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FIGURE 1 in Petrocephalus leo, a new species of African electric fish (Osteoglossomorpha: Mormyridae) from the Oubangui River basin (Congo basin)

FIGURE 1. Map of the hydrographic system of the central part of the Oubangui River basin showing the Petrocephalus localities surveyed (top-left inset showing the location of the Congo basin in Africa). Filled black and open stars indicate the type locality and the second locality on the Kotto River, respectively, of Petrocephalus leo sp. nov.

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FIGURE 2 in Petrocephalus leo, a new species of African electric fish (Osteoglossomorpha: Mormyridae) from the Oubangui River basin (Congo basin)

FIGURE 2. Petrocephalus leo sp. nov. and Petrocephalus zakoni from the Oubangui River basin, Central African Republic. Top, photograph of a live specimen of Petrocephalus leo sp. nov. of about 70 mm standard length showing the live coloration (untagged specimen; photo by Roger Bills, SAIAB). Center, photograph of the preserved holotype of Petrocephalus leo sp. nov. (CU 95314, scale bar = 1.0 cm; photo by John P. Sullivan, CUMV). Bottom, photograph of a preserved specimen of Petrocephalus zakoni of about 70 mm standard length from the Oubangui River (Field station JPF 06-009, CU 91852; photo by John P. Sullivan, CUMV).

Figure 16 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 16. Nine species of Paramormyrops from Lower Guinea showing, from left to right, head shape viewed from above, the outline of the body, and representative female and male EOD waveforms. Head shapes are camera lucida tracings of the holotypes for each species from the snout to end of opercular opening. The first six have sharp V-shaped head profiles and the last three have relatively blunt U-shaped heads. All but the last two have electric organs composed of Type NPp electrocytes (exhibiting Non-Penetrating stalks innervated on the posterior face). The last two have electric organs composed of Type Pa electrocytes (with Penetrating stalks innervated on the anterior face). All known mormyrids with Type Pa electrocytes have an initial, head-negative peak, P0, in the EOD waveform as illustrated here for P. kingsleyae. The P0 peak is absent in all species with Type NPp electrocytes. The EOD of P. batesii is unknown, but the electric organ is composed of Type Pa electrocytes.

Figure 9 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 9. Histology of para-sagittal section of paralectotype of P. sphekodes specimen MNHN 1998-1050 (Female, 98.7 mm, SL) shows electrocytes of type NPp (Non-Penetrating stalks with posterior innervation). The specimen, collected from Doumé Falls by Alfred Marche in 1876–1877 and preserved in alcohol, was embedded in plastic, sectioned with a tungsten carbide knife at 7 µm and stained with toluidine blue. E = main body of the electrocyte; anterior = anterior face of electrocyte; post = posterior face of same electrocyte; c = collagen layer separating two electrocytes; S = stalk of electrocyte which is innervated by the axons from the electromotor nerve (not shown); s = stalklets, or small branches from a dividing stalk that eventually fuse with posterior face of the electrocyte. Stalks are innervated on the posterior side of the electrocyte and all branches of the stalk system remain posterior to the main body of the electrocyte without crossing to the opposite or anterior side.

Figure 11 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 11. (A, B) Collection localities near the rapids at Doumé (0.84245°S, +12.96249°E) on the Ogooué River of Gabon, where P. sphekodes is sympatric with P. ntotom sp. nov. (B) shows local villagers fishing with hoop nets at Doumé. (C, D) View of the Sébé River (0.93494°S, 13.35767°E) where the two species are also sympatric. Both habitats are moderate-sized rivers with gentle flow or rapids over rocky outcroppings, interspersed with sandy beaches, surrounded by dense rain forest. The Ogooué River is 75–100 m wide at Doumé, 3 m in depth, and the water had low conductivity (13.9 µs/cm) at pH 7.04 and 6.66 mg/L O2 (83.1% saturated) at 26.7 °C. The Sébé River is 55–75 m wide, approximately 3.1 m deep, 16.0 µs conductivity, 7.08 pH and 7.5 mg/L O2 (93.6% saturation) at 26.6°C).

Figure 12 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 12. Holotype of P. ntotom sp. nov. CUMV 98138, tag number JPS-1189, male, 178 mm SL, from top to bottom photographed when alive, preserved in alcohol left and right sides, and radiograph. Scale bars = 1 cm.

Figure 4 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 4. The short EOD and SN4 Paramormyrops differ in the ratio of head length (HL) to head depth (HD) when measurements are taken from radiographs. (A) HLx/HDx is plotted against standard length for 41 specimens including short EOD specimens (n = 9, blue circles), SN4 specimens (n = 30, red squares) and the two existing types (* = lectotype of P. sphekodes and 'x' = the paralectotype). Solid lines show linear regression lines showing that head shape changes little with overall size. The measurements of the lectotype (LT) of P. sphekodes (MNHN-A893) and paralectotype (PLT) (MNHN 1998-1050) identify the short EOD individuals as P. sphekodes. The specimens with SN4-type EODs belong to a new species (red * indicates the new species holotype). Specimen 1185 is shown in x-ray in C. (B) Non-overlapping histograms of HLx/ HDx allow for good diagnosis of the two EOD types even if no EOD is available, as with the two types of P. sphekodes. (C) Radiographs of two specimens (Specimen CUMV 98134 tag number JPS-1185, an SN4 fish and MNHN-A893) illustrate landmarks used for measuring HLx and HDx (see Material and Methods). Scale bars = 1 cm.

