Lepidiolamprologus kamambae, Kullander, Sven O., Karlsson, Magnus & Karlsson, Mikael, 2012

Kullander, Sven O., Karlsson, Magnus & Karlsson, Mikael, 2012, Lepidiolamprologus kamambae, a new species of cichlid fish (Teleostei: Cichlidae) from Lake Tanganyika, Zootaxa 3492, pp. 30-48 : 31-38

Lepidiolamprologus kamambae , new species

( Figs. 1–5 ; Table 1 )

Holotype. NRM 61943. 1, 137.2 mm SL. Tanzania, Rukwa Province: Nkansi: Lake Tanganyika, Kamamba Island. 7 23' 51'' S, 30 33' 16'' E. 27 Oct. 2008. M. Karlsson & M. Karlsson.

Paratypes. All with same data as holotype. NRM 51514. 1, 119.2 mm SL.— NRM 51558. 9, 118.9–135.2 mm SL.

Diagnosis. A species of the restricted group of Lepidiolamprologus sensu Schelly (2007) , characterized by emarginate or truncate caudal fin (vs. rounded, subtruncate, or lyreate in other Lamprologini ), small scales (61–74, vs. less than 60, usually less than 40 in other Lamprologini , but up to 60 and 71 in Neolamprologus pleuromaculatus (Trewavas & Poll) and N. cunningtoni (Boulenger) , respectively), and presence of dermosphenotic bone combined with absence of other infraorbital ossicles (vs. absence in other Lamprologini except in Lamprologus lemairii Boulenger , and N. cunningtoni ). Similar to L. elongatus , L. kendalli and L. mimicus in color pattern composed of three horizontal rows of dark blotches on each side of body. Distinguished from all of these species by presence of a broad dark stripe on cheek. Distinguished from L. elongatus by more slender body (depth 20.8–23.6% of SL vs. 23.9–29.0%), narrower interorbital space (width 4.9–5.9% of SL vs. 6.0–7.0%), and presence of frontal pattern of light spots on dark brown ground. Distinguished from L. mimicus by narrower interorbital space (4.9–5.9% of SL vs. 6.0–6.8%), shorter upper jaw (length 12.5–13.5% of SL vs. 13.8–14.5%), and presence of frontal pattern of light spots on dark brown ground. Distinguished from L. kendalli by shorter last dorsal-fin spine (11.2–13.3% of SL vs. 13.3–15.1%), and lateral blotches distinct or only partly contiguous (vs. forming lateral bands separated by narrow light stripes). Distinguished from L. profundicola by presence of a row of dark blotches along middle of side (reported in L. profundicola only from unvouchered specimens), cheek naked except for a few scales posterodorsally (vs. numerous scales in regular rows on cheek), more scales in a longitudinal row (64–71 vs. 61–65), and presence (vs. absence) of dark markings on cheek and top of head. Distinguished from L. attenuatus by possession of three (vs. two) horizontal rows of dark blotches on each side of body, all blotches of similar intensity (vs. median blotch particularly prominent, other blotches often obsolete), and presence of frontal pattern of light spots on dark brown ground (vs. absence).

Description. All specimens examined are adult males. Elongate, moderately compressed laterally, trunk about elliptic in cross section anteriorly. Predorsal outline about straight ascending to or slightly in advance of dorsal-fin origin; dorsal-fin base contour slightly sloping. Ventral profile almost straight and horizontal, anal-fin base slightly ascending. Caudal peduncle contours slightly constricted at middle. Mouth large, slightly upwards directed, lower jaw slightly protruding before upper jaw. Maxilla reaching caudad to or not quite to vertical from anterior margin of orbit; lower jaw articulation below middle of orbit. Ascending processes of premaxillae forming minor elevation dorsally on snout. Snout tip obtuse. Orbit and eye lateral, in about middle of length of head, in upper half of head. Eye exposed in dorsal view of head, barely exposed in ventral view of head. Interorbital area flat, narrower than snout and mouth. Nostril situated at one-third distance from orbital margin to tip of upper jaw. Lips relatively thick, fold of lower jaw broadly interrupted anteriorly. Elongate labial ossification present on each side of lower lip.

