Abstract:The community metrics chosen generally had robust statistically significant associations with both physicochemical and contaminant variables, which supports the ecological relevance of these parameters as indicators of aquatic environmental health. Within the study area, the shoal flounder and their parasites live in a polluted environment with relatively high levels of hydrocarbons and nitrate. Regarding nitrate, we emphasise that if uncontrolled sewage discharge continues in the southern Gulf of Mexico, hypo… Show more
“…Sediment samples were placed in high-density polythene bags and maintained at 4 °C for transportation to CINVESTAV-IPN-Mérida. Hydrocarbon sampling procedures are described elsewhere [3]. The physicochemical characteristics and the hydrocarbon and heavy metal concentrations of the sediment were determined at the Laboratory of Geochemistry (CINVESTAV-IPN-Mérida).Fig.…”
Section: Methodsmentioning
confidence: 99%
“…For the comparison of parasite community metrics, raw quantitative infracommunity data (the number of individuals of each parasite species in/on each individual host) of all 127 individual dusky flounders from each of the 17 sampling stations from the Yucatan shelf, and the 200 shoal flounders from 33 sampling stations of the Campeche Sound, were used [3]. All these data were transformed by fourth square root, and a Bray-Curtis similarity matrix was built to test the hypothesis of non-differences in the infracommunity composition among both regions (The Yucatan Shelf and the Campeche Sound) using analysis of similarity (ANOSIM).…”
Section: Methodsmentioning
confidence: 99%
“…During the last 20 years, the Mexican oil company, PEMEX, has provided financial support for environmental studies along the continental shelf of the Gulf of Mexico, from which several studies on parasites as bioindicators of environmental impact have been published [3, 4, 7, 12, 13]. Most of these studies were focused on the Campeche Sound, which is where most of the oil-extraction activities in Mexican waters occur.…”
Section: Introductionmentioning
confidence: 99%
“…Even when the geographical distribution range of S. papillosum includes the Campeche Sound [23], we found few individuals there, probably because it prefers a bottom of calcareous material [23]. In the Campeche Sound, muddy and sandy bottoms dominated in our sampling stations, being the preferred habitat for the shoal flounder ( Syacium gunteri ) [3]. In fact, since S. papillosum and S. gunteri are sympatric and their feeding habits and parasite fauna overlap [23–25], we assume that their parasite infracommunities are comparable.…”
Background
We assessed metrics of the metazoan parasite infracommunities of the dusky flounder (
Syacium papillosum
) as indicators of aquatic environmental health of the Yucatan Shelf (YS) prior to oil extraction. We sampled the dusky flounder and its parasites along the YS, mostly during the 2015 north wind season (November–April). Our aims were: (i) to determine whether the parasite infracommunity metrics of
S. papillosum
exhibit significant differences among YS subregions; (ii) to determine whether the probability of the occurrence of its parasite species and individuals were affected by environmental variables, nutrients, heavy metals and hydrocarbons at the seascape level; and (iii) to determine whether there were statistical differences between the parasite infracommunity metrics of
S. papillosum
from YS and those of
Syacium gunteri
from the Campeche Sound. Multivariate statistical analyses and generalised additive models (GAMs) were used to examine the potential statistical associations between the contaminants, environmental variables and parasite community metrics, and the maximum entropy algorithm (MaxEnt) was used to characterise the habitat’s suitability for the parasite’s probability of occurrence.
Results
We recovered 48 metazoan parasite species from 127
S. papillosum
, with larval cestodes and digeneans being the most numerically-dominant. Multivariate analyses showed significant differences in parasite infracommunity metrics among Western YS, Mid YS and Caribbean subregions, with the latter being the richest in species but not in individuals. The GAM and MaxEnt results indicated a negative effect of top predators (e.g. sharks and rays) removal on parasite metrics. The parasite infracommunities of
S. papillosum
were twice as rich in the number of species and individuals as those reported for
S. gunteri
from the Campeche Sound.
