Toxic effect of dinoflagellate Alexandrium species on Cladocera Moina mongolica Daday

Abstract

The main objective of this study was to investigate toxic effects of the dinoflagellate Alexandrium species, on cladocera Moina mongolica in the laboratory. Ten strains of Alexandrium species, including Alexandrium tamarense (AT-6, ATHK, ATCI02, ATCI03 and AT5-1), A. catenella (ACDH), A. affine (AC-1 and AS-1), A. lusitanicum and A. minutum were tested. The results showed that A. tamarense (ATHK, ATCI02 and AT5-1) and A. affine (AC-1 and AS-1), but not A. tamarense (AT-6 and ATCI02), A. catenella (ACDH), A. lusitanicum and A. minutum had significantly negative effects on the survival of M. mongolica; when exposed to these ten strains of Alexandrium species in densities of 3 000 cells/cm 3 for 7 d, respecyively. M. mongolica could feed on A. tamarense (AT-6, ATHK, ATCI02, ATCI03 and AT5-1), A. catenella, A. lusitanicum and A. minutum, but exhibited little or no grazing on A. affine (AC-1 and AS-1), based on the changes in gut pigment after exposure to alga for 1 and 12 h. A. affine AC-1, which had the strongest toxicity on the survival of M. mongolica, was chosen to further study the negative effects on M. mongolica. The results showed that the effect of A. affine AC-1 on the survival of M. mongolica was density-dependent, and its lethal effects on one-day, two-day and three-day old M. mongolica were exacerbated with increasing age; The whole algal culture, re-suspended algal cells, cell fragments and cell contents all had adverse impacts on the survival of M. mongolica. Moreover, both juvenile numbers and life-span time of M. mongolica were decreased significantly when they were cultured in A. affine AC-1 of 10 and 50 cells/cm 3 , combined with 3×10 6 cells/cm 3 of Chlorella spp., respectively. As a non-PSP producer, A. affine may produce other toxins, responsible for the strong negative effects on M. mongolica.

Chemical Response of the Toxic Dinoflagellate Karenia mikimotoi Against Grazing by Three Species of Zooplankton

“…; Yan et al. ). Copepods are widely distributed and ecologically highly important in marine ecosystems, especially in marine food chains.…”

Physiological Effects of Oxidative Stress Caused by Saxitoxin in the Nematode Caenorhabditis elegans

“…PSTs pose major public health threats through paralytic shellfish poisoning in consumers, thus, causing symptoms including a tickling sensation or numbness around the lips, numbness of the extremities, gastrointestinal problems, and fatal respiratory paralysis [2]. Beyond humans, PSTs affects marine organisms, such as zooplankton [3][4][5][6], shellfish [7][8][9][10][11][12], finfish [13][14][15][16], crustaceans [17,18], and even marine mammals [19,20], through either direct exposure or dietary uptake. PSTs cause major negative effects on animal health, including physiological activity [6,11], reproductive de-velopment [9,12] and growth ability [21,22], and can even lead to mass mortality [14,15,23] and decreases in the biomass and yield of aquatic systems [2,9,15,19,24,25].…”

“…Beyond humans, PSTs affects marine organisms, such as zooplankton [3][4][5][6], shellfish [7][8][9][10][11][12], finfish [13][14][15][16], crustaceans [17,18], and even marine mammals [19,20], through either direct exposure or dietary uptake. PSTs cause major negative effects on animal health, including physiological activity [6,11], reproductive de-velopment [9,12] and growth ability [21,22], and can even lead to mass mortality [14,15,23] and decreases in the biomass and yield of aquatic systems [2,9,15,19,24,25].…”