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