Effects of Microplastics on Reproduction and Growth of Freshwater Live Feeds Daphnia magna
Round 1
Reviewer 1 Report
Review for the paper "Effects of microplastics on reproduction and growth of freshwater live feeds Daphnia magna" by Chih-Hsiung Huang, Tah-Wei Chu, Chiu-Hui Kuo, Ming-Chang Hong, Yu-Yun Chen, Bonien Chen submitted to "Fishes".
General comment.
Plastics have been considered as the major marine debris to ubiquitously pollute the marine and freshwater environments. Recent studies reported high concentrations of microplastics in estuarine, coastal waters and sea samples. The increasing amounts of microplastics in the aquatic environments have raised concerns regarding their incorporation into food webs. Their small size makes them available to a wide range of marine and freshwater biota. Microplastic ingestion has been widely reported in various aquatic organisms, including micro-crustaceans. Ingested microplastics might induce gut blockage and limit food intake and microplastics have the capacity to adsorb persistent organic pollutants, biocides and trace metals posing a threat to the environment and organisms, such as the effects of eating contaminated fragments, consequently, reducing the nursery function of aquatic habitats. The present study deals with the common cladoceran Daphnia magna and its response to microplastics ingestion. The authors detected that the survival rate of adult Daphnia magna and their offspring were similar in control and experimental groups. However, negative effects for the population were found under high microplastics concentrations. D. magna juveniles and neonates were found to be suppressed with higher microplastics concentration. This case report improves somewhat our knowledge regarding the role of plastics in aquatic systems and may be interesting for ecologists dealing with ecotoxicology. The main results are illustrated with relevant Figures and Table. However, my major concern is that the Discussion is very short and does not interpret the main findings in a clear manner. I also have some minor suggestions to improve the article before being accepted in "Fishes".
Major concern.
Discussion must be improved by comparing the main results with other studies dealing with microplastic influence of aquatic animals. The authors must also propose biological mechanisms explaining responses of D. magna to the MP treatment obtained in their experiments.
Specific remarks.
L18. Consider replacing "MPs" with "microplastics".
L31. Consider replacing "MPs" with "Microplastics".
L35. Consider replacing "Microplastics" with "microplastics".
L36. Consider replacing "Nanoplastics" with "nanoplastics".
L37. Consider replacing "Primary Microplastics" with "primary MPs".
L38. Consider replacing "Secondary Microplastics" with "secondary MPs".
L41. Consider replacing "Microplastics" with "MPs".
L49. Provide reference after 'SAPEA (2019)'.
L58. Provide relevant references regarding MP effects on marine animals.
L62. Consider replacing "Planktons" with "Plankton organisms'.
L73. Jemec et al. [30] is out of the reference list.
L79-82. The authors must emphasize the aims of the study more clear and provide an explanation why this study is important, i.e. highlight the novelty of their investigation.
L85-87. The sentence should be moved in the Introduction.
Section 2.1. Provide a description of the procedure used to collect the animals.
Also, experimental animals are often acclimated before the experiment. However, I have not found text regarding acclimation of D. magna. Explain this concern.
L111. Procedures to evaluate number of ingested MPs and survival rate of D. magna must be described more carefully.
L118. Consider replacing "microscopic" with "microscope".
L121. Please, clarify if the data were tested for normality. One-way ANOVA may be applied when data demonstrate normal distribution. In other cases, the Kruskal-Wallis test should be used to compare different groups.
L130. Insert "particles" after ‘23.82±0.38’.
L136. ‘behavior of egg clutches’. Unclear term. May be occurrence of egg clutches?
L141-142. Consider replacing "In 4th day to 7th day, the average 1.00±1.00, 3.67±0.58, 4.67±4.62 and 0.67±0.58 141 of ovigerous D. magna were observed" with "In 4th day to 7th day, the average number of ovigerous D. magna (1.00±1.00, 3.67±0.58, 4.67±4.62 and 0.67±0.58) were observed".
L143. Consider replacing " the 0.1 mg/l treatment of MPs was showed the average 0.33±0.58, 2.67±0.58 and 2.00±1.00 D. magna with clutching of eggs" with "The 0.1 mg/l 0.1 mg/l treatment of MPs was the average 0.33±0.58, 2.67±0.58 and 2.00±1.00 of D. magna bearing eggs".
L146. Consider replacing "tended to a significant decrease" with "tended to be decreased significantly".
L147. Consider replacing "were showing that the eggs of " with "showed that the number of eggs in".
L148. Consider replacing "than 0.02," with "than in 0.02,".
