ARK - Arizona Rivulin Keepers

The Scheel Letters, No. 19

Possibly it might be considered an audacity trying to deal with this messy genus within the African killies. But as we keep several "species" now and possibly more will turn up in the future, I certainly take the risk diving into the problem, hoping that one day some skilled zoologist will try to put in order this confused group of fish. The Old World's Rivulinii (or Rivulinae) consist of the genera Aplocheilus (Asia), Epiplatys, Pachypanchax, Aphyosemion and Nothobranchius.

The genus Nothobranchius was erected by Peters in 1868 using Cyprinodon orthonotus which he described in 1844 from Mozambique as the type. For many years however the name in most cases was replaced by Fundulus (this name now is used only in connection with killies from North America) or Adiniops (now not in use). About 18-20 different "species" have been described by zoologists, but many might be races possibly of variable "orthonotus".

The distribution of the genus is very interesting. Indeed the main area of distribution is in coastal areas from Somalia to Mozambique, but a few species have been found far from the East African Coast. One typical Nothobranchius was found in 1933 in Gambia, about 200 km upstream in temporary rainwater pools by Svensson. Another (possibly more doubtful) species was described from Northern Nigeria and one species lives in the South Eastern corner in the Congo Basin. As these fishes mostly are rather small and live in temporary small freshwaters some species might exist somewhere between Gambia-Nigeria and the coastal waters in East Africa. One (or two?) species is found in the Seychelles Islands, but there are no reports of this genus from the lowlands of Madagascar.

To the aquarist the name of Nothobranchius means a small, rather deep fish being 5-8 cm long. Male with brilliant greenish to bluish metallic cast on the whole side of the body and head. Each scale should have a red edge or a red dot. These red markings forming a more or less regular net pattern along the sides of the body in particular on the hindmost part. As in Aphyosemion (their closest relatives??) there are "wormlike" red markings on the gill covers. Eye is brilliant green to blue. The vertical fins might be more or less covered by red dots or streaks in the dorsal and anal fin and in the caudal fin the red colour very often spreads in the way forming a completely uniformly red colour. The vertical fins might be edged with more or less black colour. In some species the ground colour of the dorsal and anal fin is yellowish. Dorsal and anal fins, in particular in the male, are big and rounded. They are used in the spawning act to keep the female in the right position as in Aphyosemion and other genera. No pronounced rays in vertical fins. The female is uniformly brownish to greenish and might have more or less conspicuous dark dots in particular on the hindmost part of the body. It is very difficult to distinguish the small specimens of females Cynopoecilus ladigesi from p.i. small specimens of N. "palmquisti". If in doubt, look at the hindmost edge of the dorsal fin; "ladigesi" uses to fold that edge in a particular way.

In nature these fish live in stagnant small freshwaters which possibly dry out during the dry season. These waters mostly are found in the open country exposed to the sun. The pools were described as dirty and water as turbid (Henry Hansen) and temperature might vary greatly in these pools. The chemical composition of the waters is not very well known and also no doubt vary greatly within the period in which the pools hold water. It is interesting that the Gambia species exclusively was found in the rainwater pools and not in the neighboring pools which had some sort of connection with the Gambia River during the rainy season. The natural conditions for the Nothobranchius possibly are not far from those of the Cynolebias in South America.

In aquaria all hitherto imported species showed great weakness and all might be considered among the most difficult and feeble aquarium fishes we ever kept. They might be considered as a standing challenge to our capability as aquarist. Their weakness in particular seems to be connected with the sexual maturity and at that time mass dying often occurs and often without any warning at all. In the dead bodies lots of bacteria of the tuberculosis type were found whenever I dissected. I was not able to stain these bacteria, not even by prolonged use of boiling Carbol-fuschin. The bacteria measured up to 20 _ (1_ = 1/1000 millimeter) and therefore might be considered not as a real bacteria but more as a primitive sort of fungus. This disease often called "fish tuberculosis" no doubt is a typical "aquarium disease" which we are not able to avoid whatever we do.

