Labeotropheus candipygia, Pauers and Phiri, 2023

Pauers, Michael J. & Phiri, Titus B., 2023, Six New Species of Labeotropheus (Cichliformes: Cichlidae) from the Malaŵian Shore of Lake Malaŵi, Africa, Ichthyology & Herpetology 111 (2), pp. 263-292 : 274-278

Labeotropheus candipygia, Pauers and Phiri , new species

urn:lsid:zoobank.org:act:2AF772CB-E420-4196-8FDE- B0EB728D68BE

Figures 6–9 ; Tables 7–10

Holotype.— SAIAB 211376, adult male, 82.1 mm SL, Malaŵi, Lake Malaŵi, Chitende Island, –10.3982807, 34.2579842, Michael J. Pauers, Titus B. Phiri, Victor Nantunga, and Shaibu Fisha, 31 July 2018.

Paratypes.— FMNH 145011, 1 male, 80.8 mm SL, 1 female, 86.1 mm SL, Malaŵi, Lake Malaŵi, Chitende Island, –10.3982807, 34.2579842, Michael J. Pauers, Titus B. Phiri, Victor Nantunga, and Shaibu Fisha, 31 July 2018; MPM Fi50067, 9 males, 8 females, 67.9–90.8 mm SL, Malaŵi, Lake Malaŵi, Chitende Island, –10.3982807, 34.2579842, Michael J. Pauers, Titus B. Phiri, Victor Nantunga, and Shaibu Fisha, 31 July 2018; MPM Fi50068, 11 males, 8 females, 63.7–81.9 mm SL, Malaŵi, Lake Malaŵi, Chitende Island, –10.3982807, 34.2579842, Michael J. Pauers, Titus B. Phiri, Victor Nantunga, and Shaibu Fisha, 31 July 2018; MPM Fi50078, 7 males, 4 females, 64.2–97.2 mm SL, Malaŵi, Lake Malaŵi, Chitende Gap, –10.3975493, 34.2560859, Michael J. Pauers, Titus B. Phiri, Victor Nantunga, and Shaibu Fisha, 2 August 2018; SAIAB 211377, 1 male, 70.6 mm SL, 2 females, 70.2 and 74.4 mm SL, Malaŵi, Lake Malaŵi, Chitende Island, –10.3982807, 34.2579842, Michael J. Pauers, Titus B. Phiri, Victor Nantunga, and Shaibu Fisha, 31 July 2018.

Diagnosis.— Labeotropheus candipygia differs from all other species of Labeotropheus by the typical nuptial coloration of the males. Male L. candipygia have a distinct iridescent silvery-blue or silvery-white ventral surface; this unique coloration extends from the branchiostegals to the anus in all individuals, and will extend to through the caudal peduncle to the ventral attachment of the caudal fin in some individuals. Above this silvery-white ventrum, males are ochreous orange, which covers most of the head and can extend to the base of the dorsal fin, and extends posteriorly through the caudal peduncle to the base of the caudal fin, or they will be a dull grayish blue with ochreous-orange highlights on the scales of the dorsum. Both color patterns feature a brilliantly iridescent white dorsal fin that has ochreous-orange tips and patches of iridescent blue, black, orange, or red pigmentation.

Labeotropheus candipygia differs from the slender-bodied Labeotropheus , L. trewavasae , L. simoneae , L. chirangali , new species, except L. rubidorsalis , new species, due to its greater body depth (32.0–38.6% SL vs. 26.3–33.4% in L. trewavasae ; 26.9–30.8% in L. simoneae ; 26.6–33.2% in L. chirangali , new species); it does have a generally deeper body than L. rubidorsalis , new species, although the ranges overlap (31.6– 36.1% in L. rubidorsalis , new species). It differs from L. rubidorsalis , new species, primarily in the nuptial coloration of the males, but also by a generally shorter snout length (19.7–33.9% HL vs. 29.8–42.7%), a longer snout pad (11.3– 19.2% HL vs. mean 10.3–14.4%), and a greater number of tooth rows in the upper jaw (4–6 vs. 3–4).

