Revision of the Congo River Lamprologus Schilthuis, 1891 (Teleostei: Cichlidae), with Descriptions of Two New Species

2004·2.1 MB·English

by  Robert C. Schelly

PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY
CENTRAL PARK WEST AT 79TH STREET, NEW YORK, NY 10024
Number 3451, 40 pp., 31 figures, 8 tables August 23, 2004
Revision of the Congo River Lamprologus
Schilthuis, 1891 (Teleostei: Cichlidae), with
Descriptions of Two New Species
ROBERT C. SCHELLY1 AND MELANIE L.J. STIASSNY2
ABSTRACT
TheCongoRiverLamprologusarerevisedandtwonewspeciesaredescribed.Lamprologus
teugelsi, n.sp., from Malebo Pooland the lowerCongo River rapids,and L.tigripictilis,n.sp.,
fromthelowerCongoRiverrapids,arereadilydistinguishedfromtheremainingCongoRiver
Lamprologus based on counts, measurements, osteology, and color pattern. Monophylyofthe
Congo River Lamprologus species is tentatively accepted and a key to the group is provided.
Allavailablecollectionlocalitiesforre-identifiedLamprologusmaterialfromtheCongoRiver
are plotted for each species. Maps of collection localities reveal large distributional voids,
suggesting that Congo River lamprologine diversity remains incompletely sampled.
INTRODUCTION (1986) classification of the Lake Tanganyika
cichlid assemblage. Most lamprologines are
The African cichlid genera Altolamprolo- found in lacustrine habitats (Poll, 1986;
gus Poll, 1986, Chalinochromis Poll, 1974, Stiassny, 1997). About 90% of the species
Julidochromis Boulenger, 1898, Lamprolo- are restricted to Lake Tanganyika and asso-
gus Schilthuis, 1891, Lepidiolamprologus ciated rivers and streams, while 10% are
Pellegrin, 1904, Neolamprologus Colombe found in the remaining Congo River drain-
and Allgayer, 1985, and Telmatochromis age. Despite the predominance of lacustrine
Boulenger, 1898, currently totaling some 90 taxa in the Lamprologini, the first lamprolo-
species, comprise the Lamprologini in Poll’s gine to be described was fluviatile; the type
1Division of Vertebrate Zoology (Ichthyology), American Museum of Natural History; Department of Ecology,
EvolutionandEnvironmentalBiology,andCenterforEnvironmentalResearchandConservation,ColumbiaUniver-
sity,NewYork([email protected]).
2DivisionofVertebrateZoology (Ichthyology),AmericanMuseumofNaturalHistory([email protected]).
Copyright(cid:113)AmericanMuseumofNaturalHistory2004 ISSN0003-0082
2 AMERICAN MUSEUM NOVITATES NO. 3451
species of the genus Lamprologus is con- ogines first diversified in Lake Tanganyika
goensis, a species originally based on three andonlysecondarilyinvadedtheCongoRiv-
specimens from Malebo Pool (Stanley Pool) er system. Others have argued that ancient
on thelowerCongoRiver(Schilthuis,1891). riverine lamprologines existed prior to the
Within just a few years, several expeditions rift and invaded the rocky inshorehabitatsof
to the rift valley lakes, including that of Lake Tanganyika upon its formation, subse-
Moore in 1895–1896 (Moore, 1903), provid- quently radiating to achieve their present di-
ed enough material to begin describing the versity (De Vos et al., 2001). Roberts (1982)
lamprologine-rich ichthyofaunaofLakeTan- goes so far as to suggest that life in rocky
ganyika (Boulenger, 1898a, 1898b, 1899a, rapids habitats preadapted cichlids such as
1899b, 1901, 1906; Pellegrin, 1904). Subse- Haplochromis, Lamprologus, and Nanoch-
quent to the descriptions of L. tumbanus romis to colonize lake habitats characterized
Boulenger, 1899 and L. mocquardiPellegrin, by rocks and boulders.
