Petrocephalus Marcusen, 1854

Kramer, Bernd, Bills, Roger, Skelton, Paul & Wink, Michael, 2012, A critical revision of the churchill snoutfish, genus Petrocephalus Marcusen, 1854 (Actinopterygii: Teleostei: Mormyridae), from southern and eastern Africa, with the recognition of Petrocephalus tanensis, and the description of five new species, Journal of Natural History 46 (35 - 36), pp. 2179-2258 : 2228-2233

Genus Petrocephalus Marcusen, 1854

Diagnosis 1

(Translated from Taverne 1969, reproduced with permission granted from the author.)

“Fairly short body; eye medium to large; snout much shorter than the postorbital portion of the skull and rounded; mouth underslung and located below the eye; nostrils slightly closer to the eye than to the end of the snout; caudal peduncle 2.5 to 3 times as long as high; 19 to 33 rays on the dorsal fin; two initial unbranched spines on the dorsal fin instead of one like the other Mormyridae ; 25–39 rays on the anal fin; 9 or rarely 10 rays on the pectoral fin; 6 rays on the ventral fin; 39–44 rays on the caudal fin;

Petrocephalus magnoculis 43982 Petrocephalus magnoculis 43992 Petrocephalus magnoculis 43984 P. magnoculis Petrocephalus magnoculis 43983 Petrocephalus magnoculis 43991 Petrocephalus magnoculis 43987 Petrocephalus longicapitis 51428

Petrocephalus Petrocephalus longicapitis longicapitis 51430 51429

P. longicapitis

Petrocephalus longicapitis 51431 catostoma 35836

catostoma 35837

P. catostoma

50695

50696 50698

P. wesselsi

50699

Marcusenius altisambesi 57467 100 Marcusenius altisambesi 50679

0.02

pelvic fins a bit closer to the pectorals than to the anal fin; scales more or less round and 90–105% as wide as they are long; 35–50 scales in lateral series; 6–15 / 11–15 scales in a transverse line on the body; 7–14 / 8–16 scales in a transverse line between the dorsal and anal fins; 8–16 scales around the caudal peduncle; jaws have 7–24 / 15–36 bicuspid teeth (10–26 / 16–36 according to Boulenger); the height of the skull (from the basioccipital bone to the top of the supra-occipital bone) measures 85–95% of the width of the skull (from one ex-occipital to the other); a lateral ethmoid is present; massive median ethmoid, vertically orientated, more or less bulging dorsally and measuring about 50% of the length of the frontal bone; 6 circumorbital bones with the dermosphenotic attached to the sphenotic, and antorbital and the first infraorbital separately ossified; massive dentition with short and wide branches, no rudimentary third branch and with the dental portion of the sensory mandibular canal very enlarged and open all along its course; uneven orbitosphenoid with 2 lateral branches that join to form a single septum which rests on the parasphenoid; olfactory nerve (I) passes through the orbitosphenoid, bulging into a nerve centre below the lateral ethmoid and passing into the olfactory sac between the median and lateral ethmoids; a single foramen for the left and right optical nerves (II) between the orbito-sphenoid and the basisphenoid bones; a single foramen between the pleurosphenoids and the pro-otics for the rami palatini of the left and right facial nerves (VII); basi-pterygoid process of the parasphenoid present; anterior portion of the parasphenoid is very high and only interlaces by means of 2 posterior extensions (instead of four) in the basi-occipital; the length of the toothed area of the parasphenoid measures 25–44% of the total length of this bone; the basi-occipital bone has a pair of tapering lateral processes touching the auditory diverticula of the swim bladder; very wide ectopterygoids which articulate with the lateral wings of the vomer; horizontal ventral median extension of the basi-occipital is longer than the lateral extensions; the angular does not extend into a thick point beyond the square; supra-occipital crest massive, already beginning to develop on the parietals and largely bypassing the posterior level of the skull; there is a basi-sphenoid; the crests of the epiotics extend very clearly on to the parietals; the frontal portion of the supra-orbital sensory canal opens into a large groove towards the front, only spanned by a bony bridge (vestigial remains of the dorsal vault of the canal) and foramen linking the supra-orbital canal to the interior of the skull, visible on the exterior plane of the frontal bone; a small vomer with lateral wings which are not ventrally fused and which are linked in the ectopterygoids; 2 toothed suprabasihyalic plates both bearing a few well developed conical teeth, the first of these plates does not extend towards the front beyond the level of the basihyal; indeterminate element (hypohyal bone?) of the hyoid skeleton; eight branchiostegal rays on each side of the skull; foramen of the scapular girdle pierced through in the hypercoracoid or between the hypercoracoid and hypocoracoid bones; the anterior end of the hypocoracoid almost reaches the anterior extremity of the cleithrum; 37–43 vertebrae (42–44 according to Boulenger); 13–17 supraneurals; 8 or 9 pairs of dorsal ribs; 7–9 pairs of ventral ribs directly attached to the vertebral centre; 2–5 pairs of ventral ribs resting against the hemapophyses; each pair has well-developed Gemmingerian bones and a central fusing plate between the two bones of each pair; caudal skeleton with four hypural bones.

