A new Cyprinodont species with a uniquely-colored female, Aphyosemion hera n. sp. (Cyprinodontifonnes, Pisces), from northwestern Gabon
Author
Jean H. HUBER
text
Revue Suisse De Zoologie
1998
105
2
331
338
journal article
10.5281/zenodo.33580
DESCRIPTION OF
Aphyosemion hera
n. sp.
(male, fig. l and female, fig. 2: not preserved topotypes).
Materia1 Holotype: MHNG 2590.64, a male of 31.4 mm S.
L
. and 37.5 mm T.L.,
R
. Knimenacker and
H
. Romer. coll. July 27, 1996.
Paratypes: MHNG 2590.65, a female of 29.2 mm S.
L
. and 35.4 mm T.
L
.; MNHN 1997- 184, 2 males,
MNHN
1997- 185, 4 females, USNM 347463, 3 specimens and BMNH 1998.1.21: 1 -2-3, 3 specimens, all collected with the holotype; all maintained a few months in aquarium, except the
USNM
and the
BMNH
material which is from the F 1 aquarium generation.
TYPE LOCALITY: Gabon, 45 km northeast of Larnbaréné (starting point: the bridge
over
the Ogooué river in the city)
on
the road to Bifoun, near Benguié, lower Ogooué basin. Geographical coordinates in degrees and hundredths: 0.47 S, 10.32E. At this point, the Ogooue’ river flows less
than
10 km away to the east; the Mbiné river, one of its tributary is about the same distance away
to
the west.
DIAGNOSIS:
Aphyosemiun hera
is a medium-sized species with a strong sexual dimorphism and dichromatism: the female is not subdued, as
usual
in the genus, but
Well
specifically colored. The new species is besides diagnosed by the opposite
insertion
of the vertical fins (D/A: +0.4, average), by the asymmetrical pattern of the vertical and caudal fins in male, by the rare, in non annual
species
, trilobate caudal shape
in
male and by the deep anal fin in female;
in
addition, the longitudinal dark mid-band of the young male and the female at all stages is permanent and does not depend on mood, like the one seen in some other species, especially those of the subgenus
Kathetys
Huber, 1977.
Methods of measurements and counting have been detailed in
HUBER (1992)
. Morphomeristic data of the first quoted eight types, the holotype first
in
bold (after confirmation by radiophotographs): sex: male, female, male, male, female, female, female, female.
D= 11, 11, 12, 11, ll, 11, 12, 11 (mean: 11.25; S.D .. 0.43). A = 12, 12, 12, 12, 12, 12, 12, 11 (mean: 11.88; S.D .. 0.33). D/A: + 1, +2, +1, 0, - 1, + 1, + 1, 0 (mean: +0.62; S.D .. 0.86). LL: 28+2; 28 +4; 29+2; 27+4; 28+3ç 28+4; 28+3; 29+3 (mean: 28.12+3.12; S.D.: 0.6). Predorsal scales: 14, 15, 13, 13, 14, 13, 14, 14 (mean: 13.75; S.D .. 0.7). Transversal scales (TRAV.) = 9, 9, 10, 10, 10, 9, 10, 9 (mean: 9.6; S.D.: 0.5). Circumpeduncular scales (CIR)= 15, 14, 16, 16, 17, 16, 17, 16 (mean: 15.9; S.D.: 0.9). S.L. (in mm): 31.4; 29.2; 36.7; 28.0; 25.4; 23.8; 22.4; 20.4. T.L. (in % of S.L.) = 119, 121, 125, 129, 118, 121, 120, 125 (mean: 122.3; S.
D
.: 3.5). P. D. (predorsal length): 62; 64, 60, 61, 63, 65, 64, 69 (mean: 63.7; S.D.: 2.8). P.A.