1903, 56 years elapsed before the discovery When existing morphological evidence is
of a fourth Congo River species, L. werneri considered, the relationship of the Congo
Poll, 1959, among the riverine taxa. Since River Lamprologus to Lake Tanganyika en-
1959, only two Congo River species have demics is far from resolved. Poll’s (1986)
been described, both based on very small classification of his tribe Lamprologini re-
numbersofspecimenswithnarrowlyrestrict- stricted the genus Lamprologus to include
ed distributions: L. symoensi Poll, 1976, and the Congo River species and 11 Lake Tan-
L. lethops Roberts and Stewart, 1976, which ganyika species on the basis of their all hav-
is the only known blind cichlid. This history ing the second or third pelvic fin ray thelon-
suggests, tantalizingly, that the sampling of gest, as opposed to the condition seen in the
Congo River lamprologine diversity is far remaining lamprologines in which the first
from complete, and in the course of the pre- ray is the longest. However, this scheme is
sent study two additional riverine species undercut by Stiassny’s (1997) labial ossifi-
have been recognized, bringing the total of cation character. In members of several lam-
known species to eight.3 prologine genera, including 8 of the 11 Lake
Recently, the intrarelationships of lam- Tanganyika Lamprologus, a fully ossified
prologines have been investigated, and with sesamoid bone is suspended in the labiallig-
lamprologine monophyly well supported by ament, but no such bone occurs in any ofthe
bothmorphological(Stiassny,1997)andmo- Congo River species.
lecular (Sturmbauer et al., 1994; Salzburger Additionally, in most lamprologines, the
et al., 2002) evidence, speculationhasturned post-lachrymal infraorbital series is entirely
to thenatureandnumberofmajorevolution- absent. Exceptional among Lake Tanganyika
ary transitions within the clade. Some of the lamprologinesareNeolamprologustoaePoll,
most intriguing of thesequestionsarewheth- 1949, with a complete series of infraorbitals
er ancestral lamprologines arose in rivers or stretching from the lachrymal to the postor-
lakes, and the number of transitions between bital process, and Variabilichromis moorii
the two modalities in the history of the Boulenger, 1898, which presents one or two
group. Molecular analyses that included infraorbitals adjacent to the dermosphenotic
some of the Congo River species of Lam- (Stiassny, 1997). The Congo River Lamprol-
prologus (e.g., Sturmbaueret al.,1994;Salz- ogus are unique among lamprologines in
burger et al., 2002) apparently support Re- having, as an invariant condition, a reduced
gan’s (1920, 1922) contention that lamprol- infraorbital series of one or more (typically
two to three) tubular infraorbitalsadjacentto
thelachrymal.Thischaractertentativelysup-
3Additionally,NeolamprologusdevosifromtheMal-
agarasi River on the eastern shore of Lake Tanganyika portsthemonophylyoftheCongoRiverspe-
hasbeennewlydescribed(Schellyetal.,2003),bringing cies, a contention that is additionally sup-
the total number of exclusively fluviatilelamprologines ported(atleastforthethreeincludedspecies)
inthegreaterCongobasintonine.Neolamprologusde-
by the molecular analysis of Sturmbauer et
vosi is not a member of the Congo River Lamprologus
al. (1994). Of course, the condition might
clade (Schelly et al., 2003), and is therefore excluded
fromthistreatment. alsorepresentanintermediatestageofatran-
2004 SCHELLY AND STIASSNY: CONGO RIVER LAMPROLOGUS 3
sition series in a non-monophyletic portion INSTITUTIONAL ABBREVIATIONS
of the phylogeny. While the ultimate reso-
AMNH American Museum of Natural History,
lution of the question of Congo River Lam-
New York
prologus monophyly awaits a thorough phy-
BMNH The Natural History Museum, London
logenetic analysis of all known lamprolo-
IRSNB Institut Royal des Sciences Naturelles
gines (Schelly, in prep.), the reality of the de Belgique, Brussels
group as a circumscribed clade is tentatively MCZ Museum of Comparative Zoology,
accepted here. Cambridge
GiventhecentralimportanceoftheCongo MNHN Muse´um National d’Histoire Naturelle,
RiverLamprologustoafullunderstandingof Paris
MRAC Muse´e Royal de l’Afrique Centrale,
the evolutionary pathways that have given
Tervuren
rise to present-day lamprologine diversity, a
USNM National Museum of Natural History,
precise taxonomy of thegroupisanecessary
Washington, D.C.
