Abstract:Perinereis aibuhitensis Grube is an important feed for fish, shrimp, and crabs in the shores of China, and there have been extensive studies in biology, culturing technology and ecophysiology of this species. Although much less is known about their habitat environment, knowledge about this is important for us to better understand the biology of polychaete. In this experiment, we investigated various features of the sediments in different depths and tidal zones in a typical natural habitat of P. aibuhitensis, including hydrogen sulfide, organic matters, carbon, nitrogen, the moisture content, and the particle size. The results showed that the hydrogen sulfide concentration in the high tidal zone was significantly lower than those in the other two tidal zones (P<0.05). The hydrogen sulfide concentration was significantly higher in the depth of 25 cm than those in others (P<0.05). There was no difference in the hydrogen sulfide concentration and the moisture content of the pore water among three different tidal zones (P>0.05). There was also no difference in different depths (P>0.05). The contents of organic matters and nitrogen in the low tidal zone were significantly lower than those in the high and mid tidal zones (P<0.05). The levels of carbon were similar among different tidal zones (P>0.05). As the depth increased, the contents of organic matters and nitrogen in the sediment went up. The proportion of silt was the highest in all three tidal zones and in different depths of the same tidal zone, while the proportion of sand was the lowest. The median particle size in the low tide was higher than those in other two tidal zones (P<0.05). The median particle size remained unchanged in different depths (P>0.05). These results suggested that the hydrogen sulfide concentration was high in the sediment of the selected habitat of P. aibuhitensis. It became higher as the depth increased. There was a significant correlation between the contents of organic matters and carbon, and so were the contents of carbon and nitrogen. The dominant ingredient of the sediment was clayey silt. Compared to the low tidal zone, the high tidal zone had higher contents of organic matters and the moisture, which was probably caused by the smaller particles in this zone.
