Neoandracantha peruensisn. gen. n. sp. (Acanthocephala, Polymorphidae) described from cystacanths infecting the ghost crabOcypode gaudichaudiion the Peruvian coast

Abstract

The cystacanths of Neoandracantha peruensis n. gen. n. sp. are described from the ghost crab Ocypode gaudichaudii collected from the Pacific coast of Peru. While it is uncommon to describe acanthocephalan taxa from immature stages, the presence of clear-cut distinguishing features separating the present material from its nearest congeneric taxa, and the absence of adults, justifies the erection N. peruensis. The new genus is distinguished by having three separate fields of trunk spines. Specimens of N. peruensis have a slender trunk with two anterior swellings, 3 separate fields of spines on the foretrunk swelling, and no genital spines on the hindtrunk. The proboscis of the new species is heavily armored with 21–22 longitudinal rows of 22 hooks each. Hook no. 14 is more robust ventrally than dorsally. Cystacanths of N. peruensis also have a long tubular hindtrunk and the males have diagonal testes in the midtrunk swelling. Specimens of the closely related Andracantha Schmidt, 1975 have anteriorly enlarged pear-shaped Corynosoma-like trunks, only two fields of anterior trunk spines with occasional genital spines, and bilateral or tandem testes. Proboscides of species of Andracantha have considerably fewer hooks that gradually decrease in size posteriorly. The taxonomic component of this work is amplified by metal analysis of hooks and spines that shows a marked amount of magnesium (Mg) in hooks but not in spines. The highest level of sulfur (S) was found in the outer layer of hooks and anterior spines. The metal footprint of hooks and spines varies in different species of acanthocephalans and has an interspecific diagnostic value.

Description of Acanthocephalus anguillae balkanicus subsp. n. (Acanthocephala: Echinorhynchidae) from Proteus anguinus Laurenti (Amphibia: Proteidae) and the cave ecomorph of Asellus aquaticus (Crustacea: Asellidae) in Slovenia

“…an. balkanicus is similar to those observed in other acanthocephalan species (see Heckmann et al 2007, Brázova et al 2014, Amin and Heckmann 2017. As expected from these studies, the proboscis hooks had a consistent level of the 3 key ions, i.e., calcium, phosphorus, and sulfur, with the latter predominantly concentrated in the cortical layer of hooks.…”

New perspectives on Nephridiacanthus major (Acanthocephala: Oligacanthorhynchidae) collected from hedgehogs in Iran

“…Note the thin outer layer (figs 1e, f and 2d) of the hook that relates to the sulphur content in the hook of N . major , which is less than what was found in other acanthocephalans (Amin & Heckmann, 2017; Amin et al ., 2018). The hook centre in middle cuts has a completely different calcium profile than the cortical layer (table 3).…”

“…major show differential composition and distribution of metals in different hook parts with the calcium and phosphorus being considerably higher at the centre of the middle of hooks where tension and strength are paramount compared to other metals (table 3). The chemical elements present in the hooks are typical for acanthocephalans (Amin & Heckmann, 2017; Amin et al ., 2017, 2018; Ha et al ., 2018). Note the thin outer layer (figs 1e, f and 2d) of the hook that relates to the sulphur content in the hook of N .…”

Redescription and molecular analysis ofPallisentis(Pallisentis)nandaiSarkar, 1953 (Acanthocephala: Quadrigyridae) in India

“…Note the moderate outer layer (fig. 40) of the hook which relates to the sulphur content (tables 5 and 6) in the hook of P nandai , which is different than in other acanthocephalans (Amin & Heckmann, 2017; Amin et al ., 2017, 2018a; Ha et al ., 2018). The high sulphur content shows up in the outer edge of X-ray scans of hooks (tables 5 and 6; Amin et al ., 2018b).…”

“…Results of the X-ray scans of the gallium-cut hooks (dual-beam SEM) of P. nandai show differential compositions and distributions of metals in different hook parts, with calcium and sulphur levels being considerably higher at the basal arch of hooks where tension and strength are paramount compared to the hook tip and edge where the level of sulphur was considerably higher (tables 5, 6 and figs 11 and 12). The chemical elements present in the hooks are typical for acanthocephalans (Heckmann et al ., 2007, 2012; Standing & Heckmann, 2014; Amin & Heckmann, 2017). Note the moderate outer layer (fig.…”