The present paper deals in the maturity stages, ova diameter and spawning season, of Otolithus argenteus from Karwar waters. The seven stages of maturity were determined based on the macroscopic appearance and microscopic study of intra ovarian eggs. The average size at first maturity was found to be 160 mm. The diameter of ova varies from 0.01 to 0.82 mm. with various modes, indicating the nature and the frequency of spawning

Kusuma, M.S.

Neelakantan, B.

Satpathy, D.

Aquatic Commons

journal of the Indian Fisheries Association, 
16 & 17,1986-87,17-23 
MATURITY & SPAWNING OF OTOLITHUS ARGENTEUS (CUVIER) FROM 
KARWAR WATERS 
D. SATPAlHY, B. NEElAKANTAN AND M.S. KUSUMA 
Department of lltfarine Biology, [W,rnatak University, Kodibag, Karwar-581 30:3. 
ABSTRACT' 
The present paper deals in the maturity stages, ovu diameter, spawning season 
etc., of Otolithus argenteus from Karwar water. Tite seven stages of maturity have been de-
termined based on the macroscopic appeamnce and microscopic study of intra ovari;ut 
eggs. The average size at first maturity was found to be 160 mm. The diameter of ova vary 
from 0.01 to 0.82 mm. 'With various modes, indicatirtg the nature and the frequency of 
spawning. 
INTRODUCTION 
It is well recognised that the maturation and spawning habits in fishes, 
particularly teleosts are highly variable in tropical and sub-tropical waters. In In-
dia, Karandikar and Palekar (1950) were among the first to study these aspects, 
especially on the frequency of spawning. Toor (1960) while dealing with the fish-
cry biology of Lethrinus lentjan gave a detailed account on its maturation and 
spawning habits. Although sufficient infmmation is available on the reproduca 
tive biology of economically important fishes from the Indhm region (Prabhu, 
1956; Annigeri 1963 and Qasim, 19'73) not much has been done on Otolithus 
argenteus. 
As part of the biological studies of Karwar waters an attempt has been 
tnade in this account to study some aspects of the maturity stages, ova diameter, 
spawning season etc., of Silver Banded Jew fish 0. argenteus, a widely distrib-
uted species in the coastal waters. Economically it is the most valuable among the 
ground fishes of Karwar. 
MATERIAL AND METHODS 
The present study is based on the analysis of 820 specimens obtained dur-
ing:the ~riod. November 1978 to April1979. The fishes were collected fresh, once 
18 SATPATHY,NE.ELAKANTAN AND KUSUMA 
a week, from Trawl catches at the fish landing centre of Karwar. The fishes were 
measured for total length, weighed and dissected to determine the sex, colour of 
gonad etc. A small part of each ovary was examined microscopically for deter-
mining the stage of maturity. The ovaries were pr~served in 2% formalin for fur-
ther study. 
Small pieces from different regions of the ovary were taken for ova diame-
ter measurement using a stage micrometer. Two hundred or more ova from each 
ovary were measured. 
The stage of maturity have been determined based on the macroscopic 
appearance of the gonad and microscopic study of the intra-ovarian eggs. Clas-
sification is based on seven maturity stages, as defined by the international coun-
cil for exploration of the Sea (Wood, 1930). 
Stage I (Immature) : Ovary short, thread-like, white in colour, occupying less 
than 1/3 the body cavity. The ova are not visible to the naked eye and the ova di-
ameter range from 0.01 to 0.07 mm. 
Stage II <Maturing): Ovary short, slightly thick, whitish in colour, extending 1/2 
the body cavity. Eggs are transparent, ranging from 0.01 to 0.19 mm. with a mode 
of largest group of ova at 0.14 mm. 
Stuge III (Maturing) :Ovary yellow in colour, and occupying nearly 2/3 of the 
