Experimental evidence for shaping and bloom inducing effects of decapod larvae of Xantho poressa (Olivi, 1792) on marine phytoplankton

Abstract

To study zooplankton–phytoplankton relationships in the diatom-dominated plankton communities of the northern Adriatic we performed feeding experiments with diatoms and zoea I larvae of the brachyuran Xantho poressa. We found that zoea I of X. poressa feed on diatoms of different forms (centric, pennate, colony forming, single celled, with or without setae) and size classes. In a laboratory setup, we presented the zoeas with a mix of diatom species similar to communities observed during blooms regularly found in the northern Adriatic. We report that the grazing activity resulted in a decrease of the relative abundance of the toxic diatom Pseudo-nitzschia calliantha. For the colonial, bloom-forming diatom Skeletonema marinoi our results show a chain length reduction in the presence of zoea I. Of particular interest is the observation that the presence of larvae also resulted in an increased growth rate and abundance of S. marinoi, which resembles bloom induction by grazer presence.

Zooplankton-phytoplankton biomass and diversity relationships in the Great Lakes

“…We acknowledge that previously published assumptions around edibility are overly simplistic, and that edibility of a given phytoplankton taxon is likely grazer-specific. For instance, some larger zooplankton taxa may be equipped to disaggregate large, filamentous diatoms into edible sizes, as noted in a limited set of species-specific studies from marine systems (e.g., [46]). Such nuances should be considered in the future, but we treat our analyses as a first attempt to evaluate this phenomenon in the Great Lakes.…”

Methods to study organogenesis in decapod crustacean larvae II: analysing cells and tissues

“…Note that more details of the setae on the exopods of the maxillipeds are visible. c Two-channel image of Zoea 1 of Xantho poressa combining brightfield image with chlorophyll autofluorescence in the intestine after feeding with diatoms (red) (modified from [33]). d Fully motorised upright fluorescent microscope Nikon Eclipse 90i (image S. Harzsch).…”

“…For about 15 to 20 years, it is known that early zoea stages, which for a long time were thought to be exclusively carnivorous, also feed on phytoplankton such as diatoms. Tanković et al [33] have detected and visualised chlorophyll in the intestine of Zoeae with the fluorescence microscope and even quantified the number of diatoms. This is possible because early Zoeae are transparent.…”

Introduction to the Proceedings of the 52nd European Marine Biology Symposium

“…M. Pfannkuchen explained in his keynote lecture the high variability in phytoplankton species and their life strategies to compete for nutrient release. In this issue, Smodlaka Tanković et al (2018) provides new evidence about zoea grazing on diatoms, including induced consequences on growth and abundance of Skeletonema marionoi, and also a decrease in the abundance of the toxic Pseudo-nitzschia calliantha.…”

“…In this issue, Smodlaka Tanković et al . (2018) provides new evidence about zoea grazing on diatoms, including induced consequences on growth and abundance of Skeletonema marionoi , and also a decrease in the abundance of the toxic Pseudo-nitzschia calliantha .…”