prerequisite for further investigations. This
revision is intended to provide such a foun-
ANATOMICAL ABBREVIATIONS
dation. In the course of this study we found
that over 50% of Congo River Lamprologus BD body depth
material housed in museum collections was FR frontal ridge
misidentified, including some of the vouch- HL head length
ers representing specimens used in various LPJ lower pharyngeal jaw
NLF0 neurocranial lateral line foramen 0
molecular analyses. Thus, in an age of mo-
PSC process for insertion of supracarinalis
lecular phylogenetics, the importance of mu-
muscle
seum collections and morphology-based tax-
SL standard length
onomicworkisclearlystillofparamountim- SOC supraoccipital crest
portance, and the critical need to depositand TL total length
curate voucher specimens in museumcollec-
tions is underscored. KEY TO SPECIES OF CONGO RIVER
LAMPROLOGUS
METHODS
1. 32 or more scales in lateral line; 30 or more
vertebrae; head length 34.6% SL or less ..
Meristic counts and morphometric mea-
.................................. 2
surements followed Barel et al. (1977), and
– 29–31 scales in lateral line; 28–29 vertebrae;
were made on the left side of specimens ex- head length 34.6–37.0% SL; four sensory
cept in cases where damage necessitated use poreopeningsonthelachrymal;nointerdig-
of the right side, with digital calipers to 0.1 itation at LPJ suture (fig. 1a); supraneurals
mm. Specimens were cleared and counter- absent; relatively elevated supraoccipital
stained following Dingerkus and Uhler crestcontinuouswithfrontalridgeextending
to median coronal pore (fig. 2a) .......
(1977). Where sufficient material was avail-
................ Lamprologus tumbanus
able,dissectionsweremadeoftheabdominal
2. Flank scales irregular in size (fig. 3a), obscur-
cavity to measure gut length and analyze
ing parallel rows; scaleless patch on head
stomach contents. Whenever possible, ap- extending caudally well beyond dorsal fin
proximately equal numbers of males and fe- origin (fig. 4a); supraoccipital crest low, no
males of various size classes and collection frontal ridge extending to median coronal
localities were selected for measurement. pore (fig. 2c) ...................... 3
With the exception of recently collected ma- – Flank scales are of uniform size (fig. 3b), ar-
terials for which Global Positioning System ranged in parallel rows; nape scaled to dor-
sal fin origin or beyond (fig. 4b,c); supra-
(GPS) data were available, when geographic
occipital crest variable ............... 4
coordinatesaregivenforcollectionlocalities,
3. Eyes greatly reduced and covered by thick
these data have been taken from the MRAC
skin;bodydepigmented;headdorsoventrally
geographical database or derived from gaz- flattened; body depth 17.9% SL; 43–49
etteers, and the implied precision should be scalesinlateralline;foursensoryporeopen-
approached with caution. ings on the lachrymal; strongly interdigitat-
4 AMERICAN MUSEUM NOVITATES NO. 3451
Fig. 1. Schematic of lower pharyngeal jaw
ventral suture: (a) no interdigitation; (b) strongly
interdigitating.