body cavity. Ova are visible to naked eye, ranging from 0.01 to 0.27 mm. with a 
mode of largest group of ova at 0.22 mm. 
Stage IV (Mature): Ovary yellowish in colour, thick, occupying more than 2/3 of 
the space in the body cavity. The ova diameter varying from 0.01 to 0.46 rrun. 
with a mode of largest group of ova at 0.41 mm. 
Stage V (Mature advanced stage) : Ovary yellowish red (fleshy). Blood vessels 
are markedly seen. Ova semitransparent measuring in the size range of 0.01 mm. 
to a maximum of 0.7.2 mm. 
Stage VI (Ripe) : Ovary occupying almost the entire length of the body cavity, 
eggs golden yellow in colour being filled with yolk. The mode of largest group of 
ova is at. 0.72 mm. 
MATURITY AND SPAWNING OF OTOLITHUS ARGENTEUS 19 
Stage VII (Spent) : Ovary is shrunken.and flacid with few large residual eggs. 
The mode of the largest group of eggs falls at 0.39 mm. 
25 Stage VIJ 
0 
25 
0 
0 
<3 25 Sto9e v 
-0 0 
,... 
g 25 Stage IV .., 
;::ll 
0" 
.., 
... 
u.. 
Stage Ill 
-1: .., 
(.) 
... 
.., 
0... 25 Sto ge II 
50 65 eo 
Micrometer Divisions 
Figl. Size at first mart,J.tiy in females of O.argenteus 
20 SA'IPATHY, NBELAKANTAN AND KUSUMA 
RESULTS AND DISCUSSION 
Size at first maturity : 
The size at which 0. argenteus attains maturity was determined from the 
percentage occurrence of fish in various stages of maturity in each 10 mm group. 
Fishes m stage I of maturity were treated as immature, II and III as maturing and 
the stage N and above were considered as mature for the purpose of calculating 
the size at first maturity. 
It was seen that female specimens measuring below 120 rom in total 
length were immature. In the size group of 140-150 mm., 41% of the specimens 
only were mature~ In the next size group of 150-160 mm. 48% of females were 
found to be mature. In the size-group of 160-170 mm, as high as 58% of female 
specimens were mature. In higher groups, however, the percentage occurrence of 
female were in the increasing order (Fig.l). Hence it is reasonable to deduce that 
the average size at first maturity (size at which 50% of the fish mature) is about 
160mm. 
Development of ova to maturity : 
Th.e size distribution of ova in stages I, IT, III, N, V, VI and VII of maturity 
are shown in Fig.2; The size of ova vary from 0.01 mm. in stage I to 0.82 mm. in 
stage VI. In stage I (immature), the ovary predominantly contains small transpar-
ent immature ova, measuring a maximum of 0.07 mm, can be regarded as the 
general immature egg stock. The size of ova in stage II (maturing) reaches a 
maximum of 0.19 mm. The polygons for this stage indicate the passing of the 
immature eggs into maturing ones with a mode at 0.14 mm. In the stage III (ma-
turing ) the ova diameter frequency polygons indicates a total of two modes be-
gining from 1st a:t 0.22 mm and 2nd at 0.07 mm. The maturing ova of the mode at 
0.22 mm are partly opaque, wherein yolk deposition has commenced around the 
nucleus and a distinct peripheral zone of Cytoplasm can be viewed under the 
microscope. In stage IV (mature), the first batch of maturing ova which are 
opaque advances further in size at a fast rate towards maturity with the mode of 
the largest group of mature ova at about 0.42 mm. In the advanced mature stage 
(V), the first mode stands at 0.58 mm. Ova of this mode are in the advanced ~tage 
of maturity, opaque, fully laden with yolk, transparent at the periphery and 
measure a maximum of 0.72 mm. Stage VI (ripe) has ripe ova at mode 0.72 mm. 
-.... 
::::s 
-0 
E 
MATURITY AND SPAWNING OF OTOLITHUS ARGENTEUS 
90 
Total length of fish (mm) 
Fig.2. Ova diameter frequency·polygons showmg the gr,:wlh of immature 
