Description of Nothobranchius cardinalis spec. nov.

Sep/Oct/Nov/Dec 2007 

Journal of the American Killifish Association 40 (5 & 6) 

Description of Nothobranchius 

cardinalis spec. nov. 

(Cyprinodontiformes: Aplocheilidae), 

an annual fish from the Mbwemkuru 

River basin, Tanzania 

By Brian R. Watters *, Barry J. Cooper** and Rudolf H. Wildekamp *** 

Abstract 

Nothobranchius cardinalis, new species, is described. This new species is an annual 

killifish that inhabits ephemeral pools on the floodplain of the Mbwemkuru River system in 

southeastern Tanzania. It is classified in the N. guentheri sister species subgroup of the N. 

guentheri group. It is considered to be closely related to N. rubripinnis and N. annectens. 

Information is given on habitat and range of these species, and the factors controlling their 

distribution. N. cardinalis can be distinguished from other members of the group, including 

N. rubripinnis and N. annectens, by a combination of color pattern, morphometric, and 

meristic characteristics, as well as distribution. 

Introduction 

The Mbwemkuru River basin in southeastern Tanzania is one of a number of lesser 

river systems in that part of the coastal plain between major river systems to the north and 

south, the Rufiji and Ruvuma rivers, respectively. The Lisinjiri River is a seasonal tributary to 

the upper Mbwemkuru River. 

The Nothobranchius species described herein was first collected on June 30, 1985 by 

R. Wildekamp, L. Seegers, O. Roth, and I. Van Dooren from a swamp marginal to the lower 

reaches of the Mbwemkuru River. Seegers (1986) included some specimens from this collection 

into the set used for the description of N. rubripinnis Seegers, 1986. The data presented 

in that description made no distinction between the Mbwemkuru specimens and 

those from the Mbezi River, the type area for N. rubripinnis. Subsequently, Seegers (1997, 

1998) referred to the Mbwemkuru population as “N. spec. aff. rubripinnis” suggesting that 

he no longer regarded the Nothobranchius from that location to be representative of N. 

rubripinnis. 

The second known population of this new species was discovered by the present authors 

on June 6, 1997 in a remnant pool of the Lisinjiri River. Subsequent study of the 

specimens collected from this site, both as preserved and live material, as well as consideration 

of the distribution of the two known populations relative to that of N. rubripinnis, led 

* 6141 Parkwood Drive, Nanaimo, British Columbia V9T 6A2, Canada. 

** 27505 Riggs Hill Road, Sweet Home, Oregon 97386, U.S.A. 

*** Royal Museum of Central Africa, Vertebrate Section, 3080 Tervuren, Belgium 

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Journal of the American Killifish Association 40 (5 & 6) Sep/Oct/Nov/Dec 2007 

to the conclusion that the Mbwemkuru and Lisinjiri populations should be regarded as representative 

of a distinct species. 

Watters et al. (1998) distinguished a N. guentheri (Pfeffer, 1893) group within the subgenus 

Nothobranchius, in addition to the N. melanospilus group that was defined in 

Wildekamp et al. (1998). Watters et al. (1998) further split the N. guentheri group into two 

subgroups of sister species, the N. guentheri species subgroup and N. korthausae species 

subgroup. 

The synapomorphic characters for the N. korthausae species subgroup were regarded 

as: light margins to the dorsal and anal fins, red vermicular markings or irregular bars in the 

unpaired fins of the male, and polymorphism in some species. In the case of two polymorphic 

members of this subgroup, N. korthausae Meinken, 1973, and N. eggersi Seegers, 

1982, different populations may have either a barred or a plain caudal fin. Other species 

regarded as belonging to this subgroup are: N. albimarginatus Watters, Wildekamp, and 

Cooper, 1998; and N. kilomberoensis Wildekamp, Watters and Sainthouse, 2002. 

The species described here, N. cardinalis, is regarded as belonging to the N. guentheri 

group and, specifically to the N. guentheri subgroup of species including: N. annectens 

Watters, Wildekamp and Cooper, 1998; N. foerschi Wildekamp and Berkenkamp, 1979; N. 

guentheri (Pfeffer, 1893); N. palmqvisti (Lönnberg, 1907); N. patrizii (Vinciguerra, 1927); 

and N. rubripinnis Seegers, 1986. Further, N. cardinalis is considered to be most closely 

related to N. rubripinnis and N. annectens as shown by a comparison, presented herein, 

between the morphology, color pattern and distribution characteristics of N. cardinalis and 

these two closely related species. This contention is also supported by mitochondrial DNA 

evidence (Collier, pers. comm., 2007). 

The N. guentheri sister subgroup shares the synapomorphic characters of a red “patch” 

on the gill cover formed by enhanced red scale margins in that area, a pattern of rearwardpointing 

chevron bands on the posterior part of the body formed by the red scale margins, 

and a red caudal fin. In some species, such as N. foerschi, the chevron pattern is only 

vaguely developed. While most species of this subgroup have a black marginal band to the 

caudal fin this is not common to all species; N. palmqvisti, N. patrizii, and N. foerschi appear 

to lack this feature. A gray, rearward-pointing chevron pattern on the posterior part of the 

body is shared by the females of all the species included in this subgroup, although in some 

this may be only very faintly developed. 

The distribution of Nothobranchius species is such that they will most commonly occur 

throughout a particular drainage basin and, if their distribution extends beyond a single 

system, as is commonly the case, then they will be found contiguously in adjacent river 

basins throughout their range (Watters, 2006). Therefore, in view of distinct differences in 

color pattern as well as profound geographical separation of their respective distribution 

ranges, an affinity closer than subgroup status between N. cardinalis and the other members 

of the subgroup, N. guentheri, N. foerschi, N. palmqvisti, N. patrizii and N. steinforti, is 

considered highly unlikely. 

