Notoglanidium pallidum Roberts & Stewart 1976

Notoglanidium pallidum Roberts & Stewart 1976 View in CoL

( Figs. 4 View FIGURE 4. A C, 4D & 10F)

Holotype. MCZ 50236: Congo River near Bulu, west of Luozi, Democratic Republic of the Congo (Congo- Kinshasa); 5° 01’ S, 14° 01’ E; 53 mm SL (only images of specimen examined).

Paratypes. MCZ 50294: Congo River at Tadi, near Kibunzi, Democratic Republic of the Congo (Congo- Kinshasa); 5° 14’ S, 13° 56’ E; 5 out of 16 spec. examined, 19–83 mm SL. BMNH 1976.5.21.24–25: same locality; 2 spec., 40–63 mm SL. MRAC 76-17-P-5–6: same locality; 2 spec., 36–76 mm SL. MCZ 50237: same locality as holotype; 20 mm SL (not examined). MCZ 76321: same locality; two out of four cleared and stained spec. examined, 41–58 mm SL. MCZ 50379: Zaire River main stream a few km northeast of Kinganga; 73 mm SL (not examined).

Diagnosis. Notoglanidium pallidum differs from other species in the genus in having: a small eye diameter (3.8–7.0% HL) [ vs. larger in N. boutchangai (7.5–10.4% HL), N. walkeri (7.8–10.6% HL), N. thomasi (9.1–12.5% HL) and N. macrostoma (9.1–13.3% HL)]; a small interorbital distance (20.0–23.3% HL) [ vs. larger in N. akiri (24.1–32.8% HL), N. macrostoma (28.0–40.4% HL), N. maculatum (35.3–36.8% HL), N. thomasi (41.0–46.7% HL) and N. walkeri (27.8–33.3% HL)]; a small combined premaxillary tooth plate width (11.1–15.3% HL) [ vs. larger (>18.2% HL) in N. akiri , N. boutchangai , N. depierrei , N. macrostoma and N. pembetadi ]; an average number of soft dorsal-fin rays (8–10) [ vs. seven rays in N. akiri , N. boutchangai and N. macrostoma , and>10 rays in N. maculatum (16–22), N. thomasi (12–16) and N. walkeri (11–15)].

Description. Both head and body dorsoventrally flattened, with depth almost constant from head to body (predorsal body depth 10.6–14.3% SL, minimal caudal peduncle depth 9.1–10.4% SL, head depth 9.8–13.8% SL). Branchiostegal membranes fused along anterior half only, with a slit separating the posterior halves (they may overlap). Adipose fin low (2.3–3.3% SL). See also Table 4.

Colouration in life. Pallid pink, without any markings (pale brownish when preserved).

Maximum size recorded. 81 mm SL.

Etymology. The species name indicates the pale ( pallidus, Latin) skin of the species.

Distribution. Congo River west of Luozi, and more downriver at Tadi (Kibunzi; Fig. 13 View FIGURE 13 ).