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2013 • Gaspard Banyankimbona et al.

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Research article

um:lsid:zoobank.org:pub:D40ElDD7-6472-4EA7-B2C2-242F6QlBlFD3

A revision of the genus Astatoreochromis

(Teleostei, Cichlidae), East-Africa

Gaspard BANYANKIMBONA Emmanuel VREVEN and Jos SNOEKS *

^ KU Eeuven, Eaboratory of Biodiversity and Evolutionary Genomics, Charles Deberiotstraat 32,

B-3000 Eeuven, Belgium. E-mail: [email protected]

^ Royal Museum for Central Africa, Vertebrate section. Ichthyology, Eeuvensesteenweg 13, B-3080

Tervuren, Belgium. E-mails: [email protected] : [email protected]

^ University of Burundi, Department of Biology, RO. Box 2700, Bujumbura, Burundi.

* Corresponding author: E-mail: [email protected]

^ um:lsid:zoobank.org:author:6B0D1714-87BA-46D0-A9B7-E097878BE91D

^ um:lsid:zoobank.org: author: 852BA52E-FF0C-4E39-B4A7-0967DA0AE79A

^ um:lsid:zoobank.org:author:8841919C-2A14-4DEB-9CC4-69E3C8CA3295

Abstract. A taxonomic revision of the cichlid genus Astatoreochromis is presented. Eighteen meristic

and 23 morphometric measurements were taken on 185 individuals, including type specimens. While

fin counts separate populations from the Fake Victoria region {Astatoreochromis alluaudi) from those

of the Rusizi and Malagarazi rivers in the Fake Tanganyika basin {A. vanderhorsti and A. straeleni

respectively), clear differentiation was not detected between the latter two. Mann-Whitney U-tests on

specimens of comparable size from the two Tanganyika populations revealed significant differences in

specimens < 75 mm SE, mainly in pharyngeal jaw proportions, but also in some other measurements

on the head and body. However, these differences were not detected in specimens >75 mm SE and

Astatoreochromis vanderhorsti is herein considered a junior synonym of A. straeleni. A re description of

the two valid species of Astatoreochromis, A. alluaudi and A. straeleni, is provided.

Key words, pharyngeal jaw proportions, haplochromine cichlid, synonym. Fake Victoria basin. Fake

Tanganyika basin.

Banyankimbona G., Vreven E. & Snoeks J. 2013. A revision of the genus Astatoreochromis (Teleostei, Cichlidae),

East Africa. European Journal of Taxonomy 39: 1-21. http://dx.doi.org/10.5852/eit.2013.39

Introduction

By far the highest diversity of cichlids occurs in the east and central African lakes Tanganyika, Victoria

and Malawi, where they have speciated in great profusion (Stiassny & Meyer 1999; Snoeks 2001).

However, the taxonomic status of many species remains umesolved, and it has been suggested that the

Cichlidae may actually pose more systematic problems than any other fish family (Snoeks 2004).

European Journal of Taxonomy ?>9\ 1-21 (2013)

Astatoreochromis Pellegrin, 1904 is a haplochromine genus (sensu Greenwood 1979) deseribed by

Pellegrin (1904) for A. alluaudi, based on four speeimens eolleeted by C. Alluaud in the Kavirondo

Gulf of Lake Vietoria (Kenya). Aeeording to Pellegrin (1904), the genus is distinguished from other

haploehromine genera in having V-Vl anal fin spines (v^. Ill in Haplochromis) and XVlll-XIX dorsal

fin spines (v^. XII-XVl in Haplochromis). Boulenger (1907), however, plaeed Astatoreochromis in

synonymy with Haplochromis, arguing that the higher number of dorsal and anal spines was due to a

transformation of soft rays into spines and henee the inerease in spine number related to a deerease in

soft fin ray numbers and as sueh did not merit a different generie status. Greenwood (1959) redeseribed

the genus, adding more diagnostie features sueh as possession of a rounded eaudal fin and the laek of

marked sexual dimorphism. He reeognized two subspeeies: the nominal subspeeies A. a. alluaudi from

lakes Vietoria and Kyoga, and the Vietoria Nile; and A. a. occidentalis from lakes Edward, George,

Nakavali and Kaehira, and the Semliki River. Astatoreochromis a. occidentalis was distinguished from

A. a. alluaudi in having a shorter, narrower and less massive lower pharyngeal jaw (LPJ) with fewer

enlarged and molariform teeth. Relative LPJ size was expressed by Greenwood (1959) as a ratio of LPJ

width to head length. However, Greenwood (1965 a) later examined an aquarium-bred speeimen from

the Lake Vietoria stoek raised on a virtually mollusk-free diet at the AMNH (speeimen not traeeable) and

eoneluded that, eomparedto the natural populations of A. a. alluaudi andX. a. occidentalis, the aquarium-

raised speeimen, whieh appeared to be in good eondition, had a mueh finer LPJ, with fewer enlarged,

less fiattened and less molariform teeth, and a reduetion of the overall dimension of the neuroeranial

apophysis. Based on these observations Greenwood (1965a) no longer reeognized subspeeifie division

and eonsideredX. alluaudi as a phenotypieally variable speeies.

The original deseription of Haplochromis straeleni Poll, 1944 was based on a single speeimen from the

Lukuga River (Demoeratie Republie of Congo). Later, Poll (1974) reported eight additional speeimens

from the Rusizi River and redeseribed the speeies. Based on these new speeimens, whieh had 3-4 anal

spines, rounded eaudal fins and shared elose similarities in eolour pattern and the arrangement of anal

oeelli withX. alluaudi. Poll (1974) realloeated H. straeleni to the genus Astatoreochromis.

Greenwood (1954) deseribed a third nominal speeies as Haplochromis vanderhorsti, based on a holotype

and 49 paratypes from the Malagarazi basin, and distinguished it from other fiuviatile haploehromine

speeies by its massive LPJ and dentition. Lurthermore, H. vanderhorsti differed from H. straeleni in

having a slightly deeper laehrymal, whieh eovered the maxilla exeept for its posterior tip and with a

mouth that is almost horizontal, rather than inelined as in A. straeleni.

The generie status of A. alluaudi, A. straeleni and//, vanderhorsti was reviewed by Greenwood (1979).

As a result, he agreed with Poll’s (1974) realloeation of H. straeleni to Astatoreochromis and also

realloeated H. vanderhorsti to the same genus. Greenwood (1979) still reeognized X. vanderhorsti and

A. straeleni as distinet speeies but noted they elosely resemble eaeh other, differing only slightly in

dorsal spine eounts (XVl-XVll in A. vanderhorsti vs. XVll-XVlll in A. straeleni)', in anal-fin spine

eounts (111 in A. vanderhorsti v^. III-IV in A. straeleni)', in LPJ size and shape (more massive v^. thinner),

and the number of molariform teeth on the LPJ (more v^. less molariform teeth). Hoogerhoud (1986)

agreed with this realloeation but stipulated that the elose resemblanee of A. straeleni andX. vanderhorsti

raises questions as to their validity as different taxa, a view later shared by De Vos et al. (2001a). To

elarify this situation, a detailed morphometrie study of the three nominal Astatoreochromis speeies was

eondueted, and the results are presented below.

Material and methods

Acronyms

AMNH = Ameriean Museum of Natural History, New York

BMNH = British Museum of Natural History (eurrently the Natural History Museum), London

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

IRSNB = Institut Royal des Sciences Naturelles de Belgique, Brussels

MNHN = Musee National d’Histoire Naturelle, Paris

MRAC = Musee Royal de PAfrique Centrale, Tervuren

Other abbreviations

LPJ

MWU-test

PCA

Head Length

Lower Pharyngeal Jaw

Mann-Whitney U-test

Principal Component

Principal Component Analysis

Standard Length

The specimens studied originate from various museum collections (MRAC, AMNH, BMNH, IRSNB

and MNHN). Additional specimens recently collected (December 2008 to December 2012) by one of

the authors (GB) from the Rusizi and the Malagarazi basins (Burundi) and deposited at the MRAC,

were also included. In total, 185 specimens were examined (see catalogue numbers in the specimens

examined sections below). This total includes 87 specimens labelled as A. alluaudi from lakes Victoria

(12, including the lectotype and the three paralectotypes), Kyoga (2), Edward (5), George (3), Kayanza

(4), Nakavali (13), and Nabugabo (4), the Semliki River (1), and the Upper and Middle Akagera basin

