Labeotropheus alticodia, Phiri and Pauers, 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 : 266-269

Labeotropheus alticodia, Phiri and Pauers , new species

urn:lsid:zoobank.org:act:1FF94795-F35C-4E43-B4EB- 5A04F906A3B3

Figures 2–4 ; Tables 3–5

Holotype.— SAIAB 211372, adult male, 78.2 mm SL, Malaŵi, Lake Malaŵi, Maleri Island, –13.9089591, 34.6260792, Michael J. Pauers, Titus B. Phiri, and Sanudi Likupe, 16 January 2020.

Paratypes.— FMNH 145009, 1 male, 79.4 mm SL, 1 female, 85.5 mm SL, Malaŵi, Lake Malaŵi, male: Maleri Island, –13.9089591, 34.6260792, female: Nankoma Island, –13.8840189, 43.6118803, Michael J. Pauers, Titus B. Phiri, and Sanudi Likupe, 16 January 2020; MPM Fi50085, 1 male, 77.1 mm SL, Malaŵi, Lake Malaŵi, Maleri Island, –13.9089591, 34.6260792, Michael J. Pauers, Titus B. Phiri, and Sanudi Likupe, 16 January 2020; MPM Fi50087, 1 female, 63.0 mm SL, Malaŵi, Lake Malaŵi, Maleri Island, –13.8926036, 34.6221075, Michael J. Pauers, Titus B. Phiri, and Sanudi Likupe, 16 January 2020; SAIAB 211373, 2 females, 79.4 and 85.1 mm SL, Malaŵi, Lake Malaŵi, Nankoma Island, –13.8840189, 34.6118803, Michael J. Pauers, Titus B. Phiri, and Sanudi Likupe, 16 January 2020.

Diagnosis.— Labeotropheus alticodia differs from the slender-bodied Labeotropheus , L. trewavasae , L. simoneae , L. chirangali , new species, and L. rubidorsalis , new species, as well as L. chlorosiglos , due to its greater body depth (37.4–40.6% SL vs. 26.3–33.4% SL in L. trewavasae ; 26.9–30.8% SL in L. simoneae ; 26.6–33.2% SL in L. chirangali , new species; 31.6–36.1% SL in L. rubidorsalis , new species; 31.9–34.7% SL in L. chlorosiglos ). It also differs from the slender Labeotropheus due to a greater distance between the insertion of the dorsal fin and the insertion of the anal fin (16.4–18.1% SL vs. 12.7–15.5% SL in L. trewavasae ; 14.6–16.0% SL in L. simoneae ; 13.7–15.7% SL in L. chirangali , new species; 13.5–15.7% SL in L. rubidorsalis , new species). Labeotropheus alticodia differs from all other robust-bodied Labeotropheus , except L. fuelleborni , by the nuptial coloration of the males. Male L. alticodia have a pale, powder-blue body, and the dorsal and caudal fins are whitish blue with yellow trailing edges, while the anal fin is a pale yellow orange; additionally, the pelvic fins are a pale yellow orange with white leading edges. The morphometric and meristic values largely overlap with the other robust Labeotropheus , with the following exceptions: L. alticodia differs from L. fuelleborni due to a longer distance between the tip of the snout and the origin of the dorsal fin (33.6– 35.9% SL vs. 30.8–33.7%), a longer rostral length (42.0– 48.4% HL vs. 40.4–42.0%), a shorter upper jaw (14.4–20.1% HL vs. 20.2–23.9%), and a smaller snout pad (11.6–14.8% HL vs. 14.9–17.2%). Labeotropheus alticodia differs from L. artatorostris due to a deeper preorbital depth (26.9–34.5% HL vs. 19.7–26.8%) and a typically longer rostral length (42.0–48.4% HL vs. 22.9–43.7%). It differs from L. candipygia , new species, by greater distances between the insertion of the dorsal fin and the insertion of the anal fin (16.4–18.1% SL vs.13.9–16.7%) as well as between the insertion of the dorsal fin and the origin of the anal fin (31.3–32.9% SL vs. 27.4– 31.7%). Labeotropheus alticodia differs from L. aurantinfra , new species, by a greater distance between the tip of the snout and the attachment of the pelvic fins (41.0–49.1% SL vs. 36.9–43.7%), a greater preorbital depth (26.9–34.5% HL vs. 21.3–31.7%), and a greater snout length (30.4–35.7% HL vs. 26.7–33.1%). Finally, L. alticodia differs from L. obscurus , new species, due to a smaller eye diameter (24.9–27.5% HL vs. 27.3–32.4%) and more teeth in the left half of the lower jaw (29–35 vs. 20–26).