L156. Consider replacing "The detail was presented " with "There were".
L160. Consider replacing "were no" with "were not".
L161-162. Consider replacing "were 49.17±12.90 and 33.36±5.82, which was significantly different than other groups" with "accounted for 49.17±12.90 and 33.36±5.82 that was significantly different from other groups".
L162-164. Consider replacing "As similar, the treatment with 0.1 mg/l MPs was showed 45.68±11.00 of D. magna individuals in neonate stage which was sharing a significant difference than other treatments" with "Similarly, the treatment with 0.1 mg/l MPs showed 45.68±11.00 individuals of D. magna in neonate stage that was significant different compares with other treatments".
L167. Consider replacing "were showed" with "showed".
L171. Consider replacing "were significantly raised" with "significantly raised".
L172. Consider replacing "were appeared" with "appeared".
L176. Consider replacing "were presented" with "presented".
L180. Consider replacing "were decreased" with "decreased".
L181, 187-188. Consider replacing " were showing" with "showed".
L179, 183 and Fig. 4. "D. magna" should be italicized.
Footnote Table 1. Consider replacing "The D. magna" with "D. magna".
L188-190. Consider replacing "It may suggested that the removal of MPs after 7-days MPs treatment was still resulting in the increasing of D. magna. juveniles and neonates that indicated their growth was reduced or inhibited." with "It may be suggested that the removal of MPs after 7-days MPs treatment resulted in the increasing number of D. magna juveniles and neonates that indicated their growth was reduced or inhibited." And move this sentence in the Result section.
L192. Consider replacing "Plankton is" with "Plankton are".
L192-196. Provide relevant references.
L202. Consider replacing "was showing in" with "was shown for ".
L207-208. Consider replacing "the results were showed the number of newborn offspring were continued increased followed raising of MPs in water." with "our results showed the number of newborn offspring continued to increase followed raising of MPs in water."
L208. Consider replacing "shared" with "obtained".
L210-211. Consider replacing "Same result correlated with body length of D. magna were found in current study." with "The same result regarding correlation of D. magna body length with MP content was found in current study."
L227. Consider replacing "with D. magna" with "of D. magna".
Conclusion must summarize main findings but the present form of Conclusion just stated that the study was conducted.
I have reviewed literature regarding MP effects on D. magna with Google Scholar and found a lot of studies not cited in the paper. For example:
Zimmermann L, Gottlich S, Oehlmann J, Wagner M, Volker C (2020) What are the drivers of microplastic toxicity? Comparing the toxicity of plastic chemicals and particles to Daphnia magna. Environ Pollut 267:115392.
Schrank, I., Trotter, B., Dummert, J., Scholz-Böttcher, B. M., Löder, M. G., & Laforsch, C. (2019). Effects of microplastic particles and leaching additive on the life history and morphology of Daphnia magna. Environmental Pollution, 255, 113233.
Renzi, M., Grazioli, E., & Blašković, A. (2019). Effects of different microplastic types and surfactant-microplastic mixtures under fasting and feeding conditions: a case study on Daphnia magna. Bulletin of environmental contamination and toxicology, 103(3), 367-373.
Rehse, S., Kloas, W., & Zarfl, C. (2016). Short-term exposure with high concentrations of pristine microplastic particles leads to immobilisation of Daphnia magna. Chemosphere, 153, 91-99.
Kokalj, A. J., Kunej, U., & Skalar, T. (2018). Screening study of four environmentally relevant microplastic pollutants: uptake and effects on Daphnia magna and Artemia franciscana. Chemosphere, 208, 522-529
Bosker, T., Olthof, G., Vijver, M. G., Baas, J., & Barmentlo, S. H. (2019). Significant decline of Daphnia magna population biomass due to microplastic exposure. Environmental pollution, 250, 669-675.
Schür, C., Weil, C., Baum, M., Wallraff, J., Schreier, M., Oehlmann, J., & Wagner, M. (2021). Incubation in wastewater reduces the multigenerational effects of microplastics in Daphnia magna. Environmental science & technology, 55(4), 2491-2499.
Imhof, H. K., Rusek, J., Thiel, M., Wolinska, J., & Laforsch, C. (2017). Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?. PloS one, 12(11), e0187590.
Schür, C., Zipp, S., Thalau, T., & Wagner, M. (2020). Microplastics but not natural particles induce multigenerational effects in Daphnia magna. Environmental Pollution, 260, 113904.
Martins, A., & Guilhermino, L. (2018). Transgenerational effects and recovery of microplastics exposure in model populations of the freshwater cladoceran Daphnia magna Straus. Science of the Total Environment, 631, 421-428.