In addition to the differences between L. candipygia and both L. alticodia , and L. aurantinfra , noted above, L. candipygia differs from the other robust-bodied Labeotropheus primarily via male nuptial coloration. While the morphometric and meristic values largely overlap with the other robust Labeotropheus , there are some distinctions. Labeotropheus candipygia has a greater distance between the tip of the snout and the origin of the dorsal fin (32.2–36.8% SL vs. 30.8–33.8%), a shorter distance between the insertion of the dorsal and anal fins (13.9–16.7% SL vs. 16.5–17.4%), and fewer teeth in the left side of the lower jaw (23–34 vs. 31–43) than L. fuelleborni . Labeotropheus candipygia typically has a shorter snout (19.7–33.9% HL vs. 25.2–40.8%), greater rostral length (35.1–49.7% HL vs. 22.9–43.7%), and a larger snout pad (11.3–19.2% HL vs. 7.4–16.1%) than L. artatorostris . Labeotropheus candipygia has a narrower interorbital width (32.7–42.8% HL vs. 40.1–43.5%) and typically fewer infraorbital neuromasts (13–33 vs. 25–40) than L. chlorosiglos . Finally, L. candipygia differs from L. obscurus , new species, due to a shorter distance between the insertions of the dorsal and anal fins (13.9–16.7% SL vs. 15.8–17.8%), a shorter distance between the insertion of the dorsal fin and the origin of the anal fin (27.4–31.7% SL vs. 30.3–33.2%), a typically shorter lower jaw (21.5–39.4% HL vs. 27.6–40.4%), more rows of teeth in the upper jaw (4–6 vs. 3–4), more teeth in the left half of the lower jaw (23–34 vs. 20–26), and fewer infraorbital neuromasts (13–33 vs. 22–46).

Description.— Morphometric and meristic data summarized in Table 10. Body compressiform; ovoid shape. Body depth 32.0–38.6% SL; body consistently deep throughout its length. Body moderately wide at pectoral fin and opercular tab. Scales on belly and anterior abdomen cycloid and tightly crowded. Flank scales ctenoid; exposed portion of scale fan-shaped and approximately hexagonal. Anterior lateral line overlapping posterior lateral line by 0–3 scales. Dorsal fin long, with 16–19 spines and 7–10 rays. Origin of dorsal fin anterior to or opposite opercular tab. Dorsal rays 3, 4, 5 long, reaching beyond hypural to caudal fin. Anal fin angular and kite-shaped. Anal rays 3, 4, 5 long in most males and some females, reaching past caudal peduncle to caudal fin; most female specimens with short anal-fin rays, reaching only to caudal peduncle. Anal-fin origin opposite dorsal-fin spine 14, 15, or 16; anal-fin insertion anterior to or opposite dorsal-fin insertion. Caudal fin subtruncate. Pectoral fin rounded, 13– 15 rays. Pelvic fin long, minimally reaching origin of anal fin and longer in the majority of specimens. Pelvic-fin ray slightly produced and filamentous in all males and most females; produced and non-filamentous in some females. Pelvic-fin attachment opposite dorsal-fin spine 4, 5, or 6.

Head long (29.8–35.3% SL) and relatively shallow. Strongly curved profile with slight concavity above eye and prominent snout. Snout short but wide with long snout pad (11.3– 19.2% HL). Cheek compact with 2–6 scale rows. Infraorbital pores 9 or 10 with 13–35 neuromasts among them. Oral jaws short and wide. Oral teeth tricuspid and closely set on both upper and lower jaws; 4–11 tricuspid teeth on lateral portion of left upper jaw. Gill rakers stout, triangular, and widely spaced; 6–10 ceratobranchial and 1–3 epibranchial gill rakers on first gill arch. All specimens with 1 raker between the cerato- and epibranchial rakers.

