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In 1882, Sauvage in France described a new Rivulin from West Africa under the
name Haplochilus chaperi. Sauvage's material came from swamps at the bottom
of the Lagune Assinie from a locality named Couacrou. We have not been able to
find such a locality at the bottom of the Lagune Aby, but some 16 miles east of
the northernmost part of the lagune there is a village named Kouakro which may
be identical with Sauvage's locality for this new species. In 1895, this species
was synonymized by Garman with H. senegalensis Steindachner 1870. This synonymizing
indeed was incorrect. In 1933, Myers identified the species described by Peters
in 1863 as Poecilia sexfasciata with Sauvage's species. At present it is not
quite certain if Myers' identification is right. Also it will be correct to
reserve the species name sexfasciatus for Epiplatys sexfasciatus Gill 1862, which
is not found west of the Dahomey Gap.
On 13 Jan. 1908, a shipment of live aquarium fishes arrived at Hamburg and was
inspected by amateur zoologist J.P. Arnold. He noticed that the shipment contained
a "sexfasciatius like" Rivulin and also a couple of small Rivulins unknown to him.
He kept these two unknown Rivulins in his tanks for some months waiting for a male
to be imported, as his two individuals developed into females. After some time
he preserved these two fishes and mailed them to his friend Boulenger in London
who based his description of Haplochilus liberiensis on this material (Aphyosemion
liberiense is a form which seems to be very close to the forms known as A. calabaricum
and A. roloffi). Arnold also took a pair of the "sexfasciatus like" Rivulin and
he was soon able to raise an aquarium strain of this species. As he was unable
to identify this fish, he mailed specimens to Boulenger who identified the fish
as H. chaperi Sauvage. From his publications on this species it is quite clear
that Arnold was not satisfied with Boulenger's identification and he examined
the original description of H. chaperi and found that the colors and color patterns
of his fish did not agree with those described by Sauvage. As usual, however,
he suppressed his doubt and used the name that Boulenger recommended.
Except for the pair of E. "chaperi" which Arnold bought, all the rest of the
specimens imported in that shipment were taken by a breeder who lost them all and
did not raise a single individual. Arnold's offspring from his pair however were
numerous and were delivered to aquarists all over Germany. From information in
German aquarium magazines of 1911 and 1913 we know that all E. "chaperi" kept by
aquarists at that time originated from Arnold's pair. Also it is likely that
even the present strain of E. "chaperi" kept by aquarists all over the world are
all descendants from Arnold's pair. If this is true it is difficult to explain
some findings on the present strain of E. "chaperi". Both Boulenger and Arnold
inspected the fins of Arnold's breeding male and found that this specimen corresponded
with Sauvage's species. However, the present E. "chaperi" has 11-12 dorsal rays,
whereas Sauvage counted 7 dorsal rays only. Sauvage's type material had 15 anal
rays whereas the present strain has 16 to 17. We are wondering why these alterations
of the fin counts apparently have not been noticed by authors of aquarium books, etc.,
which still use the data given by Sauvage (and Boulenger etc.). Arnold's breeding
male measured 52 mm total length when fully developed. The present strain reaches
at least 65 mm. However, this change may be a result of the selection of individuals
for breeding. Arnold's description and color picture of his strain make it quite
sure that the fish that we now call E. "chaperi" is identical with the one imported
back in 1908.
To make things even more complicated, Boulenger in his Catalogue of African Freshwater
Fishes 1915 mentioned that the material that he received from Arnold originated from
Sierra Leone and he pictures Arnold's breeding male (probably) with that locality.
Arnold for his part however wrote in the "Wochenschrift" that the shipment came
from Monrovia in Liberia. Oddly enough, Boulenger's type locality for his H. liberiensis
imported as "odd balls" inside the shoal of E. "chaperi" is Liberia and not Sierra
Leone. As we mentioned under A. nigerianum in connection with Boulenger's Haplochilus
calliurus, the type locality given for this species also does not correspond with
the information given in the "Wochenschrift" by Arnold. As all material used by
Boulenger for the descriptions of these forms was delivered to him by Arnold who
had the information about the origin of these fishes first hand from the sailors,
we do not doubt that Arnold's information is true (as true as such information from
collectors could be). This means that the origin of Arnold's E. "chaperi" is without
much doubt Monrovia in Liberia, whereas the type locality of H. calliurus Boulenger -
freshwater pools of Sierra Leone - is more more doubtful (as Arnold did not consider
the information given by the collector as quite true).
