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Zootaxa 3790 (3): 425–438 www.mapress.com /zootaxa / Copyright © 2014 Magnolia Press Article ISSN 1175-5326 (print edition) ZOOTAXA ISSN 1175-5334...
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Zootaxa 3790 (3): 425–438 www.mapress.com /zootaxa / Copyright © 2014 Magnolia Press

Article

ISSN 1175-5326 (print edition)

ZOOTAXA

ISSN 1175-5334 (online edition)

http://dx.doi.org/10.11646/zootaxa.3790.3.2 http://zoobank.org/urn:lsid:zoobank.org:pub:D3B2BFCF-8BA4-45FD-B353-F76BB81DE07F

Chalinochromis cyanophleps, a new species of cichlid fish (Teleostei: Cichlidae) from Lake Tanganyika SVEN O. KULLANDER1, MIKAEL KARLSSON2, MAGNUS KARLSSON2 & MICHAEL NORÉN1 1

Department of Zoology, Swedish Museum of Natural History, P.O. Box 50007, SE-104 05 Stockholm, Sweden. E-mail: [email protected], [email protected] 2 African Diving Ltd, P. O. Box 7095, Dar es Salaam, Tanzania. E-mail: [email protected]

Abstract Chalinochromis cyanophleps is described from nine specimens, the largest 129 mm SL, from Namansi. It differs from other species of Chalinochromis in plain trunk colouration, absence of black stripes on the head, relatively narrow lips, presence of tricuspid jaw teeth, and presence of five rather than four dentary lateralis foramina. The blue iridescent stripe below the eye is shared with other lamprologin cichlids, but is broader and more conspicuous in C. cyanophleps. Chalinochromis cyanophleps occurs at depths between 6 and 45 m in rocky habitats along the Tanzanian coast of Lake Tanganyika, from Mvuna Island south to Kalala Island, a stretch of about 90 km. Field observations were made of specimens up to 18 cm total length. The COI DNA barcode sequence differs by 1.8% from that of C. popelini. Key words: DNA Barcode, endemism, meristics, morphometry, taxonomy

Introduction The endemic Lake Tanganyika cichlid genus Chalinochromis Poll (1974) presently includes two species characterized by steep head profile and thick papillose lips. Chalinochromis brichardi Poll (1974) was described from near Magara in Burundi and is uniformly beige with black stripes on the head and has an approximately rounded caudal fin. Chalinochromis popelini Brichard (1989) from Moba on the Congo coast is beige with black horizontal stripes and has a more or less emarginate caudal fin (Brichard 1989; Konings 1998). Two additional forms have been recognized in aquarium literature, and are considered as either distinct species or colour variation in C. brichardi or C. popelini, viz. C. “bifrenatus” with horizontal stripes along the side, and C. “ndobhoi” with series of blotches along the side (Konings 1998). In 1991 one of us discovered a rock-dwelling lamprologin cichlid at Ulwile Island on the Tanzanian coast of Lake Tanganyika, similar in shape to known species of Chalinochromis. It was distinguished by its larger size and colour pattern, which is almost uniformly dark, with a blue stripe below the eye and shimmering blue fins (Karlsson & Karlsson 2012). A longer, illustrated description of the species was given by Karlsson & Karlsson (2012), in which article it was referred to as Chalinochromis sp. “blue vein”. Morphological analysis shows that the dark species from Ulwile Island departs significantly from both C. brichardi and C. popelini not only in colour but also in the shape of the mouth and dentition. The objective of this paper is to provide a formal description of the new species.

Material and methods Specimens were collected by scuba diving, using a net of 1x5 m, mesh size 10 mm, with float and bottom lead, and also small hand net. Specimens were fixed in formalin and preserved in 70% ethanol. Prior to fixation the right pelvic fin was removed from one specimen and placed in 95% ethanol for DNA analysis.

Accepted by J. Sparks: 3 Mar. 2014; published: 22 Apr. 2014 Licensed under a Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0

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Measurements and counts were recorded as described by Roberts & Kullander (1994) and Kullander et al. (2012). The length of the caudal peduncle is measured from the base of the last ray of the anal fin to the middle of the base of the caudal fin. Scales in a longitudinal row include the scales of the upper lateral line followed by those of the horizontal row containing the lower lateral line, starting with the first scale in the oblique row (sloping rostrad and ventrad) next behind that containing the last scale of the upper lateral line. Lateral line scales on the caudal fin are not counted. Counts of lateral line scales include all scales up to the posteriormost canal-bearing scales in the upper lateral line, and to the anteriormost canal-bearing scale in the lower lateral line. That means that, especially in the lower lateral line, the count may include several scales from which neuromast pits or bone canals are absent. Vertebral counts and counts of fin rays in unpaired fins were taken from X-radiographs. Vertebral counts include the last half-centrum. Teeth were counted in the outer row on one side (predominantly the left side) of the upper and lower jaw. Counts of caudal-fin rays include unsegmented procurrent rays, the marginal unbranched segmented ray, and the branched rays separated by periods, counts of upper and lower lobe separated by a plus sign. X-radiographs were made on Kodak X-omat V film using a Philips MG-105 low voltage X-ray unit. Morphometric data were managed and analysed using IBM Statistics 21 (IBM 2012) except that the principal component analysis (PCA) of measurements was made using a separate procedure for component shearing, partialling out multivariate size residues from the second and further components as described by Humphries et al. (1981). The PCA analysis was made with log-transformed measurement data to tenth of a millimetre in a covariance matrix, and without rotation. DNA sequences were obtained as described by Fernholm et al. (2013). Abbreviations: NLF0 = neurocranial lateral line foramen 0; SL = Standard length. Specimens and tissue samples studied are deposited in the Swedish Museum of Natural History, Stockholm (NRM). Undescribed species are designated with the names commonly used in the aquarium trade, and in quotes to mark that they are not available as scientific names: Chalinochromis “ndobhoi”, and C. “bifrenatus”, the latter also known as “Kipili.”

