Seminal
vesicle and testis secretions in Heteropneustes fossilis (Bloch):
composition and effects on sperm motility and fertilization
I. Chowdhury, K.P. Joy-2001
Aquaculture, 193 (3-4): 355-371
Abstract:
In spawning catfish Heteropneustes fossilis, seminal
vesicle (SV) plasma (SVP), testicular plasma (TP) and blood plasma (BP) all
showed considerable differences in physical and chemical characteristics.
SVP is more viscous (4.61±0.08 centipoise), and its specific gravity
(1.06±0.003) and osmolality (277.4±8.32 m osmol kg-1) are
significantly higher than BP and TP. SVP has a near neutral pH (6.99±0.07).
BP is slightly basic and TP is slightly acidic. SVP has significantly higher
concentrations of Na+(135.64±15.90 mmol l-1), Ca2+(19.80±0.60
mmol l-1), Mg2+(1.81±0.08 mmol l-1) and Cu2+(0.18±0.02
mmol l-1), proteins (11.50±0.80 g l-1) and
hexosamines (694.68±91.25 mg l-1) than TP, while the
concentrations of K+(15.30±1.30 mmol l-1), Zn2+(0.10±0.02
mmol l-1), glucose (76.18±24.29 mg l-1), fructose
(333.33±45.64 mg l-1), lipids (in mg l-1:
phospholipids (PL), 112.84±18.40; free cholesterol (FC), 109.99±15.45;
esterified cholesterol (EC), 170.72±10.56) and glycosidases (µmol mg
protein-1 h-1: β-glucuronidase, 7.20±0.56;
β-N-acetylglucosaminidase, 83.00±12.29) are similar to TP.
Dilution of SV fluid at ≥400 times with
distilled water activated motility of spermatozoa and the motility rate
increased with the dilution factor. The duration of motility increased with
motility rate up to 600--700 times dilution, but then on, declined sharply.
A similar motility behavior was found for TM with the addition of SVP. The
fertilization efficiency was evaluated in the presence of SVP or SV fluid
(SVF). The addition of freshly collected SVF and SVP increased the
fertilization ability of TM from 72.0% to 95.6% and 87.8%, respectively.
Pure SVF and SVP resulted in only 29.6% and 0.0% fertilization,
respectively. Heat denaturing abolished the stimulatory effect of SVF or
SVP. Storage of spermatozoa in SVF at 4°C after dilution with ringer
solution (1:4) displayed varied effects on fertilization of eggs; in SVF
groups fertilization decreased minimally (21.7% on day 12), but in TM group,
it decreased more significantly with the time of storage.
(Department of Zoology, Banaras Hindu University,
Varanasi 221005, India)
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