(preanal length): 64, 61, 59, 61, 61, 63, 62, 66 (mean: 62.2; S.D.: 2.0). P.V (preventral lenth): 50, 49, 50, 53, 52, 52, 52, 53 (mean: 51.3; S.D .. 1.3). Height at Anal level: 22, 19, 21, 21, 19, 21, 19, 22 (mean: 20.4; S.D .. 1.2). Height at peduncle level: 13, 13, 15, 14, 13, 14, 13, 13 (mean: 13.4; S. D.: 0.6). Head length: 27, 28, 25, 27,27, 26, 28, 29 (mean: 27.2; S.
D
.. 1.2). Interorbitar= 16, 17, 17, 14, 15, 15, 14, 15 (mean: 15.4; S.
D
.. 1.0). Eye diameter: 9, 9, 8, 9, 7, 8, 8, 9 (mean: 8.4; S.D .. 0.7). Snout: 7, 6, 6, 8, 6, 6, 6, 7 (mean: 6.4; S.D.: 0.6).
The caudal fin of the dominant male is strongly trilobate, with short streamers on upper and lower tips; the dorsal and, less so, the anal fins bear short streamers; the female is having an
unusual
deep anal fin and a somewhat pointed dorsal.
The D/A deviation has been checked on the radiophotographies of 6 additional specimens with the following results: + 1 ›, - l l,¬ - 1, + 1, 0, + 1; for the total 14 specimens, the mean value is +0.43 and the standard deviation, 0.80.
Vertebrae (abdominal+caudal), on 8 specimens: 13 + 15, 12+ 15, 11 + 15, 12+ 15, 11 + 15, 12+ 15, 12+ 15, 12+ 16 (mean: 27.0; S.D .. 0.71).
The hypural plate is fully divided in the middle, an unusual situation.
The frontal scalation is of the G-type, but less regular than usual, one female being F-type. The frontal neuromast pattern is open, like in all Aphyoseıııion from Gabon: the channels are unusually wide,
not
protected by fleshy lobes. A few ctenoid scales are available on the old male sides.
Colour in life: male, little pigmented on a blue green metallic background; the " shield" pattern (red lines, longitudinal below lip, oblique on operculum) is not conspicuous; only
a
few red blotches on the upper part of sides and near the basis of the dorsal, ventral and anal fins can be noticed; the middle of the dorsal, pectoral and caudal fins are flamed with red along rays; in addition, two submarginal red bands, the lower being wider, occur on the caudal but not on the dorsal fin; light blue margins are seen on dorsal, pectoral, and caudal fins, but not on ventral and anal fins, which are yellow-green overall, except their basis. Female, strongly pigmented with red spots over upper sides and with red flames on all fins; the dorsal fin and the upper part of the caudal fin is black margined, like the lower lip and the area below the eye; besides, a broad conspicuous dark band is present (also in the juvenile male) from behind the eye (in prolongement of the lower lip black line) until the tail; below this band, the entire belly is colored with a contrasting apple to gold yellow, like all paired and unpaired fins.
Colour in
alcool
: male, with around 20 light big spots on upper sides over a dark brown background; the lower mid-sides
are less
dark; head, dark with two darker lines on lower lip and somewhat below the first one; dark shield,
well
marked; dark rays on vertical fins, except a light broad margin at lower caudal and a light edge at its upper part; the dorsal fin bears a streamer and reaches, like anal, the caudal peduncle level. Female, with a broad dark longitudinal band from snout until the caudal peduncle where it ends larger by
a blotch
;
a
second dark thiner line, parallel to the lower lip,
goes
beyond the rear part of eye, underlying it; above the broad band, the region of upper sides is mottled with grey markings, while below it, it is unmarked and yellow; all fins, except pectorals, irregularly
and
discontinuously flamed with black, especially on mid-caudal following the band; in both sexes, a dark thin line 0n back from the A-scale to the dorsal fin insertion.