First dorsal-fin spine inserted above pectoral-fin base, at or slightly posterior to vertical from caudal margin of opercle; spines subequal from 4th–6th, gradually slightly longer to last spine; soft dorsal-fin rays all branched, gradually slightly longer to 7th, beyond which shorter; soft portion ending in acute tip slightly beyond vertical from caudal-fin base. First anal-fin spine inserted opposite antepenultimate dorsal-fin spine; spines gradually increasing in length to last; soft anal-fin rays all branched, increasing in length to 6th ray, posterior rays shorter; soft portion ending in blunt tip at or slightly posterior to vertical from caudal-fin base. Pectoral fin short, reaching halfway to vertical from first soft ray of anal fin; rounded, 4th and 5th rays longest, forming rounded tip. Pelvic fin short, reaching to genital papilla; subacuminate, posterior branch of first soft ray and anterior ray of second soft ray forming rounded tip. Caudal-fin hind margin very slightly indented medially, lobes slightly convex, corners rounded. Caudal fin rays x.1.7+7.1.ix (8), viii.1.7+7.1.viii (1), ix.1.7+7.1.ix (1), ix.1.7+7.1.viii (1).

Trunk scales small, ctenoid. Cheek naked except for a group of minute cycloid partly embedded scales posterodorsally. Predorsal scales minute, cycloid, about 20 along midline; squamation extending anteriorly to slightly posterior to orbits. Abdominal scales small, with free margin, ctenoid. Prepelvic and chest scales very small, cycloid, embedded. Upper lateral line distance from dorsal-fin base anteriorly at about 12, posteriorly at about three scales; reaching posteriorly to about middle of caudal peduncle, but posteriorly may include scales or short sequences of scales from which tubes absent. Lower lateral line reaching forward to above spinous anal fin, anterior to that continued by short series or scattered pores or tubed scales at most up to 8 scales distance from cleithrum. Five rows of scales separating upper and lower lateral lines where overlapping above anal fin. Circumpeduncular scales 26 (1), 27 (2), 28 (2), 29 (4), 30 (2); comprising 12 (2) or 13 (9) above, and 12 (2), 13 (3), 14 (4), 14 (2) below lateral lines.

Gill rakers sparse, 4+1+9 (8), 4+1+10 (2), 5+1+9 (1); epibranchial and lower ceratobranchial rakers simple, needle-like, upper ceratobranchial rakers bifurcate distally. Microbranchiospines present externally on second through fourth gill arches. Lower pharyngeal tooth-plate ( Fig. 2 ) slender, only slightly wider than long and toothed surface about as long as posterior width. Pharyngeal teeth erect, slender, compressed, sparse; most teeth beveled with distinct blunt posterior cusp preceded by sharp edge or 1–3 minor cusps; anteriormost teeth with slightly recurved tip and usually a minor cusp subapically on the posterior aspect; larger posteromedian teeth tending to conical with erect more or less sharp cusp, and less pronounced cusp gap and minor cusps. Coronalis pore (NFL0) double. Six lacrimal lateralis openings; infraorbitals 2–5 absent, substituted by series of free neuromasts, infraorbital 6 (dermosphenotic) present.

Both upper and lower jaw marginally with anterior pair of minute caniniform teeth close to symphysis, followed on each side by three long (about 2–3 mm) caniniform, erect, distally recurved teeth, followed by much shorter, posteriorly gradually shorter, erect caniniform teeth; an inner band of minute, dense sharp teeth, about 6–8 teeth in width. Usually one or two of anterior long caniniform teeth and/or minute symphysial teeth in outer row absent. Total teeth in outer row hemiseries in upper/lower jaw 17/25, 18/25, 18/28, 19/31, 20/33, 20/34, 21/27, 21/ 28, 21/31, 22/31, 23/28.