The only Nothobranchius species known from the area immediately to the south of the 

Mbwemkuru River basin are a N. melanospilus-like species (Wildekamp, Shidlovsky and 

Watters, in prep.) and N. hengstleri (Valdesalici, 2007). The former has a very wide distribution, 

extending from the Ruvuma River basin as far southward as the Melela River (~150 

km northeast of Quelimane) in Mozambique, whereas the only known locality of N. hengstleri 

is in northeastern Mozambique. Both of these species have been classified in the N. 

melanospilus group (Wildekamp et al., 1998) and are not comparable to N. cardinalis. 

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Materials and methods 

This description is based on specimens collected by the authors, and preserved after 3 

months aquarium maintenance. The material used was initially fixed in approximately 7% 

formalin and, after about 3 months, placed in 70% ethanol for conservation. Aquarium 

maintenance was undertaken for observation of coloration, behavior, and breeding biology. 

From these specimens aquarium stocks were established and distributed. 

Morphometric measurements were taken by means of a micrometer and compass, 

partly under a dissecting microscope. Counts, methods, and definitions follow Amiet (1987), 

Skelton (1993), and Coad and McAllister (2007). Measurements, including sub-units of 

head, are presented as percentages of standard length (SL). The number of all visible rays of 

dorsal and anal fins were counted. The count of scales in the mid-longitudinal series is the 

number of scales between the upper attachment of the opercular membrane and the base 

of the caudal fin. Excluded are the small scales posterior to the hypural junction, which were 

counted separately. Nomenclature for supra-orbital (frontal) scalation follows Hoedeman 

(1958). Terminology for cephalic neuromast systems follows Scheel (1968). 

Data used for comparison purposes are from the following sources: 

(a) New data from the measurement of specimens of N. rubripinnis from the Lukwale 

River drainage, collected by the authors on May 31, 1997, and from the Luhule River 

drainage on June 2, 2002 by the first and second authors and O. Schmidt. Material examined 

comprised 4 males and 4 females from the Lukwale River area (MRAC 2007-37-P-6- 

13), and 1 male and 1 female from the Luhule River drainage (MRAC 2007-37-P-4-5). Note 

that the Lukwale River is a tributary of the Mbezi River and the collection location of the 

specimens examined were taken from a locality within 850 m of the type location for this 

species. The Luhule River represents a distinct minor system immediately to the south of the 

Mbezi/Lukwale system. 

(b) Data for N. annectens, taken from Watters et al. (1998). These data were derived 

from: The holotype (MRAC 97–82-P-22) and 4 paratype females (MRAC 97-82-P-23-26) 

from the type location; one male and 8 females representing the Bagamoyo population 

(MRAC 98-08-P-19-27); and one male and one female representing the Somanga population 

(MRAC 97-82-P-27-28). 

All types, as well as specimens used for comparison purposes, are lodged with the 

Musée Royal de l’Afrique Centrale, Tervuren (MRAC). 

Nothobranchius cardinalis, new species 

(Figures 1, 2, 3 and 4) 

Nothobranchius rubripinnis: Seegers (1986) [misidentification, in part] 

Nothobranchius spec. aff. rubripinnis: Seegers (1997, 1998) 

Nothobranchius rubripinnis: Wildekamp (2004) [misidentification] 

Holotype 

MRAC 2007-37-P-1; Male, 27.1 mm SL; Tanzania; pool in the course of the seasonal 

Lisinjiri River, a tributary of the Mbwemkuru River, 91 km northwest of the town of 

Nachingwea, in the direction of the village of Liwale, and near Mtawatawa village (Figure 5 

and 6); 09 o 54.102' S; 38 o 15.384' E; B.R. Watters, B.J. Cooper, and R.H. Wildekamp, 6 

June, 1997; preserved after 3 months aquarium maintenance. 

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Paratypes 

MRAC 2007-37-P-2-3; Male, 26.6 mm SL; female, 23.0 mm SL. Same data as holotype. 

Description 

(Morphometric and meristic characters are given in Table 1.) 

Male: Snout rounded, mouth terminal, directed upward. Dorsal profile slightly curved. 

Dorsal fin origin anterior to the anal fin origin and behind the mid-length of the body. Dorsal 

Figure 1: Nothobranchius cardinalis, wild-caught male, holotype, MRAC 2007-37-P-1; 27.1 mm SL, 

33.0 TL, southeastern Tanzania; about 91 km northwest of Nachingwea, in the direction of Liwale; 

ephemeral pool in the floodplain of the Lisinjiri River, a tributary of the upper Mbwemkuru River. Photograph 

taken about 4 weeks after capture. Population code: TAN 97-27. Photograph B.R. Watters. 

Figure 2: Nothobranchius cardinalis, captive-bred female, about 30 mm TL, not preserved; southeastern 

Tanzania; Lisinjiri River population (TAN 97-27). Photograph B.J. Cooper. 

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fin 15 rays; anal fin 13-14 rays. Scales on mid-longitudinal series 26 plus 3 on caudal fin 

base. Transverse rows of scales above pelvic fin 12; scale rows around caudal peduncle 16. 

Ctenii on the scales on the posterior half of the body. Three rows of scales behind the eye. 

Supra-orbital squamation in a G-type pattern in the sense of Hoedeman (1958). Frontal 

part of supra-orbital squamation partly covered with epidermal tissue. 

Up to about 40 mm TL (about 33 mm SL), observed on adult aquarium-bred specimens. 

Body laterally compressed and relatively deep. Unpaired fins rounded. Dorsal and 

anal fin ray tips project only very slightly from the membrane. Both fins covered with epider- 

Figure 3: Nothobranchius cardinalis, captive-bred F1 male, about 40 mm TL, not preserved; southeastern 

Tanzania; Lisinjiri River population (TAN 97-27). Photograph B.R. Watters. 