Fig.2. Schematicofvariousmanifestationsof
supraoccipitalcrestandfrontalridge:(a)Elevated
ing LPJ suture (fig. 1b); supraneural absent
supraoccipital crest continuous with frontal ridge
................. Lamprologus lethops
toneurocraniallaterallineforamen0;(b)lowsu-
– Eyes not reduced; body pigmented; head not
praoccipital crest continuous with frontal ridge to
flattened; body depth 22.5–27.4% SL; 35–
neurocraniallaterallineforamen0;(c)lowsupra-
42 scales in lateral line; five sensory pore
occipital crest, no frontal ridge extending to neu-
openingsonthelachrymal;nointerdigitation
rocranial lateral line foramen 0.
atLPJsuture(fig.1a);supraneuralpolymor-
phic ............ Lamprologus symoensi
4. Darkpigmentaroundentirecaudaledgeofeach
scale, giving chain-link fence appearance of elevated supraoccipital crest, continuous
intersecting bands on sides of body; scales with frontal ridge extending to median cor-
extendanteriorlyontonape,oratleasttodor- onal pore (fig. 2a,b) ................. 6
sal fin origin(inL.teugelsi,n.sp.);singlesu- – Pelvic fin very seldom (only in some large L.
praneural present or polymorphic ....... 5 werneri males) or never reaching to anus;
– Darkpigmentrestrictedtodorsalhalfofcaudal interdigitation at LPJ suture weak or absent
edge of each scale, giving appearance of (fig. 1a); low supraoccipital crest, continu-
oblique parallel bands; nape and region just ous with frontal ridge extending to median
below dorsal fin origin scaleless (fig. 4b); coronal pore (fig. 2b) ............... 7
supraoccipital crestlow,nofrontalridgeex- 6. 32–35 scales in lateral line; 14 precaudal, 30–
tending tomediancoronalpore(fig.2c);su- 31 total vertebrae; BD 21.0–27.8% SL; el-
praneural absent ..................... evated supraoccipital crest, (fig. 2a); 5–6
............... Lamprologus mocquardi dark vertical bars on flanks; nuccal humpof
5. Pelvic fin extending posteriorly beyond anus; fatty tissue forms in adult males .......
interdigitation at LPJ suture strong; low or ............... Lamprologus congoensis
2004 SCHELLY AND STIASSNY: CONGO RIVER LAMPROLOGUS 5
Fig. 3. Schematic of flank squamation pat-
terns:(a)scalesofirregularsize,suchthatparallel
oblique rows are obscured; (b) scales of uniform
size, forming parallel oblique rows.
– 35–37 scales in lateral line; 14 precaudal, 31–
33 total vertebrae; BD 17.1–24.4% SL; low
supraoccipitalcrest,(fig.2b);9–10darkver-
tical bars on flanks ..................
.......... Lamprologus tigripictilis, n.sp.
7. 34–37 scales in lateral line; 15 precaudal, 31–
33 total vertebrae; 12–15 total gillrakers on
first gill arch; shallow bodied, BD 17.3–
20.3% SL ......... Lamprologus werneri
– 32–34 scales in lateral line; 14 precaudal, 30–
32 total vertebrae; 8–11 total gill rakers on
first gill arch; relatively deep-bodied, BD Fig. 4. Schematic of nape squamation pat-
21.9–28.6% SL ..................... terns: (a) scaleless patch extends posteriorly well
............. Lamprologus teugelsi, n.sp. beyond dorsal fin origin; (b) nape scales extend
anteriorly to dorsal fin origin; (c) nape scales ex-
tend anteriorly well beyond dorsal fin origin.
TAXONOMIC SECTION
Lamprologus congoensis Schilthuis, 1891 LECTOTYPE: BMNH 1891.12.29.10, Kin-
Figures 5–8, Table 1, shasa, 4(cid:56)15(cid:57)2(cid:48)S, 15(cid:56)25(cid:57)0(cid:48)E, A. Greshoff.
Plate 1a (This specimen is here designated the lecto-
type as it is the largest of the remainingsyn-
types; BMNH 1899.9.6.1, the largest syn-
Acanthochromis seminudus Vaillant, 1886: 18
type, is lost.)
(nomen nudum) (Type locality: Nganchou).
LamprologuscongoensisSchilthuis,1891:85,fig. PARALECTOTYPE: BMNH 1891.12.29.11,
collected with lectotype.
1 (Type locality: Kinshasa, Stanley Pool).