Figure 10 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 10. Distribution map of West-Central Africa showing collection localities of specimens of P. sphekodes (blue), P. ntotom sp. nov. (red) and P. curvifrons (green). Stars mark collection locations of holotypes (or lectotype) and circles mark locations of other specimens.

Figure 6 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 6. Relevant portion of the phylogram produced from maximum likelihood analysis in RAxML of cyt-b sequences from nine individuals of the 'short EOD' form (blue), eight specimens of species 'SN4' from the Doumé and Sébé sites (red) aligned to data matrix (73 Paramormyrops individuals) of Sullivan et al. (2002), rooted with sequence of M. ntemensis (not shown). Sequence of P. curvifrons individual is shown in green. For species codes, follow Sullivan et al. (2002). Bootstrap values are shown at nodes (filled circles). Haplotypes of SN4 and 'short EOD' do not constitute monophyletic groups. However, no haplotypes are shared between these forms and nowhere on the tree do haplotypes from the two forms appear as nearest relatives. This result is consistent with the hypothesis of heterospecificity of the two forms.

Figure 7 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 7. Five specimens of P. sphekodes from Ogooué basin of Gabon. From top to bottom: specimen tag number 1192, female, 113.5 mm; 1201, female, 111 mm from the Ogooué River at Doumé; 1214, male, 112.5 mm; 1230, male, 133 mm and 1238, male, 119 mm from the Sébé River nearby. Scale bars = 1 cm.

Figure 3 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 3. The Paramormyrops specimens with short EODs, and those called SN4 have overlapping meristics but differ in a number of morphometric ratios. Here, the short EOD specimens are shown as blue circles, while '*' indicates the lectotype of P. sphekodes and '+' indicates the paralectotype. The red circles show those with longer EODs referred to as SN4 specimens. The short EOD forms have elevated ratios of interorbital width to snout length and correspondingly blunter snout angles than the SN4 specimens. They also have slightly reduced caudal peduncle depth to length ratios. There is overlap in each ratio taken separately, but combined they provide a convenient morphological basis for diagnosis between these two EOD types. EOD traces are 10 ms long.

Figure 1 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 1. (A) Paramormyrops sphekodes (Sauvage, 1877) MNHN A.893 photographed in 1984 by W. Harder at which time the lot contained two specimens, suspended vertically in a tall jar from a glass floater. The original MNHN catalogue shows two specimens accessioned in 1878 under this number. The larger specimen (SL = 113.8 mm) is currently catalogued as A 893; the smaller specimen (SL = 98.7 mm) was subsequently catalogued in 1998 as MNHN 1050-1998. Sauvage's original description indicates multiple specimens with a largest of 140 mm total length, but he designated no holotype. We regard these specimens as syntypes prior to our designation of the larger as lectotype. (B) Radiograph of MNHN A893.

Figure 2 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 2. Electric organ discharge (EOD) waveforms recorded from 40 specimens of P. sphekodes-like mormyrids from the Ogooué River Basin of Gabon suggest the possibility of two species with distinct EOD waveforms. (A) For each specimen, EOD duration is plotted against standard length (SL). (B) Histogram of EOD durations reveals two modal peaks: one for short EODs, <2 ms duration, and one for longer EODs,> 2 ms. (C) EOD waveforms of longer (above) and shorter duration (below) are superimposed after each EOD's amplitude is normalized to the same peak-to-peak height and centred on the zero-crossing between positive and negative peaks. Blue lines are males and red lines are females. Head positivity is upward. EOD duration is measured between T1 and T2 (in E), first and last points of the waveform that deviate above or below the baseline by more than 2% of the peak-to-peak height. In previous publications, the longer EOD type was referred to by the code name 'SN4'. The fish with the 'short EOD' waveform is new to this study. (D) Histograms of SLs of all 40 specimens separated by EOD-type and by sex/age class show that within each EOD type there are males recognized by their dimorphic anal fins. Within each group, males tend to have the longest duration waveforms. This sex difference is especially pronounced for SN4 males recorded during the breeding season. Fish of both EOD types co-occur at two sites in Gabon: the main channel of the Ogooué River at Doumé and the Sébé River nearby (see map). (E) EOD waveform of specimen CUMV 98177 tag JPS-1238 showing how EOD duration is measured.

