Petrocephalus magnitrunci

General description: 

Original description from Kramer et al (2012):

Rounded-oval body of egg-like shape. Rounded head with a small ventrally positioned subterminal mouth, situated ventral to the eye; head and body dorsolaterally compressed. Dorsal fin (a) origin situated about two-thirds of standard length from snout, (b) obliquely orientated, anteriorly higher and posteriorly lower, (c) distal margin crescentic with anterior two or three rays longer than posterior rays, and (d) number of rays 19 (n = 2), 20 (n = 3), 21 (n = 5), 22 (n = 1); no spot below dorsal fin origin. Anal fin (a) longer than dorsal fin, (b) opposite dorsal fin with slightly more anterior origin, (c) obliquely orientated, anteriorly lower and posteriorly higher, (d) anterior 10 or so rays longer than posterior ones, especially in males where they also appear stronger, (e) margin broadly rounded, (f) rays posterior to first 10 with distal margin straight, (g) number of rays 27 (n = 1), 28 (n = 2), 29 (n = 3), 30 (n = 2), 31 (n = 3). Forked tail fin with rounded lobes. Scales cycloid with reticulate striae, scales extending anteriorly to operculum and pectoral fins (beyond pelvics). Scales in lateral series, 39 (n = 5), 40 (n = 3), 41 (n = 3). Scales on caudal peduncle circumference, 11 (n = 1), 12 (n = 10). Caudal peduncle slender, subcylindrical entire length, usually 19.2% (17.6–21.5%) of SL. Males with kink in anal fin base, which is absent in juveniles and females where the anal fin base is straight.

Colour in preservation: intense brown, with dark back, breast and belly lighter.

Diagnostic description: 

From Kramer et al (2012):

Number of scales in lateral line row, SLS, median 40 (range 39–41); body depth, BD, mean 0.344 (range 0.327–0.368) of SL; eye diameter as defined by orbital rims, OD, mean 0.232 (range 0.218–0.250) of HL, head length; number of dorsal fin rays, nD, median 21 (range 19–22); anal fin length, LA, mean 0.254 (range 0.235–0.27) of SL; length of snout to posterior orbital rim of eye, LSo, mean 0.464 (range 0.449–0.481) of HL; head length, HL, mean 21.2 (range 17.6–24.1) times Na, distance between the pair of nares of one side.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith