International Journal of Aquaculture, 2017, Vol.7, No.14, 94-100
94
Research Report
Open Access
Effect of Sperm Sac (Testis) in Cryopreservation Protocol of Milt (Spermatozoa)
of
Clarias gariepinus
Ubah S.A.
1
, Okere N.C.
2
, Nwankwo P.A.
1
, Orokpo I.A.
3
1 Department of Theriogenology, Faculty of Veterinary Medicine, University of Abuja, Nigeria
2 Fish and wild life unit, Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, Nigeria
3 Department of Physiology and Biochemistry, Faculty of Veterinary Medicine, University of Abuja, Nigeria
Corresponding author Email:
International Journal of Aquaculture, 2017, Vol. 7, No.14 doi:
Received: 29 Jun., 2017
Accepted: 31 Jul., 2017
Published: 18 Aug., 2017
Copyright © 2017
Ubah et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article
:
Ubah S.A., Okere N.C., Nwankwo P.A., and Orokpo I.A., 2017, Effect of sperm sac (testis) in cryopreservation protocol of milt (spermatozoa) of
Clarias
Gariepinus
, International Journal of Aquaculture, 7(14): 94-100 (doi:
Abstract
This study was carried out to assess the adequacy of cryopreservation protocol of milt (spermatozoa) of
Clarias garipenus
,
using the sperm sac (testis) intact with the objectives of evaluating the milt for percentage live, motility and mass activity for a period
of seven days at -20°C. Semen samples (milt) were collected from mature male broodstocks of
Clarias gariepinus
of 14 months old
and weighing 1.5 kg. There were two groups comprising test and control groups. Test group comprising of the sperm sac was dipped
in Na-Citrate and placed in a properly labelled container and preserved at -20°C while control group comprised of milt extended in
Na-Citrate dispensed into seven insulin syringes, properly labelled and stored at 4°C. These were observed for a period of seven days
and percentage motility, percentage live as well as mass activity of spermatozoa of these samples were recorded. Student’s t test was
used in analyzing the data. Results showed statistically significant difference (p<0.05) in motility, percentage live and mass activity
between test and control groups, with test group showing mean percentage motility, percentage live and mass activity of 24.29±76%,
24.29±76% and 1.14±1.8 respectively while the control showed values of 48.57±65%, 48.57± 65% and 2.0±1.0 respectively. It was
concluded that use of the sperm sac at -20°C can only be adopted within three days of collection from the fish. It was recommended
that farmers adopt the protocol only for a short term period to eliminate the frustration of artificial spawning failure due lack of good
semen to complete the synchronous reproductive process.
Keywords
Sperm sac; Milt; Cryopreservation; Catfish; Artifical spawning
1 Background
The African catfish,
Clarias gariepinus
(Burchell, 1822) is considered one of best suitable alternatives to tilapia
for subsistence for fish farming. African Catfish is a good source of animal protein and has a very tasty delicacy.
It is cultured for its high growth rate, disease resistance and its’ tolerant of a wide range of temperature, as well as
oxygen and high salinity level (Haylor, 1993). This has attracted a lot of stakeholders whose major problem is to
satisfy the increasing demand for the fish; one of the challenges of African catfish farming is making fingerlings
available all year round. There is need to research on various methods of milt preservation so as to ensure the
possibility of developing effective and easier methods of milt preservation. Proper preservation of milt will ensure
an all year round availability of gametes to farmers and easy access to genetically improved milt for African
catfish reproduction.
This research work is concentrating solely on a method of preservation and it is believed with no doubt that it will
give adequate information on the role of the sperm sac on preserved milt of the African catfish.
This research will give more insight on the adequacy of cryopreservation protocol of milt (spermatozoa) of
Clarias gariepinus
using the sperm sac (testes) intact with the objectives of evaluating the milt for percentage live,
motility and mass activity for a period of seven days at -20°C.
To obtain spermatozoa it is necessary to sacrifice male brood fish (Steyn and Van Vuren, 1987) or surgically
remove part of their testes (Bart and Dunham, 1990). Although this method is efficient it jeopardizes selection and
genetic improvement. Such reproductive dysfunctions are mainly due to the fact that fish in captivity do not