It is interesting that guppies might be just as feeble as Nothobranchius under certain conditions. A few years ago I made up my mind to study the various genetic sex linked factors (for colour and pattern ) in guppies in order to find out if the many factors described by Winge, Goldrich, Harris, a.o. solely were responsible for the colour pattern in modern guppies. But at that time all my tanks had standardized "rainforest water" (the type was equal to the present type but without any NaCl added). Under these conditions my many breeding stocks of selected guppies behaved as most difficult fishes and in particular the "fish tuberculosis" was a pest. In some cases even under the best conditions the guppies died by up to 10% of the stock a day. No medicine used gave any results. Not even the parachlorophenoxyethanol so effective against fungus and fungus-like organisms. The best way to save the guppies from dying completely out was to keep the water clean and plants at healthy growth. Indeed if removed to tap water tanks there were no problems, but I did not want to change my about 3000 liters of special water to ordinary tap water. In some of the big tanks with old peat mud in use for several years normally nothing happened to the guppies. Also I found that a handful of very acetic peat-like mud from the small swamp connected with the "river" of Moelleaen which flows near my house very often could stop mass dying in the stock of guppies if only I stirred this "dirt" into the water. Possibly certain antibiotic producing organisms in the dirt acted. My Nothobranchius when dying are showing the same pattern of behavior as did the guppies, they are growing very thin, they wriggle and tremble, they are nervous or blunt. No doubt the cause of their death is just the same as in the guppies and other killies.

The typical Nothobranchius in nature possibly lives without any connection to the main fauna of freshwater fishes of the country. Maybe we find the particular weakness of the various species not only in the diverse conditions (compared with conditions in nature) in tanks but also in certain parasitic organisms not present in their natural waters.

As I now once more try to raise my stocks of Nothobranchius I was forced to use copper (solid, a net) in connection with the aquarium water. Not for the whole period of growth, but at once I spot the trace of Oodinium (thin white pattern on scales, in particular on head). This helps very much but it should not be a permanent solution of the problem. We severely need developing of a special aquarium type for the fishes of this interesting genus. When the specimens have passed the difficulties of maturing they very often are rather hard fishes and might live for a long time. My first pair of "melanospilus" (came in as eggs from Jack Scheidnass in 1958) lived for about 11 months. But he had a crisis now and then about the maturing period. Also adding of common salt to the water seems to be a solution, although neither this is not very natural indeed. Normally aquarists add 800 to 1200 ppm (mg/l) of NaCl, but up to 1650 ppm have been in use.

Well, I try to keep the tanks and the water very clean, changing water and peat at once when blue-green algae occur. But my friend Claus Peteron in 1958 raised possibly thousands of Nothobranchius guntheri in tanks which not at all could be considered as clean and which did not have any plants. These fish also were heavily crowded. I know that he had some difficulties, but possibly not more difficulties than I had in my "clean" tanks. Also the information given by Henry Hansen on his collecting of Nothobranchius rachovi in the backland of Beira, Mozambique shows that these fish in nature may live under very dirty conditions in very polluted and turbid water. Possibly there is no particular temperature problem. 16-25_C.

The aquarium-kept species are guzzlers. They consume enormous lots of food if you do not ration the supply. They prefer live food and coarse food indeed, but you might train them to eat any dry food normally used for aquarium fish. Also they grow very quickly from the hatching and until maturity. But after maturity possibly most of the food is used for the production of sexual cells. They then are growing rather slowly. The great consumption of food makes the maintenance in aquaria (if clean conditions are wanted) difficult and therefore the tank possibly should not be too small and the plants and light plentiful.

The spawning act takes place at the upper layer of the bottom peat or sand in a way much like the Aphyoesmion in the "gulare group". Some of my pairs "guntheri" and "palmquisti" use to dig hollows in the fine mud used but I am not sure if they did this purposely or if these hollows only came from repeated spawnings at the same place. The bottom of their tank was like the moon's face.

The eggs from "palmquisti" and "guntheri" are small (about 1.0 mm outside) whereas eggs form the "melanospilus" and "kuhntae" are much bigger being about 1.3 mm (1.3 x 1.3 x 1.3 = 2.2, that will say that eggs of the species last mentioned have a volume 2.2 times the eggs from the species first mentioned). Also fry just hatched are of proportional sizes. 3.5-3.7 mm in "palmquisti" and "guntheri" and about 5.2 in "melanotaenia" and "kuhntae". Egg "rachovi" see page 71. Egg surface has a hair structure which differs from the other African aquarium kept killies. The filaments on membrane are short and stiff, often standing bristly out from surface and superficially they remind of eggs from "Cynopoecilus" which these species in so many respects remind of. Eggs are rather transparent and easy to inspect as they do not adhere any particles of peat. Odd enough eggs Oryzias latipes also have such stiff hairs. The various phases in the development of eggs are not very well known. On low water the free entrance of air samples of eggs (palmquisti and guntheri) most did develop and were ripe after about 4 weeks. The two other species did not develop so willingly and may stay transparent most of them for much longer time even under these favorable conditions. They then stop at the phase of "resting embryo". Hard egg drying up at once after collecting of eggs seems to force many if not all eggs into the phase of "resting eggs" (or resting embryo?), whereas a more moist drying seems to act as the keeping on low water. More investigations are needed.