Conclusions
The significant differences among subregions in parasite metrics were apparently due to the interruption of the Yucatan current during the north wind season. The fishing of top predators in combination with an influx of nutrients and hydrocarbons in low concentrations coincides with an increase in larval cestodes and digeneans in
S. papillosum
. The dusky flounder inhabits a region (YS) with a larger number of metazoan parasite species compared with those available for
S. gunteri
in the Campeche Sound, suggesting better environmental conditions for transmission in the YS.
Electronic supplementary material
The online version of this article (10.1186/s13071-019-3524-6) contains supplementary material, which is available to authorized users.
“…Sediment samples were placed in high-density polythene bags and maintained at 4 °C for transportation to CINVESTAV-IPN-Mérida. Hydrocarbon sampling procedures are described elsewhere [3]. The physicochemical characteristics and the hydrocarbon and heavy metal concentrations of the sediment were determined at the Laboratory of Geochemistry (CINVESTAV-IPN-Mérida).Fig.…”
Section: Methodsmentioning
confidence: 99%
“…For the comparison of parasite community metrics, raw quantitative infracommunity data (the number of individuals of each parasite species in/on each individual host) of all 127 individual dusky flounders from each of the 17 sampling stations from the Yucatan shelf, and the 200 shoal flounders from 33 sampling stations of the Campeche Sound, were used [3]. All these data were transformed by fourth square root, and a Bray-Curtis similarity matrix was built to test the hypothesis of non-differences in the infracommunity composition among both regions (The Yucatan Shelf and the Campeche Sound) using analysis of similarity (ANOSIM).…”
Section: Methodsmentioning
confidence: 99%
“…During the last 20 years, the Mexican oil company, PEMEX, has provided financial support for environmental studies along the continental shelf of the Gulf of Mexico, from which several studies on parasites as bioindicators of environmental impact have been published [3, 4, 7, 12, 13]. Most of these studies were focused on the Campeche Sound, which is where most of the oil-extraction activities in Mexican waters occur.…”
Section: Introductionmentioning
confidence: 99%
“…Even when the geographical distribution range of S. papillosum includes the Campeche Sound [23], we found few individuals there, probably because it prefers a bottom of calcareous material [23]. In the Campeche Sound, muddy and sandy bottoms dominated in our sampling stations, being the preferred habitat for the shoal flounder ( Syacium gunteri ) [3]. In fact, since S. papillosum and S. gunteri are sympatric and their feeding habits and parasite fauna overlap [23–25], we assume that their parasite infracommunities are comparable.…”
Background
We assessed metrics of the metazoan parasite infracommunities of the dusky flounder (
Syacium papillosum
) as indicators of aquatic environmental health of the Yucatan Shelf (YS) prior to oil extraction. We sampled the dusky flounder and its parasites along the YS, mostly during the 2015 north wind season (November–April). Our aims were: (i) to determine whether the parasite infracommunity metrics of
S. papillosum
exhibit significant differences among YS subregions; (ii) to determine whether the probability of the occurrence of its parasite species and individuals were affected by environmental variables, nutrients, heavy metals and hydrocarbons at the seascape level; and (iii) to determine whether there were statistical differences between the parasite infracommunity metrics of
S. papillosum
from YS and those of
Syacium gunteri
from the Campeche Sound. Multivariate statistical analyses and generalised additive models (GAMs) were used to examine the potential statistical associations between the contaminants, environmental variables and parasite community metrics, and the maximum entropy algorithm (MaxEnt) was used to characterise the habitat’s suitability for the parasite’s probability of occurrence.
Results
We recovered 48 metazoan parasite species from 127
S. papillosum
, with larval cestodes and digeneans being the most numerically-dominant. Multivariate analyses showed significant differences in parasite infracommunity metrics among Western YS, Mid YS and Caribbean subregions, with the latter being the richest in species but not in individuals. The GAM and MaxEnt results indicated a negative effect of top predators (e.g. sharks and rays) removal on parasite metrics. The parasite infracommunities of
S. papillosum
were twice as rich in the number of species and individuals as those reported for
S. gunteri
from the Campeche Sound.
