| Nothobranchiidae (African rivulines) |
| 3.12 cm SL (male/unsexed); 3.02 cm SL (female) |
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benthopelagic; freshwater, |
| Africa: ephemeral pools and swamps on floodplains in coastal lowlands north of the lower Zambezi River in east-central Mozambique (Ref. 85866). |
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Dorsal spines (total): 0-0; Dorsal soft rays (total): 15-17; Anal spines: 0-0; Anal soft rays: 15-17. Diagnosis: Nothobranchius krysanovi is distinguished from other species of the genus Nothobranchius by the following combination of characters: males with bright colouration consisting of alternating light blue and orange-red oblique bars on body, dorsal and anal fins, and orange-brown caudal fin with orange subterminal and black terminal band; female with faint brown oblique bars on posterior part of flanks (Ref. 85866). It can be distinguished from the other species of the subgenus Nothobranchius as follows: from N. furzeri by male colouration, higher number of dorsal fin rays, 15-17 vs. 14-15; from N. kadleci by male colouration and shape of the frontal region, higher number of dorsal and anal fin rays, 15-17 vs. 13-14 and 15-17 vs. 13-14; and from N. orthonotus by male and female colouration, and lower number of scales on the mid-longitudinal series, 27-29 vs. 28-33 (Ref. 85866). Nothobranchius krysanovi can also be distinguished from N. rachovii by its higher number of diploid chromosomes, 2n=18 vs. 2n=16; and from N. pienaari by its much lower diploid chromosome number, 2n=18 vs. 2n=34 (Ref. 85866).
Description: Robust Nothobranchius of medium size; snout pointed, mouth terminal, directed slightly upward; body laterally compressed and deep; dorsal profile concave on head, convex from nape to end of dorsal fin; more convex in older males than in younger specimens; profile of caudal peduncle nearly straight (Ref. 858666). Supraorbital squamation G-type with frontal part partly covered with epidermal tissue; frontal and central supraorbital neuromast systems fused and forming two distinct shallow grooves; both lined with three shallow lobes at both sides of the groove; posterior cephalic neuromast systems in two curved grooves (Ref. 85866). Dorsal fin rays 15-17, anal fin rays 15-17; pelvic fins short, not reaching origin of anal fin; pectoral fins reaching to first pelvic fin rays (Ref. 85866). Scales on the median longitudinal line 27-29 + 3 on caudal fin base, most with shallow pit with one neuromast; transverse row of scales above pelvic fins 11, circumpeduncular scales 12 (Ref. 85866).
Colouration: Live male: body colour iridescent light-blue; scales with distinct orange-red margins; margin of some scales on posterior part of body and caudal peduncle more distinct, forming oblique bars, lower end forward; snout and head carmine-red to orange-red, throat orange-red; back anterior to dorsal fin carmine-red or brown-red; operculum with 2-3 orange-red oblique stripes; projecting part of branchiostegal membrane red to orange-red; iris yellow-bronze to gold with incomplete dark vertical bar; caudal fin orange-brown in the inner three quarters followed by a lighter orange subterminal band and black margin; dorsal fin bright blue with red or red-brown spots, larger in proximal part and smaller distally; spots may merge into oblong markings across fin; dorsal fin with narrow blue-white margin; anal fin similar to dorsal fin with lighter iridescent blue distal part lacking spots; ventral fins bright blue with dark red proximal spots; pectoral fins transparent translucent red with wide blue-white margin; iris golden with dark vertical bar (Ref. 85866). Live female: body colour grey-brown, darker on the back to silver on abdomen; several faint brown oblique bars, lower end to front, on posterior part of flanks; all fins colourless; iris bronze or gold with incomplete vertical dark bar (Ref. 85866). |
| Found in ephemeral pools and swamps on floodplains; water level in the habitats is subject to seasonal changes and generally the water disappears completely during the dry season (Ref. 85866). Grass vegetation is usually found near the habitat margins; much of the swamps may be utilised by local inhabitants for the cultivation of rice; aquatic vegetation may comprise Nymphea, Ottelia, Lagarosiphon and Utricularia species (Ref. 85866). It has an annual mode of reproduction (Ref. 85866). |
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Vulnerable (VU); Date assessed: 23 December 2018 (B1ab(iii)) Ref. (130435)
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| harmless |
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