In 1942, L.P. Schultz in the USA reported E. chaperi in preserved material collected
near Harbel and Monrovia in Liberia. In 1948, Daget reported this form from Yapo
and Banco in Ivory Coast. The material reported by Schultz probably is identical
with Arnold's strain, whereas the material reported by Daget needs further investigation.
During fall 1952, Dr. L. Sheljuzhko from Germany collected freshwater fishes suited
for the aquarium for Werner at Munich. His collections took place around Abidjan
in Ivory Coast and up to a distance of 50 miles north of this city. In a small
pool near Port Bouet he caught some small fishes that he first considered as juveniles
of E. "chaperi". As the individuals were very small, he looked around the collecting
area to find further populations, but he did not find this species elsewhere.
Live specimens of the Port Bouet population were mailed to Munich and were sold
as aquarium fishes. Some specimens reached E. Roloff in Karlsruhe who sent material
of this form to Dr. M. Poll in Belgium for identification. In 1953, Poll described
this fish as Epiplatys dageti. The description was based on an adult pair. Poll
and Sheljuzhko both were aware that this form was very much like the Rivulin called
E. "chaperi" by aquarists. Poll however found sufficient differences between these
two forms to be able to separate them at species level. Males of the Port Bouet
population did not develop the very characteristic red area of the male throat
which is always present on adult males of the Monrovia E. "chaperi". The aquarium
strain of the Port Bouet population of E. dageti disappeared rather quickly from
the aquarium trade, probably because this fish is not very handsome or interesting,
although it is very easy to keep and to breed. The interest in this fish was so poor
that not even an article has been published about it in German aquarium magazines.
In summer 1962, Stenholt Clausen discovered E. dageti inside the plain and swampy
landscape around Awiebo in SW Ghana and not very far from the type locality of this
species. At Awiebo the species seems to prefer just the same sort of biotope as
that of Port Bouet. Port Bouet is situated on the southern part of a long and narrow
island which separates the large Lagune Ebrie from the Atlantic. This island is
partly covered by a particular type of sublithoral forest. Such forest and the
corresponding type of soil stretches out as a narrow strip along the coast of Ivory
Coast from Gran Lahou eastwards into southern Ghana.
In summer 1963, Bruce Turner in the USA sent us live specimens of an Epiplatys
apparently related to both E. "chaperi" and E. dageti. This form was imported into
the USA from "Nigeria". From our personal knowledge of the Nigerian Rivulin fauna
we consider it as a fact that this form does not belong to the Rivulin fauna east
of the Dahomey Gap and that is likely that the form originated somewhere near the
coast of Ghana, Ivory Coast or Liberia. Apparently, Bruce's strain is a link between
the populations of E. dageti Awiebo and Arnold's "E. chaperi".
Dr. Poll kindly lend us preserved specimens of the Port Bouet population (aquarium
raised) and then we were able to compare the three populations of E. dageti mutually
and in connection with the aquarium strain of E. "chaperi". The differences within
the normal zoological counts and measurements do not permit us to separate these four
strains, at least not at species level.
The Monrovia strain (E. "chaperi") seems to possess a few more rays in the dorsal
and anal fins: D 10-11 / A 16-17 versus D 9-10 / A 14-16 for the three populations
of E. dageti. All populations have black crossbars on the body sides of both sexes.
The Monrovia population apparently have had a very constant pattern of such bars
since the importation in 1908. If compared with the normal system of black crossbars
seen in individuals of E. sexfasciatus Gill, the Monrovia population lacks the black
bar just above the root of the ventral fins. The "V bar". The three populations of
E. dageti do not possess any constant bar pattern. At least on juveniles the bar
system is just like that of E. sexfasciatus in most cases. During maturing the
constant system often breaks down, as males loose some of the normal bars in particular
the V bar is lost or temporarily absent on one or both sides. On the contrary,
females often tend to produce doubling of the black bars. The extra bars mostly
come midway between two normal bars. They often are not fully developed and may
look like oblong spots situated high or low on the body sides. Old females of Bruce's
strain develop such a system very markedly and they appear as they were more dotted
than barred with black. On Awiebo females the extra bars mostly are complete and the
fish only looks barred. Many females of this strain however may loose many bars
temporarily or perhaps even permanently when old. These variations make it quite
impossible to describe the bar pattern of the females.