(43) [referred to here as Lake Victoria basin specimens]; 57 specimens labelled as A. straeleni from

the Rusizi drainage (including 12 dissected for gut content and gonad analysis) and the Lukuga River

(2, including the holotype); and 41 specimens labelled as A. vanderhorsti including the holotype and

the 19 paratypes from the Malagarazi [referred to as Lake Tanganyika basin specimens]. Counts and

measurements follow Snoeks (2004). On each specimen 18 counts and 23 morphometric measurements

(Fig. 1) were taken on the left side of the fish with dial calipers at 0.1 mm precision. For the two

specimens from the Fukuga River, including the holotype of A. straeleni, the FPJ is missing and

measurements could not be taken. Gut contents of 12 freshly collected specimens of A. straeleni from

the Rusizi basin were also examined. Fog-transformed measurements were analyzed with PCA based on

the correlation matrix. The first component, having loadings of the same sign and of the same magnitude,

was interpreted as a latent variable serving as a proxy for size (Bookstein et al 1985). PCA on the

meristics were performed on the correlation matrix of the raw data. Non-parametric Mann-Whitney

U-tests, corrected with sequential Bonferroni correction (Rice 1989) for multiple comparisons, were

performed on the meristics and the morphometric measurements. Additional qualitative observations

such as the shape of oral and FPJ teeth, caudal fin shape, and shape of gill rakers were made following

Barel et al. (1977). Data on colour patterns were taken from the literature, and from photographs and

observations on live specimens (GB).

Results

Meristics

A first PCA on 22 meristics for all examined specimens revealed the presence of two major groups with

minor overlap, one situated mainly on the negative part of the first axis and containing the Fake Victoria

basin specimens, and the other, mainly situated on the positive part of the first axis, containing the Fake

Tanganyika basin specimens (Fig. 2A). This first axis is mainly defined by the number of anal and dorsal

spines and soft fin rays (see Table 1).

Measurements

A PCA performed on 23 log-transformed measurements did not result in a good separation between the

Fake Victoria and the Fake Tanganyika basin populations (Fig. 2B). Interestingly, the highest loadings

on the second axis were found for three measurements on the FPJ, i.e., dental area length, jaw width and

European Journal of Taxonomy ?>9\ 1-21 (2013)

dental area width (Table 2). A seeond PC A, exeluding LPJ measurements, allowed for the inelusion of

more speeimens, but did not result in a separation of the Lake Vietoria and Lake Tanganyika speeimens

either (results not shown). To further explore the strueture within the two main groups, further PC As

were performed on the log-transformed measurements on eaeh basin separately, first ineluding and then

Fig. 1. Morphometrie measurements of Astatoreochromis speeimens (Snoeks 1994). Body

measurements. 1. Standard length (SL). 2. Body depth. 16. Dorsal fin base length. 17. Anal fin base

length. 18. Predorsal distanee. 19. Preanal distanee. 20. Prepeetoral distanee. 21. Prepelvie distanee.

22. Caudal pedunele length. 23. Caudal pedunele depth. Head measurements. 3. Head Length.

4. Head width. 5. Interorbital width. 6. Snout length. 7. Lower jaw length. 8. Premaxillary pedieel length.

9. Cheek depth. 10. Eye diameter. 11. Laehrymal depth. Lower pharyngeal jaw (LPJ) measurements.

12. Lower pharyngeal length. 13. Lower pharyngeal width. 14. Dentigerous area length. 15. Dentigerous

area width.

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

Variable

PCI

PCII

PCIII

Upper jaw teeth outer rows

0.400115

-0.255875

0.477645

Lower Jaw teeth outer rows

0.317332

-0.015766

0.430572

Rows of teeth in the upper jaw

-0.365635

0.408450

0.425929

Rows of teeth in the lower jaw

-0.261905

0.361547

0.506096

Gill rakers on the ceratobranchial

0.130150

0.686250

-0.421600

Gill rakers on the epibranchial

0.296867

0.659946

0.050869

Total gill rakers

0.271459

0.870584

-0.288812

Dorsal fin spines

-0.859783

0.049764

0.173681

Dorsal fin soft rays

0.843430

-0.019729

0.252684

Dorsal fin total rays

-0.060116

0.046733

0.641217

Anal fin spines

-0.932267

0.115080

-0.058894

Anal fin soft rays

0.824954

-0.004825

0.217621

Anal fin total rays

-0.438535

0.209896

0.238043

Pectoral fin rays

-0.285275

-0.156201

-0.149899

Longitudinal line scales

0.086237

0.391265

0.248040

Upper lateral line scales

0.368165

0.178543

0.200635

Lower lateral line scales

-0.351788

0.152771

0.136138

Upper transversal line scales

-0.110426

-0.158029

0.043765

Lower transversal line scales

-0.439168

0.169728

0.227318

Scales between pectoral and pelvic fins

-0.393767

-0.206011

0.057224

Series of scales on the cheek

-0.338541

0.055883

0.116712

Prp. Totl

0.221947

0.115337

0.092417

Table 1. Principal component loadings of the meristics on the first three axes of all Astatoreochromis

specimens examined.

2,0

1,5

1,0

0,5

.2 0,0

^ -0,5

®"-l,0

-1,5

- 2,0

- 2 ,

•A A-

!0 40 60 80 100 120 140 160

Standard length (mm) _

3,0

2,0

1,0

0,0

■ 1,0

■ 2,0

40 60 80 100 120 140 160

standard length (mm)

Fig. 2. Plots of PCA scores against standard length for all Astatoreochromis specimens examined.

(A) scores on the first axis of a PCA on the meristics and (B) on the second axis of a PCA on the log-

transformed morphometries. Lakes Victoria and Kioga (A); Lakes Edward-George-Kayanza-Nabugabo-

Nakavali-Semliki (A); Akagera basin (•); Lukuga River (□), Malagarazi basin (^); Rusizi basin (O).

Full line polygon for Lake Tanganyika basin, dashed line polygon for Lake Victoria basin specimens.

European Journal of Taxonomy 'i9: 1-21 (2013)

Fig. 3. Plots of the scores on the second axis of a PCA on the log-transformed measurements of Lake

Victoria basin specimens against standard length, (A) including and (B) excluding lower pharyngeal

bone measurements. Lakes Victoria and Kioga (A); Lakes Edward-George-Kayanza-Nabugabo-

Nakavali-Semliki (A); Akagera basin (•).

Fig. 4. Plots of the scores on the second axis of a PCA on the log-transformed measurements of Lake

Tanganyika specimens against standard length, (A) including and (B) excluding lower pharyngeal bone

measurements. Lukuga River (□), Malagarazi basin (^); Rusizi basin (O).

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

excluding the LPJ measurements. For the first series of analyses, the most important loadings on the

second axis again included LPJ measurements (Table 2), i.e., dental area length and jaw width for Lake

Victoria, and jaw length and width, and dental area width and length for the Lake Tanganyika basin.

The Lake Victoria specimens separated with minor overlap in two groups on the second axis in the first

analysis (Fig. 3 A), whereas, after removal of LPJ measurements, an overlap appeared on the second axis

(Fig. 3B). The two groups correspond to (1) the specimens from lakes Victoria and Kyoga, the Upper

and Middle Akagera and (2) those from lakes Edward, George, Kayanza, Nakavali, and Nabugabo,

and the Semliki River. Within the Tanganyika basin, a separation was observed between the Rusizi

and Malagarazi populations on the second axis in the first analysis (Fig. 4A). After removal of LPJ

measurements, also in this case, the overlap became greater (Fig. 4B). The position of the two Lukuga

specimens is equivocal; one of them, the holotype of A. straeleni, appears to be situated amongst the

Malagarazi specimens rather than with the remaining Rusizi specimens.

