| Diagnosis: |
Dorsal spines (total): 14-16; Dorsal soft rays (total): 9-10; Anal spines: 3-3; Anal soft rays: 7-8. Diagnosis: Pelvicachromis silviae is distinguished from other species of Pelvicachromis by a combination of characters (Ref. 93865). It differs from P. subocellatus in somewhat greater body depth, being 37.4-43.0% of standard length vs. 34.5-41.6%; shorter snout length, 20.4-28.1% of head length vs. 23.4-30.9%; greater eye orbit diameter, 31.3-35.7% of head length vs. 28.9-32.9%; greater lower jaw length, 30.9-38.5% of head length vs. 25.4-35.3%; lesser scales between pelvic and pectoral, 3-5 vs. 5-6; in males in lappet-like elongation of some rays of caudal fin vs. no such elongation; and in females in greenish and yellow coloured parts on dorsal parts of body, situated over red belly region, vs. silver coloured scales around red belly region (Ref. 93865). It differs from P. sacramontis in greater body depth, being 37.4-43.0% of standard length vs. 29.0-36.5%; greater head length, 33.2-36.9% of standard length vs. 27.0-32.0%; greater caudal peduncle depth, 15.8-17.5% of standard length vs. 14.0-15.3%; shorter snout length, 20.4-28.1% of head length vs. 26.2-38.7%; greater postorbital distance, 40.4-45.7% of head length vs. 31.7-41.8%; shorter interorbital distance, 24.0-27.9% of head length vs. 29.4-45.3%; and shorter preorbital distance, 16.3-17.3% of head length vs. 18.7-26.5% (Ref. 93865). It differs from P. pulcher in greater body depth, being 37.4-43.0% of standard length vs. 32.6-38.3%; greater head length, 33.2-36.9% of standard length vs. 27.8-32.0%; greater caudal peduncle depth, 15.8-17.5% of standard length vs. 13.0-15.3%; shorter caudal peduncle length, 12.4-14.5% of standard length vs. 13.8-16.5%; shorter snout length, 20.4-28.1% of head length vs. 27.6-36.6%; greater postorbital distance, 40.4-45.7% of head length vs. 34.8-40.4%; shorter interorbital distance, 24.0-27.9% of head length vs. 25.9-33.1%; and shorter preorbital distance, 16.3-17.3% of head length vs. 21.0-33.8% (Ref. 93865). It differs from P. roloffi in greater body depth, being 37.4-43.0% of standard length vs. 33.6-37.6%; geater head length, 33.2-36.9% of standard length vs. 31.5-33.0%; greater caudal peduncle length, 15.8-17.5% of standard length vs. 9.4-12.2%; and higher number of pored scales of lateral line, 26-28 vs. 24-26 (Ref. 93865). It differs from P. taeniatus in greater body depth, being 37.4-43.0% of standard length vs. 29.9-36.4%; greater head length, 33.2-36.9% of standard length vs. 28.4-33.8%; greater pre-anal distance, 66.2-69.8% of standard length vs. 62.8-66.7%; greater prepelvic distance, 37.9-44.3% of standard length vs. 36.0-37.5%; shorter preorbital distance, 16.3-17.3% of head length vs. 18.6-21.1%; and fewer spines in dorsal fin, 14-16 vs. 17-18 (Ref. 93865). It differs from P. kribensis in greater body depth, being 37.4-43.0% of standard length vs. 30.4-37.3%; greater prepelvic distance, 37.9-44.3% of standard length vs. 32.5-37.7%; shorter preorbital distance, 16.3-17.3% of head length vs. 17.0-22.3%; and lesser spines in dorsal fin, 14-16 vs. 17-18 (Ref. 93865). It differs from P. sp. aff. taeniatus "Wouri" in greater body depth, being 37.4-43.0% of standard length vs. 28.7-35.1%; greater prepelvic distance, 37.9-44.3% of standard length vs. 33.4-39.5%; greater eye orbit diameter, 31.3-35.7% of standard length vs. 22.6-32.5%; more slender caudal peduncle, its length 73.2-85.3% of its depth vs. 93.9-124.6%; and fewer spines in dorsal fin, 14-16 vs. 17-18 (Ref. 93865). It differs from P. humilis, P. rubrolabiatus and P. signatus in absence of 7-8 vertical bars on body, visible in several behavioural situations; in three infraorbital bones vs. two; in greater body depth, 37.4-43.0% of standard length vs. 26.4-34.1%; shorter caudal peduncle length, 12.4-14.5% of standard length vs. 13.1-18.1%; greater anal-fin base length, 18.6-22.5% of standard length vs. 13.6-21.0%; shorter snout length, 20.4-28.1% of head length vs. 25.3-43.0%; greater interorbital distance, 24.0-27.9% of head length vs. 18.2-25.6%; and shorter preorbital depth, 16.3-17.3% of head length vs. 19.8-28.7% (Ref. 93865).
Description: Body moderately elongate, head relatively short but deep (Ref. 93865). Jaws isognathous; dorsal head profile slightly rounded; dorsal profile curving gently downward along length of dorsal fin base; ventral profile gently rounded in males and non-ripe females, more rounded in ripe females (Ref. 93865). First ray of pelvic fin always longest in males, tip of pelvic fin reaching anterior base of anal fin or beyond; in females, first ray of the pelvic fin shorter or of equal length to second ray (Ref. 93865). Caudal fin mostly rounded in both sexes, but with some elongated rays in upper portion in males, forming a small lappet (Ref. 93865). Some rays in posterior parts of dorsal and anal fins pronounced, but always much longer in males (Ref. 93865). Premaxilla with 2 rows, dentary with 2 or 3 rows of regularly set unicuspid teeth; anteriorly in lower jaw a few teeth are slightly rotated and point inward (Ref. 93865). Scales cycloid; 1-3 rows of scales on cheek; 4 horizontal rows on opercle; dark spot on outer edge of opercle unscaled; chest-scales smaller than body scales, 3-5 scales between pectoral en pelvic fins; upper lateral-line separated from dorsal-fin base anteriorly by three scales, at 8th pored scale by 1-1.5 scales, and at last pored scale by 0.5-1.5 scale; end of upper lateral-line never overlapping lower lateral-line, separated from beginning of lower lateral line by 1-3 rows of scales; about 1/3-1/4 of caudal fin covered with scales, all other fins unscaled (Ref. 93865).
Colouration: Head and body pale brown to yellowish brown; dorsum a bit darker than ventral parts of body; dark scaleless spot on outer edge of opercle; upper and lower lips yellow to brown (Ref. 93865). A black mid-lateral band from posterior edge of opercle extending to end of caudal peduncle, not reaching into caudal fin; a black dorsolateral band reaching from front of head to about end of dorsal fin, contiguous with a soft dorsal-fin base at most posterior parts, separated from mid-lateral band by a pale, yellowish to brownish band of about equal depth than dark mid-lateral band; two dark interorbital stripe and a dark stripe from lower parts of anterior edge of eye to angle of mouth (Ref. 93865). All dark bands can disappear in several behavioural situation, e.g. dominant and aggressive or courting specimens; sometimes the two longitudinal bands on body can be disentangled to dark blotches, but connected with dark vertical bars from dorsum to middle of body; this pattern is often to see in specimens doing broodcare (Ref. 93865). A pale bluish to turqoise iridescent stripe can appear on ventral and posterior edge of preopercle; eye golden-yellow to brownish; pelvic fins with a blue margin on anterior edge, followed by a blackish submargin and a thin, iridescent blue band, rest of this fin reddish to violet; pectoral fins clear to pale yellowish (Ref. 93865). |