No red (orange red) color was noticed on the throat of males from the Port Bouet
population. Superficially seen, this is also the case for the Awiebo population.
Now and then one may notice a certain pinkish color where the red color normally
is present on male E. "chaperi". Bruce's strain show just as much red on male's
throat as do the E. "chaperi". If the Awiebo male is crossed with the Bruce strain
female, the "hybrid" male does not develop a red throat. However, the pigmentation
of the throat looks more pinkish to yellowish than that of the pure Awiebo males.
These "hybrid males" however are not fully grown at present. They have been breeding
for months so it is not likely that the pigmentation will increase much. The
development of a relatively large area of brilliant red pigmentation on the anterior
part of the male's throat represents (so far) a quite exceptional type of throat
signal patters within African Rivulins. The red pigmentation however is not the
only component of the throat pattern that is unique. The system of black pigments
on the throat of both sexes also differs from that of most West African Rivulins
and in particular from those of Epiplatys. The E. dageti system seems to come
closest to that of Aphyosemion bivittatum. Among the four populations of E. dageti
considered here, there are some minor differences of the black pattern. There seems
to be no difference between the males of Bruce's strain, the Monrovia and the Port
Bouet populations. The female pattern differs from that of the males not only in
the absence of red pigmentation (if present on males) but also rather markedly by
a certain black pigmentation inside the area which is red on male's throat. Oddly
enough, the male of the Awiebo population develops the same black system as seen
on females of the Port Bouet population and Bruce's strain. To compensate for
this, the females of the Awiebo population develop more black pigments. See drawings.
The "hybrids" from Awiebo male to Bruce's female show the black pattern of the latter
population. Juvenile individuals possess the "basic" red pattern of West African
Rivulins: a narrow red line just behind the lower lip and a like line more posteriorly.
Red pigments are seen in between these two basic red lines. It is likely that the red
pigmentation of the males of some populations comes from a leaking of red pigments from
these lines into the adjacent area followed by an increase of the development of red
pigment cells. There are no red dots on the body sides of the males of any of the four
populations. The scales are edged with a dark violet red color. Males of the Awiebo
population develop a certain yellowish brown shine on body sides. The Monrovia population
and Bruce's strain develop the same general color of fins and body sides. The pectoral
fin color is a warm orange on all males (not described for the Port Bouet population).
Males of the Monrovia population and of Bruce's strain develop a short "sword" by the
way that the lower rays of the caudal fin produce with maturity. The dark black edge
of the lower part of that fin runs into the sword. E. dageti shares the development
of such "swords" with E. sheljuzhkoi and also but less developed with some populations
of Nigerian E. sexfasciatus. The "sword" is very weakly developed on males of the
Awiebo population and it is not mentioned in the description of the type from Port Bouet.
Females of the Awiebo population develop a very conspicuous black band along the
anal fin. This band it shares with E. grahami, E. macrostigma females, however
inside the Awiebo females it is much broader and much more visible. Also females
of E. sheljuzhkoi develop such anal fin band, but we never saw such a band on
females of E. sexfasciatus.
The Monrovia population (E. "chaperi") probably grows to the largest size and may
reach 65 mm or even more (caudal fin included). The Awiebo population no doubt
is the smallest fish as we never managed to raise males above 40-41 mm (= 31-32 mm
standard length). The types of the Port Bouet species were 44 mm/42 mm long. The
individuals of Bruce's strain may grow bigger than this, but so far this is not
known with certainty.
After this review of four strains of E. dageti-like forms we may return to the
H. chaperi Sauvage described from an area near the Awiebo and the Port Bouet populations
and identified as similar to the form which Arnold received back in 1908. We do not
consider the Monrovia strain as identical with Sauvage's species for the following reasons:
Copyright 2022 Richard J. Sexton |