Enteromius validus (Stiassny, Liyandja & Monsembula Iyaba 2016)

Diagnosis: It is distinguished from all other African smiliogastrin species by the following features that, in combination, uniquely diagnose the species: scales in midlateral series not enlarged relative to impinging rows above and below; barbels well developed, maxillary pair extending beyond level of mideye, mandibular pair reaching level of midopercle; numerous conical tubercles over snout and cheek, and dorsum of head; small circular occipital fontanel often present and located medially at parietal suture; gill rakers well developed, 8 or 9 on hypo- and ceratobranchial elements of first arch; last unbranched dorsal-fin ray weakly ossified, flexible, and lacking serrations along posterior edge; dorsal fin creamy white proximally, distal half to two thirds darkly pigmented (Ref. 106731).Description: A robust, deep-bodied "Barbus" species; head relatively small, eyes large, mouth subinferior; barbels robust and prominent, maxillary pair extending beyond level of mideye, mandibular pair reaching level of midopercle; mature males with rows of large conical tubercles over snout, and numerous smaller tubercles scattered over dorsum of head; tubercles present, generally smaller and less prominent in females and juveniles (Ref. 106731). Small, circular, occipital fontanel usually present, located in midline at parietal suture, contained entirely within parietals; 5 infraorbitals (IO): IO1 deepest of series, IO2–4 with infra-orbital canal portion of bone occupying dorsal half of each element, IO3 longest of series, twice length of IO1, IO5 reduced to canal (Ref. 106731). Scales radially striated, 22–25 in lateral line + 2–3 scales over caudal fin base, 3.5/1/2.5 body rows, 11-12 circumpeduncular rows, and 7–8 predorsal rows; lateral line complete, scales not enlarged relative to those along impinging rows above and below (Ref. 106731). Dorsal fin iii.8, positioned midway between snout and caudal-fin base, origin anterior to pelvic-fin insertion; last unbranched ray long and flexible, lacking serrations on posterior border; anal fin iii.5; forked caudal fin, 9 + 10 principal rays, 7–8 + 8–10 procurrent rays; pelvic fin i.7 rays; pectoral fin i.14–15 rays (Ref. 106731). Gill rakers well developed, 8-9 arrayed along hypo- and ceratobranchial of first arch, one smaller epibranchial raker usually present (Ref. 106731). Total vertebrae 34-35, 18–20 abdominal, 15–17 caudal; 13-14 pleural ribs; 4–5 supraneurals located between neural spines of vertebral centra 4–8; first dorsal-fin pterygiophore between neural spines of vertebral centra 9–10, and first anal-fin pterygiophore directed at hemal spine of vertebral centra 19 or 20; caudal-fin rays supported by neural and hemal spines of preural centra 2–3; pleurostyle, single epural, parhypural + 7 hypural elements present (Ref. 106731).Gut morphology: digestive tract short; esophagus leads to large, elongate, thick-walled stomach; intestine exits directly from distal end of stomach, making a single rostrocaudad loop before descending to anus; total length of tract, unraveled but not stretched, ca. 80%–90% of standard length (Ref. 106731).Colouration: Preserved specimens: base body colouration yellowish brown, darker dorsally, becoming pale ventrally and over belly, cheek, and jaws; snout and dorsum of head dark grayish brown; faint trace of a cleithral stripe present in large individuals but often obscured by opercular margin; body scales with a dark chevron-shaped marking along proximal edge, strongest dorsally and particularly along lateral line, less clearly marked ventrally; dorsal fin creamy white proximally, distal half to two thirds darkly pigmented; pectoral and pelvic fins smoky gray, strongly so in larger males; scales over region of caudal flexion somewhat darker than preceding scales and forming a trace of a caudal bar; base of caudal fin pale gray proximally, hyaline distally (Ref. 106731). Colouration immediately post mortem: similar to that in preservation but overlain with a silvery reflectance and pale rose flush on ventrum; rosy flush particularly evident in large males where it extends onto pectoral, pelvic, and anal fins (Ref. 106731).

Dorsal spines (total): 0; Dorsal soft rays (total): 11; Analspines: 0; Analsoft rays: 8; Vertebrae: 34 - 35

This species is omnivorous and opportunistic (Ref. 106731). Gut contents contained disarticulated insect remains, woody debris, seeds, macerated grasses and terrestrial arthropod remains of spiders and ants (Ref. 106731). Specimens collected in June, July, and August showed no sign of maturation of ovaries or testes; most large individuals collected in March had enlarged testes or ovaries filled with numerous small, round eggs suggesting that peak breeding occurs at that time (Ref. 106731).

fisheries:

Enteromius validus is a species of ray-finned fish in the family Cyprinidae. It is endemic to the Democratic Republic of the Congo where it inhabits the N’sele River and Mayi Ndombe River in the Congo River basin. Its natural habitat is freshwater marshes.