Figure 4: Nothobranchius cardinalis, captive-bred F2 male, about 38mm SL, not preserved, southeastern 

Tanzania; lower Mbwemkuru River population (KTZ 85-28). Photograph B.R. Watters. 

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6 

Figure 5: Map of the southern and central coastal plains region of Tanzania, including the Mbwemkuru 

River basin. The star symbols indicate the presently known localities for Nothobranchius cardinalis. 

The red star represents the type location on the floodplain of the Lisinjiri River, a tributary of the upper 

Mbwemkuru River. The black star indicates the only other known locality of N. cardinalis on the floodplain 

of the lower Mbwemkuru River. The black circle and diamond symbols represent the known 

locations of the comparative species, N. rubripinnis and N. annectens, respectively. Note that for these 

two species a single symbol may represent multiple locations in close proximity to one another. 

mal tissue. The branchiostegal membrane projects slightly from the operculum; distal end 

wrinkled. Small contact organs in the form of papillae on the dorsal and anal fins. 

Female: Smaller than male, reaching about 35 mm TL (about 29 mm SL), observed on 

adult aquarium-bred specimens. Body less laterally compressed and slightly shallower than 

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the male. Dorsal and caudal fin rounded. Anal fin triangular, tip rounded, rays 4-7 longer 

and more rigid. Anal fin positioned relatively more posteriorly than in male. Caudal peduncle 

relatively shorter and not as deep as in the male. Opercular membrane does not 

project distally. No papillae or epidermal tissue present on dorsal and anal fin. 

Coloration 

Live male (Figures 1, 3 and 4): Body and head scales are iridescent light blue with 

distinct red margins which are widest on the operculum. The red scale margins form a strong 

reticulated pattern. Scales on the frontal parts of the back are iridescent golden green with 

Character 

Morphometric Data 

Holotype 

male 

Table 1: Morphometric and meristic data for Nothobranchius cardinalis new species. For morphometric 

data, Standard Length (SL) is in mm, all other measurements are expressed as a percentage of 

Standard Length. The component of the lateral line scale count placed in parentheses represents the 

number of small scales on the hypural plate. nd = not determined. 

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Paratype 

male 

(n=1) 

Mean for 

males 

Paratype 

female 

(n=1) 

Standard length (SL) 27.1 26.6 26.9 23.0 

Total length 121.6 119.9 120.8 119.3 

Body length 67.5 71.4 69.5 69.0 

Body depth 30.1 31.6 30.9 28.3 

Body width 19.5 17.3 18.4 18.7 

Head length 32.4 28.6 30.5 32.4 

Orbital diameter 9.6 11.3 10.5 11.3 

Interorbital width 10.5 13.2 11.9 7.7 

Snout length 7.6 7.1 7.4 5.1 

Snout to eye end length 17.3 17.3 17.3 16.4 

Predorsal length 57.9 55.3 56.6 60.3 

Preanal length 58.2 60.5 59.4 67.0 

Prepelvic length 48.1 47.0 47.6 53.7 

Caudal peduncle length 19.8 22.9 21.4 18.6 

Caudal peduncle depth 13.1 14.3 13.7 10.8 

Dorsal fin height 18.1 nd nd 21.4 

Base of dorsal fin 27.2 24.4 25.8 21.0 

Anal fin height 18.9 nd nd 22.0 

Base of anal fin 20.7 20.7 20.7 12.6 

Meristic Data 

Dorsal fin rays 15 15 15 16 

Anal fin rays 14 13 13.5 14 

Scales on lateral line 26 (+3) 26 (+3) 26 (+3) 25 (+3) 

Scales, transverse, at ventral fins 12 12 12 11 

Scales around caudal peduncle 16 16 16 14


Figure 6: Type locality of Nothobranchius cardinalis. Tanzania; about 91 km northwest of Nachingwea, 

in the direction of Liwale; ephemeral pool in the floodplain of the Lisinjiri River. Photograph taken June 

6, 1997, by B.R. Watters. 

less distinct red margins. The color of the scale centers is iridescent blue, grading to pink on 

the abdomen, although still with distinct red margins. On the caudal peduncle of some 

specimens the reticulation on the body forms a barely discernible rearward-pointing chevron 

pattern. The snout, throat, and projecting part of the branchiostegal membrane are 

deep red. The latter feature has a white edging. The background color of the basal parts of 

the dorsal fin is bright blue-green, grading outwards to golden green, with a transition into a 

narrow submarginal zone of darker green to black, followed by a narrow pale blue or white 

margin. Fin rays in the dorsal fin are red and most prominent in the frontal half of the fin. 

Red spots are present in the outer and posterior parts of the dorsal fin and these merge to 

form irregular transverse bands, most prominent in the posterior part of the fin. The anal fin 

displays a narrow light blue zone at the base grading outward to a solid red. Rays in the 

basal zone are also red and there is a small but prominent blue-green patch on the posterior, 

basal part of the fin. The caudal fin is solid red except for a narrow, black marginal band. 

Pelvic fins are solid red. Pectoral fins are solid red except for a discontinuous, narrow light 

blue edge in some specimens. The iris is a reflective blue-green. 

Some minor intra- as well as interpopulation variability in color pattern is apparent, as 

based primarily on captive-bred specimens. As shown by Figures 1, 3 and 4, the width of 

the red scale margins is variable and in some specimens is very wide, resulting in an almost 

solid red body coloration. In the Lisinjiri River population the marginal band on the dorsal 

fin is usually light blue, whereas in the Mbwemkuru River population this feature may be 

either white or light blue. Some specimens of the Mbwemkuru population show a narrow 

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white or pale yellow marginal band to the anal fin, whereas this feature has not been seen 

in either wild or captive-bred specimens of the Lisinjiri population. The black marginal 

band on the caudal fin is consistently narrow in the Lisinjiri River population whereas in the 

Mbwemkuru River population this feature tends to be more variable, ranging from narrow 

to relatively broad (Figure 4) and commonly is of an irregular nature. 

