Freshwater Shrimp Research Articles

Oxidative stress in the freshwater shrimp Caridina africana following exposure to atrazine.

The toxicity of pesticides to non-target organisms continues to be important in understanding the dynamic interactions between anthropogenic chemicals and ecosystem health. This study assesses biochemical markers to determine the effects that varying concentrations of atrazine (13.1-5557µg/l) have on the freshwater shrimp, Caridina africana. Exposure and oxidative stress biomarkers were analysed and followed by univariate, integrated biomarker response v2 (IBRv2) and Kendall Tau correlation statistical analyses, to gain insight into the concentration-dependent responses. Oxidative stress biomarkers such as reduced glutathione content (GSH), glutathione-S-transferase activity (GST), superoxide dismutase activity (SOD) and catalase activity (CAT) were significantly correlated with increasing atrazine exposure concentration (p < 0.01). Bimodality has been seen when looking at both the univariate statistically significant differences as well as the IBRv2, with the first peak at 106.8µg/l and the second peak at 5557µg/l atrazine. The results indicate that while individual responses may indicate statistically significant differences, using correlation and integrated statistical analysis can shed light on trends in the adaptive response of these.

Assessment of the accumulation of some trace metals in whole body of fresh water shrimp Atyaephyra desmaresti mesopotamica from Shatt Al-Arab River, Basrah, Iraq

Concentrations of heavy metals (Pb, Mn, Ni, Fe, Cu, and Zn) were determined in shrimp Atyaephyra desmaresti mesopotamica collected from Shatt Al-Arab River, Basrah, Iraq. The elements content were determined in whole body biomass. The seasonal variations of the element concentrations, and the relationship between element concentrations in males and females were estimated in this study. Measurements were done to evaluate trace metals in shrimps tissues in Qurmat-Ali in Shatt Al-Arab River between summer (May- August) 2008 and spring (March and April) 2009. Samples were collected seasonally. Tissue samples were analyzed by flame atomic absorption spectrophotometry. Females accumulated the trace metals in their bodies in spring higher than other seasons. Males accumulated the trace metals in their bodies in Spring higher than other seasons, except for Pb and Mn. Regarding to concentrations; the highest values were 141.80 µg g-1 d.w in males and 136.79 µg g-1 d.w in females for Iron, while the lowest values were 2.49 µg g-1 d.w in males and 2.96 µg g-1 d.w in females for Lead. Regarding to seasons; in Summer the concentrations of trace metals were higher in males than in females, except Zn, in Autumn they were higher in males than in females, except Pb and Ni, in Winter they were higher in males than in females, except Pb and Zn, in Spring they were higher in males than in females, except Pb, Mn and Zn.&#x0D;

Checklist of the freshwater shrimps (Crustacea, Decapoda, Caridea) from the Banggai Archipelago, Central Sulawesi, Indonesia

The mainland of Sulawesi is well known for its high diversity of freshwater shrimps. However, many small islands surrounding Sulawesi have been neglected and have not been unexplored. Here, we report on the freshwater shrimps of the Banggai Archipelago, eastern Sulawesi, based on field collections between 2017 and 2019 on four islands, Peleng, Labobo, Bangkurung, and Banggai. Eleven species were found: Caridina brevidactyla J. Roux, 1920, Caridina brevicarpalis De Man, 1892, Caridina gracilipes De Man, 1892, Caridina gracilirostris De Man, 1892, Caridina serratirostris De Man, 1892, Caridina typus H. Milne Edwards, 1837, Caridina weberi De Man, 1892, Macrobrachium australe (Gu&amp;eacute;rin-M&amp;eacute;neville, 1838), Macrobrachium equidens (Dana, 1852), Macrobrachium lar (Fabricius, 1798), and Macrobrachium latidactylus (Thallwitz, 1891). One species, C. brevidactyla, is a newly recorded from Sulawesi. Knowledge of the diversity of the freshwater shrimp fauna can contribute to the conservation of species and their habitats.

