Protomelas krampus, Dierickx & Snoeks, 2020

Dierickx, Katrien & Snoeks, Jos, 2020, Protomelas krampus, a new paedophagous cichlid from Lake Malawi (Teleostei, Cichlidae), European Journal of Taxonomy 672 (672), pp. 1-18 : 7-16

Protomelas krampus sp. nov.

urn:lsid:zoobank.org:act:5C1913C2-E6C9-43CD-BB1C-5522DFC60B8C

Figs 4–5 ; Tables 4–5

Diagnosis

Protomelas krampus sp. nov. differs from most species of Protomelas , i.e., P. annectens (Regan, 1922) , P. fenestratus (Trewavas, 1935) , P. kirkii (Günther, 1894) , P. labridens (Trewavas, 1935) , P. macrodon Eccles, 1989 , P. marginatus (Trewavas, 1935) , P. pleurotaenia (Boulenger, 1901) , P. similis (Regan, 1922) , P. spilonotus (Trewavas, 1935) , P. taeniolatus (Trewavas, 1935) , P. triaenodon (Trewavas, 1935) and P. virgatus (Trewavas, 1935) , by having only one inner tooth row, whereas the other species have two rows.

It can be distinguished from P. spilopterus by a shorter premaxillary pedicel (17.0–19.2 vs 21.8–28.4% HL), a larger gape inclination (70–80 vs 40–60°), a shallower body (33.3–34.3 vs 36.0–42.8% SL), a smaller predorsal (27.4–29.1 vs 33.4–37.4% SL) and prepectoral distance (29.4–29.8 vs 31.8–40.0% SL), a shorter and more slender head (length 27.8–29.2 vs 30.4–34.6% SL and width 39.3–40.3 vs 41.4– 50.7% HL, respectively), and a smaller interorbital width (22.9–23.4 vs 25.0–33.6% HL). In addition, P. krampus sp. nov. has more gill rakers on the outer epibranchial (further mentioned as upper gill rakers) than P. spilopterus (5 vs 3–4) and more vertebrae (31–32 vs 29). The inner teeth are tricuspid in P. krampus sp. nov. while mixed unicuspid/tricuspid or unicuspid in P. spilopterus . The outer teeth of the lower jaw of P. krampus sp. nov. are oriented straight up, whereas those of P. spilopterus are angled forward, except for in one specimen which has slightly inwards curved teeth.

Protomelas krampus sp. nov. differs from P. insignis by a shorter premaxillary pedicel (17.0–19.2 vs 27.9–30.0% HL), a deeper cheek (31.6–40.2 vs 23.2–28.5% HL), the larger gape inclination (70–80 vs 30°), a smaller predorsal (27.4–29.1 vs 34.2–35.9% SL) and prepectoral distance (29.4–29.8 vs 32.7– 35.4% SL), a shorter and more slender head (length 27.8–29.2 vs 31.6–34.3% SL and width 39.3– 40.3 vs 41.3–44.8% HL, respectively), a shallower lacrimal (19.6–20.4 vs 21.4–22.4% HL), a smaller interorbital width (22.9–23.4 vs 26.9–32.8% HL), and a longer lower jaw (37.7–38.8 vs 31.2–37.3% HL). The upper jaw has fewer outer teeth in P. krampus sp. nov. than in P. insignis (37–40 vs 43–50). Outer lower jaw teeth are straight in P. krampus sp. nov. but curved inwards in P. insignis .

