Nothobranchius torgashevi Valdesalici, 2015

Family:  Nothobranchiidae (African rivulines)
Max. size:  4.31 cm SL (male/unsexed); 3.26 cm SL (female)
Environment:  pelagic; freshwater; pH range: 8.3 - 8.3
Distribution:  Africa: Mhwala River, Lake Eyasi basin, in Tanzania (Ref. 116436).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 16-17; Anal spines: 0-0; Anal soft rays: 17-18; Vertebrae: 29-29. Diagnosis: The colour pattern of Nothobranchius torgashevi males is compparable to that of other N. ugandensis group members, comprising light blue scales and a broad, irregular reticulated pattern on the body, vivid orange or red oblique bars on the head and dorsum, a yellow or blue anal fin, and large vivid red spots on the dorsal and anal fins; other shared characters include: head rounded with a slightly concave to nearly straight dorsal profile; predorsal region convex between the nape and posterior extremity of the dorsal fin base; cephalic squamation variable (Ref. 116436). Nothobranchius torgashevi can be distinguished from all other species in the N. ugandensis group by the following combination of characters: flank scales with red margins; caudal fin plain red; pectoral fin hyaline with a few proximal red dots; anal fin light blue with red dots proximally, yellow or creamy white distally; dorsal and anal fins with red margin; 16-17 dorsal fin rays; 17-18 anal fin rays; 31-33 scales in the median lateral series; 11-12 transverse scale rows; 16 circumpeduncular scales (Ref. 116436). Description: Dorsal profile convex on head and from nape to posterior extremity of dorsal fin base; ventral profile convex, slightly concave to nearly straight on caudal peduncle posterior to dorsal and anal fins; snout slightly pointed, mouth directed upwards, lower jaw longer than upper jaw, posterior end of rictus level with or slightly above centre of eye (Ref. 116436). Dorsal and anal fin origins posterior to mid-body; anal fin origin at vertical through dorsal fin rays 1-2; pectoral fin approximately triangular, posterior tip not reaching pelvic fin; pelvic fin short, tip reaching anus; caudal fin subtruncate; dorsal-fin rays 16-17; anal-fin rays 17-18; caudal-fin rays 37; pectoral-fin rays 19; pelvic-fin rays 6 (Ref. 116436). Scales cycloid, body and head entirely scaled; cephalic squamation pattern irregular; scales in median lateral series 31-33+5 on caudal-fin base; transverse scale rows 11-12; circumpeduncular scales 16 (Ref. 116436). Frontal neuromast pattern of 'open' type; anterior supraorbital neuromast series in a shallow groove with three or four neuromasts; posterior supraorbital neuromast series curved with three neuromasts; preopercular neuromast series in an open groove, distal ridge slightly overlapping opercle; few scales in lateral series with neuromast (Ref. 116436). Basihyal bone sub-triangular, basihyal cartilage spatulate; six branchiostegal rays; vomerine teeth in a small patch; lateral process of post-temporal absent, a single antero-dorsal process of urohyal present; second pharyngobranchial with one tooth; total number of verebrae 29; premaxilla and dentary with many, irregularly distributed, unicuspid, slightly curved teeth of variable size, a small number of larger teeth on the outer row in both jaws (Ref. 116436). Colouration: In life, males exist in white and yellow colour morphs; flank light blue with red reticulations; side of head light blue with red reticulations; frontal and superior portions of head, dentary, and upper portion of lower jaw red; iris silvery with yellowish reflection, a faint black vertical bar through centre of eye; branchiostegal membrane white; dorsal fin light blue with dark red dots; in the white morph, anal fin light blue with red dots on basal half, creamy white on distal half; in the yellow morph, anal fin light blue with red dots on basal half, yellow on distal half; margin of dorsal and anal fins red; caudal fin red; pectoral fin hyaline with dots on proximal portion and light blue posterior margin; pelvic fin light blue to whitish with red dots (Ref. 116436). Females with body and head scales light brown-grey, whitish ventrally; posterior scale margins darker than remainder, forming a reticulated pattern; opercular region whitish with light blue reflection; scales on dorsal surface and upper body reflective light blue posteriorly; fins hyaline; iris silvery (Ref. 116436).
Biology:  Found in a seasonal ditch, less than 1 m deep and without aquatic vegetation, the water light clay grey and turbid with a pH of 8.3 and temperature varying from 25 to 30°C (Ref. 116436).
IUCN Red List Status: Vulnerable (VU); Date assessed: 12 January 2019 (B1ab(iii)) Ref. (130435)
Threat to humans:  harmless


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