1) The figures pertaining to the proportions of the body and the number of rays and scales are taken from Boulenger’s works.” (End of quotation from Taverne 1969.)

[Note: Taverne’s 1969 diagnosis of the genus Petrocephalus is based on one specimen each of 10 species: Petrocephalus bane (Lacépède 1803) , P. balayi Sauvage 1883 (spelled ballayi by Taverne), P. grandoculis Boulenger 1920 , P. microphthalmus Pellegrin 1908 , P. sauvagii (Boulenger 1887) (spelled sauvagei by Taverne), P. schoutedeni Poll 1954 , P. christyi Boulenger 1920 , P. haullevillii Boulenger 1912 (spelled haullevillei by Taverne), P. simus Sauvage 1879 , P. bovei (Valenciennes 1847) (authority given as “Cuv. et Val.” without year by Taverne). This diagnosis includes the most salient aspects of the diagnosis given by Orts (1967). Whereas Taverne’s main focus was on skeletal features, Orts studied the anatomy of the soft tissues.]

Additional elements to a Diagnosis by present authors. Waveform of EOD with three phases (strong P1, very strong N, weak P2 phase), short duration (250–1200 µs at “2% of P1 amplitude criterion” and 25 ◦ C). Strength of P2 phase dependent on body size. Diurnal activity in aquarium more prominent than in other mormyrid genera.

Type species: Petrocephalus bane (Lacépède, 1803)

Included species (valid unless otherwise stated)

affinis , Petrocephalus Sauvage, 1879 . Current status: synonym of Stomatorhinus walkeri (Günther, 1867) .

amblystoma, Mormyrus Günther, 1896 . Current status: synonym of Petrocephalus balayi Sauvage, 1883 .

ansorgii , Petrocephalus Boulenger, 1903 .

anterodorsalis, Petrocephalus David and Poll, 1937 . Current status: synonym of Pollimyrus tumifrons (Boulenger, 1902) .

balayi , Petrocephalus Sauvage, 1883 .

ballayi, Petrocephalus Bertin 1940 . Current status: synonym of Petrocephalus balayi Sauvage, 1883 .

balteatus, Petrocephalus Rochebrune, 1885 . “Loanda, Gabon; Bathurst, Gambia, western Africa Museo Bouvieri, whereabouts unknown” ( Eschmeyer 2011).

bane , Mormyrus Lacépède, 1803 . Current status: valid as Petrocephalus bane (Lacépède, 1803) .

binotatus, Petrocephalus Pellegrin, 1924 .

bovei , Mormyrus Valenciennes, 1847 . Current status: valid as Petrocephalus bovei (Valenciennes, 1847) .

brevipedunculatus, Petrocephalus Svensson, 1933 . Current status: synonym of Petrocephalus bovei (Valenciennes, 1847) .

catostoma , Mormyrus Günther, 1866 . Current status: valid as Petrocephalus catostoma ( Günther, 1866)

christyi , Petrocephalus Boulenger, 1920 .

comoensis, Petrocephalus bane de Merona, 1979 . Current status: synonym of Petrocephalus bane (Lacépède, 1803) .