Live female (Figure 2): The background body color is light gray-brown, darker on the 

back, grading to white or pink on the abdomen. Scale centers have small, iridescent pale 

blue patches, most prominent on the gill covers and the mid-section of the body. The 

branchiostegal membrane projects only slightly from the gill cover. Scale margins are a graybrown 

and narrow, producing a vague reticulated pattern that is most obviously developed 

on the caudal peduncle. In some specimens, the faint reticulation on the caudal peduncle 

takes the form of a vague rearward-pointing chevron pattern. The dorsal and anal fins are 

translucent; the caudal fin is hyaline. The iris is silver. 

Diagnosis and comparison 

The color pattern of males of N. cardinalis and N. rubripinnis (Figure 7) have some 

features that are quite similar: red snout; red pectoral, anal, and caudal fins; narrow black 

marginal band to the caudal fin. There are, however, some consistent differences. The anal 

fin of the latter has a blue-green background color with red rays and red spots that form 

irregular transverse bands, especially apparent in the outer, posterior part of the fin. By 

contrast, the anal fin of the former is almost a solid red. Similarly, the pectoral and ventral 

fins of N. cardinalis are a solid red, whereas in N. rubripinnis these fins are not as intensely 

colored and have a translucent quality. There are also some important differences in body 

color in that in N. rubripinnis the background iridescent blue-green is dominant and the red 

scale margins are relatively narrow. In the case of N. cardinalis the red scale margins are 

much wider, resulting, in some specimens in a dominantly red body. The former also always 

shows a strongly developed, rearward-pointing, chevron pattern on the posterior part of the 

body, due to the arrangement and slightly increased width of the red scale margins. In N. 

cardinalis this feature is very weakly developed and barely discernible. 

The principal difference in the color pattern of the females of these two species is the 

strong and consistent presence of a rearward-pointing chevron pattern on the rear part of 

the body of N. rubripinnis. This is most strongly developed on the caudal peduncle and is 

due to enhanced, dark gray scale margins. On females of N. cardinalis the scale margins on 

the rear part of the body are pale gray and narrow, and may, in some specimens only, form 

an almost indiscernible chevron pattern on the caudal peduncle. 

Differences in color pattern between males of N. cardinalis and N. annectens (Figure 8) 

are more profound. Details of the color pattern of N. annectens are given in Watters et al. 

(1998). The principal differences when compared to N. cardinalis are: The main body color 

of N. annectens is iridescent blue with golden yellow scale margins. In the rear half of the 

body there is a strongly developed rearward-pointing chevron pattern caused by red scale 

margins to every second to fourth row of scales. As already mentioned, the scale margins on 

N. cardinalis are red, wide, and uniform across the body and, if a chevron pattern is present 

at all, it is barely discernible. The caudal fin of N. annectens is red with a broad black, 

vertical, marginal bar, quite different to the relatively narrow marginal band shown by N. 

cardinalis. The pectoral and ventral fins of N. annectens are pale yellow, whereas on N. 

cardinalis they are a bright solid red. The anal fins are quite different and, while that of N. 

cardinalis is almost completely red, the anal fin of N. annectens is pale blue, grading out into 

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pale yellow in some populations. In contrast to both N. cardinalis and N. rubripinnis, N. 

annectens lacks the light blue or white margin to the dorsal fin. In N. annectens the dorsal 

fin margin, if present at all, is always red. The throat and abdomen of the latter tends to be 

yellow in most populations, rather than the striking red seen in N. cardinalis. 

Morphological characteristics (Tables 1, 2 and 3) further point to a distinction between 

N. cardinalis and the other two related species: 

Although there is some small overlap in the ranges of some characters, males of N. 

Figure 7: Nothobranchius rubripinnis, wild-caught male; Mbezi River basin, east-central Tanzania; 

population TAN 02-6. Photograph B.R. Watters. 

Figure 8: Nothobranchius annectens, wild-caught male; lower Rufiji River basin; population: Kitonga 

south TAN 97-34 (type locality), east-central Tanzania. Photograph B.R. Watters. 

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Males (n=5) Females (n=5) 

