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<p>A mass mortality event involving cultured blood cockles (<italic>Tegillarca granosa)</italic> occurred in the Welu estuary in Chanthaburi Province, Thailand, during July and early August of 2013. We collected surviving blood cockles (n = 30) shortly after the mortality event in mid-August and evaluated the physiological conditions of the specimens by performing histological observations of various organs. We found that most specimens of both sexes were at the peak of spawning. Histological observations revealed an absence of food in their digestive ducts and flattened epithelial cells in their midgut glands. The specimens had been experiencing low food availability and nutrient uptake. In addition, rainfall data for Chanthaburi Province revealed that the rainfall in July 2013 was more than twice the average amount received in previous years, and surface salinity data from around the aquaculture site revealed that salinity was &lt; 10 Practical Salinity Unit for longer than a month. Therefore, we concluded that prolonged low-salinity conditions were a major cause of this mass mortality event.</p>
</abstract>

A mass mortality event involving cultured blood cockles (Tegillarca granosa) occurred in the Welu estuary in Chanthaburi Province, Thailand, during July and early August of 2013. We collected surviving blood cockles (n = 30) shortly after the mortality event in mid-August and evaluated the physiological conditions of the specimens by performing histological observations of various organs. We found that most specimens of both sexes were at the peak of spawning. Histological observations revealed an absence of food in their digestive ducts and flattened epithelial cells in their midgut glands. The specimens had been experiencing low food availability and nutrient uptake. In addition, rainfall data for Chanthaburi Province revealed that the rainfall in July 2013 was more than twice the average amount received in previous years, and surface salinity data from around the aquaculture site revealed that salinity was < 10 Practical Salinity Unit for longer than a month. Therefore, we concluded that prolonged low-salinity conditions were a major cause of this mass mortality event.

Histological observations of the blood cockle, <italic>Tegillarca granosa</italic> (L.), after a mass mortality event in Welu estuary, Thailand

Japan International Research Center for Agricultural Sciences

Fisheries & Aquatic Life

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Histological observations of the blood cockle,  (L.), after a mass mortality event in Welu estuary, Thailand

A mass mortality event involving cultured blood cockles (Tegillarca granosa) occurred in the Welu estuary in Chanthaburi Province, Thailand, during July and...

Histological observations of the blood cockle, Tegillarca granosa (L.), after a mass mortality event in Welu estuary, Thailand

Published Online: Feb 02, 2022

Page range: 230 - 238

Received: Nov 06, 2020

Accepted: Dec 12, 2021

DOI: https://doi.org/10.2478/aopf-2021-0025

Keywords
mass mortality, histological observation, mangrove estuary, Thailand

© 2021 Tatsuya Yurimoto et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Histological observations of the blood cockle, Tegillarca granosa (L.), after a mass mortality event in Welu estuary, Thailand

Published Online: Feb 02, 2022

Page range: 230 - 238

Received: Nov 06, 2020

Accepted: Dec 12, 2021

DOI: https://doi.org/10.2478/aopf-2021-0025

Keywordsmass mortality, histological observation, mangrove estuary, Thailand

© 2021 Tatsuya Yurimoto et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
mass mortality, histological observation, mangrove estuary, Thailand