TY - JOUR

T1 - Chemical and morphological defenses of Pseudo-nitzschia multiseries in response to zooplankton grazing

AU - Zhang, Shuwen

AU - Zheng, Tingting

AU - Lundholm, Nina

AU - Huang, Xiaofeng

AU - Jiang, Xiaohang

AU - Li, Aifeng

AU - Li, Yang

PY - 2021

Y1 - 2021

N2 - Pseudo-nitzschia species frequently blooms in coastal waters, and some species are able to produce the toxin domoic acid (DA), hereby causing harm to the marine ecosystem and humans. Laboratory studies were conducted to investigate the influence of different levels of grazing pressure on the morphological and chemical response (in terms of cellular DA production) of Pseudo-nitzschia. Subsequently, zooplankton grazer responses to these defenses were examined. The cellular DA content of P. multiseries ranged from 0.11-0.27 pg cell-1 without grazers, and increased up to 44% with the presence of grazers (Artemia nauplii) and with grazer concentration. Grazing also affected the density of P. multiseries chains and average chain length which became -25% higher and -8% longer, respectively, than without grazers. These effects could either be caused by size-dependent grazing or by grazer-cue-induced effects on chain formation. A negative correlation between cellular DA content in P. multiseries and clearance and/or ingestion rates of Artemia nauplii indicate that DA might have a negative effect on the grazing of Artemia nauplii. Such interaction might result in a decrease in grazing pressure on toxic blooming species, like P. multiseries, and hence potentially a prolonged bloom. This indicates that the interaction between toxic diatoms and grazers may have implications on aquatic food web structure and the progression of Pseudo-nitzschia blooms.

AB - Pseudo-nitzschia species frequently blooms in coastal waters, and some species are able to produce the toxin domoic acid (DA), hereby causing harm to the marine ecosystem and humans. Laboratory studies were conducted to investigate the influence of different levels of grazing pressure on the morphological and chemical response (in terms of cellular DA production) of Pseudo-nitzschia. Subsequently, zooplankton grazer responses to these defenses were examined. The cellular DA content of P. multiseries ranged from 0.11-0.27 pg cell-1 without grazers, and increased up to 44% with the presence of grazers (Artemia nauplii) and with grazer concentration. Grazing also affected the density of P. multiseries chains and average chain length which became -25% higher and -8% longer, respectively, than without grazers. These effects could either be caused by size-dependent grazing or by grazer-cue-induced effects on chain formation. A negative correlation between cellular DA content in P. multiseries and clearance and/or ingestion rates of Artemia nauplii indicate that DA might have a negative effect on the grazing of Artemia nauplii. Such interaction might result in a decrease in grazing pressure on toxic blooming species, like P. multiseries, and hence potentially a prolonged bloom. This indicates that the interaction between toxic diatoms and grazers may have implications on aquatic food web structure and the progression of Pseudo-nitzschia blooms.

KW - Pseudo-nitzschia

KW - Artemia nauplii

KW - Morphological defense

KW - Domoic acid

KW - Ingestion rate

KW - Survival rate

KW - DOMOIC ACID PRODUCTION

KW - TEMORA-LONGICORNIS

KW - TOXIN PRODUCTION

KW - FOOD-WEB

KW - MARINE

KW - BACILLARIOPHYCEAE

KW - PHYTOPLANKTON

KW - PHOSPHATE

KW - KRILL

KW - INDUCTION

U2 - 10.1016/j.hal.2021.102033

DO - 10.1016/j.hal.2021.102033

M3 - Journal article

C2 - 34023076

VL - 104

JO - Harmful Algae

JF - Harmful Algae

SN - 1568-9883

M1 - 102033

ER -