Chalinochromis cyanophleps, new species (Figs. 1–5; Table 1) Type material. Holotype. NRM 11993, adult female, 113.7 mm SL. Tanzania, Rukwa Region, Nkansi District, Lake Tanganyika, western shore of Namansi village, depth 5–10 m, 7°37'15"S, 30°39'24"E. 22 May 2008. M. Karlsson & M. Karlsson. Paratypes: All with same data as holotype. NRM 59606, adult female 111.2 mm SL; NRM 59607, 5 adult males, 103.3–129.3 mm SL, 2 adult females, 108.7–111.5 mm SL. Diagnosis. Distinguished from Chalinochromis brichardi by flank colour brown to dark grey vs. beige or light grey (Fig. 1); dark brown (conspicuous blue in life) stripe below eye, vs. contrasting black vertical stripes on head (Fig. 1); iris and eye ring partly orange, vs. orange colour not or only faintly visible; opercular blotch absent vs. prominent (Fig. 1); black blotch posteriorly in dorsal fin absent vs. present (Fig. 1); dorsal and caudal fins dark with white dots vs. pale and dots absent (Fig. 1); black spot at pectoral–fin base absent vs. present (Fig. 1); more teeth in upper jaw (13–16 vs. 5–10 in hemiseries), and lower jaw (17–26 vs. 2–3 in hemiseries); and slender caudal peduncle (depth 9.9–10.7% SL vs. 11.6–12.4 %). Distinguished from all other species of Chalinochromis by absence of stripes and blotches on head (vs. present); lips not folded over adjacent jaw and not callous or papillate on lip surface outside that close to teeth (vs. lips wide and folded over adjacent premaxilla and dentary, and more or less extensively papillose on aborad surfaces) (Fig. 2); presence of tricuspid inner teeth (vs. exclusively unicuspid); five mandibular lateralis foramina (vs. four). Distinguished from all species of Altolamprologus, Lamprologus, Lepidiolamprologus, Neolamprologus, Paleolamprologus, and Variabilichromis by number of dorsal-fin spines (22–23 vs. 14–20, occasionally 21); from all species of Congo River Lamprologus by first pelvic-fin ray longest (vs. second to third rays longest), and lateral line scales 37–39 vs. 29–37; from all species of Telmatochromis by dentition (inner teeth mostly unicuspid vs. only or predominantly tricuspid), posterodorsal corner of opercle rounded (vs. pointed), and upper jaw projecting (vs. jaws equal); from all species of Julidochromis by absence of bars and bands on body, and scales in longitudinal row 37–39 vs. 36 or less. Description. Based on all specimens in type series. For general aspect, refer to Fig. 1. Measurements are summarised in Table 1. Elongate, moderately compressed laterally. Trunk anteriorly elliptic in cross section, posteriorly more compressed; sides vertical, dorsum and venter rounded. Head relatively short; frontal contour

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steep, ascending straight or slightly curved, strongly curved above orbit, joining about straight dorsal-fin base contour. In both sexes a low soft swelling anterior to dorsal-fin origin. Interorbital space wide, convex; head contour well removed from orbit. Orbit lateral, in middle of head length, in dorsal half of head, well separated from mouth by deep lachrymal bone. Eye exposed in dorsal view of head, not exposed in ventral view of head. Ventral profile almost straight, horizontal; anal-fin base slightly ascending. Caudal peduncle contours slightly constricted at middle. Snout short, blunt. Mouth low, at ventral contour, relatively small, narrower than interorbital space; upper jaw protruding slightly before short lower jaw. Ascending processes of premaxilla not reaching orbit. Maxilla not reaching to vertical from anterior margin of orbit. Lower jaw articulation anterior to vertical from anterior margin of orbit. Nostril situated at one-third distance from orbital margin to tip of upper jaw. Lips (Fig. 2A) relatively narrow, thick; fold of lower lip broadly interrupted anteriorly. Lips smooth except close to teeth where surface beset with short papillae similar to tissue in toothed field of jaws. TABLE 1. Standard length (in millimetres) and proportional measurements in percent of standard length of Chalinochromis cyanophleps. SD= standard deviation. Regression line parameters, a (intercept), b (slope) (where ANOVA p