Data from monogenean and endohelminth communities in twospot livebearer Pseudoxiphophorus bimaculatus (Teleostei: Poeciliidae) populations in a neotropical river

The data presented in this article are related to the research article entitled “Competition from sea to mountain: interactions and aggregation in low diversity monogenean and endohelminth communities in twospot livebearer Pseudoxiphophorus bimaculatus (Teleostei: Poeciliidae) populations in a neotropical river.” accepted for publication in Ecology and Evolution. The data describes the communities of helminth parasites in 11 populations of a small poeciliid freshwater fish Pseudoxiphophorus bimaculatus (Heckel, 1848) sampled along the La Antigua river basin in Veracruz, Mexico. We examined 19 P bimaculatus from one locality, 21 from another locality, and 20 from each of the other nine locations sampled in June 2016. A total of 220 individual fish were examined, and in this paper we provide the data for 18 helminth parasite taxa recorded from them. The material in this Data paper comprised the raw data on the abundance, i.e. the number of helminth individuals of each of 18 taxa found in each one individual of P. bimaculatus from each of 11 localities. The data set is contained in a single text-table including one matrix containing each of the 220 host P. bimaculatus examined from 11 localities (lines). Measures for each host P. bimaculatus include total length, standard length, maximum deep and sex, documented for everyone fish examined, plus data of the number of individual helminth of each taxa collected by each examined fish are placed in the columns. These data might be used to examine spatial distribution of helminth parasite taxa. These data might be reused to examine the spatial variation in community structure of helminth parasites of freshwater fish. This kind of data could be used to provide an assessment of human environmental impacts, or for public awareness of conservation objectives.


a b s t r a c t
The data presented in this article are related to the research article entitled "Competition from sea to mountain: interactions and aggregation in low diversity monogenean and endohelminth communities in twospot livebearer Pseudoxiphophorus bimaculatus (Teleostei: Poeciliidae) populations in a neotropical river." accepted for publication in Ecology and Evolution. The data describes the communities of helminth parasites in 11 populations of a small poeciliid freshwater fish Pseudoxiphophorus bimaculatus (Heckel, 1848) sampled along the La Antigua river basin in Veracruz, Mexico. We

Description of data collection
All helminths (except for Gyrodactylid monogeneans) found were fixed in 4% hot formaldehyde, stained with Mayer's paracarmine or Gomori ś triple stain and mounted whole on Canada balsam, to get permanent slides for microscopical examination. Taxonomic identification of helminths was performed based on morphometric analysis of the specimens, and in the case of Gyrodactylids  Value of the Data • There are few available raw data regarding helminth parasites of freshwater fishes. The present data can be useful to compare population or community characteristics of helminth parasites, i.e. presence, abundance, spatial distribution, temporal variation, richness of communities. • These data could be important for parasitologists, helminthologists, ecologists, biogeographers and general zoologists; as well as aquaculturists, veterinarians, conservationists, regulatory agencies and stakeholders who seek to protect the public and their goods or values by limiting the adverse environmental impacts of development. • These data might be used to examine spatial distribution of helminth parasite taxa. These data migth be reused to examine the spatial variation in community structure of helminth parasites of freshwater fish. These data could support to explore characteristics of the structure assemblages as nestedness or patterns of decay of similarity with distance. And might also assist to compare patterns of structure of assemblage vs. appropriate null models. • This kind of data could be used to provide an assessment of human environmental impacts, or for public awareness of conservation objectives. Host-parasite system knowledge can be used to indicate changes in parasite biodiversity status [5] .

Data description
The next 18 helminth taxa were recorded from the parasitological examinantion of 220 fish Pseudoxiphophorus bimaculatus from 11 localtions along the La Antigua River basin Veracruz, during July 2016. Each helminth taxa is referred with the microhabitat from where it was collected, i.e., the tissue or organ of the fish it parasites. Helminths are referred in a phylogenetical order: Platyhelminthes are first listed then Nematodes. Inside the Platyhelminths, Monogeneans (Class) precede to the Digeneans or Trematodes (Class), and all are referred by Families ordered alphabetically. Adult helminths are first listed and then larvae (metacercariae are the larvae of trematodes). MONOGENEA: Family Dactylogyridae Bychowsky, 1933; Urocleidoides vaginoclaustroides Mendoza-Franco, Caspeta-Mandujano, Salgado-Maldonado and Matamoros, 2015 (parasitizing the gills); Family Gyrodactylidae van Beneden and Hesse, 1863 ; Gy- Table 1 Abbreviations and unities used in the table of data (  Table 2 . Data set. The data set is contained in a single tex-table including one matrix containing each single host P. bimaculatus examined from 11 localities (lines). Measures for each host P. bimaculatus include total length, standard length, maximum deep and sex, documented for everyone fish examined, plus data of the number of individual helminth of each taxa collected by each examined fish are placed in the columns. We examined 19 P bimaculatus from one locality, 21 from another locality, and 20 from each of the other nine locations sampled in June    2016. A total of 220 individual fish were examined, and in this paper we provide the data for 18 helminth parasite taxa recorded from them. The material in this Data paper comprised the raw data on the abundance, i.e. the number of helminth individuals of each of 18 taxa found in each one individual of P. bimaculatus from each of 11 localities.