Color pattern in preservative ( Figs. 1 , 3 ). Ground color off-white, ventral aspect whitish. Dark markings on head and trunk brown to dark brown. Horizontal row of six dark brown blotches next to dorsal-fin base and slightly extended onto dorsal-fin base; in line with those a dark blotch posteriorly on dorsal margin of caudal peduncle. Dorsal blotches of slightly different shape on left and right side, shape roundish or subrectangular, variably including a light center; extended ventrally to slightly below upper lateral line, or portion on lateral line separate and forming separate horizontal row of round or slightly elongate blotches. Along middle of flank a row of eight or nine dark brown blotches, roundish or slightly deeper than wide; penultimate blotch contiguous with dark blotch dorsally on caudal peduncle; last blotch posteriorly on caudal peduncle and partly on caudal fin base; each blotch usually connecting dorsally with blotches on upper lateral line; blotches margined ventrally by a faintly pigmented band spanning entire horizontal row of contiguous blotches. Head with complex pattern of dark and light stripes and blotches dorsally ( Fig. 3 ). On cheek a light to dark brown blotch or wide stripe variably extending posteroventrad from orbit minimally to halfway point, maximally to contact with inner margin of preopercle. A dark brown blotch immediately posterior to orbit. Opercular blotch dark brown, small; usually connected by narrow stripe to blotch posterior to orbit. Lachrymal stripe brown.

Dorsal fin with hyaline lappets and margin underneath very thin black margin along distal edge. Rest of dorsal fin pale brownish with very large hyaline spots forming continuous oblique stripes on soft portion. Anal fin pale greyish, almost hyaline, withup to six oblique rows of hyaline spots with brownish interspaces on soft portion. Pelvic fin pale greyish, anterior margin white. Margin of caudal fin hyaline, rest of tin pale brownish grey with dense pattern of small whitish or hyaline spots; lighter and spots less distinct on lower lobe compared to upper lobe. Pectoral fin hyaline.

Live coloration ( Figs. 4 & 5 ). Ground color variable, beige, yellowish, or greyish white. Dark blotches on side and dark spots on head as in preserved specimens, dark brown. Between rows of dark blotches, minute whitish spots forming three irregular horizontal stripes. A turquoise stripe from lower margin of orbit to upper lip. Many small whitish spots on caudal and anal fins, and posterior part of dorsal fin.

Comparative morphometry and coloration. Proportional measurements, selected meristics, a principal component analysis of measurement data, and habitus images are provided for L. kamambae and the most similar species L. elongatus , L. kendalli , and L. mimicus in Tables 1–10 and Figs. 1 , 4 , and 6.

Etymology. The specific epithet is a genitive based on the name of Kamamba Island at which the type series was collected.

Geographical distribution. Specimens are available so far only from the type locality, the Kamamba Island slightly off the southern Tanzanian coast of Lake Tanganyika ( Figs. 7 , 8 ). The species was observed, but not sampled at Kerenge Island, about 350 m to the northeast. It is likely that L. kamambae occurs also at the nearby Mwila and Nkondwe Islands. These two islands exhibit biotopes similar to those at Kamamba and Kerenge Islands. We have not observed L. kamambae either to the south or north of the vicinity of Kamamba and Kerenge Islands. We did not observe it at Mswa Point 10 km north of Mwila Island, or at the southern islands of Mvuna, Lupita, and Ulwile, or at Kipili.

Field observations. Lepidiolamprologus kamambae was observed for the first time in April 2008, at Kamamba and Kerenge Islands. We first considered it as a population of L. kendalli , similar in body shape, but distinguished by the coloration, which was much lighter, especially underwater where the L. kamambae looked whitish ( Fig. 5 ). The color pattern resembles more that of L. elongatus , a species that accepts a wide variety of biotopes and that is found in the whole lake, whereas L. kendalli is overall dark in color ( Figs. 1 and 4 ). During a second trip to Kamamba Island in October the same year, we had the opportunity to study the L. kamambae more closely and capture voucher specimens. At Kamamba Island L. kamambae is found in the transition zone between rocks and sand at 15 m depth. The habitat consists of sparsely scattered stones of 0.2–2 m in size on white sand bottom. The coloration of the fish blends in well with the light substrate. This biotope differs considerably from that of L. kendalli , which consists mainly of rocks of various sizes with plenty of dark caves and hide-outs. In contrast to L. kendalli , which sneaks up on its prey among the rocks, the L. kamambae hunt similar prey among the few scattered stones on the open sand floor. The food of L. kamambae probably consists of cichlid fish juveniles, but actual prey capture was not observed. Individuals of L. kamambae are often seen swimming half a meter over the bottom. Lepidiolamprologus kamambae was observed only in small numbers. Mostly solitary adults of 15–20 cm total length were encountered. Younger fish of about 10 cm total length were seen in pairs or smaller groups of at most four individuals.

