A new species of Aplectana Railliet &amp; Henry (Nematoda: Cosmocercidae) <br />in Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae) from Minas Gerais State, Brazil

Abstract

In the present study, we described and illustrated Aplectana minaensis n. sp. (Ascaridida: Cosmocercidae) from the intestinal caecum of Amphisbaena alba Linnaeus (Squamata: Amphisbaenidae). Aplectana minaensis n. sp. is the 5th species described in Brazilian hosts and 58th species assigned to the genus. This species differs from its congeners by a set of unique characters in males: the presence of one unpaired precloacal papilla and gubernaculum, the papillae pattern (4+1:2:6) and total number (12+1), and the size of spicules (400–605 µm). Among the Aplectana species with an unpaired precloacal papilla and gubernaculum, only A. minaensis n. sp. and A. nebulosa Gomez, González &amp; Sanabria, has less than 20 pairs of caudal papillae. However, these species differ in the number of caudal papillae in males (12+1 vs. 13–14+1, respectively); the number and arrangement of post cloacal papillae (6 pairs: 1st to 4th pairs ventral, 5th pair laterodorsal, 6th pairventral vs. five pairs: 1st and 2nd ventral, 3rd lateral, 4th ventral, 5th lateral); and by the size of spicules (413–600 vs. 85–126 µm).

A new species of Aplectana (Nematoda: Cosmocercidae) in Amphisbaena darwinii (Squamata: Amphisbaenidae) from Argentina

“…The species that present both a Muniz-Pereira and Aplectana nananae n. sp. (Vieira et al, 2020;current study). However, the size of male body structures and the number and arrangement of caudal papillae can also differentiate these nematodes (Bursey et al, 2018a, b).…”

“…We assigned the nematodes of the current study to the genus Aplectana due to the following characteristics: well developed lateral alae, numerous minute somatic papillae, 3 large lips with 4 submedian large cephalic papillae, 1 pair of lateral amphids, an oesophagus with a short cylindrical pharynx, cylindrical corpus and oesophageal bulb, and an excretory pore anterior to the oesophageal bulb. The prodelphic females with many eggs in the uteri and contain ovaries anterior to the vulva, and males present 2 equal spicules and the tail of males without rosettes or plectanes (Gibbons, 2010;Vieira et al, 2020).…”

“…Currently, 59 nominal species of Aplectana are recognized (Vieira et al, 2020). We can separate the Aplectana species presenting gubernaculum and unpaired precloacal papillae in 2 groups: species with less than 20 pairs of caudal papillae and those with more than 20 pairs.…”

“…Aplectana tucumanensis Ramallo, Bursey & Goldberg, 2008 described in Amphisbaena bolivica Mertens (Amphisbaenidae) from the Province of Tucumán, Argentina, does not contain an unpaired preanal papilla. Likewise, Aplectana minaensis in Amphisbaena alba L., 1758 (Squamata: Amphisbaenidae) from Brazil (Vieira et al, 2020) also presents unpaired precloacal papillae, a gubernaculum and a posterior region with less than 20 pairs of caudal papillae. https://doi.…”

“…The Cosmocercoidea are mainly parasites of vertebrates and presumably evolved in amphibians and reptiles (Vanderburgh & Anderson, 1987). Studies focusing on helminth parasites of amphisbaenian hosts in the Neotropical region are scarce, with 6 species of Aplectana occurring in Neotropical amphisbaenians (Amorim et al, 2017;Ávila & Silva, 2010;Vieira et al, 2020): in Brazil, Aplectana albae Adamson & Baccam, 1988 was reported in Amphisbaena alba Linnaeus, 1758 and Amphisbaena ridleyi Boulenger, 1890, Aplectana raillieti Travassos, 1925 in Amphisbaena alba, Aplectana nordestina Amorim, Da Silva, Morais, Da Silva, Ávila, 2017in Leposternon polystegum, Aplectana pusilla (Miranda, 1924) Adamson & Baccam, 1988 in Amphisbaena sp., and Aplectana minaensis Vieira, Araujo Gonçalves, De Souza Lima, De Sousa & Muniz-Pereira, 2020 in Amphisbaena alba. Aplectana unguiculata Rudolphi, 1819 in Amphisbaena sp.…”