Conclusions
The significant differences among subregions in parasite metrics were apparently due to the interruption of the Yucatan current during the north wind season. The fishing of top predators in combination with an influx of nutrients and hydrocarbons in low concentrations coincides with an increase in larval cestodes and digeneans in
S. papillosum
. The dusky flounder inhabits a region (YS) with a larger number of metazoan parasite species compared with those available for
S. gunteri
in the Campeche Sound, suggesting better environmental conditions for transmission in the YS.
Electronic supplementary material
The online version of this article (10.1186/s13071-019-3524-6) contains supplementary material, which is available to authorized users.
“…El cestodo O. wageneri ya ha sido registrado en otros elasmobranquios para la misma zona de estudio (Méndez & Dorantes-González, 2017;Méndez et al, 2018;Martínez-Aquino et al, 2019). Vidal-Martínez et al (2014) (Fusco & Overstreet, 1978) Cárdenas & Lanfredi, 2005 es conocido por infectar peces de la familia Scaridae, la cual está incluida en la dieta de la raya látigo. Se encuentra en estado larvario en los teleósteos, completando su ciclo en otros peces como H. americanus.…”
Section: O S C E S T O D O S a C A N T H O B O T H R I U M S P 1 Yunclassified
La raya del sur Hypanus americanus (Hildebrand & Schroeder, 1928) se distribuye desde los Estados Unidos hasta Brasil, pasando por el Golfo de México. Se alimenta de moluscos, crustáceos y peces óseos, su amplia distribución se puede denotar en su helmintofauna. Por lo tanto, el estudio de sus parásitos resulta muy útil para obtener información ecológica, patrones de migración y biología de su hospedero. Se determinó la composición de especies de helmintos parásitos de H. americanus en Chachalacas, Veracruz. Se examinaron 27 intestinos y se aplicó la técnica parasitológica de acuerdo con el grupo de parásitos encontrados. Se calcularon los parámetros ecológicos de prevalencia, abundancia e intensidad media de infección. Obteniendo 2154 cestodos pertenecientes a 10 especies y 14 nematodos correspondientes a dos especies. El 66,6% de los hospederos fueron parasitados por el cestodo Pterobothrium sp. con una intensidad media de 14,8±16,7, seguida de Acanthobothrium sp. con una prevalencia de 62,9% y una intensidad media de infección de 44±46,2. Los helmintos de la raya H. americanus están siendo evaluados para aumentar el conocimiento sobre estos y poder compararlos con especies de hospederos cercanos. La identificación de los parásitos de cada región puede servir como indicadores biológicos, debido a que nos permite comprender mejor las interacciones parásito-hospedero a una escala geográfica mayor.
Unregulated economic growth in Latin America has resulted in environmental degradation, including the release of toxic compounds into the environment. One strategy to understand and prevent the outcomes of this harmful environmental degradation is the use of bioindicators. These are free-living or parasite species that respond to habitat alterations with changes in their numbers, physiology or chemical composition. The aim of this review was to determine whether there is evidence of a significant parasite response to environmental damage in Latin America. We collected 26 papers published between 2003 and 2015 and conducted a meta-analysis to test the null hypothesis that there is no significant overall effect of environmental insults on parasites. The meta-analysis showed a low but still significant negative mean overall effect (Hedges' g = -0.221; 95% CI: -0.241 to -0.200; P < 0.0001). However, the magnitudes and directions of the significant effects varied widely. These results suggest that different groups of parasites have distinct responses to various environmental insults and that the groups should be separately analysed after the accumulation of a sufficient number of studies. For future studies on this topic in Latin America, we suggest: (1) using field and experimental approaches to determine the response of parasites to environmental degradation; (2) using an interdisciplinary approach, including different types of biomarkers in both parasites and individual hosts to generate long-term datasets in polluted and reference areas; (3) conducting studies on parasites as accumulation bioindicators.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