Taking advantage of transparency: A proof-of-principle for the analysis of the uptake of labeled microplastic particles by organisms of different functional feeding guilds using an adapted CUBIC protocol

The analysis of the ingestion of microplastics (MP) by biota is frequently performed through invasive procedures such as chemical digestion protocols or by histological analysis of thin sections. Different, promising approaches for the observation of ingested MP particles pose so called tissue clearing methods. They are currently applied to organs, tissue samples, or whole organisms, rendering the sample transparent and enable to look inside an otherwise opaque environment. To date, there is a lack of methods to detect labeled MP inside an opaque organism's digestive tract without interfering with the sample's integrity. Therefore, our goal was to adapt the CUBIC tissue clearing protocol (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational Analysis) for aquatic and terrestrial organisms of various functional feeding groups for the analysis of the uptake of fluorescent labeled microplastic (MP) particles. We included the buff-tailed bumblebee Bombus terrestris, the compost worm Eisenia fetida, the woodlouse Porcellio scaber, the freshwater shrimp Gammarus roeselii, and the quagga mussel Dreissena bugensis in the analysis. The adapted CUBIC method has led to transparency in all normally opaque organisms. It further offers a simple way of locating fluorescent labeled MP inside the digestive system of the different organisms while leaving them intact.

Can hypoosmotic shock and calcium influx lead to translocation of aquaporin-1 in shrimp muscle cells?

The physiological variations during the crustacean molting cycle have intrigued researchers for many years. Maintaining osmotic homeostasis in the face of hemolymph dilution and dealing with dynamic intracellular and extracellular calcium fluctuations are challenges these animals continuously confront. It has recently been shown that water channels present in the cell membrane (aquaporins) are essential for water uptake during premolt and postmolt. This study aims to investigate whether hypoosmotic shock and intracellular and extracellular calcium variations can lead to translocation of Aquaporin 1 (AQP-1) from the intracellular region to the plasma membrane during premolt and postmolt, thus allowing increased water flow in these stages. For this, we investigate in vitro the rapid change of AQP-1 positions in the abdominal muscle cells in the freshwater shrimp, Palaemon argentinus. Using cell volume analysis and immunohistochemistry, we show that hypoosmotic conditions and an elevation of the intracellular and extracellular calcium concentrations are concurrent with the translocation of AQP-1 to the plasma membrane. These results indicate that calcium flux and hypoosmotic shock may be regulators of AQP 1 in the translocation process.

The effect of addition of calcium oxide (CaO) on the cultivation of Litopenaeus vannamei in freshwater

Indonesia, as the fourth-largest global producer of Vannamei shrimp, is facing increasing demand for shrimp, necessitating higher production. In response, the cultivation of Vannamei shrimp in freshwater has gained traction. However, freshwater environments are limited in essential calcium minerals required for shrimp growth. To address this issue, research on the addition of calcium oxide (CaO) in freshwater Vannamei shrimp cultivation was conducted. The main objective of this study was to assess the impact of calcium oxide (CaO) and determine the optimal dosage for the survival rate and growth of Vannamei shrimp in freshwater. The experimental method was employed, consisting of five different dosage treatments: seawater control, freshwater control, 40 ppm, 80 ppm, and 120 ppm of calcium oxide. The findings of this study revealed that the treatment with 120 ppm of calcium oxide exhibited the most favorable growth, with a weight of 16.40 g in the freshwater treatment. Additionally, the 80 ppm treatment demonstrated the highest survival rate, reaching 67% in the freshwater treatment.

Haemolymphatic Parameters in Two Aquaculture Crustacean Species Cherax destructor (Clark, 1836) and Cherax quadricarinatus (Von Martens, 1868).

Simple SummaryThe spread of freshwater crustacean farms, in particular of the Australian species Cherax, has been widespread in recent years and has aroused particular interest at an economic level. Knowledge of the basic levels of some biochemical parameters becomes particularly important to understanding the health status of the animals and, therefore, for the maintenance of aquaculture facilities. In this study, the values of some biochemical parameters of two species of Cherax, Cherax destructor and Cherax quadricarinatus, reared in an Italian aquaculture plant, were evaluated for the first time. These parameters should contribute to assessing the health status of these animals on a farm and to understanding if they will be affected by stressful conditions or not.In the last few years, there has been a notable development in the breeding of freshwater shrimp (astaciculture), which involved various species and in particular, the two Australian Parastacidae species, Cherax destructor and Cherax quadricarinatus. Information about the haemolymphatic parameters of these two species is fragmentary, and filling these gaps becomes important given their importance in aquaculture. Cellular and biochemical parameters were analyzed in both species to create a reference baseline for these parameters to identify the state of welfare or suffering of these animals. The results showed that the total haemocyte count, haemocyte subpopulations, enzymatic activities and pH are similar between the two species, while total protein and osmolality are higher in C. destructor than C. quadricarinatus. Knowledge of these parameters could assist in evaluating the good health status of these species kept in aquaculture facilities.