Protomelas krampus sp. nov. differs from the undescribed species mentioned by Snoeks & Hanssens (2004) as Hemitaeniochromis . sp. ‘ insignis like’ by a shorter premaxillary pedicel (17.0–19.2 vs 24.7– 30.7% HL), a deeper cheek depth (31.6–40.2 vs 22.5–28.8% HL), a larger gape inclination (70–80 vs 40–60°), a shorter predorsal (27.4–29.1 vs 33.5–38.3% SL) and prepectoral distance (29.4–29.8 vs 31.1–38.1% SL), a shorter and more slender head (length 27.8–29.2 vs 31.3–34.5% SL and width 39.3–40.3 vs 40.8–46.8% HL, respectively), and a longer lower jaw (37.7–38.8 vs 28.9–35.0% HL). Protomelas krampus sp. nov. has more gill rakers on the outer epibranchial than H. sp. ‘ insignis like’ (5 vs 3–4). There are more dorsal fin rays in P. krampus sp. nov. than in H. sp. ‘ insignis like’ (11–12 vs 9–10). The outer teeth of the lower jaw of P. krampus sp. nov. are oriented straight up, whereas those of H. sp. ‘ insignis like’ are angled forward.

Protomelas krampus sp. nov. differs from both species of the genus Hemitaeniochromis by its continuous midlateral stripe, which places it in Protomelas , whereas H. urotaenia and H. brachyrhynchus have an anteriorly spotted stripe.

In addition, P. krampus sp. nov. differs from H. urotaenia by a shorter premaxillary pedicel (17.0–19.2 vs 27.5–28.9% HL), a deeper cheek (31.6–40.2 vs 27.3–30.6% HL), a larger gape inclination (70–80 vs 30–50°), a longer dorsal fin base (53.6–58.3 vs 49.3–50.5% SL), a shorter predorsal (27.4–29.1 vs 37.0–38.7% SL) and prepectoral distance (29.4–29.8 vs 35.2–36.7% SL), a shorter and more slender head (length 27.8–29.2 vs 34.9–37.3% SL and width 39.3–40.3 vs 40.5–42.5% HL respectively), and a shallower lacrimal (19.6–20.4 vs 22.7–23.3% HL). Protomelas krampus sp. nov. has more vertebrae (31–32 vs 30), more gill rakers on the outer epibranchial (5 vs 2–4) and more dorsal fin rays (11–12 vs 9–10) than H. urotaenia . Protomelas krampus sp. nov. has only one inner tooth row with tricuspid teeth, whereas H. urotaenia has two rows of mostly unicuspid teeth. The outer lower jaw teeth are straight in P. krampus sp. nov., whereas they are curved inwards in H. urotaenia .

Protomelas krampus sp. nov. differs from H. brachyrhynchus by a shorter premaxillary pedicel (17.0– 19.2 vs 27.1% HL), a deeper cheek (31.6–40.2 vs 21.4% HL), a larger gape inclination (70–80 vs 45°), a shallower body (33.3–34.3 vs 37.7% SL), a shorter predorsal (27.4–29.1 vs 37.8% SL), preventral (39.0–44.4 vs 46.1% SL) and prepectoral distance (29.4–29.8 vs 37.0% SL), a shorter anal fin base length (18.3–18.8 vs 21.2% SL), a shorter and more slender head (27.8–29.2 vs 35.3% SL and 39.3–40.3 vs 43.8% HL, respectively), a longer snout (33.3–34.2 vs 30.1% HL), a deeper lacrimal (19.6–20.4 vs 17.2% HL), a smaller eye (22.5–27.0 vs 32.2% HL), and a longer lower jaw (37.7–38.8 vs 32.9% HL). Protomelas krampus sp. nov. has more vertebrae (31–32 vs 30), upper gill rakers (5 vs 4) and dorsal fin rays (11–12 vs 10) than H. brachyrhynchus . The outer teeth of the lower jaw of P. krampus sp. nov. are oriented straight up, whereas those of H. brachyrhynchus are angled forward and slightly outwards.

Protomelas krampus sp. nov. differs from the paedophagous species of the genus Caprichromis by its melanin pattern: it has a midlateral band from behind the opercle to the base of the caudal fin, whereas species of Caprichromis have a diagonal stripe from the nape to the base of the caudal fin.

Protomelas krampus sp. nov. further differs from C. orthognathus by a shorter premaxillary pedicel (17.0–19.2 vs 21.9–25.4% HL) and a shorter prepectoral distance (29.4–29.8 vs 30.2–33.4% SL). There are more soft dorsal fin rays in P. krampus sp. nov. than in C. orthognathus (11–12 vs 10) and more gill rakers on the outer epibranchial (5 vs 3–4). Protomelas krampus sp. nov. has fewer outer teeth in the lower jaw (31–36 vs 42–50).