Resting fry is the normal phase of eggs kept on shallow water, but now and then some eggs do hatch normally giving us belly sliders. However such hatchings also give a few normal swimming fry. Resting fry are easily hatched by adding dry food, but the percentage of belly sliders then is very high.

Summary of the Species described 1) N. amsinki (described by Ahl in 1929) the paper is not in Copenhagen.

2) N. brieni (described by Poll in 1938) this is a typical Nothobranchius in the aquarist's sense. It was caught at the southeastern corner of the Congo Basin, not far from the territory where Congo freshwater fauna mixes with the East African fauna. The locality is given as pools (?) near the river Lualaba, near the National Park, near Bukama. 6 cm. The colours of the live fish are not known. Preserved specimens (males) have red dots on each scale, these dots forming a more or less regular pattern and vertical lines. The vertical fins, in particular the dorsal fin, are dotted with red. The anal fin has a broad red band and its edge is black. Female has very weak dark dotting on sides. Poll's figures show us a typical, rather robust Nothobranchius. Never imported.

3) Nothobranchius eiminii (???) (described by Ahl in 1935 only on one specimen, possibly a female). Near N. rachovi. 6 1/2 cm. Hindmost part of the body and the vertical fins are dotted with dark colour. Caught at Konoran-Bott in Tanganyika (can not find this locality on my maps).

4) Nothobranchius gambiensis (described by Svensson in 1933 and much more in detail by Johnels in 1954) A typical Nothobranchius in our sense. Sides of male are brilliant azure with irregularly distributed, big red dots. The gill covers are red. The vertical fins are orange with deep red border. The female is brown with few dark dots on fins and hindmost part of body. 5 cm. Caught in rainwater pools very near the River Gambia. Who knows somebody in Gambia?

5) Nothobranchius guntheri (?) (described by Pfeffer in 1893 on some specimens in the Hamburg Zoological Museum) Zanzibar and possibly also on the coast opposite the Island. The best known species in tanks. Male has brilliant greenish blue metallic cast on sides of body and head. Each scale is edged by red and these red lines on the hindmost part of body (at least in the recent aquarium stock ) form vertical red bars. Dorsal and anal fin have a yellowish ground colour heavily dotted with red or brown and these fins have more or less blackish edge. Caudal fin is brilliant red and edged with rather broad black band. Female uniformly brownish with no dark dots. Specimens grow up to 85 mm. Imported (Germany in 1913 and several times later the recent stock came in 1957?).

6) Nothobranchius kiyawensis (described by Ahl in 1928 on one male and one female) Colours of the live fish are not known. 5 cm. Caught in (by?) the river Kiyawa near Katagum in Northern Provinces in Nigeria. This locality is logically compared with the "gambensis", but from Ahl's description it is not easy to find out how this fish stands to "gambiensis".

7) Nothobranchius mayeri (??) (described by Ahl in 1935) Typical Nothobranchius, with dominating red colouration on fins and body, mostly (possibly) by a further development of the red edges on scales and dots in fins. Ahl wrote that this species stands close to his "kuhntae", but as "kuhntae" is identical with "orthonotus", this species possibly also is a race of "orthonotus". 7 cm. Female also has a red cast on sides and fins. Beira in Mozambique. Imported to Germany and possibly re-imported in 1958 (Roloff?).

8) Nothobranchius melanospilus (??) (described Pfeffer in 1896) This is a typical Nothobranchius. Male has brilliant metallic cast in blue to greenish blue on sides and head, but the brilliance varies (apparently) more in this species than in the other aquarium kept species. This variation seems to have something to do with the health of the fish but possibly also some males always are more brilliant than others. In this species (I mean the fish now kept in aquaria = Scheidnass' stock or Henry Hansen's stock) the red pattern of the red edges of the scale forms a very regular net pattern on the sides of the body in the male (just like in "palmquisti"). The dorsal and anal fins often are edged with white and there is much red (and black) in these fins. Caudal fin is deep red and has on hindmost part a broad black vertical band. 6 cm. Female has conspicuous dark spots on hindmost part of body and the dots seem to concentrate near the sideline and may enter into the root of the caudal fin. Has been confused with "seychellensis". Caught in Tanganyika near the coast. Imported to the USA (H. Hansen) in 1955.