Coloration of males.— Ground color pale blue, fading to silvery blue or silvery white across ventral surface of head and flank; snout, jaws, operculum, throat, anterior abdomen, ventrum, and ventral portion of caudal peduncle all silvery blue or silvery white. All portions of head, operculum, flank, and caudal peduncle dorsal to the dorsal attachment of pectoral fin with ochreous-orange coloration; scales of flank and caudal peduncle either entirely ochreous orange or ringed with ochreous orange around pale blue or silvery blue center of scale. Opercular tab black, sometimes with faint greenish sheen. Ground color of dorsal-fin membrane silvery blue or silvery white, sometimes overlain by red patches throughout fin, or by ochreous-orange patches along proximal portion. Tips of dorsal fin ochreous orange. Caudal fin blue or silvery blue, grading to black posteriorly; thin orange trailing edge. Anal fin white or bluish white, with 3–5 orange-yellow eggspots. Pelvic fin pale red posteriorly with bright white leading edge; thick black band between white leading edge and posterior red color.

In preservative, males uniformly dark brown or gray with 11 faint vertical bars visible across flank and caudal peduncle on some specimens.

Coloration of females.— Head, body, and caudal peduncle uniformly light brown, with 11 faint dark bars extending across flank and caudal peduncle. Opercular tab black. Scales of flank and caudal peduncle with small orange spots close to insertion of scale. Throat and branchiostegals orange. Dorsal fin brownish gray with orange tips and orange trailing edge. Caudal fin brownish gray with thin orange trailing edge. Anal fin brownish gray with 1–2 yellow eggspots and orange trailing edge. Pelvic fin pale orange posteriorly with bright white leading edge; thick black band between white leading edge and posterior orange color.

In preservative, females uniformly dark brown or gray with 11 faint vertical bars visible across flank and caudal peduncle on some specimens.

Multivariate analyses.— Due to the overlap of morphometric and meristic characteristics between L. candipygia and the other Labeotropheus , we compared the body depth–standard length ratios of L. candipygia and its geographically proximate congeners ( Fig. 6 ). This ratio clearly places L. candipygia within the robust Labeotropheus , and distinguishes it from the slender L. simoneae and L. chirangali , new species, as well as the intermediate L. chlorosiglos ( Table 7). We also performed canonical discriminant function analyses on the meristic and Log 10 -transformed morphological data for L. candipygia , L. chlorosiglos , L. fuelleborni , and the geographically proximate L. aurantinfra . The canonical discriminant function analyses were robust and significant ( Table 8 ). While L. chlorosiglos is distinct along the first morphometric canonical function, and L. fuelleborni is particularly distinct along the second meristic canonical function, L. candipygia and L. aurantinfra overlap along all three canonical functions we plotted ( Fig. 7 ). Despite the lack of resolution between L. candipygia and L. aurantinfra based upon the canonical discriminant function analyses, we found that L. candipygia has smaller width to length ratios of both the lower jaw and snout than both L. aurantinfra and L. fuelleborni ( Fig. 8 , Table 9).

Distribution.— Labeotropheus candipygia is endemic to the Malaŵian shore of Lake Malaŵi, and appears to be restricted to Chitende Island and the nearby Chitende Gap, between Chitende Point (the remnants of a peninsula that once connected Chitende Island to the mainland) and Chitende Island.

Remarks.— Ribbink et al. (1983a) state that they found the males of the robust Labeotropheus at Chitende Island to have a sky blue head, dorsum, and body, with an orange chest and dorsal fin. We did not find any robust Labeotropheus at Chitende matching this description; indeed, this description seems most similar to L. aurantinfra from Chirwa Island. Interestingly, they describe the slender Labeotropheus at Chitende as having coloration similar to that of L. candipygia (Ribbink et al., 1983a, 1983b). We did not find any slender Labeotropheus at Chitende; L. candipygia was the only species of Labeotropheus present.

Etymology.— The specific epithet combines the Latin adjective for white or brilliant, candidum, and the New Latin noun pygia, meaning rump or buttocks. This refers to the bright white or bluish-white ventrum of the males.

Figures

FIG. 6. Body depth–standard length relationships among L. fuelleborni, L. trewavasae, L. chlorosiglos, L. simoneae, and the three new species of Labeotropheus from the northwestern portion of Lake Malaŵi. (A) All seven species; (B) same plot as A, but L. fuelleborni and L. trewavasae are omitted for clarity. The ANOVA accompanying these data is in Table 7.