Log-variable

VandT

V minus

phar. jaw

T minus

phar. jaw

PCI

PC2

PCI

PC2

PCI

PC2

PCI

PC2

PCI

PC2

Lachrymal depth

-0.980

0.015

-0.981

0.078

-0.983

-0.062

-0.968

-0.061

-0.965

0.119

Snout length

-0.974

0.055

-0.982

0.043

-0.984

0.000

-0.935

0.158

-0.946

0.133

Lower jaw length

-0.979

-0.007

-0.978

0.038

-0.980

0.019

-0.967

-0.052

-0.968

0.102

Premaxillary pedicel length

-0.972

-0.027

-0.974

-0.061

-0.973

0.110

-0.952

-0.038

-0.956

0.048

Cheek depth

-0.971

-0.068

-0.976

-0.021

-0.976

0.016

-0.949

-0.184

-0.945

0.202

Eye diameter

-0.969

-0.092

-0.976

-0.063

-0.976

0.127

-0.939

-0.095

-0.939

0.081

Inter orbital width

-0.976

0.106

-0.980

0.109

-0.983

-0.094

-0.957

0.159

-0.967

-0.059

Head width

-0.988

0.003

-0.989

0.063

-0.990

-0.057

-0.979

-0.018

-0.978

0.050

Standard length

-0.992

0.100

-0.994

0.075

-0.996

-0.039

-0.984

0.134

-0.991

-0.097

Head length

-0.994

0.012

-0.995

0.027

-0.996

0.016

-0.987

0.034

-0.987

0.098

Body depth

-0.985

0.073

-0.987

0.109

-0.990

-0.078

-0.970

0.082

-0.976

-0.033

Dorsal fin base

-0.974

0.165

-0.981

0.149

-0.985

-0.109

-0.961

0.173

-0.973

-0.146

Anal fin base

-0.971

0.125

-0.977

0.129

-0.979

-0.108

-0.938

0.219

-0.952

-0.212

Predorsal distance

-0.985

-0.049

-0.992

-0.012

-0.991

0.044

-0.969

-0.039

-0.970

0.080

Prepectoral distance

-0.985

0.046

-0.991

-0.003

-0.991

0.041

-0.959

0.136

-0.966

0.056

Prevental distance

-0.981

0.089

-0.988

0.043

-0.990

-0.010

-0.954

0.173

-0.957

0.068

Preanal distance

-0.989

0.087

-0.993

0.053

-0.994

-0.027

-0.980

0.116

-0.985

-0.031

Caudal peduncle length

-0.916

0.069

-0.936

-0.173

-0.936

0.299

-0.889

0.104

-0.888

-0.339

Caudal peduncle depth

-0.967

0.167

-0.979

0.096

-0.982

-0.071

-0.957

0.183

-0.967

-0.135

Pharyngeal jaw length

-0.975

-0.164

-0.980

-0.128

-0.947

-0.251

Pharyngeal jaw width

-0.964

-0.223

-0.969

-0.200

-0.932

-0.295

Dental area length

-0.940

-0.287

-0.955

-0.232

-0.865

-0.435

Dental area width

-0.959

-0.211

-0.967

-0.139

-0.927

-0.256

Prp.Totl

0.948

0.015

0.959

0.011

0.966

0.009

0.904

0.031

0.926

0.018

Table 2. Principal component loadings of the first two axes of the log-transformed morphometries for five

PCAs performed on the Astatoreochromis specimens examined: PCA on Victoria (V) and Tanganyika

(T) systems, PCA within the Lake Victoria system including (V) and excluding (V minus LPJ) the lower

pharyngeal jaw measurements, and similarly for the Lake Tanganyika system (respectively T and T

minus LPJ).

European Journal of Taxonomy ?>9\ 1-21 (2013)

Mann-Whitney U-tests

MWU-tests were used to further explore the differenees observed in three eomparisons: (1) the

Lake Vietoria {A. alluaudi) versus the Lake Tanganyika basin, (2) within the Lake Tanganyika basin

between the Malagarazi and the Rusizi, and (3) within A. alluaudi between lakes Vietoria and Kyoga

(Greenwood’s^, a. alluaudi) and lakes Edward, George, Kayanza, Nakavali, Nabugabo, and the Semliki

River (Greenwood’s A. a. occidentalis) (Table 3). For the Lake Vietoria basin, only naturally oeeuring

populations were ineluded; henee the introdueed populations from the Akagera system were omitted.

Signifieant differenees between speeimens from the Vietoria and Tanganyika systems were present in

six of the meristies and five of the morphometries examined (Table 3).

Victoria v^.

Tanganyika

Victoria

Meristies

Upper jaw teeth (outer row)

Dorsal fin spines

•k-k-k

Dorsal fin soft rays

kkk

Dorsal fin total rays

Anal fin spines

kkk

Anal fin soft rays

kkk

Anal fin total rays

kkk

Measurements

%SL

Body depth

Dorsal fin base

Anal fin base

Predorsal distanee

Caudal pedunele length

kkk

Caudal pedunele depth

%HL

Interorbital width

Pharyngeal jaw length

kkk

Pharyngeal jaw width

kkk

Dental area length

kkk

Dental area width

kkk

Table 3. Results from Mann-Whitney U-tests, eomparing meristies and measurements of speeimens of a

similar size elass. Three eomparisons were made (1) between the Lake Vietoria (n = 27) and Tanganyika

(n = 80) systems [43.7-94.5 mm SL; p = 0.316], (2) within the Tanganyika system between the Rusizi

(n = 43) and the Malagarazi (n = 39) [43.7-111.3 mm SL; p = 0.464] and (3) within the Vietoria system

between lakes Vietoria and Kyoga (n = 12) and the remaining basins (lakes Edward, George, Kayanza,

Nabugabo and Nakavali; n = 16) [76.1-137.5 mm SE; p = 0.631]. Only variables with a signifieant

differenee are listed. Signifieant levels are based on Bonferroni eorreeted values as follows: ns = not

signifieant; * = signifieant, p < 0.05; ** = highly signifieant, p < 0.01; *** = very highly signifieant,

p< 0.001.

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

Five meristics were very highly significantly different (p < 0.001), all relating to fin ray numbers. Of

the morphometries, one was very highly (caudal peduncle length) and one highly significantly (body

depth) different. Within the Tanganyika basin, the Rusizi populations differed significantly from the

Malagarazi population in one meristic (dorsal spine number), and in eight morphometries, four of which

(all LPJ measurements), differed very highly significantly (Table 3). No difference was observed in

meristics between the different populations representing the former subspecies of A. alluaudi within the

Lake Victoria basin, while three measurements (three LPJ measurements) were very highly significantly

different.

While examining plots of the variables that differed significantly against standard length, we noted that

some variables appeared to be size-related. Additional MWU-tests were thus performed on two size

ranges (smaller and larger than 75 mm SL). Since few large specimens were available for Lake Victoria,

specimens from the Upper and Middle Akagera populations, introduced from Lake Victoria (De Vos et

al. 2001b), were included. Significant differences found among small specimens (< 75 mm SL) from the

Malagarazi and the Rusizi were absent in larger specimens (Table 4). In contrast, most of the differences

found in larger specimens > 75 mm SL between the two former subspecies of A. alluaudi were greatly

reduced or absent in smaller specimens (Table 4).

Tanganyika

SL<75 mm

Tanganyika

SL>75 mm

Victoria

SL <75 mm

Victoria

SL >75 mm

%HL

Lachrymal depth

Snout length

Cheek depth

Inter-orbital width

Head width

Pharyngeal jaw length

HsHsHs

Pharyngeal jaw width

HsHsHs

Dental area length

HsHsHs

Dental area width

%SL

Head length

Pre-dorsal distance

Dorsal fin base

Caudal peduncle length

Anal fin base

Table 4. Result from Mann-Whitney U-tests, comparing measurements of specimens of two size

classes, SL < 75 mm and SL > 75 mm. Four comparisons were made (1-2) within the Tanganyika system

between the Rusizi (n = 26, SL < 75 mm and n = 14, SL > 75 mm) and the Malagarazi (n = 31, SL < 75

mm and n = 9, SL > 75 mm) and (3-4) within the Victoria system between lakes Victoria-Kyoga and the

Akagera system (n = 37, SL < 75 mm and n = 20, SL > 75 mm), and the remaining basins (lakes

Edward, George, Kayanza, Nabugabo and Nakavali; n = 14, SL < 75 mm and n=13, SL>75 mm). Only

variables with a significant difference are listed. Significant levels are based on Bonferroni corrected

values as follows: ns = not significant; * = significant, p < 0.05; ** = highly significant, p < 0.01;

*** = very highly significant, p < 0.001.

European Journal of Taxonomy ?>9\ 1-21 ( 2013 )

From the PCAs and MWU-tests presented above, we eonelude that the Lake Vietoria basin and the

Tanganyika basin populations represent different speeies. Within the Lake Tanganyika basin, we found

little support for speeies status of A. vanderhorsti and A. straeleni, and propose the synonymy of A.

vanderhorsti. An updated definition of the genus Astatoreochromis and a redeseription of the two valid

speeies, A. alluaudi and A. straeleni, is given below.

