Volume 05 No. 01 July 1994http://dr.lib.sjp.ac.lk/handle/123456789/7552024-03-24T02:09:31Z2024-03-24T02:09:31ZThe In vitro Effect of Exogenous Melatonin on Motility of Human SpermatozoaRatnasooriya, W.D.Jayawardena, P.A.H.L.Perera, P.A.C.T.http://dr.lib.sjp.ac.lk/handle/123456789/8372022-02-24T05:35:55Z1994-01-01T00:00:00ZThe In vitro Effect of Exogenous Melatonin on Motility of Human Spermatozoa
Ratnasooriya, W.D.; Jayawardena, P.A.H.L.; Perera, P.A.C.T.
Melatonin, a hormone secreted by the pineal gland is preesnt in the semen
and melatonin binding sites have been demonstrated on the plasma membrane
of sperm. These observations suggest a possible modulatory role of melatonin
on sperm function. The aim of this study was to investigate the effects of
melatonin on motility of human sperm in vitro. The concentration tested
were 75, 150, 300, 450 and 900 pg mL-1 and the period of investigation was
120 min. The results show that, at all concentrations tested, melatonin
suppressed motility of sperm. This antimotility effect was not dose-dependent
but was time-dependent ; the greatest inhibition for a particular concentration
being evident at the highest time point of incubation. Melatonin was not
necrospermic but was only spermiostatic. Furthermore, it did not markedly
alter the functional integrity of sperm of plasma membrane as revealed from
the hypoosmotic swelling test. It is suggested that the sperm antimotility effect
of melatonin may be due to its membrane stabilizing actions.
1994-01-01T00:00:00ZSome Micronutrient and Macronutrient Contents of Some Sri Lanka Food VarietiesDeraniyagala, S.A.Mudalige, K.T.Anula, H.M.Jamburuthugoda, M.Y.P.R.http://dr.lib.sjp.ac.lk/handle/123456789/8362022-02-24T05:34:22Z1994-01-01T00:00:00ZSome Micronutrient and Macronutrient Contents of Some Sri Lanka Food Varieties
Deraniyagala, S.A.; Mudalige, K.T.; Anula, H.M.; Jamburuthugoda, M.Y.P.R.
The food tables used today in Sri Lanka contain only little data on Sri
Lanka food varieties : besides they do not contain information about some of
the nutritionally important minerals present in these food varieties. As a
result food composition data users are dependent on a food table that is
inadequate. As a remdial measure some nutritionally important minerals
(Na,K,Ca,Mg, Fe, Zn, &Cu,) present in some Sri Lanka fruits, leafy vegetables,
pulses and cereals; the total available carbohydrate content of cereals, pulses
& fruits, the protein content of cereals & pulses and the fibre & moisture
content of fruits and leafy vegetables have been determined.
1994-01-01T00:00:00ZSome Aspects of Biology of the Snakehead, Ophicephalus striatus Bloch in Muthurajawela, a Peaty Swamp in Sri LankaWijeyaratne, M.J.S.http://dr.lib.sjp.ac.lk/handle/123456789/8352022-02-24T05:35:13Z1994-01-01T00:00:00ZSome Aspects of Biology of the Snakehead, Ophicephalus striatus Bloch in Muthurajawela, a Peaty Swamp in Sri Lanka
Wijeyaratne, M.J.S.
Growth, reproduction and mortality of the snakehead, Ophicephalus
striatus Bloch, inhabiting the Muthurajawela swamp, a low pH environment in
Sri Lanka, were studied using monthly samples collected by angling and
indigenous fish traps. The asympototic standard length and growth coefficient
were estimated to be 49.5 em. and 0.194 year" respectively. These figures were
smaller than those estimated for this species in other regions of the country. The
estimated total and natural mortality coefficients were 3.7'year-1 and 1.7 year "
respectively. The exploitation ratio was 0.5 and indicates that this stock
is exploited at the optimum level. The absolute fecundity of the fish
ranging from 23.8 em to 29.5 cm in standard length varied from 3800
to 10800 eggs. These figures are higher than those recorded for O. striatus
in other regions of Sri Lanka. The relative fecundity ranged from 19 to 38
eggs/g of body weight. The minimum size at maturity for the females and
males were 19.5 em and 24.5 em respectively. The sex ratio was found to
be 1 female : 3.6 males.
1994-01-01T00:00:00ZSimilarities among Eleven Species of Cyprinids (Teleostei) as Indicated by Their Counts of Gillrakers, Meristics and MorphometryKotalawala, A.B.http://dr.lib.sjp.ac.lk/handle/123456789/8342022-02-24T05:35:13Z1994-01-01T00:00:00ZSimilarities among Eleven Species of Cyprinids (Teleostei) as Indicated by Their Counts of Gillrakers, Meristics and Morphometry
Kotalawala, A.B.
The numbers of gill rakers, 12 meristic characters and 20 morphometric
ratios were studied in 11 species of Sri Lankan cyprinids by using digested
stained specimens and preserved specimens. The statistical analysis of
characters show. d that the counts of gill rakers, vertebrae, lateral line scales,
pectoral fin rays and most of the morphometric ratios made significant
differences among the species studied. In the analysis of results of ANOV A
tests using matrices showed that the 11 species of cyprinids fall in to 4 clusters :
Danio malabaricus (Jerdon) and Chela laubuca (Hamilton - Buchanan) in
cluster one, Rasbora vaterifloris (Deraniyagala) and Horadandiya athukorali
(Deraniyagala) in cluster two, Rasbora daniconius (Hamilton-Buchanan),
Amblypharyngodon melettinus (Valenciennes), Rasbora caveri (Hora), and
Esomus danrica thermoicos (Valenciennes) in cluster three, <Tor khu dree longispinis
(Gunther), Labeo dussu mieri (Valenciennes) and Garra ceylonensis
(Bleeker) in cluster four. This separation indicate that, Dania malobaricus
of the subfamily Rasborinae is more re'ated to Chela laubuca of Abraminae
than to the other species of Rasborinae. The two smallest rasboranines,
Rasbora vaterifloris and Horadandiya athu korali were 80% similar to each
other and tend to separate from other species of Rasborinae.
1994-01-01T00:00:00Z