V E R T E B R A T A H U N GA R I C A M USE I HISTOR ICO-NATUR A L I S HUN G A R I C I

Fase. 1-2.

Ichthyological Notes II. O n the Biology of Breeding of Carassius auratus

gibelio (Bloch)

By L. Berinltey Zoological Department of the Hungarian Natural History Museum, Budapest

It is a well-known fact that the testicula of Caraasiua auratus gibelio /BLOCH/ transform into ovarla in its second year of age( to wit, the males become females. And at their subsequent spawning,the spawns are fertilised,by ggpegenese, by other species of the family Cyprlnidae. As it happens,the sperm will penetrate the spawn, and the dividing process of the egg will take place, but the sperm does not unite Itself with the ovulum and thus, in essentials, the offspring comes into being by parthenogenesis. According therefore to our present knowledge, the reproduction of this species happens, after the transformation of the males, in the way described above. The usual course of breeding is truly this, but, in my opinion, it will not infrequently happen that the sperm penetrating the spawn will unite with the ovulum, causing a regular fertilization. This seems the more probable as the frequent hybridization among the species of the family Cyprlnidae ÍB widely known. The correctness of my assumption is substantiated by the following facts.

During the gathering of the fishes of the fish-pond /fed by the waters of the Sárviz channel/ in the state farm of Nagyhörcsökpuszta on 23 October 1958, I captured two hybrid specimens of Carassius caraeslus L. and Caraeelus auratus gibelio /BLOCH/. No hybrid of the two species were as yet known. That the parent-species of the hybrids examined by me did really belong to the two species mentioned above and that the regular fertilization of the egg /the unison of the sperm and the ovulum/ did actually occur are verified by the fact that the characteristics! features of both parent species were manifest on the hybrids*

The parent species differ from each other in several morphological and osteological characters, the most conspi-cuous ones being the following: the body of the typical form of Carassius carasslua is very high, about half the length of the body. The back is highly arched. The mouth is terminal, but the oral cleft, in a lateral view, turns obli-quely upward. The dorsal fin is long and high, its posterior margin strongly convex ; the last undivided ray of the dorsal and anal fins constitutes a strong spine, densely and minutely teethed on its posterior side /number of teeth about 30/. There are regularly 6 divided rays in the anal fin.Some 32-35 scales lie along the lateral line. A vivid dark spot ornaments the caudal peduncle of juvenile specimens.becoming gradually evanescent on adult animals. The number of spines on the first branchial arch is 23-35, usually 26-31; the spines are short.The number of vertebrae vary between 31-34.

The body of Carassius auratus gibelio is lower, its dorsal outline more weakly arched.The mouth is also terminal but the oral cleft, when viewed laterally, is not oblique but straight. The dorsal fin is long and high,but its margin is not convex but straightly truncate. The last undivided ray of the dorsal and anal fins constitute a strong spine each, with rarely spaced, large teeth on its posterior side, the number of teeth may be 10-15. The scales are large, with

pi«. 1-3. Spine of dorsal fin.

Fig. 1, CaraBBius carassiuB ; fig. 2. Carassius auratus gibelio ; fig. 3. Hybrid.

/The figures were drawn by my collègue, L. ESZTERGÁLYOS./

28-31 oblique rows of scales along the lateral line. There

is no dark spot on the caudal peduncle of Juvenile speci-

mens. The branchial spines are long, 39-50 on the first

branchial arch. There may be 29-31 vertebrae .usually 29-30.

The two species differs also in several osteological

characters, but I will not discuss the differences now.

Examining the hybrid specimens from the point of view

of finding out in which of their characters they resemble

one or the other of the parent species, I was able to es-

tablish the followings: they agree with Carassius carasslus

in: 1. the situation of the oral cleft, 2. the presence

of the conspicuous black spot on the caudal peduncle, 3. the

number of the divided raye of the anal fin, 4. the numbers

of the branchial spines and 5. the vertebrae, as well as 6.

in the shape of the vomer, the frontale, and the hyomandibu-

lare. They conform to the characteristics of Carassius aura-

tus gibello in: l.the shape of the dorsal fin, 2. the number

of scales along the lateral line, 3. the length of the

branchial spines, and 4. the shape of the besloccipitale

the urohyale, and the articulare. ïinally, they occupy an

intermediate position in: 1. the number of the teeth on the

rays of the dorsal and anal fins, 2. the shape and structure

of the operculum, and 3. the shape of the pharyngeal arches

/ossa pharyngea inferiors/ /Pig. 1-9./.