A High-Density Genetic Map and QTL Fine Mapping for Growth- and Sex-Related Traits in Red Swamp Crayfish (Procambarus clarkii).

Red swamp crayfish (Procambarus clarkii) is a commercially important species in global aquaculture and most successfully invasive freshwater shrimp in China. In order to determine the genetic basis of growth- and sex-related traits, a high-density genetic linkage map was constructed using 2b-RAD sequencing technology in a full-sib family. The consensus map contains 4,878 SNP markers assigned to 94 linkage groups (LGs) and spanned 6,157.737 cM with an average marker interval of 1.26 cM and 96.93% genome coverage. The quantitative trait locus (QTL) mapping for growth and sex traits was performed for the first time. QTL mapping uncovers 28 QTLs for growth-related traits in nine LGs, explaining 7.9–14.4% of the phenotypic variation, and identifies some potential candidate growth-related genes such as mih, lamr, golgb1, nurf301, and tbcd1 within the QTL intervals. A single major locus for sex determination was revealed in LG20 that explains 59.3–63.7% of the phenotypic variations. Some candidate sex-related genes, such as vps4bl, ssrf, and acot1, were identified in the QTL intervals and found to be differentially expressed in the muscle tissues between the females and the males. Furthermore, the identified SNPs were revealed to be female heterozygotes, suggesting that red swamp crayfish might have the female heterogametic ZZ/ZW sex determination system. The present study provides a valuable resource for marker-assisted selection and genetic improvement and for further genetic and genomic research in red swamp crayfish.

The Influence of Natural Barriers on the Amphidromous Shrimp Potimirim brasiliana (Caridea, Atyidae) from Two Rivers in Southeastern Brazil.

AbstractThe migratory behavior of freshwater shrimps may be affected by natural barriers in limnetic environments. This study evaluated the river areas separated by natural barriers, such as waterfalls, which affect the amphidromous shrimps' (Potimirim brasiliana) population features and reproductive aspects. Results indicate that in the Félix and Prumirim Rivers from southeastern Brazil shrimps show few differences in sampling areas, and these differences may not be causally related to the waterfalls. This is demonstrated by the absence of a pattern in the size and sex ratio in each area and the absence of a significant difference in most reproductive aspects. The presence of juveniles and reproductive individuals in all sampling areas strongly indicates a constant migration along them in both rivers, indicating that all individuals evaluated correspond to one single patchy population structure for each river. This migration conducted by P. brasiliana, such as its crawling behavior, demonstrated that it would be important to maintain the minimum number of individuals flowing between the different river sampling areas in this shrimp group. Thus, based on a helpful model observed in P. brasiliana, the results help us understand how natural barriers may affect the populations of amphidromous shrimp and how the migration behavior up- and downstream can help sustain the population. This premise can help future construction decisions and impacts of unnatural barriers, such as dams.

FIRST DATA ON THE ICHTYOLOGICAL POPULATION OF A NEW HYDROELECTRIC LAKE: CASE OF THE DAM OF SOUBRE, COTE DIVOIRE

The new dam of Soubre in Cote dIvoire resulted in the creation of a 17.3 km2 lake in April 2017. After an 18-month ban, the exploitation of fishery resources started and is mainly carried out by foreignBozofishermen. The present study, whose main objective was to conduct the ichthyological inventory of this lake, was executed between August 2019 and July 2021. The artisanal catches of fishermen were examined monthly in the three main landing sites of the lake. The species richness of the lake was estimated at 42 species. The specific weight composition of the catches indicates the predominance of the catfish Chrysichthys nigrodigitatus with 16% of catches.For numerical abundance, the Mormyridae Marcusenius senegalensis leads the catches with a17% rate. It should be noted that this study allowed the observation of specimens of the freshwater shrimp of the genus Macrobrachium upstream of the lake, in the river-lake transition zone, while no individual of this species was captured in the lake.