Figure 5 in Rediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology

Figure 5. Morphometrics and ratios from the three species of Paramormyrops included in this study. (A–C) and (E–G) show measurement ratios useful in diagnosis of these three species. Snout angle measurements (see Material and Methods) are compared in (D) and (G). (D) plots snout angle against IOW/SNL. Holotypes or lectotypes are indicated by '*' symbols and paratypes are indicated by 'x' symbols. (H) compares IOW/SNL for specimens of differing standard lengths. Superimposed on the data points in (A–C) and (E–G) are box plots showing range, 25% quartile, median and 75% quartile. Black bars above box plots span samples where means differ significantly (P ≤ 0.05) using Tukey–Kramer multiple comparison tests for differences in sample means. See Table 1 for abbreviations.

opencc-by-4.0Apr 2014View details →

Supplementary material 1 from: Lavoue S, Sullivan J (2014) Petrocephalus boboto and Petrocephalus arnegardi, two new species of African electric fish (Osteoglossomorpha, Mormyridae) from the Congo River basin. ZooKeys 400: 43-65. https://doi.org/10.3897/zookeys.400.6743

List of specimens of Petrocephalus arnegardi and Petrocephalus boboto with EOD recording.: Explanation note: List of specimens of Petrocephalus arnegardi and Petrocephalus boboto with electric organ discharge (EOD) recording (holotypes, paratypes, non types).

Figure 9 in East-west differentiation in the Marcusenius macrolepidotus species complex in Southern Africa: the description of a new species for the lower Cunene River, Namibia (Teleostei: Mormyridae)

Figure 9. Partial molecular phylogeny of three Marcusenius species from southern Africa. Phylogeny reconstruction by Maximum likelihood is illustrated as a phylogram in which branch length is correlated with genetic distance. Bootstrap values above 50% are given below the nodes.

Figure 7 in East-west differentiation in the Marcusenius macrolepidotus species complex in Southern Africa: the description of a new species for the lower Cunene River, Namibia (Teleostei: Mormyridae)

Figure 7. Electric organ dicharges (EODs) of Cunene bulldog fish individuals with SL. Left, males; right, females.

Figure 5 in East-west differentiation in the Marcusenius macrolepidotus species complex in Southern Africa: the description of a new species for the lower Cunene River, Namibia (Teleostei: Mormyridae)

Figure 5. Electric organ discharges (EODs) recorded from fish from various origins. (A) Five specimens of Marcusenius macrolepidotus originating from the Buzi River. (B) Marcusenius altisambesi originating from the the Upper Zambezi System. Note P and N phases of exaggerated duration in male individual. (C) M. altisambesi originating from the Okavango delta. (D) Marcusenius multisquamatus sp. nov. originating from the Cunene River. M, male, F, female, J, juvenile individuals below size where sexual maturity is possible. Size given is SL. Note that in Buzi individuals an initial miniature potential is lacking which is present in the other forms of bulldog fish shown here (see EODs with clipped peaks, amplified × 3).

Figure 6 in East-west differentiation in the Marcusenius macrolepidotus species complex in Southern Africa: the description of a new species for the lower Cunene River, Namibia (Teleostei: Mormyridae)

Figure 6. Multivariate analysis on morphology for three Marcusenius species in southern Africa. (A, C, E) Principal components analyses on correlations for 14 anatomical characters; (B, D, F) discriminant analyses on same data to their left. Prin1, Prin2 and Prin3 axes represent the first three principal components. Green solid squares: Marcusenius multisquamatus sp. nov. specimens from Cunene River (escarpment, n = 15); red open squares, from Cunene River Mouth (n = 11). Blue Z symbols, Marcusenius macrolepidotus specimens from Lower Zambezi River (n = 42); blue Y symbols, Marcusenius altisambesi specimens from Upper Zambezi River (n = 42); blue X symbols, M. altisambesi specimens from Okavango River (n = 32). [Characters analyzed: PDL/SL, PAL/SL, LD/SL, LA/SL, pD/SL, CPL/SL, CPD/CPL, LSc/HL, HL/SL, BD/SL, nD, nA, SPc, SLS]

Figure 4 in East-west differentiation in the Marcusenius macrolepidotus species complex in Southern Africa: the description of a new species for the lower Cunene River, Namibia (Teleostei: Mormyridae)

Figure 4. Photographs of bulldog fish from various origins. (A) Marcusenius macrolepidotus (Peters, 1852), SAIAB 60847, coll. R. Bills 1 August 1999, Lower Zambezi; (B) Marcusenius angolensis (Boulenger, 1905), BMNH 1905.5.29.64 (holotype); (C) Marcusenius altisambesi, coll. F. H. van der Bank and B. Kramer, 21 August 1999, Upper Zambezi, Kalimbeza, live specimen of 16.5 cm SL photographed 3 July 2003 in aquarium; (D) M. altisambesi, coll. F.H. van der Bank and B. Kramer, 11/12 August 2004, Okavango River, live fish of SL 13 cm photographed 20 April 2006 in aquarium; (E) Marcusenius multisquamatus sp. nov., coll. B. Kramer and Ernst Swartz, coll. and photographed on 19 August 2006, Cunene River, below Ruacana Falls, specimen RUAC01, SL 15.4 cm.