Yuan, W., Zhou, Y., Chen, Y., Liu, X., & Wang, J. (2020). Toxicological effects of microplastics and heavy metals on the Daphnia magna. Science of The Total Environment, 746, 141254.
Trotter, B., Wilde, M. V., Brehm, J., Dafni, E., Aliu, A., Arnold, G. J., ... & Laforsch, C. (2021). Long-term exposure of Daphnia magna to polystyrene microplastic (PS-MP) leads to alterations of the proteome, morphology and life-history. Science of the Total Environment, 795, 148822.
Eltemsah, Y. S., & Bøhn, T. (2019). Acute and chronic effects of polystyrene microplastics on juvenile and adult Daphnia magna. Environmental Pollution, 254, 112919.
De Felice, B., Sabatini, V., Antenucci, S., Gattoni, G., Santo, N., Bacchetta, R., ... & Parolini, M. (2019). Polystyrene microplastics ingestion induced behavioral effects to the cladoceran Daphnia magna. Chemosphere, 231, 423-431.
Aljaibachi, R., Laird, W. B., Stevens, F., & Callaghan, A. (2020). Impacts of polystyrene microplastics on Daphnia magna: A laboratory and a mesocosm study. Science of The Total Environment, 705, 135800.
Therefore, I suggest the authors to consider these articles and discuss more carefully their results.
Author Response
Dear reviewer
Thank you very much. We have completed the modification according to reviewers.
Please see the attachment.
Than you very much.
Kind regards, Bonien Chen
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The aim of the MS of Huang et al. is to find out if there is a correlation between uptake of MPs and negative effects on reproduction and growth of offspring D. magna. The MS is related to an important field of interest and should be developed, but by itself appears very preliminary. The manuscript itself is extremely vague in many places and in addition to these major points there are a number of unclarities with regard to the methodology used in the paper which are outlined below. Although of potential interest, the manuscript has several problems which make it not acceptable for publication in Fishes in the present form.
Detailed comments supporting this recommendation follow.
the M&M are not properly described and in particular the section (Animals) related to the chemical characterization of MPs. In this section is lacking information on shape of MPs and Quality Assurance and Quality Control (QA/QC).
Moreover, the Authors indicated that D. magna were collected and kept in a 200-L FRP tank for 7 days, and disinfected with 20 ppm formalin and 10% florfenicol for one 90 week (200 ml/106 cells/day). Why the Authors used a disinfectant treatment and why a so high formalin and florfenicol concentration? How was performed the disinfectant treatment on this crustacean and how many samples of D. magna died following this treatment?
I would suggest to the Authors inserting a statement about the choice of MP concentrations used in this study, and also adding more details about the procedures utilized for preparation of MPs (1.5 mg/ml).
Please indicate how many crustacea samples were used for each of the five experimental groups. How many replicates are included in this study?
Overall, I would suggest to the Authors rewriting the Animal section including all experimental information as suggested above.
Other minor comments
L91 The water quality in a 200-L tank was maintained in 0 ‰ salinity, …….. Please check salinity value.
L62 please change the term “planktons” with zooplankton
L75 please rephrase
L80-82 out of place. Please move this sentence into discussion section
L79-82 I would suggest rephrasing the aims
L100 Please the
L116-118 out of place. I would suggest inserting it at M&M
L193 “Zooplankton”
L193-196 please rephrase since the sentence is referred to D. magna
Author Response
Dear reviewer
Thank you very much. We have completed the modification according to reviewers.
Please see the attachment.
Than you very much.
Kind regards,
Bonien Chen
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have improved the paper according to my suggestions.
Author Response
Dear Professor reviewer,
We appreciated the encouraging, critical and constructive comments on our manuscript by you and the reviewers. The valuable comments are useful in improving and increasing the scientific value of our manuscript.
Thank you for your re-consideration.
Kind regards,
Bonien Chen
Reviewer 2 Report
The Authors should have entered more details in the M&M, and throughout the MS, according to my previous comments/suggestions. I would suggest to the Authors revising it, before the MS can be accepted for publication in the journal Fishes.
Author Response
Dear Professor reviewer,
We appreciated the encouraging, critical and constructive comments on our manuscript by you and the reviewers. The valuable comments are useful in improving and increasing the scientific value of our manuscript.
Thank you for your re-consideration.
Kind regards,
Bonien Chen
Round 3
Reviewer 2 Report
The Authors enriched the Materials and Methods section according to my previous comments. The MS is now suitable for publication in the Journal Fishes.