Description.— Morphometric and meristic data summarized in Table 3. Body compressiform; ovoid to almost rectangular in shape. Body deep (37.4–40.6% SL) and consistently deep throughout its length. Anterior body 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 0–4 scales. Dorsal fin relatively short for Labeotropheus (55.8– 60.2% SL) with 16–17 spines and 8–9 rays. First dorsal spine opposite opercular tab. Dorsal rays 3, 4, 5 long, reaching to hypural plate and beyond. Anal fin angular and kite-shaped; anal-fin rays 3 and 4 long, reaching past caudal peduncle to caudal fin. Anal-fin origin opposite dorsal-fin spine 14 or 15; anal-fin insertion anterior to dorsal-fin insertion. Caudal fin subtruncate. Pectoral fin rounded. Pelvic fin long, minimally reaching origin of anal fin and longer in most specimens; males with filamentous pelvic rays, females non-filamentous. Attachment of pelvic fin opposite dorsal-fin spine 5 or 6.

Head of typical length for Labeotropheus (31.8–33.4% SL) but deep with strongly curved profile and slightly developed snout. Snout long and wide with snout pad of typical length for Labeotropheus (11.6–14.8% HL). Cheek with 3 scale rows. Infraorbital pores 9, with 23–38 neuromasts among them. Oral jaws short and wide. Oral teeth tricuspid and closely set on both upper and lower jaws; 7–10 tricuspid teeth on lateral portion of left upper jaw. Gill rakers stout, triangular, and widely spaced; 6–8 ceratobranchial and 2–3 epibranchial gill rakers on first gill arch. All specimens with 1 raker between the cerato- and epibranchial rakers.

Coloration of males.— Craniofacial region, from snout to preopercle, dark blue. Operculum grayish blue with bright metallic green opercular tab. Throat and branchiostegals white. Flank and caudal peduncle pale powder blue; 11 faint darker blue bars visible across flank and caudal peduncle. Dorsal and caudal fins whitish blue with yellow or orange trailing edges. Spinous anal fin pale orange; rayed portion white with 3–5 orange-yellow eggspots. Trailing portion of pelvic fin hyaline with white leading edge, and pale orange between.

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, caudal peduncle uniformly light gray, 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 white. Dorsal fin white with orange tips; some specimens with orange spots throughout fin, some specimens with orange trailing edge. Caudal fin brownish gray, some specimens with orange trailing edge. Rayed anal fin pale brownish orange with 1–2 yellow eggspots; spinous portion white. Pelvic fin white or hyaline, with bright white leading edge and pale orange between.

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. alticodia and the other Labeotropheus , we compared the body depth–standard length ratios of L. alticodia and its geographically proximate congeners ( Fig. 3 ). This ratio clearly places L. alticodia with the robust Labeotropheus , and distinguishes it from L. trewavasae and the sympatric L. rubidorsalis , new species ( Table 4). We also performed canonical discriminant function analyses on the meristic and Log 10 -transformed morphometric data. Both the morphometric and meristic canonical discriminant function analyses were robust and produced statistically significant results ( Table 5 ). Labeotropheus alticodia is distinct from L. artatorostris and L. obscurus , new species, along the first morphometric canonical function and the first two meristic canonical functions, although there is minor overlap with L. fuelleborni ( Fig. 4 ).

Distribution.— Labeotropheus alticodia is endemic to Lake Malaŵi and appears to be restricted to the Maleri Islands, specifically Maleri and Nankoma Islands, in Lake Malaŵi National Park, Malaŵi. We did not collect at the nearby Nakantenga Island, where Ribbink et al. (1983a) report a differently colored robust Labeotropheus .

Etymology.— The specific epithet combines the Latin adjective for deep or tall, alti, with a Latin word for head, specifically the head of a flower, codia, in reference to the striking head depth of this species.

Figures

FIG. 2. Labeotropheus alticodia, new species. (A) Live male holotype (SAIAB 211372), 78.2 mm SL; (B) live female paratype (SAIAB 211373), 85.1 mm SL; (C) holotype after preservation.

FIG. 3. Body depth–standard length relationships among L. fuelleborni, L. trewavasae, and the three new species of Labeotropheus from the southwestern portion of Lake Malaŵi. The ANOVA accompanying these data is in Table 4.

FIG. 4. Canonical function plots for robust Labeotropheus from the southwestern portion of Lake Malaŵi. (A) Morphometric canonical function 1 vs. meristic function 2; (B) meristic canonical function 1 vs. meristic function 2.