Haplochromis, Hilgendorf, 1888

Vranken, Nathan, Steenberge, Maarten Van, Heylen, Annelies, Decru, Eva & Snoeks, Jos, 2022, From a pair to a dozen: the piscivorous species of Haplochromis (Cichlidae) from the Lake Edward system, European Journal of Taxonomy 815, pp. 1-94 : 73-75

Key to the piscivorous species of Haplochromis from the Lake Edward System

This identification key is intended as a practical guide and first step towards the identification of the piscivorous species from the Lake Edward system; in case of doubt, the differential diagnoses in the species’ descriptions should be consulted. When identifying live dominant males, the colour patterns are highly diagnostic and should be checked. A simple dichotomous key cannot be compiled as overlap in character states and in the range of values is omnipresent in species of Haplochromis , especially when they have a similar ecology ( Greenwood 1973; Snoeks 1994). However, the key allows for the identification of most specimens. Within the key, terminology is used in reference to species with a piscivorous morphology (instead of the generalised Haplochromis morphology as in the rest of the manuscript).

1. Adult specimens <100 mm SL; cheek shallow [ChD 20.8–24.4 (mean 22.5) % HL]; anal fin base long [AFB 19.2–22.2 (20.5) % SL]; 16, rarely 17 caudal peduncle scales; body speckled to uniformly black ( Fig. 33c–d ). .................................................................................................. H. pardus sp. nov.

– Adult specimens> 100 mm SL; specimens <100 mm SL with cheek deep [ChD 22.4–29.6 (means 22.9–28.5) % SL], anal-fin base short [AFB 16.1–21.7 (14.8–19.8) % SL], 16–20 (medians 17–19) caudal peduncle scales, and body light coloured............................................................................... 2

2. Body shallow [BD 27.2–30.1 (28.6) % SL]; anal-fin base short [AFB 14.7–17.3 (15.7) % SL]; interorbital area broad [IOW 57.4–63.3 (60.0) % HW]; 7–8 anal fin branched rays.................................. ............................................................................................................................. H. latifrons sp. nov.

– Body deep [BD 28.4–41.7 (30.8–37.4) % SL]; anal-fin base long [AFB 16.7–21.9 (18.0–19.9) % SL]; interorbital area narrow [IOW 39.3–61.0 (43.9–55.5) % HW]; 8–11 anal fin branched rays ... 3

3. Body deep [BD 32.4–39.3 (35.7) % SL]; interorbital area broad [IOW 48.6–55.6 (51.9) % HW]; lower jaw long [LJL 47.8–58.6 (52.7) % HL]; gape steep (30–45°); rows of minute scales on basal part of membranes of both dorsal and anal fins (nearly invisible to naked eye) ( Fig. 38 ); dominant males slate blue ( Fig. 39c ). ....................................................................................... H. squamipinnis

– Body deep [BD 33.5–41.7 (37.4) % SL]; interorbital area narrow [IOW 40.5–48.7 (43.9) % HW]; lower jaw short [LJL 44.2–49.6 (47.1) % HL]; gape gentle (20–35°); rows of minute scales on basal part of membrane of anal fin in some specimens, rarely few isolated scales on dorsal fin (nearly invisible to naked eye) ( Fig. 35 ); dominant males light grey dorsally and blue-black ventrally ( Fig. 36c ).......................................................................................................... H. quasimodo sp. nov.

– Body shallow [BD 28.4–36.0 (30.8–33.2) % SL]; interorbital area broad [IOW 39.3–61.0 (44.6– 55.5) % HW]; lower jaw short [LJL 42.4–53.1 (44.7–49.5) % HL]; gape gentle (15–35°); minute scales on dorsal or anal fins absent.................................................................................................... 4

4. Head broad [HW 40.1–43.7 (42.0) % HL]; eye large [ED 30.0–31.5 (30.6) % HL]; 25–37 (median 31) outer upper jaw teeth; dominant males light grey with black head and bright red anal fin ( Fig. 21c ).................................................................................................................. H. aquila sp. nov.

– Head narrow [HW 36.8–42.3 (39.2–40.8) % HL]; eye small [ED 22.2–29.9 (24.6–28.3) % HL]; 22–47 (medians 27–36) outer upper jaw teeth. ................................................................................. 5

– Head broad [HW 39.9–48.0 (42.9–45.1) % HL]; eye variable [ED 24.6–31.5 (27.5–30.4) % HL]; 39–70 (medians 45–56) outer upper jaw teeth. ................................................................................. 8

5. Pre-dorsal distance short [PrD 33.3–37.0 (35.3–36.1) % SL]; interorbital area broad [IOW 50.9– 61.0 (53.8–55.5) % SL]; 3–4, rarely 5 infraorbital cheek scales; 25–47 (medians 30–36) outer upper jaw teeth............................................................................................................................................. 6

– Pre-dorsal distance long [PrD 36.1–39.2 (37.3–38.0) % SL]; interorbital area narrow [IOW 44.9– 52.7 (48.1–48.9) % SL]; 4–7 infraorbital cheek scales; 22–36 (medians 27–29) outer upper jaw teeth.................................................................................................................................................... 7

6. Pre-pectoral distance short [PrP 33.1–38.2 (36.0) % SL]; caudal peduncle long [CPL 15.7–17.5 (16.6) % SL]; head short [HL 33.4–37.0 (35.1) % SL]; dominant males yellow-green with a bright red anterior part of flank ( Fig. 9c ). .................................................................................. H. mentatus

– Pre-pectoral distance long [PrP 36.4–39.4 (38.1) % SL]; caudal peduncle short [CPL 13.4–16.1 (14.8) % SL]; head long [HL 35.9–37.9 (36.9) % SL]; dominant males (and females) light blue with black cheek ( Fig. 18c )........................................................................................... H. glaucus sp. nov.