Class Aetinopterygii

Division Teleostei

Order Pereiformes

Family Ciehlidae Bonaparte, 1835

Genus Astatoreochromis Pellegrin, 1904

Astatoreochromis Pellegrin, 1904

The genus Astatoreochromis ean be distinguished from 'Haplochromis" by the possession of three to

seven anal spines (v^. three in 'Haplochromis'); 16 to 20 dorsal fin spines (v^. 13-16 in 'Haplochromisf,

a rounded eaudal fin (v^". sometimes rounded, obliquely truneate, truneate, subtruneate or emarginated

in 'Haplochromis"), a large number of anal oeelli arranged in three to five horizontal rows (v^. few anal

oeelli arranged in one or two rows in 'Haplochromis"), and a less marked sexual dimorphism in eolour

pattern (v^. a marked sexual dimorphism in 'Haplochromis').

Astatoreochromis alluaudi 1904

Fig. 5

Alluaud’s haplo, loeal names: ‘Ifuro muhunde, Ifuro y’itanza, Ifuro y’ikomagi’ where Tfuro’ is the loeal

name given to all haploehromine speeies (Upper Akagera system, Burundi), ‘leyasamyi’, ‘Ikaje’ or

‘Nyiramuhundi’ (Middle Akagera system, Rwanda).

Astatoreochromis alluaudi FQllQghn, 1904: 385.

Astatoreochromis alluaudi alluaudi Greenwood, 1959: 174, figs 1-3.

Astatoreochromis alluaudi occidentalis Greenwood, 1959: 174-175, figs 2-3.

Diagnosis

Astatoreochromis alluaudi ean be distinguished from A. straeleni by the possession of 4-7 anal spines

(usually 5-6) v^. 3-4 (usually 3), 17-19 dorsal spines [rarely 16 (12) or 20 (12)] v^. 16-18 [exeeptionally

19 (fl)].

Etymology

Named after Charles A. Alluaud, who eolleeted the type speeimens.

Type material

Lectotype

MNHN 1904.137, Kavirondo Gulf, Lake Vietoria, Kenya, designated by Greenwood (1959: 167).

Paralectotypes

MNHN 1904.138-139, BMNH 1904.6.281, same data as leetotype.

Specimens examined

KENYA: MNHN 1904.137, leetotype, 121.7 mm SL, Kavirondo Gulf Lake Vietoria, eoll. Alluaudi;

BMNH 1904.6.28.1, paraleetotype, 116.0 mm SL, same data as leetotype; MNHN 1904.138-139,

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

paralectotypes, 92.8-113.8 mm SL, same data as lectotype. UGANDA: AMNH 216258 (3 specimens),

53.5-70.7 mm SL, Lake Nabugabo, coll. L.J. Chapman & C.A. Chapman, 19 May 1994; BMNH

1964.7.1.109, 85.5 mm SL, Lake Nabugabo, coll. Cambridge University; BMNH 1933.2.23.146 (11

specimens), 55.2-137.5 mm SL, Lake Nakavali, coll. E. Worthington; BMNH 1958.12.5.74-75, 63.8-

121.4 mm SL, Lake Nakavali, coll. C. Pitman; BMNH 1972.6.5.23-25,44.8-101.6 mm SL, Lake George,

coll. 1. Dunn; BMNH 1933.2.23.137-141, 61.4-79.8 mm SL, Lake Edward, coll. E.Worthington; BMNH

1929.1.24.4, 87.8 mm SE, Eake Kyoga, coll. E. Worthington; BMNH 1929.1.24.278, 70.9 mm SE,

Eake Kyoga, coll. E. Worthington; MRAC A5.42.P.2-5, 66.3-128.4 mm SE, Eake Kayanza, Kasese

factory, coll. M. Marquet, 22 Oct. 2005; MRAC 14862-3, 95.9-111.1 mm SE, Nyanza, Eake Victoria,

coll. D.E. Bayon; MRAC 90.035.P.12, 124.2 mm SE, Gaba near Kampala, Eake Victoria, 0°15’ S -

32°28’ E, coll. D. Nyeko, 18 Mar. 1990. DEMOCRATIC REPUBEIC OF CONGO: MRAC 66003, 51.3

mm SE, Semliki River, Ishango, coll. H. Damas. TANZANIA: MRAC 81.30.P.4-5, 94.5-96.5 mm SE,

Mwanza gulf, Eake Victoria, collector. HEST-Collection, 1977-1980; MRAC 90.16.P.1-3, 73.7-79.7

mm SE, Kiboko, Eake Victoria. BURUNDI: MRAC 8LP.47.512-535, 63.7-112.7 mm SE, Nyagisozi,

Eake Rweru, 02°28’ S - 30°18’ E, coll. G. Ntakimazi, 6 May 1981; MRAC 93.149.P.27, 71.7 mm SE,

Yaranda, maison Turquien, Eake Cohoha, 02°32’ S - 30°06’ E, coll. J. Snoeks et al., 28-29 Jul. 1993;

MRAC 93.149.P.41, 83.8 mm SE, Yaranda, maison Turquien, Eake Cohoha, 02°32’ S - 30°06’ E, coll.

J. Snoeks et al, 28-29 Jul. 1993; MRAC 93.149.P.28-40, 57.2-121.6 mm SE, Eake Rwihinda, Tac aux

oiseaux’, 02°35’ S -30°06’E, coll. J. Snoeks etal, 9-10 Aug. 1993. RWANDA: MRAC 87.11.P.2827-

2828, 73.6-83.4mm SE, EakeHago, Akagerapark, coll. E. De Vos, 12 Oct. 1986;MRAC 87.P. 11.2852,

MRAC 87.11.P.2852-55, 61.5-71.9 mm SE, Eake Mpanga, ‘a Eentree du pare Akagera’ coll. E. De Vos,

5 Nov. 1986; MRAC 86.0LP. 1955, 99.2 mm SE, Eake Birengero, Akagera park, coll. E. De Vos, 14 Sep.

1985.

Redescription

Based on 87 specimens including lectotype and three paralectotypes. Morphometries and meristics are

given in Table 5. Small to medium-sized species [maximum size, 163 mm SE (Greenwood 1959)]

with moderately compressed body; dorsal head profile fairy steeply sloping, straight or decurved,

becoming concave in large individuals. Mouth horizontal or slightly oblique. Jaws equal anteriorly or

lower somewhat projecting; posterior tip of maxilla reaching, or almost reaching, vertical to anterior

orbital margin. Gill rakers short and stout; generally 8 or 9 [7(fl), 8 (f30), 9 (f49), 10 (f7)] on the lower

limb of the first gill-arch. Flank scales around lateral line ctenoid, elsewhere cycloid; generally 29-32

longitudinal line scales, excluding the small scales on caudal fin base [26 (H), 27(f2), 28 (f5), 29 (f8),

30 (20), 31 (129), 32 (H4)]; cheek with 3 (124), 4 (f57) or 5 (f5) series of scales; scales between pectoral

and pelvic fins 4 (135), 5 (f40) or 6 (18) [rarely 3 (H)]. Dorsal fin spines 17-19 [rarely 16 (12) or 20 (12)],

soft rays 7 (129) or 8 (f51) [occasionally 6 (12) or 9 (f5)]. Anal fin spines 4-7 [(4 (17), 5 (f63), 6 (H7)

and 7 (12)], rays 6 (19), 7 (f56) or 8 (120) [rarely 9 (12)]. Pectoral fin rays 13 (132) or 14 (f54) [rarely 15

(H)]. Caudal fin rounded. Posteriormost teeth in outer row of upper jaw unicuspid. In small specimens,

outer row teeth unequally bicuspid and relatively stout (occasionally only stout unicuspid teeth in small

specimens) becoming a mixture of weakly bicuspid and unicuspid in large specimens. 28-48 outer row

teeth in upper jaw and 20-42 outer row teeth in lower jaw with numbers increasing with size, 1 or 2

(occasionally 3) inner rows of small tricuspid or occasionally unicuspid teeth in both lower and upper

jaws. EPJ triangular, longer than, or almost as long as, wide (EPJ width 78.1-108.5% of EPJ length);

lateral teeth in the posterior rows slender and cuspidate, the central two to four (occasionally six) rows

with a mixture of molariform (anterior part of the dentigerous area) and enlarged but cuspidate teeth.

The specimens from Eake Victoria have a more massive EPJ and a greater proportion of molariform

teeth compared to the similarly sized specimens from other lakes and rivers in the Victoria basin.

