SEASONAL CYCLE IN THE GONADS OF
CIRRHINA REBA* (Hamilton)
A. G. SATHYANESAN,** Annamalai University, Annamalainagar
Received on December 23, 1957 and accepted for publication on February 6, 1958
(With Two Plates)
Seasonal histological changes in the gonads of Fundulus heteroclitus [Mathews, 1938],
Lepomis macrochirus and Huro salmoides, [James, 1946] have been studied in detail. Studies on the
ovarian eggs of some teleosts were made by Ransom [1887], Schraff [1888], Calderwood [1892],
Cunningham [1897] and Wheeler [1924]. Accounts on the history of germ cells in Cottus bairdii,
[Hann, 1927], ovarian structure of Lucifuga and Stygicola [Lane, 1903], regeneration of the
gonads in Placoglossus ativelis after spawning season [Kazuo Suzuki, 1939], seasonal changes
in the immature ovary of Merluccinus merluccinus [Hickling, 1935], and reproductive cycle of
minnow in relation to environment [Bullough, 1939] are also available. Some of the detailed
studies on the reproductive cycle of ovo-viviparous fishes are those of Bailey [1933], Mendoza
[1939, 1940, 1941, 1943], Stolk [1951] and Turner [1938]. The seasonal changes
occurring in the testis of perch [Turner, 1919], and Gasterosteus aculeatus [Craig-Bennett, 1931]
have been fully investigated. Histological studies of the testis in the sexual cycle of Oncorhynchus
nerka, Xiphophorus helleri and Salmo salar were made by Weisel [1943], Van Oordt [1925]
and Jones [1940] respectively.
Related studies on Indian fishes are meagre. Ghosh and Kar [1952] have studied
the seasonal changes occurring in the gonads of Heteropneustes fossilis. The maturity of
Coilia dussumeri during different months of the year is recorded by Palekar and Karandikar
[1953]. However, sufficient literature is available on the bionomics, breeding habits and in-
teresting aspects in the development of Indian fishes [Jones, 1949, 1951].
MATERIAL AND METHODS
Specimens used in this investigation were collected from the Annamalai University
reservoirs. The total and the standard lengths of each fish were recorded to the nearest milli-
meter. Bouin's fluid, alcoholic Bouin, Zenker's mercuro-formal were used as fixatives. Pereney's
fixative was also used in the case of ovary. Serial sections were cut at 5, 8 and 10 µ thickness
and stained in Delafield's Haematoxylin and Heidenhain's iron Haematoxylin. The weight
of the gonad was recorded to the nearest milligram when it was transferred to 70 per cent
alcohol. The condition factor indicating the state of the gonads during their growth was com-
puted for each month by applying the formula:
C = Weight of the g o n a d / L × 10 -8
Where C is the condition factor and L is the standard length of the fish [Allison 1951].
General morphology of the ovary
The ovaries of Cirrhina reba are paired elongated structures, lying postero-dorsally in the
body cavity, ventral to the air bladder. They are continued posteriorly as the oviducts which
unite together and open to the exterior. The ovary is covered with a thin tunica albuginea of
connective tissue which in turn is surrounded by a layer of peritoneum. The maximum width
of the ovary is at a place approximately one-third from the anterior end. In C. reba, the size
variation of the ovary at different periods of the year has a definite relation with its histological
changes. The description of the stages of growth of the ovary is based on Bennetts' field classi-
fication as cited by James [1946].
*This work was part of the Piscicultural Research Scheme carried out at the Annamalai University, and
sponsored and totally financed by the Indian Council of Agricultural Research.
**Present Address : Department of Zoology, Banaras Hindu University, Varanasi-5.
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