Protocol for the controlled reproduction of the edible frog Aubria subsigillata in aquaculture hatcheries in the Republic of Benin

Abstract

Context Aubria subsigillata is such a highly valued, edible species for the citizens of Benin that over exploitation has led to a rarefaction of wild populations. Aims The aim of captive breeding is to develop breeding protocols and farming practices for the species which will reduce hunting pressure on wild populations. Methods The methodology consisted of determining the concentration of ovulatory hormone and its method of injection into the breeding stock, followed by in vitro fertilisation of the unfertilised eggs of the females by the spermic urine of the males to determine the optimum injection method, hormone concentration for ovulation and sperm collections, and the development of in vitro fertilisation protocols using gametes obtained via the aforementioned methodologies. Key results Results indicated that 0.2IU/g concentration of gonadotropin-releasing hormone agonist administered intrafemorally enabled spontaneous release of spermic urine and ova in the breeding animals. The latency time between injection and collection of gametes was 13h in males and 27h in females at a temperature of 28.5°C. Females laid an average of 172 eggs weighing 1mg mass. Conclusions Aubria subsigillata is a frog that reproduces using stimuli (hormone), and in vitro fertilisation resulted in a high rate of fertilised eggs. Implications Artifical reproduction in A. subsigillata is carried out in five phases: (1) selection of mature broodstock; (2) hormonal injection; (3) gamete collection; (4) in vitro fertilisation; and (5) incubation. However, work should continue on improving the egg hatching rate.