European Journal of Taxonomy ?>9\ 1-21 ( 2013 )

Colour pattern of live specimens

See Fig. 5 for general appearanee. Anteriorly and dorsally grey yellowish, posterior-ventrally grey

greenish to bluish. A dark band, eontinuous with laehrymal stripe, runs obliquely baekwards through, or

a little behind, the eye to near the gill opening. Lower jaw faint grey bluish. Fins grey yellowish, dorsal

fin somewhat darker and with blaekish spots on soft part; eaudal fin with similar spots, pelvie blaekish

distally; anal fin of speeimens (males and females) larger than 80 mm SL with 2-3 horizontal rows of

bright orange-yellow oeelli. In speeimens less than 80 mm SL, anal oeelli may be absent or hardly

visible. Aeeording to Greenwood (1959), sexual dimorphism is less marked in this speeies than in other

haploehromine eiehlids and the eolour pattern of breeding males resembles that of females exeept that

the soft dorsal fin is more densely spotted, the spinous dorsal and entire eaudal fin are suffused with

maroon, and the eephalie marking are more intense than in females.

Colour pattern of preserved specimens

General appearanee greyish-brown to brown, lighter ventrally; five or six dark transverse bars often

interrupted ventrally on the fianks (laeking in some speeimens). No mid-lateral band present. A vertieal.

Fig. 5. Adult SS of Astatoreochromis alluaudi Pellegrin, 1904 eaught on 15 Dee. 2012 at Kumana

village, Nyagisozi zone. Lake Rweru, Upper Akagera (Rwanda), 115,3 mm SL and 100,4 mm SL not

eatalogued. (Photographs by GB)

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

or posteriorly directed, blackish bar below the eye, runs to posterior comer of mouth, occasionally

extending onto lower jaw. Blackish dots arranged in intermpted horizontal rows on soft dorsal fin and

in intermpted vertical rows on caudal fin; these are strongly marked in large males. Edge of fins dark to

blackish, anal ocelli in males, when present dark grey.

Distribution

Known from lakes Edward, Victoria, Kyoga, George, Nakavali and Kachira, and the rivers and streams

associated with these lakes, including the Semliki (Greenwood 1959). The species has been introduced

into many areas of East Africa for biological mollusc control (Greenwood 1965b; Welcomme 1988) and

now has a widespread distribution within the Victoria basin (Kenya, Uganda & Tanzania including the

Upper Akagera basin in the Bugesera depression (Bumndi & Rwanda)). Slootweg (1989) discussed the

possibility of the introduction of A. alluaudi into northern Cameroon (Benue River basin), which indeed

took place (Vreven et al 2007). There are no reports that the introduction of this species in the Congo

Republic, the Democratic Republic of Congo, the Republic of Central Africa and Zambia (Welcomme

1988) has succeeded.

Ecology

According to Greenwood (1959), A. alluaudi is not confined to a particular type of substrate and is

ubiquitous in all areas where the water is less than 20 m deep. It also occurs in papyms swamps and

feeds mainly on molluscs. Ntakimazi (1985) confirmed the occurrence of the species in papyms swamps

in Take Rwem, Bugesera depression (Bumndi & Rwanda). However, he did not find any shell fragments

of snails in the gut contents of 80 specimens, but instead found a large amount of organic debris, algae,

fish remains and benthic invertebrates. He concluded that A. alluaudi might be an omnivorous species

that switches to the most abundant food source in its environment. He noticed, however, that the

molariform teeth of the lower pharyngeal jaw are well developed, and suspected they are instmmental

in cmshing the exoskeletons of aquatic invertebrates and vegetal debris.

Reproduction

The species is a mouth-brooder. Most of the females caught in December 2012 in Take Rwem in Bumndi

had fry in their mouth. Though its breeding period is not well documented, the species may reproduce

at the end of the short rain season from November to December. Whether this is the only reproductive

season cannot be determined from our data.

Astatoreochromis straeleni (Poll, 1944)

Fig. 6

Bluelip haplo, local names: dfiiro’ (common name for all haplochromine species in the Malagarazi),

‘Ikijori’ (name for all haplochromine species in the Rusizi basin) or ‘Inunge’ (used by fishermen from

the Rusizi basin who distinguish this species from other haplochromine species).

Haplochromis straeleni Poll, 1944: 10, figs 9-10.

Haplochromis vanderhorsti Greenwood, 1954: 405-413, figs 1-3.

Astatoreochromis straeleni -VoW 1974: 100.

Astatoreochromis vanderhorsti - Greenwood 1979: 286.

Diagnosis

Astatoreochromis straeleni can be distinguished from A. alluaudi by the possession of 3-4 anal spines

(usually 3) v^. 4-7 (usually 5-6); 16-18 [exceptionally 19 (H)] dorsal spines v^. 17-19 dorsal spines

[rarely 16 (12) or 20 (12)].

European Journal of Taxonomy ?>9\ 1-21 ( 2013 )

Etymology

Named in honour of Prof. V. Van Straelen, Director of the Musee du Congo Beige, Tervuren, Belgium

from 1926 to 1954.

Type material

Holotype

IRSNB 75, Riviere Lukuga, Region d’Albertiville, DRC.

Specimens examined

Astatoreochromis straeleni: DEMOCRATIC REPUBLIC OF CONGO: IRSNB 75, 78.9 mm SL,

holotype, Lukuga River, Albertville region, coll. Dr Poyer (purchased); MRAC 107795, 81.2 mm SL,

Lukuga, ‘pres du lac d’Arbertville’, coll. Exploration hydrobiologique du lac Tanganyika, 30 Oct.

1946; MRAC 84.2.P.1-2, 51.2-54.0 mm SL, Kiliba River, coll. M. Baluku, 17 Nov. 1982. BURUNDI:

MRAC 95.98.P.199, 81.4 mm SL, Kimirabasore, Kajeke swamps, coll. L. De Vos, 9 Feb. 1995; MRAC

73.68.P. 165-170,54.6-71.3 mm SL, small branch oftheRusizi River, near Lake Tanganyika, coll. Brichard,

May 1973; MRAC 73.68.P.171, 82.9 mm SL, Rusizi swamps near Lake Tanganyika, coll. Brichard, 1973;

MRAC 73.68.P. 172-173, 50.3-65.7 mm SL, ‘Port de Bujumbura’, coll. Brichard, Feb. 1972; MRAC

91.62.P.1794, 79.9 mm SL, Gatumba swamps, 3°05’ S - 29°15’ E, coll. L. De Vos & P. Weiler, 13 Aug.

1991; MRAC 91.89.P.33, 96.4 mm SL, Gatumba swamps, 3°05’ S - 29°15’ E, coll. P. Weiler, 8 Sep.

1991 91.89.P.83-92, 66.1-103.5 mm SL, Gatumba swamps, 3°05’ S -29°15’ E, coll. P. Weiler, 1-21 Sep.

1991; MRAC A9.13.P.75-105, 55.7-75.8 mm SL, Gatumba swamps, 03°20’18.6” S - 029°13’42.7” E,

coll. Banyankimbona, 28 Jan.-ll Feb. 2009; MRAC B1.3.P.1-12, 55.5-88.4 mm SL, Gatumba swamps,

03°20’21.6” S - 029°13’56.9” E, coll. G. Banyankimbona, 07 Nov. 2010, MRAC B0.3.P.5-7, 57.2-

74.2 mm SL, Kideheri pool, Rusizi basin, Karwema village, 03°06’15.0” S - 029°15’27.8” E, coll.

G. Banyankimbona, 6 Dec. 2009; MRAC BO. 3.P.8-10, 72.4-75.0 mm SL, Kinake pool, Rusizi basin,

Nyamitanga village, 03°03’52.9” S - 029°15’40.2” E, coll. G. Banyankimbona, 9 Dec. 2009; MRAC

B0.3.P.19-20, 61.7-65.6 mm SL, Kameme pool, Rukoko natural reserve, 03°11’59.4” S - 029°13’47.8”

E, coll. G. Banyankimbona, 7 Dec. 2009.

