Serranochromis cacuchi Stauffer, Bills & Skelton, 2021 Cacuchi largemouth bream |
Family: | Cichlidae (Cichlids), subfamily: Pseudocrenilabrinae | |||
Max. size: | 19.15 cm SL (male/unsexed) | |||
Environment: | benthopelagic; freshwater | |||
Distribution: | Africa: Cacuchi River, tributary of the Cuchi-Cubango (Okavango) River in Angola (Ref. 123822). | |||
Diagnosis: |
Dorsal spines (total): 14-15; Dorsal soft rays (total): 12-13; Anal spines: 3-3; Anal soft rays: 9-9. Diagnosis: The presence of ocelli throughout the anal fin of breeding males distinguishes Serranochromis cacuchi from S. robustus and S. jallae in which the ocelli in breeding males are restricted to the posterior 4-5 membranes of the anal fin (Ref. 123822). The exposed teeth of S. cacuchi differs from those of S. stappersi and S. altus, which possess small teeth that are buried in the lips; Serranochromis cacuchi has an emarginate caudal fin, while S. macrocephalus, S. janus, and S. angusticeps have rounded caudal fins; the shorter jaw of S. cacuchi, 47.8-52.3% of head length, separates it from S. spei, 53.5-57.2% of head length; Serranochromis cacuchi has 32-33 lateral-line scales, while S. thumbergi possesses more than 39 lateral-line scales; the acute angle of the cleft of the mouth, 50-60° of horizontal, of S. meridianus delimits it from the 25° angle of S. cacuchi; the long dark pectoral fins which reach past the middle of the dorsal fin separates S. longimanus from S. cacuchi (Ref. 123822). The interorbital width, 20.0-21.7% of head length, delimits S. cacuchi from S. alvum, 14.3-15.9% of head length; the snout length of S. cacuchi, 35.2-39.6% of head length, is longer than that of S. alvum, 30.3-34.9% of head length, and S. cuanza, 26.9-34.7% of head length; the larger preorbital depth of S. cacuchi, 19.1-22.2% of head length, distinguishes it from S. swartzi, 16.2-18.9% of head length (Ref. 123822). Description: Body slender, fusiform, and compressed, deepest at origin of dorsal fin; predorsal profile straight at 30° to horizontal, with shallow kink at interorbit and gentle curve towards dorsal fin (Ref. 123822). Dorsal-fin origin at vertical through posterior edge of operculum, dorsal fin with 14-15 spines and 12-13 rays, spines increase to maximum length over 5-6 spines, spine lappets prominent; soft dorsal pointed behind, not beyond base of caudal fin; caudal fin broad, relatively short, around half the head length, emarginate; anal fin with 3 spines and 9 rays, origin well behind midline and closer to caudal-fin base than tip of snout, below vertical through base of ultimate dorsal spine, soft-rayed section with pointed hind edge, not extending to below base of caudal fin; pectoral fin close behind gill slit, base inclined ventro-lateral on flanks, obtusely pointed, to pelvic extremity; pelvic fins ventral, with strong spine half a length of fin, origin narrowly behind base of pectoral fins, not reaching to anus and anterior base of anal fin (Ref. 123822). Caudal peduncle moderately long, 16-20% of standard length, length 1.4-1.8 times depth (Ref. 123822). Scales small, with around 14 regular rows across flanks; 16 rows around the caudal peduncle, 32-33 in lateral line; upper lateral line gently curved, lower lateral line short but straight; three scale rows between anterior dorsal dn lateral line, two scale rows between soft dorsal and posterior end of upper lateral line; chest scales small, reduced, and irregular; pored scales posterior to lateral line 1-2, cheek scales 5-6 (Ref. 123822). Head elongate, 2.7 times in standard length, 36.6-37.5% of standard length, length greater than body depth, acute and pointed with marginally kinked predorsal profile, extending 30-35° above horizontal; eyes large, horizontal eye diameter 18.5-24.5% of head length, vertical eye diameter 17.7-22.3% of head length, dorso-lateral in anterior half of head, entirely above level of the mouth and at level of dorsal edge of the operculum; snout relatively long, 2-3 times orbit diameter, 35.2-39.6% of head length, nares in mid-snout before orbits; preorbital depth 1.5 times orbit diameter; cheek below and behind orbits deep with 4-5 rows of scales; post-orbit less than half length of head, interorbit sub-equal to orbit diameter, 20.0-21.7% of head length; mouth terminal, large, lower jaw 47.8-52.3% of head length, protractile, angle of closed jaw of holotype 25° below horizontal, posterior premaxilla to below anterior orbit, lips well developed, even along jaws (Ref. 123822). Teeth caniniform, exposed, narrowly spaced in two rows on upper and 2-3 rows on lower jaws (Ref. 123822). First branchial arch with 3-4,1,10-11 gill-rakers; gill opening large, curved from level of eye to midventral below vertical through eye (Ref. 123822). Colouration: Preserved specimens shades of brown and grey (Ref. 123822). Colouration in life: head with dark interorbital, dark bar from orbit to posterior maxilla and white gular; green-blue highlights and small orange-red spots on cheek, opercle and preopercle; dark opercular spot; ventral head, throat to base of pectorals and belly white; laterally dark grey patch above pectoral base, lower flanks yellow to light green, whitish ventrally, dark olive-grey across dorsum, with single thin lateral band and 8-9 short bars; dark orange-red spots in centre of each scale forming 8-10 rows, green-blue highlights between spots; dorsal fin with membranes between anterior 7-9 spines olive proximally to grey distally; posterior spinous and rayed membranes light olive yellow with rows of dark grey spots, lappets and dorsal edge to tip of soft-rayed bright red with narrow pale blue submarginal band; caudal fin light olive-yellow with dark spots scattered throughout membranes and forming bars, broad light grey margin; anal fin with yellow cast and rows of 2-5 red egg spots along membranes including distal single egg spots over spines, thin charcoal dusted margin along ventral edge; pelvic and pectoral fins clear with feint yellow cast (Ref. 123822). |
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Biology: | ||||
IUCN Red List Status: | Not Evaluated (N.E.) Ref. (130435) | |||
Threat to humans: | harmless |