Nile tilapia production in polyculture with freshwater shrimp using an aquaponic system and biofloc technology

This study aimed to evaluate the performance of Nile tilapia, freshwater shrimp, lettuce, and watercress in an aquaponic system used in conjunction with biofloc technology. Experimental units consisted of an aquaponic module comprising two containers, one to accommodate vegetables (500 L media-filled bed with gravel) and the other to stock fish and shrimps (1000 L rearing tank). The experiment was carried out in a randomized complete block design with two treatments [an aquaponic system with clear water (ASCW) and an aquaponic system with biofloc technology (ASBFT)] and two blocks (periods). Each treatment had three replicates within each block, totaling six experimental units per block. The final weights of Nile tilapia (ASCW = 546.0 g; ASBFT: 565.0 g), freshwater shrimp (ASCW = 18.82 g; ASBFT: 18.44 g), and vegetable biomass (ASCW: 1.10 kg/m2 of lettuce and 1.57 kg/m2 of watercress; ASBFT: 0.94 kg/m2 of lettuce and 1.98 kg/m2 of watercress) did not differ significantly between the two treatments. Similarly, there were no significant differences between treatments with respect to other zootechnical performance variables of the evaluated organisms. There was, however, a greater (P < 0.05) accumulation of fat in the fillets of Nile tilapia reared in the ASBFT system (0.97%) than in those of fish reared in the ASCW system (0.76%), as well as a lower oscillation of nitrite levels. Therefore, the use of biofloc technology in conjunction with aquaponics facilitated the maintenance of zootechnical performance and contributed to an increase in the fat content of Nile tilapia fillets and better control of nitrite production.

Integrated application of Iso-seq and RNA-seq provides insights into unsynchronized growth in red swamp crayfish (Procambarus clarkii)

Red swamp crayfish is one of the most important freshwater shrimps with high economic value in China. The crayfish shows obvious sexual dimorphism in growth and secondary sex characteristics, however, the mechanisms underlying the growth of muscle tissue in the crayfish still remain unclear. Both high-throughput RNA-Seq and Iso-seq strategies were applied to reveal the molecular basis of the growth difference between fast-growing and slow-growing crayfish. After splicing and assembling, 63,350 genes with an average length of 2151 bp and N50 of 2568 bp were obtained. A total of 122 growth-related differentially expressed genes (DEGs) were identified, of which 87 genes were significantly up-regulated and 35 were down-regulated. Using quantitative PCR it was confirmed that the expressions of tps, inpp5l, flna, flnc, tpnc3 and other genes was higher in the fast-growing individuals. Subsequently, 144 genes differentially expressed between males and females were identified. 130 of them, 84 up-regulated and 46 down-regulated, were identified in the fast-growing group, while only 14 genes, 3 up-regulated and 11 down-regulated, were identified in the slow-growing group. The KEGG pathway enrichment analysis indicated that the identified DEGs were mainly involved in metabolic pathways, including arachidonic acid metabolism, glutathione metabolism, alanine, aspartate and glutamate metabolism. This study provides a basis for understanding the molecular mechanism of the sexual growth dimorphism and its application for future genetic breeding in red swamp crayfish.

Genetic assessment of the rare freshwater shrimp

The lack of information is one of the major impediments to effective conservation of rare, endemic species. One of which concerns the freshwater atyid shrimp Caridina logemanni known only from three streams in Hong Kong, with an area of occupancy of less than 20 km2, further threatened by harvesting for aquarium trade and potential introgressive hybridisation with a ubiquitous congener C. cantonensis. Here, we delineated the genetic diversity and population structure of C. logemanni, and examined its extent of hybridisation with C. cantonensis, using one mitochondrial (COI), one nuclear (NaK intron) and six microsatellite markers. The two examined populations of C. logemanni exhibited strong genetic differentiation at a spatial scale of &lt;1.5 km apart, and generally low genetic diversity. Historic introgressive hybridisation is evident from the sharing of COI haplotypes between species and the more extensive inter-specific microsatellite admixture than inter-population admixture, such that both C. logemanni populations were of hybrid origin. Future conservation efforts on C. logemanni should aim at (1) minimising waterway modifications to prevent potential anthropogenic hybridisation, (2) fortifying conservation legislations to stop its harvesting, and (3) conducting continuous monitoring in case of stochastic events associated with small population size and linear habitat.

