| Diagnosis: |
Dorsal spines (total): 17-19; Dorsal soft rays (total): 8-10; Anal spines: 3-3; Anal soft rays: 7-8. Diagnosis: The dark submarginal band in the spinous part of the dorsal fin of both male and female distinguishes Petrotilapia pyroscelos from P. tridentiger, P. xanthos, P. flaviventris, and P. palingnathos, which lack such a band (Ref. 87181). Males of P. pyroscelos have blue and bronze ground color with 7-9 gray vertical bars, whitish to gray throat and purple cheek, which distinguishes it from P. genalutea, P. nigra, P. chrysos, P. microgalana and P. mumboensis; males of P. genalutea are dull gray-blue with 5-7 black vertical bars, have an orange-yellow cheek, and a black throat; males of P. nigra and P. chrysos are predominantly blue-black with 7-10 gray/brown bars, have a dark blue cheek, and a black throat; males of P. microgalana are bright blue with 5-7 faint black vertical bars, and have a light blue cheek and a yellow throat, while those of P. mumboensis are blue with 8 dark blue vertical bars, light blue cheeks, and a light blue to gray gular region (Ref. 87181). Females of P. pyroscelos are brown with faint blue and yellow highlights with a conspicuous black submarginal band in the dorsal fin; females of P. pyroscelos are distinguished from those of P. genalutea, P. nigra, P. chrysos, and P. microgalana by the brown to gray ground color on the flank which is beige or yellow in the other species and are distinguished from females of P. mumboensis which lack any horizontal elements of the flank’s pigmentation pattern (Ref. 87181).
Description: body depth at origin of dorsal fin 32.1-37.6% of standard length; dorsal head profile concave between snout tip and interorbital region (Ref. 87181). Horizontal and vertical eye diameters 28.9-35.9% of head length and 31.1-35.9% of head length, respectively; preorbital depth 22.2-28.6% of head length; snout length 33.5-39.9% of head length; isognathous jaws and thickened lips; teeth on lower jaw in 10-18 rows with outer row and inner rows tricuspid (Ref. 87181). Dorsal fin with XVII-XIX spines and 8-10 rays; anal fin with III spines and 7-8 rays; first dorsal-fin spine less than half length of tenth spine; caudal fin subtruncate to emarginate; depressed pelvic fin not reaching anal fin in most females and to first or second anal-fin spine in males; pectoral fin round and paddle-shaped (Ref. 87181). Flank scales large, ctenoid; cheek with 3-5 rows of scales; lateral line with 29-33 pored scales (Ref. 87181).
Colouration: Live males with dark gray interorbital region, no interorbital bar; cheek, preorbital, opercle, and pre-opercle blue with purple highlights and dark gray opercular spot; throat whitish to gray; flank blue with bronze highlights and 7-9 dark gray to blue bars; breast and belly whitish to gray; dorsal fin blue with broad black submarginal band and light blue lappets; caudal fin with dark gray rays and blue membranes; anal spines and membranes black, rays black to gray and with clear membranes and 1-2 yellow ocelli; pelvic fin orange with white leading edge; pectoral fin with dark blue rays and clear membranes (Ref. 87181). Live females with brown head; blue and green highlights on cheek, black opercle spot and white throat; flank brown with faint blue and yellow highlights with often vague series of midlateral and dorso-lateral spots, and 7-9 vertical bars; scales outlined in blue; pale yellow breast with white belly; anal fin with gray rays, clear membranes, and 3 yellow ocelli; dorsal fin with brown spines and rays; black submarginal band, yellow and light blue lappets with brown tips; caudal fin with gray rays and clear membranes; pelvic fin with white to light blue leading edge; pectoral fin with brown rays and clear membranes (Ref. 87181). Preserved males with dark brown head, black opercle, brown cheek, and yellowish to light brown throat; flank dark brown; faint dark vertical bars, white belly, and brown breast; dorsal fin with black submarginal band, gray membranes, and gray to brown spines and rays; caudal fin with dark gray rays and gray membranes; anal-fin spines and membranes black, rays black to gray with clear membranes; pelvic-fin spine and first three rays gray with clear membranes, posterior rays and membranes clear; pectoral fin with gray rays and clear membranes (Ref. 87181). Preserved females with brown head, black opercle, brown cheek, and a yellowish to brown throat; flank brown with blotches and faint vertical bars; breast yellow, belly white to yellow; dorsal fin with black submarginal band, gray spines and membranes; rays with brown spots; caudal fin with brown to gray rays and clear membranes; anal fin with gray to brown spines with brown to clear membranes; pelvic spines and first two rays dark with dark to clear membranes; pectoral fin with gray rays and clear membranes (Ref. 87181). |