Character Mean Range SD Mean Range SD 

Standard length (SL) 30.3 28.0 - 36.0 3.3 25.8 23.5 - 27.5 1.6 

Total length 125.6 123.9 - 129.6 2.4 123.3 119.6 - 126.7 2.6 

Body length 66.1 63.6 - 68.6 2.0 69.4 67.3 - 71.3 1.5 

Body depth 33.1 31.1 - 35.8 1.7 29.0 27.9 - 31.7 1.6 

Body width 14.2 12.9 - 16.7 1.7 15.1 13.2 - 18.8 2.5 

Head length 34.5 31.4 - 38.3 2.8 31.4 28.7 - 36.3 2.9 

Orbital diameter 9.8 9.2 - 10.5 0.6 10.2 9.5 - 11.3 0.8 

Interorbital width 13.1 12.9 - 14.6 1.6 12.1 8.3 - 13.5 2.2 

Snout length 8.6 8.0 - 9.4 0.5 6.7 5.7 - 7.5 0.8 

Snout to eye end length 18.3 17.6 - 18.9 0.5 16.9 16.5 - 17.4 0.4 

Predorsal length 58.5 54.2 - 63.7 3.8 62.1 58.9 - 66.0 2.8 

Preanal length 61.0 58.6 - 61.5 2.1 66.0 61.9 - 71.8 4.8 

Prepelvic length 48.2 44.7 - 51.5 2.7 50.7 48.6 - 53.8 2.7 

Caudal peduncle length 23.4 23.1 - 25.7 2.2 22.7 17.5 - 24.9 3.0 

Caudal peduncle depth 14.6 14.2 - 15.4 0.5 12.5 11.6 - 13.2 0.6 

Base of dorsal fin 26.1 25.0 - 28.5 2.4 21.2 17.7 - 22.9 2.1 

Base of anal fin 21.3 19.2 - 25.5 2.6 14.7 14.1 - 15.1 0.5 

Meristic Data 

Dorsal fin rays 14.0 13 - 15 0.7 14.8 14 - 16 0.8 

Anal fin rays 13.0 12 - 14 1.0 13.6 12 - 15 1.1 

Scales on lateral line 26.5 25 - 28 2.1 27.8 27 - 29 1.0 

Scales, transverse, at ventral fins 11.4 11 - 12 0.5 11.4 11 - 12 0.5 

Scales around caudal peduncle 16.0 16 0.0 15.5 15 - 16 0.6 

Table 2: Comparative morphometric and meristic data for Nothobranchius rubripinnis from the drainage 

systems of the Lukwale and Luhule rivers: one male and one female from the latter area and 

four males and four females from the former. The Lukwale River is a tributary of the Mbezi River, 

which is the type locality for N. rubripinnis Seegers, 1986. For morphometric data, Standard 

Length (SL) is in mm, all other measurements are expressed as a percentage of Standard Length. 

cardinalis differ in morphology from those of N. rubripinnis by (ranges in brackets, mean in 

parentheses): a lesser snout length [7.1 – 7.6 (7.4) % of SL vs. 8.0 – 9.4 (8.6)]; a lesser snout 

to eye end length [17.3 (17.3) % of SL vs. 17.6 – 18.9 (18.3)]; a lesser head length (28.6 – 

32.4 (30.5) % of SL vs. 31.4 – 38.3 (34.5)]; a lesser caudal peduncle depth [13.1 – 14.3 

(13.7) % of SL vs. 14.2 – 15.4 (14.6)]; a lesser caudal peduncle length [19.8 – 22.9 (21.4) 

% of SL vs. 23.1 – 25.7 (23.4)]; a greater body width [17.3 – 19.5 (18.4) % of SL vs. 12.9 

– 16.7 (14.2)]; a lesser body depth [30.1 –31.6 (30.9) % of SL vs. 31.1 – 35.8 (33.1)]; a 

greater body length [67.5 – 71.4 (69.5) % of SL vs. 63.5 –68.6 (66.1)]. The latter three 

characters in particular, point to the relatively more elongate and less laterally compressed 

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body shape of N. cardinalis. Total length of N. cardinalis, expressed as a percentage of 

standard length, is less compared to N. rubripinnis [119.9 – 121.6 (120.8) % of SL vs. 

123.9 –129.6 (125.6)] again pointing to its relatively more elongate nature. 

Morphological characteristics of the female of N. cardinalis compared to those of N. 

rubripinnis are less distinctive than for the male. The single paratype female of the former 

has: a greater body width [18.7 % of SL vs. 13.2 – 18.8 (15.1)]; a lesser interorbital width 

[7.7 % of SL vs. 8.3 –13.5 (12.1)]; a shorter snout to eye end length [16.4 % of SL vs. 16.5 

Character 


Kitonga south 

population (types) 

Holotype 

Paratype 

females 

(n=4) 

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Male 

(n=1) 

Bagamoyo 

population 

Females 

(n=8) 

Somanga 

population 

Male 

(n=1) Female 

(n=1) 

Standard length (SL) 21.3 19.1 - 23.5 33.4 21.5 - 26.6 34.1 29.4 

Body length 66.7 nd 69.8 nd 70.4 65.3 

Body depth 35.2 28.5 - 32.3 30.8 28.2 - 32.3 29.3 30.6 

Body width 14.1 15.3 - 18.8 15.0 17.0 - 20.5 15.0 22.4 

Head length 33.3 31.1 - 37.6 30.2 30.4 - 35.6 29.6 34.7 

Orbital diameter 12.7 10.2 - 12.2 10.2 10.1 - 12.0 10.3 10.9 

Interorbital width 12.2 11.1 - 12.7 12.9 10.1 - 12.6 12.9 12.2 

Snout length 8.0 6.0 - 7.9 6.6 5.7 - 7.4 7.0 5.8 

Snout to eye end length 20.7 16.2 - 20.1 16.8 15.7 - 19.4 17.3 16.7 

Predorsal length 57.7 58.3 - 64.8 56.0 56.7 - 61.3 66.0 64.6 

Preanal length 59.2 59.6 - 68.1 64.4 60.0 - 66.0 66.9 67.3 

Prepelvic length 45.1 46.8 - 52.4 43.7 47.0 - 51.2 49.9 53.1 

Caudal peduncle length 21.6 18.1 - 20.5 21.0 20.5 - 27.1 17.6 18.0 

Caudal peduncle depth 14.1 12.9 - 14.4 9.9 12.1 - 14.8 13.5 12.6 

Meristic Data 

Dorsal fin rays 15 - 17 

Anal fin rays 15 - 16 

Scales on lateral line 25 - 26 (+3-4) 

Scales, transverse, at ventral fins 11 

Scales around caudal peduncle 14 

Table 3: Comparative morphometric and meristic data for Nothobranchius annectens. Data from Watters 

et al. (1998). For morphometric data, Standard Length (SL) is in mm, all other measurements are 

expressed as a percentage of Standard Length. The component of the lateral line scale count placed in 

parentheses represents the number of small scales on the hypural plate. nd = not determined.



– 17.4 (16.9)]; a lesser caudal peduncle depth [10.8 % of SL vs. 11.6–13.2 (12.5)]; a 

shorter anal fin base [12.6 % of SL vs. 14.1–15.1 (14.7)]. Total length of the N. cardinalis 

female, expressed as a percentage of standard length, is less compared to N. rubripinnis 

[119.3 % of SL vs. 119.6–126.7 (123.3)]. In contrast to the male, the female of N. cardinalis 

would appear to be no more elongated than the females of N. rubripinnis, although the 

former is notably less laterally compressed. 