Ecological data (Romer, pers. comm., June 14, 1997): the biotope is similar to that of other
Aphyosemion
species: a shady primary forest creek ("marigot"); the water was, in summer 1996 i. e. during the
long
dry season, very shallow, 1 -2 In wide and 20 cm deep, with lots of dead leaves; the water was clear, of low conductivity, slightly acid, very similar to rain water as usual for
Aphyosemion
(a single measurement: conductivity: 20μS; pH= 6); at 2 p. rn., the water temperature was 21 °
C
. A dozen of specimens only could be caught, whereas the other sympatric species,
A.
gabzmense
was much more abundant. In the same locality, TIRBAK
eı
al. (1997) were also able to collect two other Cyprinodonts:
Epiplarys sefiasciatus
Gill
, 1862 and
E
.
singa
(Boulanger, 1899), the typical fauna of the area between Bifoun and Lambaréné.
Aquarium experience (Romer, pers. comm.): a typical non annual species which prefers dark parts of the tank, furnished with lots of plants; fairly easy to breed, despite unbalanced sex-ratios (first generation in favor of males; second in favor of females); the pair spawns on perlon mops with the standard Z-type position
of
Aphyosemíorı
; no aggressivity displayed; incubation time: 20 days at room temperature; first food:
Artemia rıauplíi
; growth: relatively
slow
. Sexual differentiation may appear at 5 months and first breeding at 7. Grell (pers. comm.) reports that the sexual maturity is reached at 7 months and the adult size, at 12 months.
Derivatio nomírıis
:
hera
(the Greek Goddess), an invariable noun in apposition, the name refers to the beauty
of
the female, probably the most beautiful in
Aphyosemion
, if not in Cyprinodonts, but this is subjective.
DISCUSSION
The main morphorneristic characters and the colour pattern of the
new
species places it undoubtedly within the genus
Aphyosemion
among the tropical West African Cyprinodonts: average dorsal and anal fin basis (D<l 6; A <16), dorsal and anal insertion, not too far from each other (D/A<+8), lyre-shaped caudal fin, red pigments on sides and fins, and notably on head (the " shield "), no dark vertical bars; its 10 W meristics (D= 11.3, A: 11.9, D/A = +0.4, on average) can only relate it to two taxa (
HUBER 1996
: average data): the subgenus
Chromaphyosemion
Radda, 1971 (
D
= 11.8; A = 13.6; D/A= 2.4) and the related genus
Diapteron
Huber and Seegers, 1977 (
D
= 10.7; A= 11.3;
D
/A = - 2.3). However the new species is distinguished from the
Chromaphynsemion
components by the absence of the two longitudinal mooddependant dark bands on sides of both sexes, by the shape of the vertical fins (pointed without long filaments, not trapezoid), by the shape of the caudal fin (without long filaments). It is distinguished from the
Diapteron
components by the shape of the vertical fins (pointed, not rounded), by the larger size (l cm larger) and by the
completely
different colour pattern of male (standard red pigments on blue background, versus the reverse).
No other
Aphyosemion
species combines a low
anal
fin count and
superimposed
vertical fins.
The colour pattern of the adult male of
A.
hem
, so important in
Aphyosemion
speeialion (the female chooses the conspecific male among sympatric species!) and systematics, reminds that of the
A
.
gaburıerıse
superspecies from the same region. This superspecies encompasses three isomorphic allopatric valid species, separated by
their
colour patterns and by their caryotypes:
A.
gabunense
(
a
blue symetrical phase),
A.
marginamm
Radda & Huber, 1977 (a yellow symetrical phase),
A.
boehmi
Radda & Huber, 1977 (a yellow phase, with an asymetrical pattern in the caudal fin). All show, unlike
A.
hem
, strong and regular series of spots on male sides and inner fins, plus a broad symmetrical red margin on dorsal and anal fins; dominant males exhibit long filarnents on caudal fin upper and lower streamers; females are grey brown, without any conspicuous dark band (
RADDA 1975
).
