Description of a new genus and two new species of killifish (Cyprinodontiformes: Nothobranchiidae) from West Africa, with a discussion of the taxonomic status of Aphyosemion maeseni Poll, 1941
Author
Sonnenberg, Rainer
Author
Busch, Eckhard
text
Zootaxa
2009
2294
1
22
journal article
10.5281/zenodo.191513
2228c9ca-2836-42aa-8ba6-bb75baf534b5
1175-5326
191513
Nimbapanchax
,
new genus
Type
species.
Nimbapanchax leucopterygius
,
new species
, by original designation.
Diagnosis.
In addition to their genetic distinctness, the species of this new genus differ from
A. guineense
by several morphological characters. In
Nimbapanchax
the frontal squamation is usually of the G-type, which might be the plesiomorphic state in
Nothobranchiidae
, versus the exceptional E-type in
A. guineense
(
Scheel 1968
;
Wildekamp 1993
). However,
Huber (1978)
reported an E-type pattern for some individuals of
Diapteron georgiae
and
Raddaella kunzi
and we found in
N. melanopterygius
,
new species
, several individuals with an E-type pattern and in one case one of the E-scales is covered by the G-scale and the other one is above the G-scale.
We found in
Nimbapanchax
a slightly lower mean number of scales along the lateral line than in
Archiaphyosemion
(see
Tables 3–5
); however,
Daget (1954)
gives the range from 30–34 scales so the upper number found in
Nimbapanchax
overlaps with the lowest in
Archiaphyosemion
.
Nimbapanchax
can also be diagnosed by lower numbers of transverse scales (8–10 vs. 11–12) and circumpeduncular scales (12–14 vs. 15–17) without overlapping ranges (
Tables 3–5
).
Nimbapanchax
usually has lower vertebrae counts as
Archiaphyosemion
(vertebrae with pleural ribs 13– 14, vertebrae with haemal spines 14–16 [total numbers 27–30] vs. 14–15 + 16–17 [total numbers 30– 31])(
Table 5
). Overlap in total vertebrae numbers is currently only known between
N. leucopterygius
new species
(29–30) and
A. guineense
(30–31), the remaining
Nimbapanchax
species have counts between 27–29 vertebrae.
The color pattern in the male caudal fin consists mostly of dark blotches or dots, stripes, if present, only short in posterior part versus contrasting light and dark stripes, usually from root of caudal to posterior fin margin between or along fin rays and no dots or blotches in
A. guineense
. Adult
Nimbapanchax
species do not reach, according the literature and own observations, the maximum total length of adult
A. guineense
(
60 mm
vs.
65 mm
, Wildekamp & Van der
Zee 2003
).
TABLE 4.
Morphometrics of
Nimbapanchax melanopterygius
,
new species
. For abbreviations see Table 3.
Holotype
Paratypes
3 mean
Paratypes
Ƥ mean all
Types
mean all
Types
range all
Types
SD Both
Nimbapanchax
and
Archiaphyosemion
are separated from the related
Callopanchax
and
Scriptaphyosemion
by the combination of the following characters: lower dorsal and anal fin counts as
Callopanchax
(D: 11–15, A: 14–18 [
Archiaphyosemion
], D: 8–14, A: 13–18 [
Nimbapanchax
] vs. D: 14–23, A:
17–20 in
Callopanchax
[data from Wildekamp & Van der
Zee 2003
]), origin of dorsal fin posterior to origin of anal fin versus origin of dorsal and anal fin nearly at the same level in
Callopanchax
; body brown to reddish brown, in males with metallic blue to blue-greenish on sides, only rarely red pigmentation (mainly in some populations of
A. guineense
,
in
N. petersi
and
N. viridis
) and no red submarginal stripes in dorsal and upper caudal fin versus an intensive blue or green background on side in males with red lines, dots or blotches and red submarginal stripes in all unpaired fins in
Scriptaphyosemion
, except for a red margin on anal fin instead of a red submarginal stripe in some populations.
