Blackspotted Nothobranch

Diagnosis: Distinguished from all congeners by the combination of the following character states: caudal fin red with black posterior margin in males, narrow white margin to dorsal and anal fins, and silver iris; posterior portion of flank and unpaired fins with black spots in females; pre-dorsal length in males 62.4-65.1% of standard length; 5 + 15-16 gill-rakers on first branchial arch; 29-31 scales in longitudinal series; 16-18 series of scales around caudal peduncle; two longitudinal rows of scales between anterior supraorbital series of neuromasts; anterior supraorbital series of neuromasts arranged continuously, with four well-developed neuromasts; four neuromasts in posterior supraorbital series; 29-31 caudal-fin rays; 30-31 vertebrae; second proximal radial of dorsal fin between neural spines of 13th and 15th vertebrae (Ref. 83514, 122075). This species differs from Nothobranchius lucius in having a plain red caudal fin with narrow margin at the upper and lower corners in male (Ref. 83514).Description: Dorsal and ventral profiles slightly convex from snout to posterior end of dorsal and anal-fin bases, approximately straight on caudal peduncle; body moderately deep, compressed; greatest body depth at vertical just in front of pelvic-fin base (Ref. 122075). Jaws short, snout slightly pointed in lateral view; mouth superior, lower jaw slightly anterior to upper jaw; jaw teeth canine, numerous, irregularly arranged; outer teeth greater than internal teeth; vomerine teeth 8-12 (Ref. 122075). Branchiostegal rays 6; gill-rakers of first branchial arch 5 + 15-16; basihyal sub-triangular, greatest width about 85% of length; basihyal cartilage about 80% of total length of basihyal (Ref. 122075). Dorsal and anal fins broad in males, extremity rounded, with short filamentous rays along distal margin; in females, dorsal fin rounded, anal fin sub-triangular and slightly longer than dorsal fin; caudal fin subtruncate to rounded; pectoral fin sub-elliptical, posterior extremity between pelvic-fin base and anus; pelvic fin small, tip reaching between urogenital papilla and anal-fin origin; pelvic-fin bases medially in contact; in males, minute papillate contact organs on first and second pectoral-fin rays and distal portion of middle dorsal-fin rays, and rows of well-developed papillate contact organs along two-thirds of most rays of anal fin; dorsal-fin origin on vertical between base of second and fourth anal-fin rays; dorsal-fin rays 15-17; anal-fin rays 16-19; caudal-fin rays 29-31; pectoral-fin rays 18-21; pelvic-fin rays 6 (Ref. 122075). Scales small, cycloid; body and head entirely scaled, except ventral surface of head; minute filamentous contact organs along posterior margin of scales on middle portion of flank and latero-ventral portion of head in males; body squamation extending over anterior 30% of caudal-fin base; no scales on dorsal and anal-fin bases; frontal squamation irregularly arranged in two longitudinal rows between anterior supraorbital neuromast series; longitudinal series of scales 29-31; transverse series of scales 9-11; scale rows around caudal peduncle 16-18 (Ref. 122075). Anterior supraorbital series of neuromasts arranged in single section placed in nearly continuous depression, with five neuromasts; posterior supraorbital series with four neuromasts placed in shallow depression; infraorbital series with 18-25 neuromasts, pre-opercular series 15-18, mandibular 17-21; one neuromast per scale of lateral line; two neuromasts on caudal-fin base (Ref. 122075). Total vertebrae 30-32; second proximal radial of dorsal fin between neural spines of 13th and 15th vertebrae; first proximal radial of anal fin between pleural ribs of 12th and 15th vertebrae; ventral process of post-temporal well-developed; hypurals completely fused, forming single hypural plate without vestige of median gap (Ref. 122075).Colouration: Colouration in life for males: flank light green to light greenish blue; posterior margin of scales red, forming red reticulate pattern, often with narrow chevron-shaped red bars overlapping red reticulum on posterior half of flank; dorsum pale brown, venter yellowish white; side of head light greenish blue; jaws, dorsal and ventral parts of head pale yellow; red pigmentation forming reticulate pattern on post-orbital region, often forming three oblique, short red bars; iris light blue; dorsal fin pale yellow, with dark red transverse oblique bars with irregular sinuous margins, broader on basal and posterior portions of fin; distal filaments white; anal fin pale yellow, basal portion with red bars irregularly arranged; filaments light grey with white tips; caudal fin red, with dorsal and ventral posterior corners of fin black, sometimes black pigmentation extending along whole posterior border, forming narrow black posterior margin; pectoral fin yellowish hyaline, with bluish white distal margin, wider dorsally; pelvic fin pale yellow with small red spots; margins white; often black pigmentation concentrated on subdistal portion of fin; in some males collected in the middle Ruvu River basin and Lower Rufiji River basin, red pigmentation was absent, making exemplars predominantly pale blue (Ref. 122075). Colouration in life for females: flank pale brown, often with horizontal rows of pale greenish blue spots on anterior portion; black dots on posterior portion of flank, and few dark grey on anterior portion; dorsum pale brown, venter white; head pale brown, opercular region pale greenish yellow; iris pale yellow; fins hyaline, with grey dots on basal portion of unpaired fins (Ref. 122075).

Annual fishes.

Dorsal spines (total): 0; Dorsal soft rays (total): 15 - 17; Analspines: 0; Analsoft rays: 16 - 19; Vertebrae: 30 - 32

Occurs in temporary pools in floodplains, rice fields, swamps, ditches and small streams (Ref. 3788). Occurs in seasonal pools and streams in the coastal region of Tanzania.

Found in temporary pools in floodplains, rice fields, swamps, ditches and small streams (Ref. 3788). Found in water-filled depressions in floodplains of rivers; with vegetation often near edges, usually grasses; occasionally grasses cover the entire pool; if aquatic vegetation is present, it may comprise of Nymphea, Ottelia, Lagarosiphon, and Utricularia species; annual species; eggs deposited in substrate where they survive dry season; hatching at onset of wet season; rapid growth of fry; sexual maturity may be attained in six weeks; may be associated with other annual or non-annual fish species (Ref. 83514). Bottom spawner; 4 months incubation; difficult to maintain in aquarium (Ref. 27139).

fisheries: of no interest; aquarium: commercial

The blackspotted nothobranch (Nothobranchius melanospilus) is a species of fish in the family Nothobranchiidae. It is found in Kenya and Tanzania. Its natural habitats are temporary pools and floodplains, rice fields, swamps, ditches, and small streams. It grows to 7.5 cm (3.0 in) total length.