Again, allowing for some small overlap in the ranges of some characters, males of N. 

cardinalis differ in morphology from those of N. annectens by (ranges in brackets, mean in 

parentheses): a greater body width [17.3 (18.4) % of SL vs. 14.1–15.0 (14.7)]; a lesser 

predorsal length [55.3–57.9 (56.6) % of SL vs. 56.0–66.7 (59.9)]; a lesser preanal length 

[58.2–60.5 (59.4) % of SL vs. 59.2–66.9 (63.5)]; a lesser number of anal fin rays [13–14 

(13.5) vs. 15-16]; a greater number of scales on the side of the body at the ventral fin 

position (12 vs. 11); a greater number of scales around the caudal peduncle (16 vs. 14). 

Morphological characteristics of the female of N. cardinalis compared to those of N. 

annectens are more distinctive than for the male. The single paratype female of the former 

has: a greater body length [69.0 % of SL vs. 65.3, for Somanga population only]; a lesser 

body depth [28.3 % of SL vs. 28.5–32.3]; a lesser interorbital width [7.7 % of SL vs. 11.1 

–12.7]; a lesser snout length [5.1 % of SL vs. 5.7–7.9]; a greater preanal length [67.0 % of 

SL vs. 59.6–67.3]; a greater prepelvic length [53.7 % of SL vs. 46.8–53.1]; a lesser caudal 

peduncle depth [10.8 % of SL vs. 12.1–14.4]; a lesser number of anal fin rays [14 vs. 15– 

16]. The greater body length in combination with a lesser body depth, indicates that 

females of N. cardinalis are relatively more elongated than those of N. annectens. 

In summary, N. cardinalis is a relatively small species that can be distinguished from the 

two closely related species, N. rubripinnis and N. annectens, by a combination of color 

pattern and morphological characters of both the male and female. 

Distribution 

The only two known locations of N. cardinalis are on the floodplain of the Mbwemkuru 

River and one of its tributaries, the Lisinjiri River. 

R. Wildekamp, L. Seegers, O. Roth, and I. Van Dooren found this species in a swamp 

close to, and on the floodplain of, the Mbwemkuru River (Figures 5 and 9), close to the 

village of Kitumbini (09 o 34.467' S; 39 o 29.763' E). This locality is about 67 km north of 

Lindi in the direction of Kilwa Kivinje, southeastern Tanzania. The second locality, the type 

locality, discovered by the present authors, is a moderately large pool in the course of the 

seasonal Lisinjiri River (Figures 5 and 6), a tributary of the Mbwemkuru River, near Mtawatawa 

village. This locality is situated 91 km northwest of the town of Nachingwea, in the direction 

of the village of Liwale (09 o 54.102' S; 38 o 15.384' E). 

At both localities N. cardinalis was found with N. melanospilus, close to, or at, the 

southernmost limits of the distribution range of the latter. Although the only two localities 

known to date are in the drainage basin of the Mbwemkuru River, it is likely that this species 

has a wider distribution, especially southward. 

Ecology 

The Lisinjiri River is seasonal and the type locality comprises a residual, ephemeral 

pool in the course of the river (Figure 6). As with all Nothobranchius habitats this pool would 

dry up completely on a seasonal basis. N. cardinalis is a typical annual cyprinodontiform 

fish. Eggs deposited in the substrate by the adult fish survive therein through the dry season, 

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Figure 9: Mbwemkuru River locality of Nothobranchius cardinalis. Tanzania; about 67 km north 

of Lindi in the direction of Kilwa Kivinje; ephemeral pool and swamp on the floodplain of the 

Mbwemkuru River, near the village of Kitumbini. Photograph taken June 1, 1997, by B.R. Watters. 

experiencing numerous phases of development with intervening diapauses. The eggs then 

hatch at the onset of the following rainy season. The type specimens were collected at the 

end of the rainy season. 

When the type specimens were collected late in the day (17:00 hours on June 6, 

1997), the water temperature at the locality was 25 o C (78 o F), the pH was 7.68, and the 

conductivity was 380 μS. Maximum water depth was approximately 1 m and it had a high 

level of turbidity. Except for some grasses on the banks that hung over into the water, the 

pool was devoid of vegetation of any sort. The substrate comprised a thick layer of very fine, 

soft, black mud. 

While N. melanospilus was fairly common in the pool, N. cardinalis was very rare and 

the types were collected close to the banks of the pool within a restricted area. An unidentified 

Barbus species was also present at the type locality. 

Etymology 

The name N. cardinalis is in reference to the striking, dominantly red coloration of the 

male. From the Latin cardinalis, meaning “principal, chief or essential,” from which the 

ecclesiastical title of cardinal was derived. The species name cardinalis, as applied here, is 

an allusion to the blood-red vesture worn by cardinals. 

It is suggested that the common name for this new species be: Cardinal Nothobranchius. 

Discussion 

Other than the differences in color pattern and morphometric characteristics between 

N. cardinalis and N. rubripinnis from the Mbezi and Luhule river basins, as described 

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above, a probable genetic differentiation between the two species has been demonstrated 

by Peterson (1996) in a hybridization experiment. N. rubripinnis from the Mbezi River area 

was crossed with N. cardinalis of the Mbwemkuru River population. An F 1 generation was 

obtained but the F 2 generation was weak and slow growing, and all died before reaching 

maturity. Specimens from the F 1 generation were back-crossed with specimens representative 

of both original populations but only a few fry resulted and those did not survive to 

maturity. 

