Relationship between osmoregulation and growth patterns of Scylla serrata gonad maturity levels in tapak mangrove waters, Semarang, Indonesia

Abstract

Mud crab (Scylla serrata) is a species that makes up biodiversity in mangrove areas spread across the coast of the archipelago, one of which is in Tugu District, Semarang City which has a mangrove area that is still relatively good. There is a need for research to determine the viability of Scylla serrata based on environmental conditions, especially salinity which affects the osmoregulation and growth of mud crabs individually to populations. This research aims to determine osmoregulation patterns, growth patterns, and their effect on the gonadal maturity level of mud crabs. The research was carried out on April 17th 2021 at the Tapak Mangrove Area, Tugurejo Village, Semarang, Indonesia. The research object was Scylla serrata to determine hemolymph osmolarity, carapace width, weight, gonadal maturity level, and media water quality. The research method uses a descriptive exploratory method with correlation analysis. Correlation (r) analysis was carried out to determine the relationship between the two variables, namely between the value of the level of osmotic work and gonadal maturity. The osmoregulation pattern is hypoosmotic and hyperosmotic with hemolymph osmolarity at station 1 ranging from 840-899 mOsm/I H2O and station 2 ranging from 857-929 mOsm/I H2O. The Osmotic Work Rate (TKO) value at station 1 is 1-40 mOsm/I H2O and at station 2 is 2-52 mOsm/I H2O. The growth pattern is negative allometric with the condition factor at stations 1 and 2 being more than 1 (K > 1) and a K value exceeding 3 which means it is not flat. TKG (Gonadal Maturity Level) has a negative linear correlation with TKO.