Paramormyrops, FROM

Rich, Madeline, Sullivan, John P. & Hopkins, Carl D., 2017, 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, Zoological Journal of the Linnean Society 180, pp. 613-646 : 638-640

KEY TO THE SPECIES OF PARAMORMYROPS FROM LOWER GUINEA

Combined with the summary figure ( Fig. 16 ) this key can be used to distinguish among seven described and one undescribed species of Paramormyrops from Lower Guinea. P. retrodorsalis (Nichols & Grissom, 1917) , P. tavernei ( Poll, 1972) and P. jacksoni ( Poll, 1967) are excluded here as they reside outside this region.

1. Te e t h b i c u s p i d, 7 i n u p p e r j aw, 8 i n l o w e r jaw……...............................……………… P. hopkinsi

Teeth bicuspid, 5 in upper jaw, 6 in lower jaw……2

2. 16 or more scales around the caudal peduncle ........…...............………………………………………..3

12 scales around caudal peduncle.....……… ……………………………………………................…..5

3. Lower jaw profile straight, submental swelling reduced or absent…..………………………………….4

Lower jaw profile concave, submental swelling present..…………………….. Paramormyrops batesii

4. Pre-dorsal distance 58–62% SL; CPL 20.7–25.5% SL…………………………………...……….. P. sp. OFF

P D D 5 5. 3 – 5 9. 4 % S L; C P L 2 4. 2 – 2 9. 8 % SL…………………………..………… P. longicaudatus

5. Head profile blunt or U shaped when viewed from above……………..……………............................……6

Head profile sharp or V shaped when viewed from above…...........................…………………………......7

6. Forehead slightly concave viewed from side; HL 24.9–27.6% SL; caudal peduncle slender, its depth 3.7–4.7% SL; interorbital distance 110–133% SNL…….........................................…… P. gabonensis

Forehead rounded: HL 19.5–28% SL; caudal peduncle depth 4.1–7.5% SL; interorbital distance 121– 202% SNL……………………………….. P. kingsleyae

7. Upper profile of head downward sloping, slightly c o n c a v e: m o u t h s u b t e r m i n a l: P r e -p e c t o r a l

distance large, PPCD more than 3 7 % SL

Figures

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.