The distribution of N. cardinalis and the two closely related species, N. rubripinnis and 

N. annectens, is such that there is no overlap of their respective known ranges (Figure 5). 

The ranges of distribution, when examined in relation to geographical and geomorphological 

features, suggests that all three species have been isolated from one another for a time 

span long enough for significant differences to develop. 

Localities of N. rubripinnis would appear to be confined to a restricted area centered 

on the Mbezi and Luhule river basins and bounded to the northwest and southwest by the 

Pugu and Mtoti ranges of hills, respectively (Figure 5). With the coastline forming the eastern 

boundary, this area has the form of a triangle, the so-called “Mbezi Triangle” (Watters, 

2004). The Mbezi area was, therefore, geomorphologically isolated from the Rufiji and Ruvu 

river basins as a result of fault-bounded tectonic activity that led to the formation of the river 

basins by subsidence, and the ranges of hills by uplift (Mpanda, 1997), the latter constituting 

a watershed between the two areas. Determination of the time of effective isolation between 

these areas is difficult and can only be speculated upon in very broad terms. The alluvial 

deposits that underlie the present-day habitats are Quaternary in age (1.8 Ma to present), 

constituting a minimum age for the process. Although the geological faults that gave rise the 

river basins and hills were active from a very long time ago, the phase of tectonism that gave 

rise to the present geomorphology of the region would appear to have occurred mainly 

during mid- to late-Tertiary times (~25 – 1.8 Ma). 

N. annectens occurs in the drainage systems of both the Rufiji and Ruvu rivers and 

there are also numerous other species of Nothobranchius that are common to both these 

river systems. This is due to the fact that the fault-bounded troughs that gave rise to these 

river basins intersected in the area that presently constitutes the upper reaches of the Ruvu 

system and the middle reaches of the Rufiji River. As a consequence, today, in that area, 

these rivers flow quite close to one another through a low-lying area that is swampy in places 

and becomes flooded during the rainy season. In the past at least, this must have allowed an 

exchange of species between the two river systems. 

Separation of these areas, as a result of geomorphological evolution of the landscape, 

allowed separate development of numerous Nothobranchius species that occur in either 

the Mbezi Triangle or the Rufiji and Ruvu river basins, but not in both. It would seem likely 

that some of these species stemmed from common ancestral forms; for example, N. rubripinnis 

and N. annectens, and N. luekei and N. janpapi. One species that is common to both the 

Mbezi Triangle and the Rufiji/Ruvu basins is N. melanospilus, suggesting that this is a very 

old species that was already widely distributed, and had reached a more advanced stage of 

evolution, prior to the time when the geomorphological barriers became effective. 

The localities of N. rubripinnis in the Mbezi and Luhule river basins lie about 280 km 

north of the localities of N. cardinalis in the Mbwemkuru River basin and a number of 

significant geographical and geomorphological barriers occur between the two areas. The 

nature of the watershed between the Mbezi area and the Rufiji River basin to the south, as 

discussed above, is one such feature. The southernmost known locality of N. annectens is 

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near the village of Somanga, close to the coast and immediately south of the Rufiji River 

delta. This is approximately 140 km north of the northernmost known locality of N. cardinalis. 

The intervening area includes several moderately large river systems; for example, the 

Matandu and Mavuji rivers. During an investigation carried out by the authors in 1997, no 

populations of Nothobranchius could be found in this intervening area. The investigation 

covered both the coastal and inland parts of the two above-mentioned river systems, including 

the Zinga River, a tributary of the Matandu River. In general, the terrain is hilly with 

a poor development of floodplains and appears largely unsuitable for Nothobranchius habitation. 

Parts of this area also experienced tectonic uplift during Cenozoic times. An unknown 

factor concerns the possible presence of N. annectens in the drainage basin of the 

Luwega River, a tributary of the Rufiji that occurs on the opposite side of a watershed separating 

it from the Mbwemkuru River basin (Figure 5). 

As is apparent from the data presented earlier, there is a greater overall distinction 

between the morphometric characteristics of N. cardinalis and N. rubripinnis as compared 

to that between the former and N. annectens. This is considered to be due to the more 

restricted and isolated distribution (with respect to natural barriers) of N. rubripinnis that has 

allowed a greater degree of separate development. It is also likely that this isolation began 

earlier than it did between the other two species. The natural barriers between N. annectens 

and N. cardinalis are not as profound and, consequently, nor are the differences in morphometric 

characteristics. As can be seen from Tables 2 and 3, the inter-population morphological 

variability of N. annectens is far greater than it is for N. rubripinnis. Again, this can be 

attributed to the relatively restricted distribution of the latter compared with the former. The 

wide distribution of N. annectens has provided an opportunity for populations to evolve 

separately to some extent, resulting in greater morphological variation. 

All of these considerations are suggestive of the relatively long-term isolation and separate 

development of N. cardinalis, with respect to both N. annectens and N. rubripinnis, 

although they may all have stemmed from a common ancestral form that occupied these 

coastal areas prior to the development of the natural barriers as discussed above. 

A Nothobranchius population possessing many of the characteristics shown by N. 

annectens was collected from the Ruhoi River region (Figure 5) by the first author and 

others in 1998. Males of this population have a mainly red anal fin and a red snout. 

However, the body pattern is very similar to that of N. annectens although with an even 

more prominent chevron pattern on the rear part of the body. The females have an identical 

color pattern to all other known populations of N. annectens. The mainly red anal fin and 

red snout notwithstanding, this population is regarded as having a much closer affinity to N. 

annectens than to N. cardinalis, and should be provisionally referred to as N. aff. annectens. 

Acknowledgements 

The authors would like to thank Dr. Ken Lazara for his critical review of the manuscript. 

Dr. Glen Collier is thanked for permitting reference to unpublished mtDNA results. 

References 

Amiet, J. 1987. Faune du Cameroun. Fauna of Cameroon. vol. 2. Le genre Aphyosemion Myers 

(Pisces: Teleostei: Cyprinodontiformes). Sciences naturales, Compiègne: 262 pp. 