Protomelas krampus sp. nov. differs from C. liemi by a shorter premaxillary pedicel (17.0–19.2 vs 24.7–28.0% HL), a deeper cheek (31.6–40.2 vs 25.5–29.5% HL), a larger gape inclination (70–80 vs 30–60°), a shallower body (33.3–34.3 vs 36.1–38.6% SL), shorter predorsal (27.4–29.1 vs 35.0–36.7% SL) and prepectoral distances (29.4–29.8 vs 34.2–36.5% SL), a shorter and wider head (length 27.8– 29.2 vs 31.9–33.6% SL and width 39.3–40.3 vs 35.9–38.2% HL, respectively), and a shallower lacrimal (19.6–20.4 vs 20.8–23.9% HL). There are fewer scales along the upper lateral line in P. krampus sp. nov. than in C. liemi (20–23 vs 25–27). Protomelas krampus sp. nov. has fewer outer teeth in the upper jaw (37–40 vs 44–47) and lower jaw (31–36 vs 44–59) than C. liemi .

Protomelas krampus sp. nov. differs from Diplotaxodon greenwoodi by the lack of a melanin pattern in the latter species. It has isognathous jaws, whereas D. greenwoodi has a protruding lower jaw.

Protomelas krampus sp. nov. differs from Naevochromis chrysogaster by its melanin pattern, which consists of three large spots on the lateral sides in the latter instead of a continuous midlateral line. It has a more strongly inclined gape than N. chrysogaster . Protomelas krampus sp. nov. has only one inner tooth row on the lower jaw, whereas N. chrysogaster has two.

Etymology

The specific name, ʻ krampus ʼ, is a noun in apposition and was chosen in reference to the European folklore character Krampus. This demon puts naughty children in a bag and takes them away, which is reminiscent of a paedophagous behaviour. The goat-like appearance of Krampus also implicitly refers to the head-butting behaviour of the species. The same implicit reference to this behaviour is also found in the genus name Caprichromis of other paedophagous species of Lake Malawi.

Material examined

Holotype

TANZANIA • ♀; Lake Malawi , Lukoma Bay; 11°22.50′ S, 34°52.00′ E; 11 Jan. 1998; SADC/GEF Taxonomy team leg.; 116.1 mm SL; MRAC 99-041-P-4768 .

Paratype

MOZAMBIQUE • 1 ♂; Lake Malawi , Mara Rocks; 12°11.34′ S, 34°41.73′ E; 22 May 1998; SADC/ GEF Taxonomy team leg.; 181.1 mm SL; MRAC 99-041-P-4767 .

Comparative material

Hemitaeniochromis brachyrhynchus ( Oliver, 2012)

MALAWI • 1 paratype; Lake Malawi , Nkhata Bay, south bay ; 11°36.22′ S, 34°19.16′ E; 27 Sep. 1997; SADC/GEF Taxonomy team leg.; 81.6 mm SL; MRAC 99-041-P-1746 .

Hemitaeniochromis urotaenia (Regan, 1922)

MALAWI • 2 specs; Lake Malawi, Kande Bay , S of Bandawe; 11°56.47′ S, 34°09.41′ E; 3 Jun. 1997; SADC/GEF Taxonomy team leg.; 142.2–182.7 mm SL; MRAC 99-041-P-1738-1739 • 3 specs [of 5 in lot]; Lake Malawi , Nkhotakota; 12°52.95′ S, 34°19.33′ E; 22 Sep. 1997; SADC/GEF Taxonomy team leg.; 87.8–119.0 mm SL; MRAC 99-041-P-1741-1745 .

