Microplastic ingestion by the farmed sea cucumber is undocumented. Microplastics were isolated from the sea cucumber Apostichopus japonicus that was collected from eight farms along the Bohai Sea and the Yellow Sea in China. To examine microplastic ingestion, the intestines were isolated, digested and then subjected to the floatation test. The microplastic abundance in the sediment ranged from 20 to 1040 particles kg À1 of dry sediment, while the ingested microplastics ranged from 0 to 30 particles intestine À1. After filtering the coelomic fluid, the extracted microplastics from the coelomic fluid ranged from 0 to 19 particles animal À1. Thus, we speculated that microplastics may transfer to the coelomic fluid of sea cucumber. The ingested microplastics did not correlate with the animal body weight but was site dependent, suggesting that sea cucumber may serve as sentinel for microplastic pollution monitoring in the sediment. The microplastics were identified by Fourier transform infrared micro spectroscopy, and the polymer types were mainly cellophane, polyester, and polyethylene terephthalate. This study revealed that, microplastics widely existed in sea cucumber farms, and that sea cucumbers ingest microplastics as suitable with their mouth open. Moreover, the microplastics might transfer to the coelomic fluid of the sea cucumber. Further investigations are needed to assess the chronic effect of the microplastics on the growth and physiological status of the sea cucumber.

The relationships between pH, dissolved oxygen (DO) and chlorophyll a in aquaculture and non-aquaculture waters are assessed in this paper. The research includes the evaluation of field and experimental studies at the Panjiakou Reservoir (between Aug and Oct 2009) and the review of international data covering two decades. The results indicated that typical eutrophic non-aquaculture water had mean concentrations of chlorophyll a of higher than 10 μg L −1 , and significant positive correlations were found between pH, DO and chlorophyll a. When the mean concentration of chlorophyll a was less than 10 μg L −1 , no correlation was found between DO and chlorophyll a for waters with a high exchange rate or heavily organically polluted natural waters. Diurnal variations were found for both pH and DO. A corresponding significant positive correlation was found between both water quality parameters. In general, when the mean concentration of chlorophyll a was less than 10 μg L −1 within aquaculture waters of low exchange rate, only a weak or no correlation at all was found between pH, DO and chlorophyll a during summer and autumn. On the other hand, a significant positive correlation between pH and chlorophyll a and a significant positive correlation or no correlation between DO and chlorophyll a were found for aquaculture waters with a high exchange rate during summer and autumn. Strong diurnal variations for both pH and DO were identified. A significant positive linear correlation between pH and DO was found for field enclosure experiments.

Asteroids (Echinodermata) experience mass mortality events that have the potential to cause dramatic shifts in ecosystem structure. Asteroid wasting describes a suite of body wall abnormalities that can ultimately result in animal mortality. Wasting in Northeast Pacific asteroids has gained considerable recent scientific attention due to its geographic extent, number of species affected, and effects on overall population density in some affected regions. However, asteroid wasting has been observed for over a century in other regions and species. Asteroids are subject to physical injury and adverse environmental conditions, which may result in very similar external manifestations to wasting, making identification of causative processes sometimes problematic. Here we review asteroid health abnormalities reported in years prior to the 2013-present Northeast Pacific wasting mass mortality, and report two additional geographically disparate wasting events that occurred concomitantly with the recent wasting outbreak.

Previous studies have demonstrated that the overexpression of Kif2a is involved in the progression, invasion and metastasis of squamous cell carcinoma of the oral tongue (SCCOT). Few studies have reported the correlation between Kif2a and apoptosis of tumor cells and which signaling pathways Kif2a is involved in remains unclear. The phosphatidylinositol‑3‑kinase (PI3K)/protein kinase B (Akt) pathway is frequently activated in many types of human cancer. The aim of the present study was to investigate the effects of downregulation of Kif2 expression on the P13K/Akt pathway in Tca8113 cells to determine whether silencing of Kif2 inhibits the P13K/Akt pathway, resulting in cell apoptosis. siRNA vector was constructed, western blot analysis was used to determine RNA interference and flow cytometry was used to determine promotion of Tca8113 cell apoptosis. The results revealed that silencing Kif2a induces apoptosis and decreases the mRNA and protein level of PI3K, Akt and B‑cell lymphoma 2 (Bcl‑2) in Tca8113 cells. The PI3K-specific agonist insulin‑like growth factor 1 (IGF‑1) eliminated the upregulation of apoptosis of Tca8113‑Kif2a cells by phosphorylation of Akt. The results suggest that silencing Kif2a induces tumor cell apoptosis, at least partially, through the PI3K/Akt signaling pathway.