Contamination status and the health risk evaluation of dietary exposure of quinolone and tetracycline antibiotics in animal derived foods in Ningbo City from 2018 to 2020

To investigate the dietary exposure of Ningbo residents to quinolones and tetracyclines antibiotics in animal derived foods, so as to estimate the health risk caused by the exposure. Animal derived foods in Ningbo markets from 2018 to 2020 were collected and analyzed by ultra-fast liquid chromatography-tandem mass spectrometry. Based on the result of the measurements, median(M), P97.5, average and the maximum values of the data were obtained. Coupling the food intake data of residents in Zhejiang Province, an international point estimate model was applied to evaluate the health risk caused by the dietary exposure. Enrofloxacin, ciprofloxacin, ofloxacin, doxycycline, oxytetracycline were detected in freshwater fishes, cultured pseudosciaena crocea, freshwater shrimps, chicken, eggs and pork. The detection rates of enrofloxacin, ciprofloxacin, ofloxacin, doxycycline, oxytetracycline were 21.2%(77/363), 11.6%(42/363), 2.8%(10/363), 1.4%(5/363), 0.6%(2/363), respectively. The dietary exposure of adults and children from animal derived foods were in the range of 0.8-909.0 and 0.6-518.9 ng/(kg·d), respectively. The hazard quotient(HQ) values were in the range of 0.000030-0.17. Quinolone and tetracycline antibiotics such as enrofloxacin and oxytetracycline have no dietary health risk to the population.

Spawning season, recruitment of juveniles and growth of the freshwater shrimp, Caridina typus H. Milne Edwards, 1837 (Crustacea: Decapoda: Atyidae) in the Heda-ohkawa River, Izu Peninsula, Shizuoka Prefecture, central Japan

Spawning season, recruitment of juveniles and growth of the freshwater shrimp, Caridina typus H. Milne Edwards, 1837 (Crustacea: Decapoda: Atyidae) in the Heda-ohkawa River, Izu Peninsula, Shizuoka Prefecture, central Japan

Filling gaps in the biology of the endemic and threatened freshwater shrimp Macrobrachium candango (Caridea: Palaemonidae) through basic morphometric and reproductive approaches

Macrobrachium candango Mantelatto, Pileggi, Pantaleão, Magalhães, Villalobos and Álvarez, 2021 is an endemic shrimp species to the Brazilian Central-West region (Brasília, Federal District). The present study aims to analyze the relative growth, morphometry, morphological sexual maturity, and fecundity of this species. Specimens were collected from tributaries of the Paranoá Lake hydrographic basin, Brasília, during sporadic periods between 1983 and 2012. Relative growth was analyzed for different structures (carapace, abdomen, second abdominal pleura, merus, carpus, and propodus). The laterality and heterochely patterns were evaluated based on the dimensions of the propodus length. Fecundity was calculated as the average total number of eggs per female and egg size was measured to obtain the volume. There were differences in relative growth (p < 0.05) of the structures analyzed between juveniles and adults, and distinct allometric patterns were observed between the life stages, which could reflect the habit of these animals at each developmental stage. No pattern of laterality and heterochely was observed between the chelipeds of the animals analyzed (p > 0.05). The lack of laterality may indicate that this species directs energy to the smallest propodus when the largest propodus is injured. Egg volume ranged from 4.41 to 7.71 mm3, and fecundity ranged from 38 to 61 eggs, indicating a life cycle with abbreviated larval development. The characteristics presented herein are unprecedented for M. candango and present relevant information needed to assess the conservation status of this species, which is currently threatened.

Trophic regime of the giant freshwater shrimp Macrobrachium vollenhoveni (Herklots, 1857) in the lower Oueme valley in Southern Benin

The diets of Macrobrachium vollenhoveni are not well known in Benin. This study aims to inventory these diets based on stomach contents. Indeed, measurements of physico-chemical parameters of the habitats, the measurement of morpho-metric lengths and the observation of the stomach contents of shrimps were carried out. Results revealed that pH varied between 6.7- 7.86, oxygen between 4-7 mg/l, temperature between 27.5°-29.1 °C, salinity between 2-5, depth between 0.83-3.82 cm, transparency between18-30 cm, conductivity between 64-69 µS/cm and total dissolved solubles between 33-36 mg/l. From the 27 feed regimes counted, animal (51%) and plant (36%) debris were majority. Clustering of individuals according to station and size class did not influence the variation in diets. The χ2 and Spearman correlation test showed that the proportions of preferred feeds varied significantly (p< 0.05). This study showed that M. vollenhoveni is an omnivorous detritivore whose diet in captivity would be less demanding.

