HORSESHOE CRAB AND ITS SPAWNING GROUND CONDITION IN JOHOR LAMA, JOHOR

This study was conducted at horseshoe crab’s natural spawning ground in Johor Lama, Kota Tinggi, Johor, Malaysia (1°35'00"N 104°00'49"E). Six nests were excavated on 4 August 2020, four hours after the highest tide. Conditions of site observed and recorded. Grain size analysis conducted. Eggs hatching rate, larvae moulting infection abnormality rate There are two types reclamation Lama: (i) concrete wall (ii) stack boulders. Mangrove muddy areas Lama still preserved good condition. Sand crab beach coarser poorly sorted ( : 0.09± 0.01 cm; 1.89 ± 0.03) as compared to one Balok, Pahang (mid-tide mark, 2012: 2.38 0.04 0.86 0.04). The quantity eggs inside each nest also accordance with other previous studies (first n: 256, second 229, third 132, fourth 123, fifth 149, sixth 134). However, rates sample this population be lower than others previously studied (31.8% – 66.1%). Two abnormalities reported study: genetic impairment that changed basic Xiphosura’s body plan external factor caused by impact substrate or predatory action would distort shape juvenile exoskeleton. Based observation, ecosystem is preservation, since it far from urbanisation has less deforestation. future doubt, many ports industrials zones located opposite side river Bahru district could lead worst water pollution.