Lamprologus congolensis: Boulenger, 1901: 402. ADDITIONALMATERIALEXAMINED:91spec-
LamprologusfuscusPellegrin,1927:52(Typelo- imens. Bolobo (02(cid:56)09(cid:57)S, 16(cid:56)14(cid:57)E) MRAC
cality: Bolobo). 19711 (HolotypeofLamprologusfuscusPel-
6 AMERICAN MUSEUM NOVITATES NO. 3451
Fig. 5. Lamprologus congoensis, male, 100 mm TL, modified from Boulenger (1915).
legrin, 1927), H. Schouteden; MRAC AMNH 233570 (n (cid:53) 2), 9/17/2002, C.
175060, 1/1/1956–12/31/1956. N’Kele; Ka- Shumway et al. Kinshasa (Le´opoldville)
sai River, Makaw (03(cid:56)28(cid:57)S, 18(cid:56)18(cid:57)E) (04(cid:56)18(cid:57)S, 15(cid:56)18(cid:57)E) MRAC 17483–17484 (1
MRAC 153440, 1/1/1954–12/31/1954, E. specimen c&s), H. Schouteden; MRAC
Jans.KasaiRiver,Bokoni(03(cid:56)9(cid:57)S,17(cid:56)10(cid:57)E) 39576, 1/1/1934–3/16/1934, A. Tinant;
MRAC 39624, 1/1/1934–4/3/1934, A. Tin-
ant; MRAC 40950–40951, 1/1/1934–4/24/
1934, A. Tinant; MRAC 41004–41005, 1/1/
1934–4/24/1934, A. Tinant; MRAC 43983,
1/1/1935–12/16/1935, A. Tinant; MRAC
55231–55232, 1/1/1937–12/31/1937, A. Tin-
ant; MRAC 76060.0116, 10/19/1960, P. Bri-
chard; MRAC 77346–77347, 1/1/1951–12/
Fig. 6. Lower pharyngeal jaw of Lamprolo- Fig. 7. Lamprologus congoensis, MRAC
gus congoensis MRAC 78144: (a) dorsal view, 118154: (a) neurocranium, first vertebra, and su-
showing medial molariform teeth; (b) ventral praneural; (b) lachrymal and adjacent infraorbi-
view, showing interdigitating suture. tals.
2004 SCHELLY AND STIASSNY: CONGO RIVER LAMPROLOGUS 7
Fig. 8. Collection localities of Lamprologus congoensis.
31/1951, A. Dubois; MRAC 78144, 1/1/ ga, Doli Lodge, by sand island in middle of
1951–12/31/1951, M.H. Pierret; MRAC channel, Central African Republic (02(cid:56)55(cid:57)N,
94009.0001–94009.0005, 1/1/1993–12/31/ 16(cid:56)15(cid:57)E)AMNH227439(n(cid:53)1),6/10/1998,
1993, W. van der Elst; MRAC 177669, 1/1/ J. Sullivan & J. Kindimoungo. Locality un-
1967–12/31/1967, P. Brichard; AMNH known:MRAC183617–183620,W.Wickler.
233613 (n (cid:53) 13, 11 c&s), aquarium trade DIFFERENTIAL DIAGNOSIS: Lamprologus
specimens from Kinshasa region, 10/27/ congoensis is distinguished from L. lethops
2003. Le´opoldville, Kalina (04(cid:56)18(cid:57)S, and L. symoensi by its regularly imbricating,
15(cid:56)16(cid:57)E) MRAC 67426, 6/1/1945–6/30/ large, uniformly sized flank scales. It is dis-
1945, J.M. Berteaux. Stanley Pool (04(cid:56)06(cid:57)S, tinguished fromL. mocquardibyanelevated
15(cid:56)15(cid:57)E // 04(cid:56)20(cid:57)S, 15(cid:56)23(cid:57)E) MRAC supraoccipital crest, presence of a single su-
88001.2808–88001.2841, 1/1/1957–12/31/ praneural, and uniformly dark pigment
1957, Brien, Poll, & Bouillon; MRAC around the exposed margin of the flank
94314–94317, 1/1/1954–5/31/1954, Dubois scales, giving the appearance of chain mail.
