Target strength of seahorse (Hippocampus kuda) based on presence dorsal and ventral aspect of brood pouch: a experiment hydroacoustic using artificial neural network

Abstract

Hydroacoustic technology is a tool can be used to study the behavior of organisms. The target strength of an object is main key in hydroacoustic technology. The value of target strength is strongly influenced by level of hardness of object, in this case the seahorse has a different level of hardness between dorsal and ventral aspect. The unique of male seahorse that experiences pregnancy and keeps it’s baby in brood pouch until it hatches. This can be used as a difference between males and females based on value of target strength. Acoustic data recording using single beam scientific echosounder SIMRAD EK-15 and Sonar-4 processing software. The results showed that mean TS value of pregnant male seahorses (with brood pouch) was smaller than of female seahorses (without brood pouch), there were differences in structure composition and anatomy of the brood pouch which backscattering strength to decrease. The artificial neural network shows that there is a difference in response between seahorse (having a brood pouch/male) compared seahorse (without a brood pouch/female). The results showed that was a difference in dorsal aspect of 87.5% and ventral aspect of 98.6%. The results of this study can be used as key to distinguish sex of seahorses using the hydroacoustic method.