COMPARATIVE STUDY ON THE EFFECTS OF NATURAL (ALOE VERA) AND SYNTHETIC (MTH) INDUCEMENT HORMONES ON SURVIVAL AND MASCULINIZATION OF NILE TILAPIA (O. Niloticus)

Abstract

The comparative effect of natural and synthetic hormones on sex reversal and
survival of O.niloticus was investigated. Male (N= 5) and female (N=10)
broodstocks of average weight 550g and 390g were procured from Bagauda fish
farm Kano and transported to the experimental site. Broodstock were
acclimatized according to ‘sex’ while spawning facility (hapas) were placed in
each container to facilitate breeding activity and fed commercial feed at 3%
body weight for 60 days. After acclimatization, the brooders spawned at a
temperature range of 22-29◦C, newly hatched fry were collected after 7 days and
randomly divided to their treatment containers at sixty (60) fry per treatment.
Two experimental feeds containing 17-αMethyl Testosterone Hormone (MTH)
and Aloe vera gel (ALV) were prepared. 3g of 17- α Methyl Testosterone
Hormone powder was dissolved in 2 litres of 95% ethyl alcohol and mixed
thoroughly. 25mls, 50mls and 75mls from the solution was mixed with 250g
commercial fry feed, dried and kept inside air tight containers and labelled. Aloe
vera leaves were procured, washed thoroughly and the gel was scrapped and
blended for a homogenous liquid. Measuring cylinder was used to measure
2.5mls, 3.75mls and 5mls of the Aloe vera gel, then mixed with 250g of
commercial diets and allowed todry under room temperature and latter grounded
and stored in an air tight container. 60 fry was stocked in triplicates for both
treatments in rectangular plastic boxes (20L each) and fed with respective
experimental diets and normal commercial diet for the control. Feeding was
administered at 5% body weight three times daily for 60 days and water changed
weekly. Results obtained revealed that ALV2.5mls had the highest percentage
survival (95%) followed by MTH75mls (93.3%) while MTH75mls recorded the
highest percentage of fish masculinized (96.42%) followed by ALV2.5mls
(96.22%) (P < 0.05). Aloe vera gel at 2.5mls/250g of feed inclusion level is ideal
for survival and masculinization of O.niloticus.