Hemitaeniochromis sp. “ insignis like”

MALAWI • 3 specs; Lake Malawi , Chipoka to Makanjila, SW arm and SE arm; 14°00.62′ S, 34°37.29′ E; 18 Nov. 1997; SADC/GEF Taxonomy team leg.; 122.0– 148.5 mm SL; MRAC 99-041-P-1747-1749 • 1 spec.; Lake Malawi , Nkhotakota; 12°52.95′ S, 34°19.34′ E; 22 Sep. 1997; SADC/GEF Taxonomy team leg.; 76.9 mm SL; MRAC 99-041-P-1750 • 1 spec.; Lake Malawi, Senga Bay ; 13°45.13′ S, 34°29.22′ E; 8 Jun. 1997; SADC/GEF Taxonomy team leg.; 145.2 mm SL; MRAC 99-041-P-1773 • 2 specs; Lake Malawi , Chipoka to Makanjila, SW arm and SE arm; 13°52.45′ S, 34°54.74′ E; 9 Oct. 1997; SADC/ GEF Taxonomy team leg.; 139.7–172.4 mm SL; MRAC 99-041-P-2625-2626 • 1 spec.; Lake Malawi, Chipoka to Makanjila, SW arm and SE arm; 13°57.77′ S, 34°43.37′ E; 10 Oct. 1997; SADC/GEF Taxonomy team leg.; 142.7 mm SL; MRAC 99-041-P-2627 • 1 spec.; Lake Malawi , SW arm; 14°07.00′ S, 34°44.30′ E; 18 Dec. 1996; SADC/GEF Taxonomy team leg.; 169.0 mm SL; MRAC 99-041-P-1755 .

MOZAMBIQUE • 1 spec.; Lake Malawi , Chiwanga Bay ; 12°39.03′ S, 34°46.56′ E; 11 Apr. 1998; SADC/GEF Taxonomy team leg.; 111.9 mm SL; MRAC 99-041-P-1753 • 1 spec.; Lake Malawi , Chiwanga Bay ; 12°39.03′ S, 34°46.56′ E; 11 Apr. 1998; SADC/GEF Taxonomy team leg.; 117.8 mm SL; MRAC 99-041-P-1754 .

Protomelas spilopterus (Trewavas, 1935)

MALAWI • lectotype, 3 paralectotypes; Lake Malawi , South End ; 1925; 147.1–166.0 mm SL; BMNH 1935.6.14.644-647 • 2 paralectotypes [of 3 in lot]; Lake Malawi , Mwaya; 1925; 149.1–153.4 mm SL; BMNH 1935.6.14.649-651 (2 of 3) • 5 paralectotypes [of 6 in lot]; Lake Malawi , Monkey Bay; 1925; 85.5–160.4 mm SL; BMNH 1935.6.14.652-657 .

Protomelas insignis (Trewavas, 1935)

MALAWI • lectotype, 3 paralectotypes; Lake Malawi , Monkey Bay ; 1925; 81.7–161.0 mm SL; BMNH 1935.6.14.839-843 .

Caprichromis liemi (McKaye & Mackenzie, 1982)

MALAWI • 1 spec.; Lake Malawi , Chipoka to Makanjila, SW arm and SE arm; 14°00.62′ S, 34°37.29′ E; 18 Nov. 1997; SADC/GEF Taxonomy team leg.; 129.2 mm SL; MRAC 99-041-P-2647 .

MOZAMBIQUE • 1 spec.; Lake Malawi , Chilola Bay ; 12°06.45′ S, 34°46.79′ E; 7 Apr. 1998; SADC/ GEF Taxonomy team leg.; 117.9 mm SL; MRAC 99-041-P-2648 • 1 spec.; Lake Malawi , Tchulutcha Reef , Metangula; 12°42.19′ S, 34°47.46′ E; 25 May 1998; SADC/GEF Taxonomy team leg.; 173.2 mm SL; MRAC 99-041-P-2649 • 2 specs; Lake Malawi , Namisse, S of Cobue; 12°10.08′ S, 34°42.97′ E; 24 May 1998; SADC/GEF Taxonomy team leg.; 103.2–144.4 mm SL; MRAC 99-041-P-5018-5019 .