9) Nothobranchius microlepis (described by Vinciguerra in 1897) Might be a typical Nothobranchius (I have not had time to make a complete translation of the original description). Only two preserved specimens are known. 5-6 cm. Locality: "raccolti nello stagno Saha, sotto il monte Egherta, tra Brava e Lugh". Somalia.

10) Nothobranchius neumanni (?) (described by Hilgendorf in 18??) I have not red the original description yet. East Africa.

11) Nothobranchius orthonotus (described by Peters in 1844) Type species of the genus. The sides of body and head are bluish green in male. There are lots of red dots on the sides giving these a reddish cast. Vertical fins also are rather reddish and have (dorsal and anal fins) deep red edges. Female also has reddish cast, rarely in the fins. 7 cm. Caught in southern Tanganyika and northern Mozambique, near the coast. Possibly this species is identical with the one kept in Germany since 1957-58 under the name of "kuhntae" (my stock came from Griem, Aquarium Hamburg through my friend C. Petersen). Female reminds of female "melanospilus" but in this "race" there are not so many dark dots and these are not concentrated near the sideline on hindmost part of body.

12) Nothobranchius palmquisti (??) (described by Loennberg in 1911) A typical Nothobranchius (I mean the "species" now kept under this name in tanks) very close to "guntheri". The pure stock might easily be distinguished from the stock "guntheri" by two factors at least: 1) this species does not have any black pigmentation on hindmost part of caudal fin, which is plain red. 2) in this fish the red net pattern on sides of male is very regular, not forming vertical lines on hindmost part of body. Also there is less black and red in dorsal and anal fins and the straw orange yellow colour on lower parts of body and head plus dorsal and anal fins are much more intense in this fish. 4-5 cm. Loennberg's specimens came from Tanga in Tanganyika. Female is plain, without any dark spots and is more greenish than female of "guntheri", but if one does not have live specimens of both "races" present it is very difficult or impossible to find out whether female is a "palmquisti" or a "guntheri". Imported by "Tropicarium", Frankfurt in 1957.

13) Nothobranchius patrizii (described by Vinciguerra in 1927) Might be a typical Nothobranchius, Vinciguerra compares with "palmquisti". 3-4 cm. Caught at river Juba in southern Somalia.

14) Nothobranchius rachovi (described by Ahl in 1926) The colour pattern of this small species differs greatly from the "typical" Nothobranchius. There is much red and orange all over the body of the male. On hindmost part of body and vertical fins there is a brilliant greenish bluish cast. Caudal fin has hindmost a black edge and close to this a brilliant orange vertical band. Lower parts of body and head are orange to orange red. Female plain (in the specimens I keep now there is little greenish cast in dorsal and anal fin). 6 cm. Mozambique (near Beira) but possibly also in Rhodesia. Imported to Germany in 1925, also several times after 1950 to USA and Germany. The present stock (which might spread around the world by our organization) might be called Roloff's stock.

I have collected the first eggs and found them identical with eggs from "guntheri" and "palmquisti". Same pattern on membrane and same size (0.95 x 0.85 mm or 1.05 x 0.80 mm, not quite circular).

15) Nothobranchius robustus (??) (described by Ahl in 1935) Only one preserved specimen is known. A male. The colouration of the live fish is known. Blue with brown edges of scales and brownish red fins. The preserved fish was plain having a black edge on dorsal and anal fins. 52 mm. Caught at Tshangarra, Northern Usinja, Tanganyika (can not find this locality on my maps).

16) Nothobranchius seychellensis (??) (described by Ahl in 1935 from old material) Near "guntheri" and "melanospilus". Only the female is known. She was brownish with black dots on hindmost part of body. 55 mm.

17) Nothobranchius taeniopygus (??) (described by Hilgendorf in 1888). Male has red edge on all scales. There are red dots on head, the sides of body and on the dorsal and anal fin. Caudal fin is red. The hindmost part of body and also dorsal and anal fins are doted with black in the female. Caught south of lake Victoria.

18) Nothobranchius vosseleri (??) (described by Ahl in 1926) I have no further information yet. Special articles on the present species (or races) kept in aquaria will be prepared.

Crossing the species at hand

For these crossings I had the pure stocks of "melanospilus" (Hansen's stock), "guntheri" (Griem's stock) and "palmquisti" (Tropicarium stock). Also a male "rachovi" (came in from Griem in 1958, possibly this male belongs to Roloff's stock??) All these (three first mentioned) stocks breed true: