**7. References**


used. This may be due to differences in extender, cryoprotectant, equilibration, egg quality, or protocol. In the present study, the interaction between the percentage of motile post-thaw sperm and fertilizing capacity was highly positive, similar to results in common carp (Linhart et al., 2000), African catfish (Rurangwa et al., 2001) and grass carp (Bozkurt et al., 2011b).

On the other hand, a wide range of temperatures used to thawed cryopreserved sperm with temperatures from refrigeration (4ºC) to 80ºC were reported (Lahnsteiner et al., 2000). A fast thawing temperature decreases the recrystallization effect in the spermatic cells and therefore diminishes the membrane damage (Tiersch et al.1998). Higher temperature such as 30ºC were also used to thaw cyprinid semen in several studies (Stoss & Hotz, 1983) that

It can be concluded that the cryopreservation protocol developed in this study is rather effective and brown trout (*Salmo trutta macrostigma*) and ornamental koi carp (*Cyprinus carpio*) sperm can be successfully cryopreserved. It seems that cryopreservation of brown trout sperm with ionic extenders containing 15% egg yolk is rather effetive on post-thaw sperm quality. In addition, based on the results obtained from this study, it is possible to suggest that sperm cryopreserved with ionic extender containing 10% DMSO packed in 0.25 mL volume straws and thawed at 30ºC are the most suitable conditions to retain the sperm quality in koi carp having optimal sperm motility, duration of motility as well as high

This study can help establish a frozen sperm bank for the conservation of genetic material of the brown trout and koi carp. On the other hand, additional research is needed on the effects of cryoprotectants, protective agents and freezing technique in cryopreservation on malformations, survival and condition of progeny produced with cryopreserved

This research was financed by Research Fund of Musafa Kemal University (1005-M-0111). The authors would like to thank the staff of the Fish Production Station of General Directorate of National Parks in Tarsus and State Hydraulic Works (SHW) Fish Production

Akcay, E.; Bozkurt, Y.; Secer, S. & Tekin, N. (2004). Cryopreservation of mirror carp semen.

Alavi, S.M.H. & Cosson, J. (2005): Sperm motility in fishes: (I) Effects of temperature and

Alavi, S.M.H. & Cosson, J. (2006). Sperm motility in fishes: II. Effects of ions and osmolality.

Alderson, R. & Macneil, A.J. (1984). Preliminary investigation of cryopreservation of

Atlantic salmon S*almo salar* and its application to commercial farming. *Aquaculture*,

*Turkish Journal of Veterinary and Animal Sciences*, 28 (5), 837-843.

pH: a review. *Cell Biol. Intern*. 29, 101–110.

fertility percentages close to the values obtained with fresh sperm.

spermatozoa of brown trout and koi carp.

*Cell Biol. Int*., 30, 1-14.

43: 351–354.

**6. Acknowledgements** 

Station in Adana, Turkey.

**7. References** 

similar with the pesent study.

**5. Conclusion** 


**16**

**Cryopreservation of the Sperm of** 

**Aquaculture Industry in Nigeria** 

*1Biotechnology Laboratory, Department of Animal Sciences,* 

Praise Amupitan1, Tijesunimi Oresanya2, Sunday Aladele2 and Wasiu Odofin2

*Obafemi Awolowo University (OAU), Ile-Ife,* 

*Moor Plantation, Ibadan,* 

*Nigeria* 

**the African Catfish for the Thriving**

Ofelia Galman Omitogun1,\*, Olanrewaju Ilori1, Olawale Olaniyan1,

*2National Centre for Genetic Resources and Biotechnology (NACGRAB),* 

The production of fish in Nigeria is still very small and cannot sufficiently satisfy the increasing demand of its population of 140 million. To solve the populace's high demand for fish, Nigerians resort to aquaculture which is currently faced with major constraints including lack of fish seed and quality of feed. The scarcity of good broodstock has necessitated the need to conserve the fish genetic resources which are wasted during natural and artificial induced spawning process of fish breeding. One way of expanding aquaculture in Nigeria is by devising a means of preserving genetic resources of our broodstock for all year round supply of fish seed through cryopreservation (Omitogun *et al*.,

The African catfish *Clarias gariepinus* Burchell, 1822 is one of the most suitable species for aquaculture in Africa. Since the 1970's, it has been considered to hold a great promise for fish farming in Africa. Some other merits of African catfish are: high growth rate reaching market size of 1 kg in 5–6 months under intensive management conditions: highly adaptable and resistant to handling and stress; can be artificially propagated by induced spawning techniques for reliable mass supply of fingerlings; commands a very high commercial value

The Clariid freshwater fishes belong to the family Clariidae with a wide geographical distribution in Africa consisting of 14 genera (Teugels, 1986a) and 32 species (Teugels, 1986b) in Nigeria. Syndenham (1980) reported that the family consists of 5 subgenera namely: Clarias, Clarioides, Anguilloclarias, Platycephaceloides, and Brevicephaloides*. C.* 

where it is highly cherished as food in Nigerian homes and hotels (Olaleye, 2005.).

**1. Introduction** 

2006).

\*

Corresponding Author