Caprichromis orthognathus (Trewavas, 1935)

MALAWI • 1 spec.; Lake Malawi , Mazinzi Bay , SE arm; 4 Sep. 1980; D.S.C. Lewis leg.; 146.7 mm SL; MRAC 81-02-P-33 • 1 spec.; Lake Malawi ; 25 Jun. 1962; 154.1 mm SL; MRAC 191849 .

MOZAMBIQUE • 1 spec.; Lake Malawi , Chiwanga Bay ; 12°38.52′ S, 34°46.37′ E; 10 Apr.1998; SADC/ GEF Taxonomy team leg.; 122.0 mm SL; MRAC 99-041-P-2644 • 2 specs; Lake Malawi , Chiwanga Bay ; 12°38.81′ S, 34°46.68′ E; 10 Apr. 1998; SADC/GEF Taxonomy team leg.; 128.3–131.4 mm SL; MRAC 99-041-P-2645-2646 .

Diplotaxodon greenwoodi ( Stauffer & McKaye, 1986)

MALAWI • 1 spec.; Lake Malawi , Senga Bay ; 13°45.25′ S, 34°40′30″ E; 8 Jun. 1997; SADC/GEF Taxonomy team leg.; MRAC 1999-041-P-10765 • 1 spec.; Lake Malawi , Chipoka to Makanjila, SW arm and SE arm; 13°57′46.19″ S, 34°43′22.19″ E; 10 Oct. 1997; SADC/GEF Taxonomy team leg.; MRAC 1999-041-P-10766 .

MOZAMBIQUE • 1 spec.; Lake Malawi , Chilola Bay , 2 nd bay of Cobwe; 12°00′44.39″ S, 34°47′16.80″ E; 8 Apr. 1998; SADC/GEF Taxonomy team leg.; MRAC 1999-041-P-10768 .

TANZANIA • 1 spec.; Lake Malawi , Weismann Bay ; 9°30′46.80″ S, 34°00′19.80″ E; 14 Jan. 1998; SADC/GEF Taxonomy team leg.; MRAC 1999-041-P-10767 .

Naevochromis chrystogaster (Trewavas, 1935)

MALAWI • 1 spec.; Lake Malawi , Mdoka; 10°19′00.01″ S, 34°12′00″ E; May 1989; A. Konings leg.; MRAC 1991-095-P-0037 • 1 spec.; Lake Malawi , Cape Ngombo near Makanjila Point; 13°44′07.19″ S, 34°51′16.20″ E; 13 Nov. 1997; SADC/GEF Taxonomy team leg.; MRAC 1999-041-P-8524 .

TANZANIA • 1 spec.; Lake Malawi , Lutara , N of bay; 10°25′57.61″ S, 34°33′33.59″ E; 11 Nov. 1998; SADC/GEF Taxonomy team leg.; MRAC 1999-041-P-5205 .

Description

Based on holotype and one paratype (see Figs 4–5 and Tables 4–5). Qualitative observations are described in the context of Lake Malawi haplochromine cichlids as conducted by Snoeks (2004).

BODY. Moderately elongate.

HEAD. Profile somewhat steep, clearly concave at eye level. Snout above upper jaw convex. Mouth very steep, vertically orientated with a gape inclination of 70–80°. Premaxillary pedicel small. Jaws isognathous. Lower jaw long. Posterior side of lower jaw protrudes anteriorly. Anterior side of lower jaw slightly wider than posterior side. Deep chin. Larger specimen with larger mouth inclination and deeper chin. Lip longer than half length of lower jaw. Lips normal. Lower lip with mucosa embedding teeth. Preopercle also inclined. Long and slender gill rakers.

TEETH. Outer row of teeth on upper and lower jaws mostly unequally bicuspid and some posterior teeth unicuspid in smaller specimen; anterior teeth exclusively unicuspid on both jaws of larger specimen. Teeth straight and not curved inwards. Anterior cusps of teeth on outer row in both jaws larger than posterior cusps in smaller specimen. Anterior teeth larger than posterior teeth in smaller specimen. One inner row of irregularly placed tricuspid teeth on both jaws in smaller specimen. Posterior and inner teeth in larger specimen not readily observable, being to a large extent or fully covered by fleshy gums. Teeth closely set (space between teeth about half to one tooth width).