SL 42.9 |
40.3 |
38.2 |
39.3 |
35.6–43.5 |
2.9 |
TL 127.2 |
125.1 |
125.2 |
125.3 |
122.0–129.6 |
2.0 |
PD 67.6 |
68.1 |
68.3 |
68.2 |
66.7–70.0 |
1.1 |
HL 25.9 |
26.5 |
26.6 |
26.5 |
24.6–28.0 |
1.0 |
pPD 52.0 |
49.3 |
49.7 |
49.6 |
47.2–52.0 |
1.2 |
pAD 60.0 |
60.3 |
61.2 |
60.8 |
59.5–62.5 |
0.9 |
dB 22.0 |
21.6 |
21.2 |
21.4 |
19.8–23.0 |
1.0 |
dC 12.9 |
12.5 |
12.1 |
12.3 |
11.2–13.2 |
0.5 |
CL 21.1 |
23.0 |
22.7 |
22.7 |
21.1–24.5 |
0.9 |
BD 17.2 |
16.9 |
16.1 |
16.5 |
14.4–18.1 |
1.0 |
BA 22.4 |
21.3 |
20.6 |
21.0 |
18.7–22.5 |
1.0 |
E 5.7 |
5.6 |
5.9 |
5.8 |
5.1–6.6 |
0.3 |
I 10.6 |
10.8 |
10.2 |
10.5 |
9.6–11.6 |
0.6 |
D 13 |
12.1 |
12.5 |
12.4 |
12–14 |
0.6 |
A 16 |
15.3 |
15.5 |
15.4 |
15–16 |
0.5 |
D/A 6 |
6.1 |
6.4 |
6.3 |
6–7 |
0.5 |
LLS 28 + 3 |
28.3 + 3.3 |
28.5 + 3.4 |
28.4 + 3.3 |
28–29 + 3–4 |
0.5 + 0.5 |
TS 10 |
9.3 |
9.9 |
9.7 |
9–10 |
0.5 |
CS 14 |
13.3 |
13.6 |
13.5 |
13–14 |
0.5 |
Included species.
Nimbapanchax jeanpoli
(
Berkenkamp & Etzel, 1979
)
,
N. leucopterygius
new species
,
N. melanopterygius
new species
,
N. petersi
(
Sauvage, 1882
)
, and
N. viridis
(
Ladiges & Roloff, 1973
)
.
Distribution.
With the exception of
N. petersi
, which inhabits the coastal plain in southeastern
Ivory Coast
and southwestern
Ghana
, all remaining species are found around the Mount Nimba region in southeastern
Guinea
, northern
Liberia
, and western
Ivory Coast
in the upper region of the coastal rivers drainage systems (Mano to Sassandra Rivers) (
Fig. 1
) (
Berkenkamp & Etzel 1979
;
Etzel 1974a
,
b
,
1992
,
1993
;
Huber 1982
,
2000
;
Paugy
et al
. 1990
;
Teugels
et al
. 1988
; Wildekamp & Van der
Zee 2003
).
Etymology.
Named after the Mount Nimba region, around which most of the included species are found, in combination with
Panchax
Valenciennes
in
Cuvier and Valenciennes, 1846
, a junior synonym of
Aplocheilus
McClelland, 1839
, an aplocheiloid genus, often used in the last century for several African species as common name. Gender masculine.
Remarks.
We erect
Nimbapanchax
as new genus to include all former
Archiaphyosemion
species except the
type
species of
Archiaphyosemion
Radda, 1977
,
A. guineense
(
Daget, 1954
)
, because the molecular data, supported by morphology, indicate that the latter is only distantly related to the species included in the new genus. The monophyly of
Archiaphyosemion
in the current usage is not supported and the former '
Roloffia
' group is represented in the molecular genetic data by four distinct lineages where
Archiaphyosemion
is the sister group to
Scriptaphyosemion
and
Callopanchax
,
and
Nimbapanchax
probably the sister group to a clade formed by these three genera.