Preliminary Study On Gonad Maturity Stages of the Sea Cucumber Paracaudina australis from Kenjeran Water, Surabaya, Indonesia

Abstract
The holothurian Paracaudina australis is belong to family Caudinidae, ordo Molpadida and class Holothuroidea. This species is among the most common holothurian widely distributed in the tropical water. The purpose of this reseach is to do preliminary study on maturity stages of sea cucumber Paracaudina australis from Kenjeran Water, Surabaya, Indonesia. This research was conducted on April 2016. Samples were collected randomly on the Kenjeran Water, Surabaya. The result showed that there are five stages of gonad maturity. At the stage of maturity 1, the gonad was not clearly distinguished, there were unbranched small tubule. At the stage of maturity 2, there were small branched of tubules. At this stage, gonad can be differentiated between male and female. At the stage of maturity 3, tubule can been branched not only for male but also female. At the stage of maturity 4, the gonad was good mature, there were clearly branched tubule. At the stage of matury 5, there were generally had empty tubule except for a few relict unreleased spermatozoa. At female gonad, there were shrunken tubule and relict oocytes were presented in the lumen of the tubule.