Stereoscan model s 2469n scanning electron microscope

For taxonomic identification, specimens were stained with Mayer's paracarmine, dehydrated in a graded ethanol series, cleared with methyl salicylate and mounted on permanent slides with Canada balsam. Mounted specimens were examined under a bright-field Leica DM 1000 LED microscope (Leica, Wetzlar, Germany), and drawings were made using a drawing tube attached to the microscope. Measurements were taken using Leica Application Suite microscope software (Leica) and are given in micrometres (μm).
Vouchers of N. emyditoides from Tlacotalpan, Veracruz (No. 6695) and the new vouchers (Nos. 11647–11653) were examined and deposited in the Colección Nacional de Helmintos (CNHE), Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico. The species identification was conducted following the revision of the genus Neoechinorhynchus by Barger (2004 ) and the original description (Fisher, 1960 (link)). For scanning electron microscopy (SEM), two specimens of N. emyditoides of each locality sampled were dehydrated with an ethanol series, critical point dried, sputter coated with gold and examined with a Hitachi Stereoscan Model S-2469N scanning electron microscope operating at 15 kV from the Instituto de Biología, UNAM.

The specimens were stained with Mayer’s paracarmine (Merck, Darmstadt, Germany), dehydrated in an ethanol series, cleared in methyl salicylate and mounted in Canada balsam for morphological analysis. Specimens were then examined using a compound microscope equipped with a bright field (Leica DM 1000 LED microscope, Leica, Wetzlar, Germany). Measurements were taken using Leica Application Suite microscope software (Leica Microsystems GmbH, Wetzlar, Germany) and are given in micrometres as range followed by mean in parentheses. Some specimens from each locality were dehydrated in ethanol series, critical-point dried, sputter coated with gold, and examined with a Hitachi Stereoscan Model S-2469N scanning electron microscope operating at 15 kV. Adults and metacercariae were deposited in the Colección Nacional de Helmintos (CNHE) of the Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), México City (CNHE. No. 12063–12066).

Selected adult acanthocephalans were gently punctured with a fine needle in the trunk, stained with Mayer's paracarmine, destained in 70% acid ethanol, dehydrated in a graded ethanol series, cleared in methyl salicylate and mounted in Canada balsam. Specimens were examined using a compound microscope Leica DM 1000 LED equipped with bright field (Leica, Wetzlar, Germany). The acanthocephalans were identified by conventional morphological criteria following Petrochenko (1958 ). In addition, descriptions of H. corynosoma and S. hispida were consulted as needed (Schmidt, 1973 (link); Nickol et al., 2002 (link); Amin et al., 2022 (link)). For scanning electron microscopy, 2 adult specimens of each species were dehydrated with an ethanol series, critical point dried, sputter coated with gold and examined with a Hitachi Stereoscan Model S-2469N scanning electron microscope operating at 15 kV from the Instituto de Biología, Universidad Nacional Autónoma de México (UNAM). Adult specimens were deposited in the Colección Nacional de Helmintos, under numbers CNHE: 11823 and 11824, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City