Spawning detection device for the black tiger shrimp Penaeus monodon broodstock

Abstract

This research is aimed at developing an automatic spawning detection system for the black tiger shrimp, Penaeus monodon. This system is composed of instruments which are attached to the inner wall of the spawning tank that contains light sensing circuits which change light intensity into electrical signals. The detection unit is composed of a polyvinyl chloride (PVC) pipe containing a light emitting diode (LED) bulb that serves as a light source transmitter, and a light-dependent resistor (LDR) that serves as a light receiver which transforms light intensity into electrical resistance. Placed between the LED bulb and the LDR is a 135μm nylon mesh screen that is stretched horizontally inside the pipe to filter out shrimp eggs. Changing signals from the LDR turns on (or off) a 220. V bulb. This device detects spawning activity as early as 22. s after the onset of spawning. There is a correlation that exists between the number of spawned eggs and the time of the onset of spawning, with earliest detection occurring with the highest number of eggs. © 2012 Elsevier B.V.