背角无齿蚌幼蚌心率对镉暴露胁迫的响应及预警评估

Response of heart rates to cadmium-exposed stress and early warning capacity in Anodonta woodiana juveniles

关键词:  “标准化”背角无齿蚌  早期幼蚌  镉  心率  毒性响应  污染预警

Key words:  “Standardized” Anodonta woodiana  Early juveniles  Cadmium  Heart rate  Toxic response  Contamination warning

摘要:

为探究“淡水贝类观察”研究体系专用指示生物“标准化”背角无齿蚌(Anodonta woodiana)幼蚌的心率对镉(Cd)暴露胁迫的响应及预警评估，在“非致死/非损伤”条件下，研究从心跳清晰可见至贝壳不再透明的典型生长阶段的早期幼蚌：EJ1 [25日龄，壳长为(1.5±0.1) mm]、EJ2 [55日龄，壳长为(10.5±0.6) mm]、EJ3 [70日龄，壳长为(20.4±0.9) mm]和EJ4 [85日龄，壳长为(30.0±2.0) mm]的心率规律，进而探索EJ4心率对不同浓度Cd2+ (0.0025、0.005、0.025、0.1和0.5 mg/L)的毒性响应特征。结果显示，早期幼蚌心率总体无显著日变化(P>0.05)；心率与日龄和壳长之间均呈显著的线性负相关(P<0.05)；心率和暴露时间仅在0.0025和0.5 mg/L的Cd2+暴露组之间呈显著线性负相关(P<0.05)；所有暴露组的心率和暴露浓度之间均呈显著线性负相关(P<0.05)。本研究表明，利用“标准化”背角无齿蚌幼蚌的心率对Cd2+浓度的响应特征，有潜力开发出基于心率为指示的新型水质Cd2+污染预警监测系统。

Abstract:

This study investigates the response of heart rates to cadmium-related stress and its early warning capacity among juveniles of “standardized” Anodonta woodiana, a unique bioindicator used in the “Freshwater Mussel Watch” project. Heart rates of early juvenile mussels at several typical growth stages, from heartbeat-clearly-observed to shells-no-longer-transparent, i.e., EJ1 [25 days old; shell length (1.5±0.1) mm], EJ2 [55 days old; shell length (10.5±0.6) mm], EJ3 [70 days old; shell length (20.4± 0.9) mm], and EJ4 [85 days old; shell length (30.0±2.0) mm], were studied under non-lethal/non-injury conditions. The response of heart rates to different concentrations of Cd2+ (0.0025, 0.005, 0.025, 0.1, and 0.5 mg/L) in EJ4 were examined. The results show that heart rates of early juveniles generally differed little between ante meridiem and post meridiem (P>0.05) states. Heart rates were linearly and negatively correlated with age and shell length (P<0.05). Heart rates were linearly and negatively correlated with exposure time in the exposure groups of 0.0025 and 0.5 mg/L Cd2+ (P<0.05). However, heart rates were linearly and negatively correlated with Cd2+ concentrations in all exposure groups (P<0.05). These results indicate that a new early warning/monitoring system for Cd2+ contamination may be developed using responses characteristic of “standardized” A. woodiana to Cd2+ concentrations.