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Studies on the reproduction of Marcia opima (Gmelin)

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Relation http://eprints.cmfri.org.in/7134/
 
Title Studies on the reproduction of
Marcia opima (Gmelin)
 
Creator Suja, N
 
Subject Theses
Clam
 
Description The annual reproductive cycle of the clam, Marcia opima (Gmelin)
from two geographically separated populations at Tuticorin and Ashtamudi was
studied. It was observed that M. opima spawns twice a year at both the places.
But the spawning periods are May to June and November to December at
Tuticorin and March to May and November to January at Ashtamudi. Fully
matured condition of the clam was associated with an increase in the values of
gonad index and condition factor and a decrease in the digestive gland index. A
slight increase in temperature initiated the spawning activity of M. opima at both
the places. The sex ratio at Ashtamudi showed a male dominance. Attempts to
induce the maturation of dams showed that fed clams matured faster than the
unfed. The gonad index, condition factor and oocyte diameter of clams, kept at
28°C with proper feed was more than that kept at 23°C. Spawning and larval
rearing of M. opima were successfully carried out in the hatchery. The settlement
of larvae took place on 11111 day. On day 75, the spats attained an average size of
2.81 x 2.37mm. The growth and survival of spats at varying salinities was
studied. Maximum growth rate and 100% survival of spat was reported at salinity
25 %0. During biochemical analysis, it was noticed that protein level increases to
maximum in the fully matured clams. A low level of carbohydrate was observed
during gametogenesis. Lipid level was more in the female gonad than the male
gonad. Studies revealed that wet meat weight of clam is directly related to
oxygen consumption, ammonia excretion and protein catabolism. The clam
fishery at Tuticorin bay constituted a number of species like Marcia opima,
Semele striata, Mesodesma glabratum, Gafrarium tumidum, Mactra cuneata and
Paphia sp. Allometric relationships of M. opima from both the sites showed a
correlation coefficient near to unity between various morphological
characteristics. Parasitic infestation was observed in the clams during some
months of the sampling period in both the populations.
 
Date 2002
 
Type Thesis
NonPeerReviewed
 
Format application/pdf
 
Language en
 
Identifier http://eprints.cmfri.org.in/7134/1/TH-110.pdf
Suja, N (2002) Studies on the reproduction of Marcia opima (Gmelin). ["eprint_fieldopt_thesis_type_phd" not defined] thesis, PGPM, Central Marine Fisheries Research Institute.