FIG. 7. Canonical function plots for the robust Labeotropheus from the Luromo Peninsula. (A) Morphometric canonical function 1 vs. meristic canonical function 1; (B) meristic canonical function 1 vs. meristic canonical function 2.

FIG. 8. Comparison of jaw and snout dimensions among L. fuelleborni and the two newly described robust Labeotropheus from northwestern Lake Malaŵi. (A) Lower jaw length versus lower jaw width; (B) snout length versus snout width. The ANOVA accompanying these data is in Table 9.

FIG. 9. Labeotropheus candipygia, new species. (A) Live male holotype (SAIAB 211376) from Chitende Island, 82.1 mm SL; (B) holotype after preservation; (C) live female paratype (MPM Fi50067) from Chitende Island, 90.8 mm SL; (D) live male paratype (MPM Fi50078) from Chitende Gap, 67.1 mm SL.

Tables

Table 8. Canonical discriminant function (CDF) analyses on (A) Log10- transformed morphometric and (B) meristic data for L. aurantinfra, L. candipygia, L. chlorosiglos, and L. fuelleborni. Standardized functions are reported. Uninformative variables are omitted.

(A) Log 10 -transformed morphometric data: Wilks’ k ¼ 0.038,
F 39,219 ¼ 11.382, P 0.001
			CDF 1 CDF 2 CDF 3
Eigenvalue			4.619 1.528 0.855
Canonical correlation			0.907 0.777 0.679
HL			0.988 1.074 1.698
Snout to attachment of pelvic fins			1.775 –0.831 –0.744
Insertion of dorsal fin to insertion of			1.705 1.153 –1.429
anal fin
Origin of dorsal fin to insertion of			0.309 0.294 2.982
anal fin
Body depth			–2.970 –0.479 –1.250
Width at opercular tabs			–1.565 –1.905 –0.512
Preorbital depth			–0.402 –1.106 –1.344
Cheek depth			–0.383 1.349 0.507
Snout length			0.838 –1.293 –0.247
Rostral length			–1.549 –0.026 0.261
Lower jaw length (LJL)			–0.777 0.240 –0.607
Lower jaw width (LJW)			0.095 1.753 –0.779
Interorbital width			2.057 –0.431 1.081
Species means
L. aurantinfra			–0.221 –1.281 –0.081
L. candipygia			–1.442 1.173 0.437
L. chlorosiglos			5.966 0.722 0.689
L. fuelleborni			0.922 1.486 –3.535
(B) Meristic data: Wilks’	k	¼ 0.052, F 60,200 ¼ 5.654, P
0.001
			CDF 1 CDF 2 CDF 3
Eigenvalue			2.872 1.418 1.069
Canonical correlation			0.859 0.766 0.719
Anterior lateral line scales (LLS)			0.305 0.228 0.433
Posterior LLS			–0.343 0.138 –0.207
Overlapping LLS			–0.083 0.023 –0.327
Dorso-lateral scale rows			–0.749 0.454 –0.443
Pectoro-pelvic scale rows			1.082 –0.326 –0.352
Cheek scale rows			–0.199 0.299 –0.319
Dorsal-fin spines (DFS)			0.181 0.141 0.288
Dorsal-fin rays (DFR)			–0.072 0.124 0.099
Anal-fin rays (AFR)			0.037 0.476 –0.304
Pectoral-fin rays			–0.131 –0.122 0.091
Pelvic-fin rays			0.029 –0.185 0.091
Upper jaw teeth rows			–0.181 0.058 0.402
Lower jaw teeth rows			–0.176 –0.153 –0.399
Teeth on left lower jaw			–0.290 –0.921 0.099
Teeth on left dentigerous premaxilla			–0.453 0.037 0.140
Total gill rakers			–0.112 0.526 0.111
Epibranchial gill rakers			0.052 –0.144 –0.028
Ceratobranchial gill rakers			0.408 –0.185 0.279
Infraorbital pores			–0.003 0.206 0.148
Neuromasts within infraorbital pores			–0.020 0.200 0.120
Species means
L. aurantinfra			1.478 –0.255 0.541
L. candipygia			–0.556 0.841 –1.016
L. chlorosiglos			–3.634 0.417 2.017
L. fuelleborni			–2.097 –4.326 –1.261