Redescription of \(\textit{Caridina cucphuongensis Dang}\), 1980 (Crustacea: Decapoda: Atyidae) from Cuc Phuong National Park, Northern Vietnam

The freshwater shrimp species Caridina cucphuongensis (family Atyidae) was poorly described by Dang (1980). Moreover, the taxonomic status of this species is hard to verify as the types have been lost. This study provides a redescription of the species and designation of a neotype specimen. The Caridina cucphuongensis Dang, 1980 is characterized by short rostrum with large teeth on the dorsal margin, long stylocerite, subrectangular endopod of male first pleopod, and short appendix interna of the male second pleopod.

Freshwater snail and shrimp differentially affect water turbidity and benthic primary producers

Benthic macroinvertebrates play key roles in shallow aquatic ecosystems and can contribute substantially to aquatic food webs. However, how macroinvertebrates with different behaviors (for example, pertaining to locomotion, foraging and burrowing) impact water quality and primary producers has not been fully explored. Here, we performed two consecutive microcosm experiments to test the effects of (1) macroinvertebrates with different behaviors (a low mobility scraper aquatic snail Bellamya aeruginosa and a high mobility shredder freshwater shrimp Macrobrachium nipponense) and (2) different shrimp biomasses on water clarity and the composition of benthic primary producers. The results showed that presence of snails significantly increased the biomass of filamentous green algae and decreased the biomass of periphyton. In contrast, presence of shrimp significantly decreased the biomass of filamentous green algae and increased the biomass of periphyton, and these effects were biomass dependent. Filamentous green algae disappeared when shrimp biomass reached 9.8 ​g ​m−2. No interactive effects of snail and shrimp presence were found. This could be attributed to different food preferences by the two consumers, with snails preferring periphyton (mainly diatoms) and shrimp preferring filamentous green algae. The presence of snails decreased water turbidity, while shrimp increased water turbidity, which showed a hump-shaped response to shrimp biomass with a peak at 24.2 ​g ​m−2. These results are likely because the snail is a low mobility grazer and can filter suspended particles, while the shrimp is a high mobility shredder with burrows, which can strongly disturb sediment. The decrease in water disturbance at high shrimp biomass might be due to food limitation, thus reducing burrowing and foraging activities. Neither snail nor shrimp affected the biomass of H. verticillata, while the biomass of V. spinulosa increased with shrimp biomass. The reason for this could be that shrimp increased nutrient availability and decreased the growth of filamentous green algae that compete with macrophytes. Our study demonstrated that different macroinvertebrates have complementary functions in benthic habitats; thus, maintaining macroinvertebrate diversity is important for shallow aquatic ecosystems. Furthermore, the freshwater shrimp M. nipponense could be a potential consumer to control filamentous green algal blooms in its native range, but their biomass should be taken into consideration.

Chemical-specific determinants for pre-conceptional exposure to emerging and legacy per- and polyfluoroalkyl substances

The exposure of preconception women to per- and polyfluoroalkyl substances (PFASs) could negatively affect her reproductive health. However, chemical-specific determinants for pre-conceptional exposure to PFASs, particularly the emerging ones, remain poorly understood. In the present study, it was found that the total PFAS concentration ranged from 8.9 to 440.3 ng/mL (median: 49.6 ng/mL) in 1060 preconception women. The PFAS exposure profile was dominated by PFOA (16.8 ng/mL), followed by PFOS (13.3 ng/mL), 6:2 Cl-PFESA (8.9 ng/mL), PFDA (2.4 ng/mL), PFNA (2.1 ng/mL), and others. The pre-conceptional exposure to the selected PFASs was significantly associated, in a chemical-specific pattern, with multiple demographic characteristics and the consumption frequency of different types of food. In particular, the exposure to 6:2 Cl-PFESA was associated with age, parity, alcohol drinking, educational level, household income, and the consumption frequency of red meat, marine and freshwater fish, shellfish, and shrimp. However, our analysis revealed that the investigated sociodemographic and diet variables only explained a relatively small proportion (1.3%–18.7%) of PFAS concentration variations, raising the need of exploring additional factors critical to pre-conceptional PFAS exposure. Overall, the identification of chemical-specific determinants would greatly facilitate the understanding of the link between pre-conceptional exposure and health outcomes, and the mitigation of human exposure to PFAS, particularly the emerging ones.