&Dubois;MRAC88001.2807,StanleyPool, Lamprologus congoensis and L. tumbanus
Stat. 5, Bamu archipelago,04(cid:56)14(cid:57)S,15(cid:56)22(cid:57)E, are similarly deep bodied and share a similar
9/9/1957, Brien, Poll, & Bouillon; MRAC flank pigmentationpattern,butL.congoensis
118140–118154 (3 specimens c&s), Stanley differs from L. tumbanus in having 32–35
Pool, Stat. 33, channel in front of Maluku, laterallinescales(vs.29–31inL.tumbanus),
04(cid:56)04(cid:57)S, 15(cid:56)33(cid:57)E, 10/4/1957, Brien, Poll, & a shorter HL as a percentage of SL (31.3–
Bouillon. Monsembe, upper Congo 34.6% vs. 34.6–37.0% in L. tumbanus), and
(01(cid:56)08(cid:57)N, 18(cid:56)32(cid:57)E) BMNH 1896.3.9.13–14 five sensory pore openings on the lachrymal
(1 specimen c&s), Rev’d. J.H. Weeks; insteadoffour.WhileL.congoensishaslong
BMNH 1898.7.9.15, Rev’d. J.H. Weeks. pelvic fins reaching beyond the anal fin ori-
Nganchou, Congo (03(cid:56)20(cid:57)S, 16(cid:56)12(cid:57)E) gin and a strongly interdigitating LPJventral
MNHN 1886.442–445 (Syntypes of Acan- suture, both L. werneri and L. teugelsi,n.sp.,
thochromis seminudus Vaillant, 1886), Sa- have short pelvic fins that rarely or never
vorgnan de Brazza. Sangha River, Bayon- reach the anus and minimal or no interdigi-
8 AMERICAN MUSEUM NOVITATES NO. 3451
TABLE1
Morphometric and Meristic Data for Lamprologus congoensis
tation at the LPJ ventral suture. While L. lateral line scales (32–35 vs. 35–37) than L.
congoensis shares with L. tigripictilis, n.sp., tigripictilis, n.sp.
relatively producedpelvicfinsandastrongly DESCRIPTION: Counts and measurements
interdigitating LPJ ventral suture, L. con- for 20 specimens, including lectotype and
goensis has 5–6 rather than the 9–10 dark paralectotype, are given in table 1. Among
barsontheflanksofL.tigripictilis,n.sp.Ad- the more deep-bodied fluviatile species of
ditionally, L. congoensis has an elevated su- Lamprologus(bodydepth21.0–27.8%,mean
praoccipital crest while L. tigripictilis, n.sp., 25.2% SL), especially so as adults. Greatest
hasalowcrest,andalmostwithoutexception body depth at about base of second or third
has fewer vertebrae (30–31 vs. 31–33) and dorsal fin spine. Head length 31.3–34.6%,
fi
Plate 1. (a) Lamprologus congoensis, MRAC 118140–53, male, 104 mm SL; (b) Lamprologus
tumbanus, MRAC 100851–53, male, 51 mm SL; (c) Lamprologus mocquardi, AMNH 5897, male, 78
mm SL; (d) Lamprologus werneri, MRAC 98158–92, male, 56 mm SL.
2004 SCHELLY AND STIASSNY: CONGO RIVER LAMPROLOGUS 9
10 AMERICAN MUSEUM NOVITATES NO. 3451
mean 32.8% SL. In smallerindividuals,head long, strongly interdigitating along ventral
profile rises at an angle of about 40(cid:56). In larg- suture. Usually 25–28 teethinmostposterior
er individuals, profile rises more steeply, at tooth row. Medial teeth enlarged and more
an angle of about 50(cid:56) from tip of snout to or less molariform; lateral teeth slender and
top of orbit. Dorsal body profile convex, either beveled or bluntly hooked.