Experimental design, materials and methods
The study was conducted at 11 sites located between 42 and 1245 m above sea level (a.s.l.) within the La Antigua River basin. The La Antigua River is a high-gradient foothill river originating from the Cofre de Perote volcano and adjacent mountains from the Sierra Madre Oriental (altitude 4200 m) in the states of Puebla and Veracruz, Mexico. The river runs approximately 100 km east of the Gulf of Mexico [3] . We examined 19 P bimaculatus from a locality named Agua Bendita, 21 from another, Puente Nacional, and 20 from each of the other nine locations sampled in June 2016. Specimens were collected under collecting permit FAUT-0105. Fish were collected using DC backpack electroshockers, seines, and gill nets. Captured individuals were placed in plastic bags filled with water, transferred to the laboratory, and kept alive in aerated containers until subsequent examination for the presence of helminth parasites (within 8 h of capture). To complete the examination, fish were euthanised with an overdose of the anaesthetic 2-phenoxyethanol (Sigma-Aldrich, St. Louis, Missouri), protocol for the use of fish in research based on the NORM -019 -STPS -1993 established by the Instituto de Ecología, Pesquerías y Oceanografía del Golfo de México EPOMEX, Campeche, Mexico; specimens collected under the Cartilla Nacional de Colector Científico FAUT-0105 issued by the Secretaría del Medio Ambiente y Recursos Naturales [SEMARNAT] to GSM. Each fish was measured (total and standard lengths), and examined under a stereomicroscope in Petri dishes containing river water. Externally, the skin, scales, mouth, branchial cavity, anus, and fins of each host were examined. The branchial arches were removed, separated from the branchial cavity, and evaluated individually. All internal tissues, including the digestive tract, body musculature, and organs were examined for helminth parasites under a stereomicroscope in Petri dishes containing saline 0.7% solution. The helminths that were obtained from the dissections were counted and recorded separately for each fish. Internal examination included the inspection of all tissues and organs, viscera and muscles, except blood and bones, of each sampled fish. All helminths found except the Gyrodactylid monogeneans (see below) were isolated and counted, and then fixed in 4% hot formaldehyde (cestodes,monogeneans and adult digeneans, as well as larvae of digeneans and nematodes). Some monogeneans were fixed with ammonium picrate [1] and mounted unstained in gray-Wess medium [4] , for analysis of sclerotized structures. Platyhelminths, including digeneans, monogeneans, and cestodes used for morphological examination of whole mounts, were stained with stained with either Mayer's paracarmine or Gomori ś triple stain dehydrated using a graded alcohol series, cleared in methyl salicylate, and mounted whole on Canada balsam. Nematodes were cleared in glycerine for light microscopy and stored in 70% ethanol. The Gyrodactylid monogeneans found were removed with the use of surgical needles and were preserved in 95% ethanol in Eppendorf tubes, and processed individually. Attachment organs (haptors) were excised under the dissection microscope and partially digested with a proteolytic solution to remove tissue enclosing the haptoral armature. Digestion was arrested by the addition of a 50:50 glycerine/formalin solution, and specimens were then coverslipped and sealed with nail varnish. Individual worm bodies that had their haptors excised were fixed in 95% ethanol and stored at −20 °C for further molecular analyses. Bodies of excised specimens whose haptors had been morphometrically characterized were placed individually in 1.5 ml Eppendorf tubes for genomic DNA extraction using DNeasy Blood & Tissue Kit (Qiagen, Valencia, California) following the manufacturer's instructions. The ribosomal region spanning the 3 end of the 18S rRNA gene, ITS1, 5.8S rRNA gene, ITS2, and 5 end of 28S rRNA gene was amplified by PCR (see [2] ).
Taxonomic identification of helminths was performed based on morphometric analysis of the specimens, and in the case of Gyrodactylids monogeneans verified by molecular tools as explained above.

Ethics statement
Protocol for the use of fish in research based on the NORM -019 -STPS -1993 established by the Instituto de Ecología, Pesquerías y Oceanografía del Golfo de México EPOMEX, Campeche, Mexico; specimens collected under the Cartilla Nacional de Colector Científico FAUT-0105 issued by the Secretaría del Medio Ambiente y Recursos Naturales [SEMARNAT] to GSM.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.