Effect of Salinity on the Growth Performance, Body Composition, Antioxidant Indexes of Perinereis aibuhitensis and Total Nitrogen in the Substrate

Abstract

In this study, the effects of different salinity levels (9,12,15,18,21,24,27,30, and 33) on the growth performance, body composition, antioxidant indexes of Perinereis aibuhitensis (initial average mass, 20.4 ± 0.3 mg) and total nitrogen in the substrate were investigated. The survival rate, specific growth rate, feed coefficient, and protein efficiency ratio under different salinity levels were measured. The results showed that the survival rate of P. aibuhitensis at the salinity level of 9 was significantly lower than that of P. aibuhitensis at other salinity levels (P < 0.05). However, the survival rate of P. aibuhitensis at other salinity levels was not significant (P > 0.05). On the basis of quadratic polynomial fitting of the relationship between salinity levels and the specific growth rate, feed coefficient, and protein efficiency ratio, it was concluded that 25.36 -25.9 is the most suitable salinity range for the growth performance of P. aibuhitensis. The main body composition (moisture, crude fat, crude protein, and ash content) was measured at different salinity levels. The results indicated that, with the increase in salinity, the moisture content of P. aibuhitensis decreased gradually; in contrast, the ash content increased gradually, as the salinity level increased. However, in the salinity range of 18 to 33, the difference in ash content was not significant (P > 0.05). Salinity had a significant influence on the crude protein content (P < 0.05), while it had no significant influence on crude body fat. Crude protein showed an increasing trend with the salinity increasing from 9 to 24, and decreased with the salinity increasing from 24 to 33. Antioxidant indexes such as superoxide dismutase, catalase, vo MDA content was as low as the antioxidant activity at the salinity level of 24; this means low in vivo contents of active oxygen free radicals and excellent growth performance. This conclusion is consistent with that for other growth indexes. The total nitrogen content of the substrate in which the P. aibuhitensis specimens were cultured for 60 days was higher than the total nitrogen in the soil. With an increase in salinity, the total nitrogen content first decreased and then increased, and the lowest value was observed at the salinity level of about 24.

Characterization of polychaetes inhabiting estuaries and inner bays by composition analysis of amino acids and lactate enantiomers

“…Perinereis aibuhitensis , a member of the Nereididae family, like T. osawai and H. diadroma , exhibits considerably high concentrations of d -Ala (3810 µmol/100 g-wet) 26 . Perhaps, P. aibuhitensis prefers areas with high salinity (approximately 20 PSU) 28 – 33 , as compared to T. osawai and H. diadroma (approximately between 1 and 10 PSU) 34 , 35 . Taken together with findings of Abe et al .…”