Astatoreochromis vanderhorsti: BURUNDI: MRAC A9.13.P.55-74, 61.3-85.7 mm SL, Malagarazi

River, Butezi village, 03°55’01,64” S - 030°15’22,3” E, coll. G. Banyankimbona, 13-15 Dec. 2008;

MRAC B0.3.P.1, 59.0 mm SL, Malagarazi river, Mutwana village, 03°51’25.2” S - 030°17’53.5”

E, coll. G. Banyankimbona, 31 Jul. 2009; MRAC B0.3.P.2, 72.2 mm SL, Malagarazi River, Butezi

village, 03°55’01,64” S - 030°15’22,3” E, coll. G. Banyankimbona, 1-2 Aug. 2009; MRAC B0.3.P.3,

62.5 mm SL, Mazimero River, Nyamateke swamp, Gasunu village, 03°53’28.4” S - 030°13’03.7” E,

coll. G. Banyankimbona, 5 Aug. 2009; MRAC 91.30.P.558, 76.5 mm SL, Butezi, fishermen’s village,

Malagarazi River, 3°55’ S - 30°15’ E, coll. De Vos & Taveme, 4 Apr. 1991; MRAC 91.61.P.944,

81.7 mm SL, Butezi, fishermen’s village, Malagarazi River, 3°55’ S - 30°15’ E, coll. Taveme, Jun. 1991;

MRAC 91.30.P.559, 43.7 mm SL, Nyamiviro rivulet, afid. Malagarazi, 6 km on road from Kinyinya to

Makebuko, 3°37’ S - 30°20’ E, coll. L. De Vos & L. Taveme, 5 Apr.1991; MRAC 91.62.P.1795-1796,

66.1-70.2.5 mm SL, Nyamiviro rivulet, affi. Malagarazi, 6 km on road from Kinyinya to Makebuko,

3°37’ S -30°20’E, coll. De Vos & Taveme, 6 Apr. 1991; MRAC 96.31.P.1425, 64.0 mm SL, Nyamiviro

rivulet, affi. Malagarazi, 6 km on road from Kinyinya to Makebuko, 3°37’ S - 30°20’ E, coll. L. De Vos &

L. Taveme, 3 Jun. 1992. TANZANIA: BMNH1953.11.4, holotype, 111.3 mm SL, from Katare swamps,

Malagarazi basin, coll. G.J. Lockley, 11 Apr. 1953; BMNH1953.11.4 (18 specimens), paratypes, 59.2-

79.8 mm SL, same data as holotype.

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

Description

Based on the holotype and 85 specimens. Morphometries and meristics are given in Table 5. Small to

medium sized species (max 111.3 mm SL) with moderately compressed body. Snout pointed or slightly

concave. Eye diameter as long as, or shorter than, interorbital width. Caudal peduncle variable, ranging

from somewhat longer than deep to just slightly deeper than long. Gill rakers on lower part of the anterior

arch thick and stout, 8-10 [8 (f33), 9 (f41), 10 (fll)], last three or four reduced to small nubs. Upper

and lower jaws with 1-3 inner rows of tricuspid teeth. Outer series in both jaws composed of unequally

bicuspid and sometimes compressed teeth, only slightly cuspidate or conical in the posteriormost part

of both jaws. Tooth number of outer rows increases with size: 32-56 in upper jaw and 23-44 in lower

jaw. Flank scales around lateral line ctenoid, elsewhere cycloid; generally 29-32 longitudinal line scales,

excluding the small scales on caudal fin base [28 (f3), 29 (flO), 30 (29), 31 (126), 32 (fl4), 33 (12)];

cheek with 3 (f49) or 4 (f35) [rarely 5 (fl)] scale rows; scales between pectoral and pelvic fins 4(f51) or

5 (f30) [rarely 3 (fl) or 6 (12)]. Dorsal fin spines 16-18 [exceptionally 19 (fl)], soft rays 8-10 [8 (f8), 9

Fig. 6. Adult SS of Astatoreochromis straeleni (Poll, 1944). A. MRAC A9-13-P-555, 70.6 mm SL,

collected on 13 Dec. 2008 in the Malagarazi. B. MRAC B1-3-P-1, 88.3 mm SL, collected on 7 Jan. 2011

in the Rusizi. (Photographs by GB)

European Journal of Taxonomy ?>9\ 1-21 ( 2013 )

(f52), 10 (26)]. Anal fin spines 3-4 (usually 3), rays 8 (fl9), 9 (63) or 10 (f4). Pectoral fin rays 13 (f47) or

14 (126) [rarely 11 (fl) or 12 (12)]. Caudal fin rounded. LPJ triangular, longer than, or almost as long as,

wide (LPJ width 83.3-102.8 % of LPJ length); its teeth in the lateral external rows slender and cuspidate,

the central two to four rows with a mixture of molariform (anterior part of the dentigerous area) and

enlarged but cuspidate teeth.

Colour pattern of live specimens

See Fig. 6 for general appearance. Dorsally and dorso-laterally dark grey-yellowish, orange yellowish

on opercle, upper part of cheek, chest and belly. Lips and lower part of cheek iridescent blue. Fins orange

yellowish, dorsal with red edge, more pronounced posteriorly. Anal fin with 3-5 horizontal rows of

bright orange-yellow ocelli. Females with similar but smaller ocelli. Caudal fin with black dots arranged

in 6-8 more or less regular vertical rows. While general appearance remains the same, live colour pattern

appears infiuenced by characteristics of the water in which the individuals live. Rusizi specimens caught

in water with a high conductivity (more than 250 ps/cm) and muddy blackish bottom substrate in the

Gatumba swamps near Lake Tanganyika during the rainy season have a darker colour pattern (Fig.

6B). Specimens caught in the pools associated with the Rusizi River more to the north and in marginal

vegetation of the Malagarazi River are generally lighter coloured (Fig. 6A).

Colour pattern of preserved specimens

General appearance dark brown for recently preserved specimens turning lighter grey or dark grey after

a couple of years of preservation. Fins dark grey, edge of anal and anterior part of dorsal and pelvic fins

dark brown to blackish. No mid-lateral band present. A large blackish blotch at upper posterior end of gill

cover, may be vague in some specimens. A blackish vertical bar below, or behind, the eye in all recently

preserved specimens; this bar may disappear in specimens kept for some time in alcohol. Blackish dots

arranged in interrupted horizontal rows in posterior portion of soft dorsal fin and in interrupted vertical

rows in caudal fin. Anal ocelli always present but less visible distally, where anal fin is dark brown to

blackish.

Distribution

Known from the Rusizi, Lukuga and Malagarazi basins and from the Luiche, a small affluent of Lake

Tanganyika just north of the Malagarazi River delta. The species apparently also enters the lake as it

was collected by Brichard in 1973 from the harbour of Bujumbura; in addition, De Vos et al. (2001)

mentioned its presence at the harbour of Ujiji near Kigoma in Tanzania. Its presence in other affluents

of Lake Tanganyika needs to be confirmed.

Ecology

Astatoreochromis straeleni is primarily a riverine species (Greenwood 1954; Poll 1956, 1974), prefering

clear water (pers. obs. GB). In the Malagarazi basin, no specimen was found in the main channel.

The most important catch was made during the rainy season when specimens were caught in swampy

Hooded areas. The species was also caught in marginal vegetation of the Mazimero River, a small

affluent of Malagarazi, with a high water transparency. In the Rusizi basin, the species was mainly

caught in the Gatumba swamps where it is more abundant than in the Malagarazi basin; here also it

was found mainly in vegetated areas with clear water. It was also common in the small swampy pools

associated with the Rusizi River. The species was never caught in nor reported by the local fishermen

from the main course of the Rusizi River. Greenwood (1954) reported the species to feed mainly on

snails, ostracods and insects in the Malagarazi basin. Examination of stomach and gut content of 12

recently collected specimens (January 2011) from the Rusizi found snails (entire and fragmented shells)

together with adult insect fragments (wings) and other invertebrate remains in four specimens. Two