ova .. of O.argenteus towards maturity. 
21 
and comparatively soft to touch, are completely separated from the follicle and 
ooze out easily when slight pressure is applied. The maximum size is 0.82 mm. In 
stage VII (spent) the larger ova are absent as they have been spawned out. There 
is a group of mature eggs at 0.39 mm. 
Spawning seasori.: 
The spawning season was determined on the basis of perc~ntage occur-
rence of individuals in different stages of maturity during different months. The 
gonads at stage V and above occurred in higher percentage during the months of 
November to March; indicating that the spawning season lasts for about five 
months. This has also been substantiated by the occurrence of spel\t stages dur-
ing the months of December to April an:d the small fish in May. 
22 SATPATHY, NEELAKANTAN AND KUSUMA 
Frequency of spawning : 
The frequency of spawning is determined by the nature of frequency dis-
tribution of mature ova. Hickling and Rutenberg (1936), Dejong (1940), Karan-
dikar and Palekar (1950) and Prabhu (1956) have all studied the spawning habits 
of different fishes and based on their observation, spawning activity of all fishes 
can be classified into four type·s. 
1. Spawning taking place only once a year during a short period of defi-
nite duration. 
2. Spawning taking place once in year with longer duration. 
3. Spawning occurs twice in a year. 
4. Spawning extending over a long period but intermittantly. 
From the frequency distribution of the ova diameter measurement of ripe 
ovary (VI), three modal groups have been apparently observed. The most ad-
vanced batch of ova is represented by a mode at 0.72 mm. These ova which are 
transparent with oil globules· constituted the batch that would be spawned first. 
·The other group of ova with the mode at 0.48 mm followed this group. The rest 
of the ova belong to the immature group. The succession of maturing group of 
ova indicated the batch wise spawning burst of 0. argenteus. Hence; 0. argen-
teus can be regarded as one which exhibits spawning characteristics of fishes in 
type 4 (Spawning extending over a long period but intermittantly) of spawning 
activities of fishes mentioned above. 
REFERENCES 
Annigeri, G.G. 1963. Maturation of the intra ovarian eggs and the spawning pe-
riodicities in few fishes of Mangalor~ area based on ova diameter meas-
urements. Indian J. Fish. 10:23-32. 
DeJong, J.K. 1940. A preliminary inves.tigation of the spawning habits of some 
fishes of the Java sea. Treubia. 17:307-30. 
Hickling, E.F. and Rutenberg, E. 1936. The ovary as an indicator. of spawning pe-
riod in fishes. J. Mar. Biol. Ass. U.K., 21:311-317. 
Karandikar, K.R. and Palekar, V.C. 1950. Studies on the ovaries of Polynemus tet-
radactylus (Shaw) in relation to its spawning habits. ]. univ. Bombay. 
19:21-2~. 
MATURITY AND SPAWNING OF OTOLITHUS ARGENTEUS 23 
Prabhu, M.S. 1956. Maturation of intra-ovarian eggs and spawning periodicities 
in some fishes. Indian J. Fish. 3:59-90. 
Qasim, S.Z. 1973. An appraisal of the studies on maturation and spawning in 
Marine teleosts from the Indian waters. Indian J. Fish. 20 (1): 166-181. 
Toor, H.S. 1960. Biology and fishery of the pigface Bream (Lethrinus lentjan) 
Lacepede, "Maturation and spawning".Indian J. Fish. 11 (2): 581-593. 
Wood, H. 1930. Scottish herring shoals. Prespawning and spawning movements. 
Scotland Fish. Bd. Sd.Inv. 1: 1-71. 


Maturity and spawning of Otolithus argenteus (Cuvier) from Karwar waters

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Maturity and spawning of Otolithus argenteus (Cuvier) from Karwar waters

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