Figures

FIGURE 1. Preserved specimens, all from Tanzania, Lake Tanganyika. A. Lepidiolamprologus kamambae, holotype, NRM 61943, 137.2 mm SL, Kamamba Island. B. L. kendalli, NRM 51590, 100.5 mm SL, Muzi. C. L. elongatus, NRM 59555, 116.4 mm SL, Udachi. D. L. mimicus, NRM 51595, 126.7 mm SL, Frontosa Reef.

FIGURE 2. Lepidiolamprologus kamambae. Lower pharyngeal jaw in occlusal (upper) and approximately lateral (lower) aspect. Scale for occlusal aspect. From paratype NRM 51558, 122.1 mm SL.

FIGURE 3. Lepidiolamprologus kamambae. Holotype, NRM 61943, 137.2 mm SL. A. Lateral aspect of snout. B. frontal aspect of snout. C. dorsal aspect of head.

FIGURE 4. Living specimens photographed in the field, showing live colors, all from Tanzania, Lake Tanganyika. A. Lepidiolamprologus kamambae, paratype, NRM 51558, 135.2 mm SL, Kamamba Island. B. L. kendalli, NRM 51544, 124.0 mm SL, Muzi. C. L. elongatus, NRM 59555, 150.1 mm SL, Udachi. D. L. profundicola, NRM 61570, 260.9 mm SL, Kansombo. Photographs by Mikael Karlsson and Magnus Karlsson.

FIGURE 5. Lepidiolamprologus kamambae. Living specimen, not preserved, photographed in natural habitat at Kamamba Island, 15 m depth. Photo by Mikael Karlsson and Magnus Karlsson, 30 April 2008.

FIGURE 7. Outline map of Lake Tanganyika showing collecting localities of L. kamambae and comparative material of L. elongatus, L. kendalli, L. mimicus, and L. profundicola.

FIGURE 8. Eastern part of Kamamba Island, type locality of Lepidiolamprologus kamambae. Photo by Mikael Karlsson and Magnus Karlsson, 30 April 2008.

Tables

TABLE 1. Standard length (in millimeters) and proportional measurements in percents of standard length of L. kamambae. SD = standard deviation. Regression line parameters, a (intercept), b (slope), and r (Pearson’s correlation coefficient) are calculated from measurements expressed in millimeters and shown for p <0.05.

	N	Holotype	Min	Max	Mean SD	a	b	r
SL mm	11	137.2	118.9	137.2	127.3 6.34
Head Length	11	33.2	31.1	34.2	32.8 0.78	-4251	0.361	0.914
Snout length	11	12.8	11.8	13.0	12.4 0.37	-0.903	0.721	0.917
Body depth	11	20.9	20.8	22.7	21.8 0.63	7.782	0.157	0.815
Orbital diameter	11	7.9	7.5	8.6	8.0 0.30	-0.617	0.085	0.831
Interorbital width	11	4.9	4.9	5.9	5.4 0.28
Preorbital depth	11	6.1	5.9	6.5	6.2 0.20	1.848	0.047	0.785
Caudal peduncle depth	11	9.9	9.8	10.6	10.1 0.25	2.727	0.080	0.869
Caudal peduncle length	11	15.4	15.4	17.6	16.5 0.75	2.622	0.144	0.691
Pectoral-fin length	11	20.3	19.3	20.9	20.1 0.47	6.075	0.153	0.878
Upper jaw length	11	12.5	12.5	13.5	13.1 0.28	0.621	0.126	0.904
Lower jaw length	11	15.9	15.9	17.4	16.5 0.48	-0.903	0.172	0.868
Last dorsal-fin spine length	11	13.1	11.2	13.3	12.5 0.69