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

A. straeleni

A. alluaudi

Holotype

86 specimens

Lectotype

87 specimens

MORPHOMETRICS

MeaniSD

Range

Mean ±SD

Range

Standard Length

78.9

70.0±1L6

43.7-111.3

121.7

81±2L4

44.8-137.5

As % of standard length

Head length

36.2

34.7±L3

31.8-38.1

33.4

35.3 ±1.4

31.7-39.2

Body depth

37.3

35.5±L8

30.9-39.7

36.9

36.5±L5

33.5-41.1

Dorsal fin base

57.8

58.2±2.2

52.7-63.6

59.5

57.4±L9

52.9-61

Anal fin base

23.3

23.7±L2

21.2-26.4

21.0

24.7 ±1.2

21.2-27.9

Predorsal distance

35.1

35.4±L6

31.6-38.0

35.2

36.6±L7

31.1-41.1

Prepectoral distance

40.9

37.5±L8

33.4-45.4

34.8

37.5±L7

33.3-41.1

Preventral distance

48.5

42.8±2.5

39.8-54.9

41.6

43.1 ±1.7

40.1-48.3

Preanal distance

69.3

66.1±L7

61.7-71.0

66.1

65.3±L8

62.4-71.9

Caudal peduncle length

11.5

13.2±L0

10.4-15.8

14.0

12.6±L2

9.7-15.2

Caudal peduncle depth

12.4

12.3±0.5

10.9-13.3

13.1

1L8±0.6

10.4-13.5

As % of head length

Lacrymal depth

13.3

14.1±0.9

11.0-16.6

15.8

14.3 ±1.2

12.2-17.4

Snout length

30.1

27.5±L5

24.6±-3L6

29.8

28.7 ±1.9

24.1-31.6

Lower jaw length

40.6

40.5±L9

34.2-45.9

38.7

40.8 ±2.2

35.3-47.9

Premaxillary pedicel length

27.3

27.5±L5

24.3-31.4

27.6

26.9 ±1.4

22.2-29.3

Cheek depth

25.5

23.6±2.1

17.7-28.2

25.4

23.9 ±2.1

19.1-28.2

Eye diameter

28.0

29.0±L8

24.5-34.9

24.6

27.7 ±2.3

23.5-33.3

Inter-orbital width

25.9

27.5±L8

23.6-32.1

30.8

27.8 ±1.6

23.6-32.1

Head width

42.0

43.7±L7

39.6-47.7

46.1

43.8 ±1.8

40.3-49.2

Pharyngeal jaw length

34.0±2.1

29.5-39.9

36.2

34.2±2.0

30.2-39.5

Pharyngeal jaw width

30.9±2.4

26.9-37.6

36.9

32.9±2.6

28.7-40.6

Dental area length

20.2±2.2

16.3-25.7

24.4

2L6±2.1

17.1-27.6

Dental area width

2L9±L4

18.5-25.6

22.7

23.5 ±1.5

19.0-27.7

As % of head width

Inter-orbital width

61.7

63.5±3.9

56.4-72.7

66.8

63.5 ±3.7

55.1-73.1

As % of caudal peduncle

length

Caudal peduncle depth

107.7

2.0±8.0

76.6-125.0

93.5

93.7 ±10.5

71.4-122.4

MERISTICS

Upper jaw teeth (outer row)

32-56

28-48

Lower jaw teeth (outer row)

23-44

20-42

Upper inner teeth rows

1-3

Lower inner teeth rows

1-3

Gill rakers

8-1-2

(8-ll)-l-(l-3)

9-1-2

(7-10)-l-(l-4)

Dorsal fin formula

XVIII/8

XVI-XIX/8-10

VXVIII/8

XVI-XX / 6-9

Anal fin formula

III/9

III-IV/8-10

V/7

IV-VII / 6-9

Pectoral fin rays

11-14

13-15

Longitudinal line scales

28-33

26-32

Lateral line scales

19/7

17-22/6-13

17/12

16-22/7-13

Transversal line scales

4/7

3-5/7-9

4/8

3-5/7-10

Scales Pectoral-Pelvic

3-6

Cheek scales

3-5

Table 5. Measurements and meristics for Astatoreochromis straeleni (Poll, 1944) and A. alluaudi

Pellegrin, 1904.

European Journal of Taxonomy ?>9\ 1-21 ( 2013 )

specimens contained some adult insect remains and other invertebrate material, but no snails. The guts

of three other specimens contained a large amount of debris, sand and small undigested plant fragments.

Finally, three mouthbrooding females had empty guts.

Reproduction

The species is a mouth-brooder but nothing has been reported about its breeding period. Among the

specimens captured in the Malagarazi in December 2008 and in the Rusizi in January 2011, females

were found with ovarian eggs at different developmental stages in their gonads. Those caught in January

appeared to be at a more advanced stage and almost mature for spawning (diameter: 1.9-2.6 mm).

Conversely, amongst the specimens caught in the Rusizi basin in February 2009, no females with

developed eggs in their gonads were found. So, most probably the species reproduces at the start of

the short dry season from December to January. Whether this is the only reproductive season cannot be

determined from our data.

Discussion

Intra-specific geographic differentiation was observed in both A. alluaudi and A. straeleni, mainly in

LPJ proportions. Within the former species, these differences were found in populations corresponding

to the two former subspecies A. a. alluaudi and A. a. occidentalis, while within the latter, differences

were found between the Malagarazi and Rusizi populations, previously identified respectively as

A. vanderhorsti and A. straeleni. Removal of the LPJ measurements from PCAs, in both species led to a

larger overlap between geographically isolated populations (Figs 2-3).

Several authors have discussed phenotypic plasticity of the LPJ in A. alluaudi (Greenwood 1965a;

Hoogerhoud 1984,1986;Huysseune 1995;Smitse^a/. 1996a; Witte a/. 1990,1997) and its consequences

on adjacent structures in the head (Barele^ a/. 1977; Smitsetal. 1996b) and the discovery of environmental

effects shaping pharyngeal structures was the reason why the subspecific division within A. alluaudi

was abandoned (Greenwood 1965a). Our results indicate that this phenotypic plasticity, in natural

conditions, is linked to differential growth trajectories of the pharyngeal jaw between the populations

examined. Interestingly, in an analysis with two size classes we observed contrasting patterns of intra¬

specific differentiation in LPJ morphology for the two species examined. In^. alluaudi few differences

were observed among small specimens {<15 mm SL) while all four LPJ measurements (and some other

measurements on the body as well) were highly significantly different in larger specimens. This finding

accords with Hoogerhoud (1986) who found a diverging allometric relationship between two other LPJ

measurements, i.e., horn width and keep depth, when comparing the Lake Victoria population with

those from other lakes in the region. In contrast, LPJ growth trajectories appear to be different within

geographically isolated populations of A. straeleni from the Lake Tanganyika basin. Here we found

all LPJ measurements to be highly significant between the Rusizi and the Malagarasi population in

specimens <75 mm SL, while not significant in larger specimens. This might indicate that enviro nm ental

effects on the pharyngeal structures do not necessarily follow the same ontogenetic pathway in closely

related haplochromine species. However, a more detailed study of pharyngeal morphology is necessary

to fully understand this phenomenon. The other measurements on head and body structures that were

also significantly different in small specimens were also not significantly different between the Rusizi

and the Malagarazi in larger specimens.

According to Greenwood (1954), A. vanderhorsti differed from A. straeleni by a slightly deeper

lachrymal, LPJ shape, and an almost horizontal mouth. However, Greenwood’s study was based on the

only two specimens of A. straeleni known at the time. We could not confirm the difference in mouth

inclination, and found no significant difference in lachrymal depth between the populations from the

Rusizi (identified as A. straeleni) and from the Malagarazi {A. vanderhorsti) as the values showed almost

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

complete overlap (11.1-15.8 v^. 12.1-16.6 % HL, respectively). However, when the test group was split

into two different size classes, a significant difference was found in specimens <75 mm SL, but was

absent in specimens >75 mm SL (Table 4). Greenwood (1954) did not state whether the shape of the

LPJ was visually evaluated or whether precise measurements were compared. In this study, the shape

of the LPJ is expressed by four different measurements, all of which were significantly different (Table

3) between individuals of the Rusizi and the Malagarazi populations. When the test group was split into

two size classes, these differences could still be observed in specimens <75 mm SL but, as for the other

features, were not evident in specimens >75 mm SL (Table 4).

Slight differences between H. straeleni andH. vanderhorsti in anal and dorsal spine counts were reported

by Greenwood (1979), a finding confirmed in this study. It should be noted that one specimen from the

Malagarazi was found with 19 dorsal spines and five specimens from the Rusizi with 16 dorsal spines,

whereas the known range for the Malagarazi basin was reported to be 16-17 dorsal spines (Greenwood

1954) and 17-18 dorsal spines for the Rusizi basin (Poll 1974). Five specimens of the 57 examined from

the Rusizi were found to have 4 anal spines. This did not result in any significant difference for all the

comparisons performed.

De Vos et al. (2001a) did not mention A. vanderhorsti in their list of fish of the Malagarazi River

basin, but instead mentioned A. straeleni, probably in anticipation of the synonymy of the two species

finally demonstrated in this revision. The presence of this species together with some other Congolese

elements in the Malagarazi system (e.g., Marcusenius stanleyanus (Boulenger, 1897); Labeo weeksii

Boulenger, 1969; Raiamas salmolucius (Nichols & Griscom, 1917); Polypterus ornatipinnis Boulenger,

1902; Polypterus endlicheri Heckel, 1847; Distichodus maculatus Boulenger, 1898; Citharinus

gibbosus Boulenger, 1899; Micralestes stormsii Boulenger, 1902; Oreochromis upembae (Thys van

den Audenaerde, 1964) ?indiAlestes macrophthalmus Gunther, 1867) are interpreted here as evidence

supporting the pre-Tanganyika connection of the Malagarazi to the Congo River through the Lukuga.