The colour pattern of the adult male of
A
.
hera
and its body and fin shapes remind also another species with two subspecies (probably valid species):
A.
pascheni pascheııi
(Ahl, 1928) and
A.
p
.
fesıivum
Amiet, 1987
from the Kribi area in southwestern Cameroun, i. e. over 350 km from our locality, with no other population inbetween. The
festivum
male pattern agrees especially with that of
hem
: red flamed colour pattern of the inner caudal fin, distinctive patterns
at
dorsal and anal fins (
a
rare feature in
Aphyosemion
); however, like the nominal subspecies, the male is heavily pigmented with red longitudinal lines and bears a red submargin at anal; and the female is gray brown with few red and
yellow
markings and without the characteristic longitudinal dark band.
Indeed, the five just
quoted
taxa share with
A
.
hera
paucity in biotope and very isolated location: all are known only from
their
type localities and eventually one or two more places (
HUBER 1981
;
AMIET 1987
); on the other hand, caryotype studies (SCI-[EEL 1990) suggest that
pascheni
is related to the
cqlliurum
superspecies (with
australe
and
ahli
), whereas
gabunense
and its allied are related to the
striatum
superspecies: these two superspecies are similar
in
fin shape, but not in body depth; they share a large part of their distribution (in Ecuatorial Guinea, Gabon, Congo), although the former is more restricted to near the coast; and they are reported sympatrically in a number of localities (in that case,it appears that the former chooses more open parts of the biotope).
Finally, the position of
A
.
hem
remains unclear with our present morphological and field knowledge: no direct relationship can seemingly be derived from isomorphic features and the new species appears to be a distinctive morphospecies, a rare case in the genus; an attractive relationship exists with
A.
pascheni
,
but
the position of the dorsal fin is very different, more advanced and there are several reported cases of colour convergence in
Aphyosemion
between
two
species belonging to
two
different phylogenies; at last, a putative relationship with the sympatric
gabunense
cannot be rejected, although related species are extremely rarely found in the same biotope in
Aphyosemion
and in Cyprinodonts in general.
FIG. 3
The biotope of
A
.
hera
.
A.
gabmieizre
,
E
.
rexfasciatiir
,
E
.
xinga
. a shady creek crossing the road. Photo René Krumenacker.
CONCLUSION
Low meristics and superimposed vertical fins,
a
colorful female, the presence of a black longitudinal band in the juvenile male and in the female, characterize
Aphyoreiiziniz hem
which lies apart in the phylogeny of its large genus: is it a primitive species linked with the
species occuring
in the same region?
ls it a relict species. like
pascheni
, of a formerly well distributed group which suffered considerable extinction? Is it an offshoot of a species living in the nearby yet unknown northern Du Chaillu mountains?
lt is expected that the DNA techniques will bring clues: no doubt that they will help to sort out the puzzle of speciation that is seen in the genus, especially
in
primary forest equatorial hilly regions, such as
that
hem
!
of
A.
It is hoped too that the nice beauties of this species and notably of will be appealing to killi-hobbyists for new collections, so that new planes am discovered and this so different species better knovm.
ACKNOWLEDGEMENTS
I am indebted to MM. H. Romer and R. Krumenacker (Winterthur, Switzerland) and to
Mr
P. Tirbak and Mr V Derugin (Palo Alto, California) and Mr A.
Kliesch
(Gelsenkirchen, Germany) for having donated preserved material from their aquarium strains or information on their collections and on the ecology, to Mr Wolfgang Grell (Erlach, Germany) for the permission of using his nice photographs and complement information on breeding, to Mr Wolfgang Eberl (Schomdorf, Germany) for
having
raised our attention towards these fishes
and
for his permanent support, and
to
Mr Patrice Pruvost (Paris, M.N.H.N.) who kindly worked out several times the difficult radiophotographs.
The manuscript has benefited from positive contributions by Prof. Jean-Louis Amiet (now retired in the South of France), who has discovered A.
festivum
, by Prof I. Daget (M.N.H.N, Paris, France) and by Univ. -Prof. Dr Alfred C. Radda (Wien, Austria), who has rediscovered A.
pascheııi
, and by anonymous reviewers. They all receive my sincere gratitude.