curving gently downward along length of Scales: Flank scales ctenoid, of uniform
dorsal fin to caudal peduncle; ventral body size. Lateral line scales 32–35. Upper and
profile somewhat rounded posteriorly, curv- lower branches of lateral line not overlap-
ing gently upward anterior to caudal pedun- ping. Cheek naked; opercle and subopercle
cle. Species sexually dimorphic, with adult partially scaled. Gradual transition to small
males displaying well-developed, fat-filled scales on belly and above lateral line near
nuchal hump (resulting in slightconcavityof dorsal fin origin, with small, embedded
dorsal head profile anterior to the nuchal scales extending beyond dorsal fin origin
hump). Males also attain larger size (largest onto nape. Dorsal and anal fins scaleless.
male 104.3 mm, largest female 75.0 mm), Small scales occur over most of caudal fin.
and have somewhat longer dorsal, anal, and Vertebrae: 30–31; 14(cid:49)16 (6), 14(cid:49)17 (7).
pelvic fins than females. Additional Osteology (fig. 7): Infraorbital
Fins: Dorsal fin XVII–XIX (mode XIX) series comprised of broad, platelike lachry-
6–9. Anal fin V–VII (mode VI) 5–7 (mode mal with 5 sensory canal openings, and 2–3
6). Spines in both fins gradually increasing tubular infraorbitals adjacent to lachrymal.
in length posteriorly. Dorsal and anal fins Dermosphenotic absent. Single supraneural
with tapering filamentous extensions reach- present. Supraoccipital crest elevated, and
ing to about midlevel of caudal fin. Caudal extendsanteriorlyaslowfrontalridgetome-
fin large, rounded, and paddle-shaped, with dian coronal pore (NLF0). In larger speci-
14 branched rays; often appears lance- mens, elongate, paired,clublikeprocesseson
shaped, subacuminate in preserved speci- supraoccipitalcrestserveasattachmentareas
mens or when adducted. Pectoral fins short, for supracarinalis anterior tendons.
not reaching vertical through anus. Pelvic Coloration: In life, base body coloration
fins in all but smallest individuals elongate, grayish lavender, with shades of yellow on
with tapering endsreachingorextendingjust belly, posterior to base of pectoral fin, along
beyond anal fin origin (pelvic fin length junction of preopercle and opercle, and
19.7–30.4%,mean24.8%SL).Secondrayof around ventral margin of orbit. Dark, scale-
pelvic fin longest in fin in both sexes. lessopercularspotpresent.Fiveorsixsome-
Teeth: Jaws isognathous, with both outer what dark vertical bars along flanks usually
and inner row teeth unicuspid and sharply present. Individual flank scales with dark
pointed. Single series of 6–8 greatly en- pigment distributed uniformly around ex-
larged, recurved, procumbent canines situat- posed posterior margin, creating intersecting
ed anteriorly, with largest teeth furthestfrom rows of thin, oblique bands of pigment that
symphysis. Inner teeth in 6–8 poorly defined present appearance of chain-link fence or
rows of tightly packed, small, recurved ca- chain mail. Small, whitish maculae along in-
niniform teeth anteriorly, gradually thinning terspinous membrane and between rays of
along length of jaw to 1 or 2 rows posteri- dorsal, anal, and caudal fins. Dorsal, anal,
orly.Lateral-mosttoothrowslightlyenlarged and caudal fins with oblique black striations.
andextendingalmostentirelengthofdentary Adultmaleswithiridescentspotsinposterior
and premaxilla. field of most flank scales; each spot situated
Gill Rakers: Relatively slender, elongate, adjacent to the overlapping edge of the pre-
non-denticulate.Gillrakersnumber6–9(typ- ceding scale. Preserved coloration yellowish
ically 7) along hypobranchial and cerato- brown, fading to uniform dull brown in very
branchialoffirstgillarch,withasingleraker old specimens, with scalepigmentationoften
positioned in angle of arch in most cases. completely lost.
Two to 5 (typically 3) rakers along epibran- DIET: Gut short and simple, with a length
chial of first gill arch. of about 50% of SL. Gut contents included
LowerPharyngealJaw(fig.6):Widerthan fragments of insects and a spider.