7. Cheek deep [ChD 27.6–33.5 (31.1) % SL]; eye small [ED 22.2–28.3 (24.6) % SL]; 22–27 upper lateral line scales; 12–16 scales between upper lateral line and first anal spine; dominant males cream-coloured with orange operculum and dorsal part of head and light blue snout ( Fig. 12c )....................................................................................................................... H. rex sp. nov.

– Cheek shallow [ChD 27.0–29.6 (28.3) % SL]; eye large [ED 26.7–29.5 (28.3) % SL]; 19–21 upper lateral line scales; 9–11 scales between upper lateral line and first anal spine; dominant males yellow with an orange anterior part of flank ( Fig. 15c )....................................................... H. simba sp. nov.

8. Body pyriform; head convex and broad [HW 42.9–48.0 (45.1) % HL]; cheek deep [ChD 27.1–35.2 (30.9) % HL]; lower jaw broad [LJW 44.7–53.3 (49.3) % LJL]; dominant males grey dorsally and yellow ventrally ( Fig. 24c ) .................................................................................. H. kimondo sp. nov.

– Body oval; head straight or slightly convex and narrow [HW 39.9–44.4 (42.6–43.4) % HL]; cheek shallow [ChD 22.4–28.0 (23.2–26.0) % HL]; lower jaw narrow [LJW 38.5–45.5 (40.8–42.5) % LJL]. .............................................................................................................................................. 9

9. Anal-fin base long [AFB 18.4–20.3 (19.3) % SL]; cheek deep [ChD 23.3–28.0 (26.0) % HL]; dominant males olive-green with an orange-red anterior part of flank and well-defined mid-lateral and dorsal-lateral bands ( Fig. 27c ). ...................................................................... H. falcatus sp. nov.

– Anal-fin base short [AFB 17.9–18.6 (18.3) % SL], cheek shallow [ChD 22.4–24.9 (23.2) % HL]; non-dominant males dusky greenish with 5–7 vertical stripes ( Fig. 30c ) ........ H. curvidens sp. nov.

Figures

Fig. 33. Haplochromis pardus sp. nov. a. Photograph of preserved holotype (RMCA 2016.035.P.0202; 89.2 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2017.006.P (HP1463); 81.4 mm SL). d. Female (RMCA 2017.006.P.0342; 75.9 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 38. Haplochromis squamipinnis Regan, 1921, holotype, ♀, 136.9 mm SL (NHMUK 1914.4.8.32). Drawn by N. Vranken.

Fig. 39. Haplochromis squamipinnis Regan, 1921. a. Photograph of preserved holotype (NHMUK 1914.4.8.32; 136.9 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2016.035.P.0250; 169.7 mm SL). d. Female (RMCA 2016.035.P(HP823); 129.6 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 35. Haplochromis quasimodo sp. nov., holotype, ♂, 120.4 mm SL (RMCA 2018.008.P.0336). Drawn by N. Vranken.

Fig. 36.Haplochromis quasimodosp. nov. a. Photograph of preservedholotype (RMCA 2018.008.P.0336; 120.4 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2018.008.P(HP3072); 123.7 mm SL). d. Female (RMCA 2018.008.P(HP3064); 116.6 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 21. Haplochromis aquila sp. nov. a. Photograph of preserved holotype (RMCA 2018.008.P.0355; 113.6 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male, the holotype. d. Female (RMCA 2018.008.P.0352; 108.7 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 9. Haplochromis mentatus Regan, 1925. a. Photograph of preserved holotype (MCZ 31523; 93.1 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2017.006.P.0424; 107.9 mm SL). d. Female (RMCA 2018.008.P(HP2453); 116.2 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 18. Haplochromis glaucus sp. nov. a. Photograph of preserved holotype (RMCA 2019.002.P.0016; 106.2 mm SL). b. X-ray image of holotype c–d. Photographs of freshly caught specimens. c. Dominant male, the holotype. d. Female (RMCA 2019.002.P.0017; 102.1 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 12. Haplochromis rex sp. nov. a. Photograph of preserved holotype (RMCA 2018.008.P.0345; 148.5 mm SL). b. X-ray image of holotype c–d. Photographs of freshly caught specimens. c. Holotype, a dominant male. d. A female (RMCA 2017.006.P.0355; 135.7 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 15. Haplochromis simba sp. nov. a. Photograph of preserved holotype (RMCA 2016.035.P.0225; 105.8 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2016.035.P.0224; 97.9 mm SL). d. Female (RMCA 2018.008.P.0348; 109.0 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 24. Haplochromis kimondo sp. nov. a. Photograph of preserved holotype (RMCA 2019.002.P.0015; 152.4 mm SL). b. X-ray image of holotype.c–d. Photographs of freshly caught specimens.c. Holotype, a dominant male. d. Female (RMCA 2018.008.P.0364; 128.1 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 27. Haplochromis falcatus sp. nov. a. Photograph of preserved holotype (RMCA 2018.008.P.0401; 101.3 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Dominant male (RMCA 2017.006.P.0416; 119.1 mm SL). d. Female (RMCA 2016.035.P.0257; 112.8 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.

Fig. 30. Haplochromis curvidenssp. nov. a. Photograph of preserved holotype (RMCA 2016.035.P.0219; 112.0 mm SL). b. X-ray image of holotype. c–d. Photographs of freshly caught specimens. c. Holotype, an adult male. d. Female (RMCA 2018.008.P.0340); 90.2 mm SL) to illustrate the live colour patterns. The contrast was slightly enhanced.