congicus , Petrocephalus stuhlmanni David and Poll, 1937 . Current status: Petrocephalus congicus ( David and Poll, 1937) .

cunganus, Petrocephalus Boulenger, 1910 .

degeni , Petrocephalus Boulenger, 1906 . Current status: Petrocephalus degeni Boulenger, 1906 .

dequesne, Mormyrus Valenciennes, 1847 . Current status: synonym of Petrocephalus bane (Lacépède, 1803) .

ehrenbergii, Mormyrus Valenciennes 1847 . Current status: synonym of Petrocephalus bane (Lacépède, 1803) .

frieli , Petrocephalus Lavoué, 2012 .

gliroides , Mormyrus Vinciguerra, 1897 . Current status: valid as Petrocephalus gliroides (Vinciguerra, 1897)

grandoculis , Petrocephalus Boulenger, 1920 .

guineensis, Petrocephalus bovei Reizer, Mattei and Chevalier, 1973 . Current status: synonym of Petrocephalus bovei (Valenciennes, 1847) .

guttatus, Petrocephalus Fowler, 1936 .

haullevillii , Petrocephalus Boulenger, 1912 . Current status: Petrocephalus haullevillii Boulenger, 1912 .

hutereaui , Marcusenius Boulenger, 1913 . Current status: valid as Petrocephalus hutereaui (Boulenger, 1913) .

joannisii, Mormyrus Valenciennes, 1847 . Current status: synonym of Petrocephalus bane (Lacépède, 1803) .

keatingii, Petrocephalus Boulenger, 1901 . levequei, Petrocephalus Bigorne and Paugy, 1990 . longicapitis , Petrocephalus Kramer, Bills, Skelton and Wink, 2012 . magnitrunci , Petrocephalus Kramer, Bills, Skelton and Wink, 2012 . magnoculis , Petrocephalus Kramer, Bills, Skelton and Wink, 2012 . longianalis , Petrocephalus Kramer, Bills, Skelton and Wink, 2012 . marchei , Petrocephalus Sauvage, 1879 . Current status: valid as Ivindomyrus marchei

(Sauvage, 1879). marchii, Petrocephalus Boulenger, 1899 . Current status: synonym of Ivindomyrus

marchei (Sauvage, 1879) . microphthalmus , Petrocephalus Pellegrin, 1908 . okavangensis , Petrocephalus Kramer, Bills, Skelton and Wink, 2012 . pallidomaculatus, Petrocephalus Bigorne and Paugy, 1990 . pellegrini, Petrocephalus Poll, 1941 . petersi , Petrocephalus Kramer, Bills, Skelton and Wink, 2012 . pictus , Petrocephalus Marcusen, 1864 . Current status: valid as Hippopotamyrus pictus

(Marcusen, 1864). sauvagii , Mormyrus (Petrocephalus) Boulenger, 1887 . Current status: valid as

Petrocephalus sauvagii (Boulenger, 1887) . schoutedeni , Petrocephalus Poll, 1954 . simus , Petrocephalus Sauvage, 1879 . soudanensis, Petrocephalus Bigorne and Paugy, 1990 . squalostoma , Marcusenius Boulenger, 1915 . Current status: valid as Petrocephalus

squalostoma ( Boulenger, 1915). steindachneri , Petrocephalus Fowler, 1958 . stuhlmanni , Petrocephalus Boulenger, 1909 . sullivani , Petrocephalus Lavoué, Hopkins and Kamdem Toham, 2004 . tanensis , Petrocephalus catostoma Whitehead and Greenwood, 1959 . Current status:

Petrocephalus catostoma tanensis ( Whitehead and Greenwood, 1959) tchadensis, Petrocephalus bane Blache and Miton, 1961 . Current status: synonym of

Petrocephalus bane (Lacépède, 1803) . tenuicauda, Mormyrus Steindachner, 1894 . Current status: valid as Petrocephalus

tenuicauda (Steindachner, 1894). vanderbilti, Petrocephalus Fowler, 1936 . Current status: synonym of Pollimyrus isidori

(Valenciennes, 1847). wesselsi , Petrocephalus Kramer and Van der Bank, 2000 .