The effect of monsoon on physiological stress indicators of Chabahar bay (Oman Sea) Bivalvia Azumapecten ruschenbergerii (Tryon, 1869) under laboratory condition

Environmental quality assessments recommend use of sessile invertebrates. Because, they are unable to escape from environmental deterioration. In addition, the ability of adaptive responses to such environmental change, would determine its survival and reproduction potential. The organism adaptability may therefore be defined by its capacity to adjust the physiology to operate with optimal efficiency in a variable environment. Indicators that are discussed in this field for Azumapecten ruschenbergerii, at the Chabahar Bay and in the time before and after the monsoon, include: the ratio of consumed oxygen to excreted nitrogen and body condition index. The first is widely used to study the metabolism of animals. The second is the occupied space of internal volume of the shell by the body. Accordingly, stress indices were determined and statistically evaluated. The average of both indices was associated with significant changes (increase for the first and decrease for the second one) in relation to pre- and post-monsoon period (P<0.05). Evaluating both indicators suggests less environmental stress in the post-monsoon period to this bivalve living in sampling sites