Acknowledgements

We thank Melanie Stiassny and Barbara Brown (AMNH), James Maclaine (BMNH), Georges Lenglet

(IRSNB) and Patrice Pruvost (MNHN) for the loan of Astatoreochromis specimens under their care, and

Miguel Parrent (collection manager) for cataloguing the specimens in the MRAC collections. Gaspard

Ntakimazi (University of Burundi) is acknowledged for his scientific support and guidance of the first

author. Gaspard Banyankimbona is supported by a PhD grant from the Belgian Technical Cooperation

(BTC) at the University of Leuven (KU Leuven) and a research grant from the International Foundation

for Science (IFS A4965-1/July 2010).

References

Barel C.D.N., Van Oijen M.J.P, Witte F. & Witte-Mass E. 1977. An introduction to the taxonomy and

morphology of the haplochromine Cichlidae from Lake Victoria. Netherlands Journal of Zoology 27:

333-389. http://dx.doi.Org/10.1163/002829677X00199

Bookstein F., Chemoff B., Elder R., Humphries J., Smith G. & Strauss R. 1985. Morphometries in

Evolutionary Biology. Special Publication 15, Academy of Natural Sciences, Philadelphia.

Boulenger G.A. 1907. Zoology of Egypt. Fishes of the Nile published for the Egyptian Government. 2

volumes. Hugh Rees, Eondon.

De Vos E., Seegers E., Taveme E. & Thys Van Den Audenaerde D.F.E. 2001a. Uichthyofaune du bassin

de la Malagarazi (systeme du lac Tanganyika): une synthese de la connaissance actuelle. Musee Royal

de lAfrique Centrale, Sciences Zoologiques 2^5: 117-135.

European Journal of Taxonomy ?>9\ 1-21 ( 2013 )

De Vos L., Snoeks J. & Thys Van Den Audenaerde D.F.E. 2001b. An annotated eheeklist of the

fishes of Rwanda (East Central Afriea), with historieal data on introduetions of eommereially

important speeies. Journal of East African Natural History 90: 41-68. http://dx.doi.org/10.2982/0012-

8317(200D90r41:AACOTF12.0.CO:2

Greenwood RH. 1954. On two speeies of eiehlid fishes from the Malagarazi River (Tanganyika), with

notes on the pharyngeal apophysis in speeies of the Haplochromis group. Annals and Magazine of

Natural History 7: 401-414.

Greenwood P.H. 1959. The monotypie genera of eiehlid fishes in Take Vietoria, part 11. Bulletin of the

British Museum (Natural History), Zoology 5: 165-177.

Greenwood P.H. 1965a. Enviro nm ental effeets on the pharyngeal mill of a eiehlid Astatoreochromis

alluaudi, and their taxonomie implieations. Proceedings of the Linnaean Society of London 176: 1-10.

http://dx.doi.org/10.1111/i. 1095-8312.1965.tb00932.x

Greenwood P.H. 1965b. The Ciehlid fishes of Take Nabugabo, Uganda. Bulletin of the British Museum

(Natural History), Zoology 9: 349-357.

Greenwood P.H. 1979. Towards a phyletie elassifieation of the 'gonus" Haplochromis (Pisees, Ciehlidae)

and related taxa. Part 1. Bulletin of the British Museum (Natural History), Zoology 35: 265-322.

Hoogerhoud R.J.C. 1984. A taxonomie reeonsideration of the haploehromine genera Gaurochromis

Greenwood, 1980 and Regan, 1920 (Pisees, Ciehlidae). Netherlands Journal of Zoology

34: 539-565. http://dx.doi.org/10.1163/002829684X00281

Hoogerhoud RJ.C. 1986. Ecological morphology of some eiehlid fishes. PhD thesis. University of

Leiden, The Netherlands.

Huysseune A. 1995. Phenotypie plastieity in the lower jaw dentition of Astatoreochromis alluaudi

(Teleostei, Ciehlidae). Archives of Oral Biology 40: 1005-1014.

Ntakimazi G. 1985. Hydrobiologie du Bugesera (Akagera - Haut-Nil), en partieulier des laes Cohoha

Sud et Rwem en vue d’une gestion qualitative de la faune piseieole. Volume 1-11. Dissertation, Fondation

Universitaire Luxembourgeoise, Luxembourg.

Pellegrin J. 1904. Contribution a F etude anatomique, biologique et taxonomique des poissons de la

famille des Ciehlides. Memoire de la Societe Zoologique 16: 41-399.

Poll M. 1956. Poissons Ciehlidae. Resultats seientifiques de Fexploration hydrobiologiques du lae

Tanganyika (1946-1947), Institut Royal des Seienees Naturelles de Belgique, Brussels.

Poll M. 1974. Contribution a la faune iehthyologique du lae Tanganyika d’apres les reeoltes de Briehard.

Revue de Zoologie Africaine 88: 99-110.

Riee W.R 1989. Analyzing tables of statistieal tests. Evolution 43: 223-225.

Slootweg R. 1989. Proposed introduetion of Astatoreochromis alluaudi, an East Afriean mollusk

erushing eiehlid, as a means of snail eontrol. Annales en Sciences zoologiques 251 \ 61-64.

Smits J.D., Witte F. & Povel G.D.E. 1996a. Dififerenees between inter- and intraspeeifie arehiteetonie

adaptations to pharyngeal mollusk erushing in eiehlid fishes. Biological Journal of the Linnean Society

59: 367-387. http://dx.doi.Org/10.llll/i.1095-8312.1996.tb01472.x

Smits J.D., Witte F. & Van Veen F.G. 1996b. Funetional ehanges in the anatomy in the pharyngeal

jaw apparatus of Astatoreochromis alluaudi (Pisees, Ciehlidae) and their effeets on adjaeent struetures.

Biological Journal of the Linnean Society 59: 389-409. http://dx.doi.Org/10.llll/j.1095-8312.1996.

tb01473.x

BANYANKIMBONA G. et al.. Revision of the eiehlid genus Astatoreochromis

Snoeks J. 2001. Cichlid diversity, speciation and systematics: examples from the Great African Lakes.

In\ Coleman R.M. (ed.) Cichlid Research: State of the Art. Journal ofAquariculture and Aquatic science

9: 150-166.

Snoeks J. 2004. The Cichlid diversity of Lake Malawi/Nyassa/Niassa: identification, distribution and

taxonomy. Cichlid Press, El Paso, USA.

Stiassny M.J.L. & Meyer A. 1999. Cichlids of the Rift Lakes. Scientific American 280: 64-69.

Vreven E.J., Musschoot T., Boden G. & Stiassny M. 2007. Introduced or alien species of Lower Guinea.

In\ Stiassny M.L.J., Teugels G.G. & Hopkins C.D. (eds) The Fresh and Brackish Water Fishes of Lower

Guinea, West-Central Africa, Vol. T. 57-101. IRD, MNHN, Paris; MRAC, Tervuren.

Welcomme R.L. 1988. International Introductions of Inland Aquatic Species. FAO Fisheries, Rome,

Italy.

Witte F., Barel C.D.N. & Hoogerhoud R.J.C. 1990. Phenotypic plasticity of anatomical structures

and its ecological significance. Netherlands Journal of Zoology 40: 278-298. http://dx.doi.

org/10.1163/156854289X003 09

Witte F., Barel C.D.N. & van Oijen M.J.P. 1997. Intraspecific variation of haplochromine cichlids from

Lake Victoria and its taxonomic implications. South African Journal of Science 40: 585-594.

Manuscript received: 13 August 2012

Manuscript accepted: 7 January 2012

Published on: 22 February 2012

Topic editor: Rudy Jocque

Desk Editor: Kristiaan Hoedemakers

Printed versions of all papers are also deposited in the libraries of the institutes that are members of

the EJT consortium: Museum National d’Histoire Naturelle, Paris, France; National Botanic Garden

of Belgium, Meise, Belgium; Royal Museum for Central Africa, Tervuren, Belgium; Natural History

Museum, London, United Kingdom; Royal Belgian Institute of Natural Sciences, Brussels, Belgium;

Natural History Museum of Denmark, Copenhagen, Denmark.