FINS. Pectoral fin origin behind level of dorsal fin origin in smaller specimen. Position of pectoral fin origin unknown in larger specimen because of damage. Pelvic fin origin positioned slightly more backwards than level of dorsal fin origin. Pectoral fin of holotype and pelvic fin in both types almost to level of anus. Anal fin anterior to level of first soft dorsal fin ray. Small scales on base of caudal fin rays.

Colour pattern in life

Based on a photograph by Konings (2016) ( Fig. 6 ). Body generally greyish. Head and pectoral fin base yellowish. Pelvic fin with white distal part of leading edge. Five orange-brownish eggspots on anal fin. Continuous dark midlateral band from about one eye length behind opercle to caudal fin. Supralateral row of darks spots. Dark spots also present just below dorsal fin. Some spots are arranged in an interrupted vertical bar pattern.

Colour pattern in preserved specimens

Based on photographs by McKaye & Kocher (1983) and Snoeks (2004) ( Fig. 5 ). Body generally brown or greyish. Dorsum somewhat darker than belly. Darker on dorsal parts of head and body contiguous with dorsal fin base. Clear dark maculae on spiny part of dorsal fin, possibly also on soft dorsal fin part and caudal fin. Continuous dark midlateral band from one eye length or about three scales behind opercle to caudal fin. One supralateral and one subdorsal row of darks spots. Some spots as subtle, incomplete vertical bars. Both types currently pale-coloured, probably due to light exposure ( Fig. 4 ).

Geographical distribution ( Fig. 7 )

The specimens of P. krampus sp. nov. were found in Lukoma Bay (11°22.50′ S, 34°52.00′ E), south of Mbamba Bay, Lake Malawi ( Tanzania) and at rocks just south of Mara Point (12°11.34′ S, 34°41.73′ E), Aldeia Mala, Lake Malawi ( Mozambique), at depths of 32.5–33.2 m. Three others specimens that also may belong to this species were caught near Otter Point (14°03′ S, 34°49′ E), Mangochi, Lake Malawi ( Malawi), at a depth of 7–20 m (McKaye & Kocher 1983). It has also been observed near Chizumulu and Likoma Islands ( Konings 2016) and Mazinzi Reef (Stauffer, pers. comm.). Hence the species has a confirmed distribution in the central-eastern part of the lake, but it may also occur in the southern part.

Ecology

The behaviour and ecology of specimens most likely belonging to this species have been observed by McKaye & Kocher (1983) and Konings (1989, 2016). They observed this species feeding on eggs and fry while stealing them from mouth-brooding females of other cichlid species. The paedophage rams these females from above on the snout and the brooding females may release some eggs or larvae upon this impact. The brood can then be snatched by P. krampus sp. nov. The inclined position of the mouth enables the fish to immediately grab the brood since it is already in a good position relative to the prey after ramming from above ( Konings 1989, 2016).

Figures

Fig. 4. Photographs of preserved specimens of Protomelas krampus sp. nov. A. Holotype (RMCA 99- 041-P-4768). B. Paratype (RMCA 99-041-P-4767). Melanin pattern strongly faded.

Fig. 5. Photograph of preserved paratype (RMCA 99-041-P-4767) of Protomelas krampus sp. nov., shortly after preservation.

Fig. 6. Photograph of live specimen of Protomelas krampus sp. nov. (specimen not preserved; length unknown) (copyright Ad Konings).

Fig. 7. Distribution map of Protomelas krampus sp. nov. Red star = holotype; red dot = paratype; green triangles = possible sightings by Konings (2016); orange square = possible sighting by McKaye & Kocher (1983); yellow diamond = possible sighting by Stauffer (pers. comm.). Inset: map of Africa with indication of area of Lake Malawi.