Abstract
As a marine ichthyotoxic dinoflagellate, Margalefidinium polykrikoides, previously named Cochlodinium polykrikoides, have caused mass mortalities of fish worldwide during blooms. Rapid detection of target species is a prerequisite for the timely monitoring and early warning of harmful algal blooms (HABs). However, it is difficult to achieve rapid identification with traditional methods. The technology of using quantitative real-time PCR (qPCR) to detect and quantify microalgae is relatively mature. Based on the accuracy, rapidity, and sensitivity of qPCR technology, it can be used in the monitoring and development of early warning systems for HABs. From 2017 to 2020, samples were collected from 15 locations off the Chinese coast or from local sea areas. Based on the qPCR detection and analysis, the target species, M. polykrikoides (East Asian ribotype, EAr), was found in samples from Tianjin, Yangtze River estuary, and offshore Fujian (East China Sea). This is the first time that M. polykrikoides (EAr) was detected in the coastal waters of Tianjin. The results reveal a distributive pattern of M. polykrikoides (EAr) along Chinese coastal waters. It is helpful to predict the future diffusion trend of M. polykrikoides (EAr) in the China Sea and provides a practical case for the future construction of monitoring and warning systems for M. polykrikoides and HABs.
Highlights
Margalefidinium polykrikoides [1], formerly known as Cochlodinium polykrikoides [2], is an ichthyotoxic unarmored dinoflagellate that has caused mass mortalities of fish worldwide during blooms, with catastrophic impacts to aquaculture and local economies [1,3,4,5,6,7]
M. polykrikoides used to take Scanning Electron Microscopy (SEM) micrographs was obtained from the East China Sea (ECS)
The study results showed that M. polykrikoides (EAr) was detected in the Bohai Sea and the East China Sea, while no M. polykrikoides (EAr) was detected in the Yellow Sea and the South China Sea
Summary
Margalefidinium polykrikoides [1], formerly known as Cochlodinium polykrikoides [2], is an ichthyotoxic unarmored dinoflagellate that has caused mass mortalities of fish worldwide during blooms, with catastrophic impacts to aquaculture and local economies [1,3,4,5,6,7]. M. polykrikoides blooms are usually characterized by large spatial scale (10 to 100 km) and high-density aggregation (>106 cells·L−1) [8]. These blooms are often accompanied by the production of strongly ichthyotoxic compounds, resulting in the death of a large number of marine organisms [9]. The ichthyotoxicity produced by M. polykrikoides can cause high mortality to marine organisms in a short period of time [9]. M. polykrikoides has been reported in tropical, subtropical, and temperate waters [10], such as the Gulf of California, United States of America [11], Korea [12], Japan [13], Middle East [5,14], Canada [7], and China [15]. Compared with other countries, such as Japan and Korea, there are few reports regarding M. polykrikoides in Chinese coastal waters, and there is still a lack of reports on the detailed distribution of M. polykrikoides in the China Sea
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call