Coad, B.W. and D.E. McAllister. 2007. Dictionary of Ichthyology. Online at website: http:// 

briancoad.com/Dictionary/introduction.htm. 

Hoedeman, J.J. 1958. The frontal scalation pattern in some groups of toothcarps (Pisces: 

—144—



Cyprinodontiformes). Bulletin of Aquatic Biology, 1 (3): 23–28, figures. 

Lönnberg, E. 1907. Fishes (Part 5): 8 pp. In: Wissenschaftliche Ergebnisse der Schwedische Zoologische 

Expedition nach dem Kilimandjaro, dem Meru und den umgebenden Massaisteppen 1905–1906 

unter Leitung von Prof. Dr. Yngve Sjöstedt. Volume 1. Koniglicher Akademie der Wissenschaften, 

Upsala, Sweden. Meinken, H. 1973. Nothobranchius korthausae spec. nov., eine hübsche 

Cyprinodonten Neuheit von der Insel Mafia (Ost Afrika). Das Aquarium, 7 (51): 351–355, figures. 

Mpanda, S. 1997. Geological development of the East African coastal basin of Tanzania. Stockholm 

Contributions in Geology, 45 (1): 121 pp. 

Peterson, C. 1996. Cross-breeding experiments. Journal of the American Killifish Association, 29 (3): 

93–98, figures. 

Pfeffer, G. 1893. Ostafrikanische Fische gesammelt von Herrn Dr. F. Stuhlmann im Jahre 1888 und 

1889. Jahrbuch der Hamburgischen Wissenschaftlichen Anstalten, 10 (2): 129–177 (separate: 1– 

49). 

Scheel, J.J. 1968. Rivulins of the old world. T.F.H. Publication, Neptune City, 480 pp. 

Seegers, L. 1982. Nothobranchius eggersi n. sp. aus dem Rufiji-Einzug in Tanzania mit Bemerkungen 

zum Vorkommen von Nothobranchius melanospilus (Pfeffer, 1896) (Pisces, Atheriniformes, 

Rivulinae). Ichthyologische Ergebnisse aus Tanzania, 1. Revue de Zoologie Africaine, 96 (3): 539– 

557, figures, map. 

Seegers. L. 1986. Beschreibung von Nothobranchius rubripinnis spec. nov. aus Tanzania. 

Ichthyologische Ergebnisse aus Tanzania, VII. Die Aquarien und Terrarien Zeitschrift (DATZ), 39 

(1): 18–22, figures. 

Seegers, L. 1997. Killifishes of the World. Old World Killis II. Aqualog Band 8. Verlag A.C.S. Mörfelden- 

Walldorf: 112 pp., figures. 

Seegers, L. 1998. Ein neuer Prachtgrundkärpfling aus Ostafrika. Die Aquarien und Terrarien Zeitschrift 

(DATZ), 51 (1): 12-16, figures. 

Skelton, P. 1993. A Complete Guide to the Freshwater Fishes of Southern Africa. First Edition. Southern 

Book Publishers, Half-way House, South Africa: 388 pp. 

Valdesalici, S. 2007. A new species of the genus Nothobranchius (Cyprinodontiformes: 

Nothobranchiidae) from the coastal area of northeastern Mozambique. Zootaxa, 1587: 61–68. 

Vinciguerra, D. 1927. Enumerazione di alcune specie di pesci della Somalia Italiana raccolte dal 

March. Saverio Patrizi. Annali del Museo Civico di Storia Naturale Giacomo Doria, Genova, (3) 

52: 246–259, figures. 

Watters, B.R. 2004. Nothobranchius habitats. DVD of talks presented at the 2004 annual convention 

of the American Killifish Association. AKA Video Committee. 

Watters, B.R. 2006. Dispersal of Nothobranchius – Fact and Fiction. Journal of the American Killifish 

Association, 39 (3–4): 137–144. 

Watters, B.R., R.H. Wildekamp and B.J. Cooper. 1998. Zwei neue Nothobranchius-Arten aus der 

Küstenebene Tansanias. Deutsche Killifisch Gemeinschaft, 30 (3): 52–63, figures, map. 

Wildekamp, R.H. 2004. A World of Killies. Atlas of the oviparous cyprinodontiform fishes of the world. 

Volume IV. American Killifish Association, Mishawaka, Indiana: 398 pp. 

Wildekamp, R.H. and H.O. Berkenkamp. 1979. Nothobranchius foerschi spec. nov., ein aquaristisch 

bekannter, jedoch wissenschaftlich neuer Prachtgrundkärpfling aus Tansania/Ost-Afrika (Pisces, 

Cyprinodontidae). Deutsche Killifisch Gemeinschaft Journal, 11 (11): 145–157, figures. 

Wildekamp, R.H., B.R. Watters and I.F.N. Sainthouse. 1997. Redescription of Nothobranchius vosseleri 

Ahl, 1924 (Cyprinodontiformes: Aplocheilidae), an annual fish from the Tanzanian coastal plains. 

Ichthyological Exploration of Freshwaters, 8 (4): 289–298, figures, map. 

Wildekamp, R.H., B.R. Watters and I.F.N. Sainthouse. 1998. Eine neue Nothobranchius-Art aus Tansania 

(Cyprinodontiformes: Aplocheilidae). Die Aquarien und Terrarien Zeitschrift (DATZ), 51 (12): 780- 

784, figures, map. 

Wildekamp, R.H., B.R. Watters and I.F.N. Sainthouse. 2002. Two new Nothobranchius 

(Cyprinodontiformes: Aplocheilidae) from the Kilombero River basin, Tanzania. Ichthyological Exploration 

of Freshwaters, 13 (1): 1–10, figures, map. 

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Description of Nothobranchius cardinalis spec. nov.

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