On the basis of the mutual presence of the characteris-

tlcal features as discussed above of the parent species on

the hybrids, it can be shown indubitably that a regular

fertilization took place.In my opinion,regular fertilization

may occur also in the case of Carassius auratus gibelio,

and the hybrids of this species may be as frequent as those

of the other species of the family Cyprlnidae.

4 S 6

Pig. 4-6. Operculum.

Fig. 4. Carassiuo caraselus ; fig. 5. CaraaaiuB auratus gibelioj fig. 6. Hybrid.

7 e »

Pig. 7-9. Os pharyngeus inferioris.

Pig. 7. Carassiu8 carassius; fig. 8. Carassius auratus gibelio; fig. 9. Hybrid

Ichthyológiai jegyzetek II. Az ezüstkárász (Carasssus auratus gibelio BLOCH)

szaporodás-biológiájáról

Irta: Berinkey László Természettudományi Múzeum, Budapest

Szerző a bevezetésben az ezüstkárász szaporodásmódját ismerteti, s közli, hogy e faj hímjeinek testiculumai 2 éves korban ovariummá alakulnak át, azaz a himek nőstényekké vál-nak. Ezután iváskor ikráikat gynogenezis utján már a Cypri-nidae család más fajai termékenyítik meg, melynek megtörtén-tével a sperma behatol ugyan az ikrába,s ennek eredméayobént meg is indul a pete barázdálódása, de a sperma az ovolummal nem egyesül,s az utód lényegében parthenogenezissel Jön lét-re. Továbbiakban a szerző leirja, hogy gyűjtései folyamán a Carasslus caraaslus L. és a Carassius auratus gibelio /BLOCH/ 2 hybrid példányára akadt, s ezeket megvizsgálta abból a szempontból, hogy mely tulajdonságaik egyeznek meg a kárász és az ezüstkárász jellegzetes morphológiai és csonttanl bé-lyegeivel. Kutatásai során megállapította, hogy mivel a hybrideken a két szülőfaj jellegzetes tulajdonságai világo-san felismerhetők, a szülők faji hovatartozása kétségtelen, s a pete szabályos megtermékenyítése /a sperma és az ovulum összeolvadása/ megtörtént. Végezetül kijelenti, hogy vélemé-nye szerint az ezüstkárásznál ugyanugy előfordulhat a szabá-lyos megtermékenyítés is, s e faj hybridjei legalább olyan gyakoriak lehetnek, mint a Cyprinidae család többi fajainál.

R e f e r e n c e s

1. BERG , L.S. : Ryby presznih vod C.C,C.?. i szopredelnih BEtran /Moszkva-Leningrád,1949,1-3, pp.1381/. - 2. BERINKEY, L.: Purther Morphological and Osteological Investigations on the Hybrid8 of Hungarian Cyprinids /Ann. Hist. Nat. Mus. Nat. Hung. 52, 1960, p.447-464/. - 3. CARAUSU, S.: Tratat de Ich-tiologie /Bucuregti, 1952, pp.802/. - 4. GROTE, W. & VOGT, C. k HOPER, B.: Die SUsswasserfIsche von Mitteleuropas /Frank-furt ara M,, 1909, pp.558/. - 5. GÜNTHER, A.! Catalogue of the Pishes in the British Museum /London, 1868, 7, pp. 512/. -6. HECKEL, J. & KNER, R.: Die SUsswasserfische der österrei-chischen Monarchie mit Rücksicht auf die angrfinzenden Länder /Leipzig,1858,pp.388/. - 7. SIEBOLD, E.Th.: Die Süsswasser-fische von Mitteleuropa /Leipzig, 1863, pp. 430/.