Search

Summary: Ransomnema bravoae from the intestine of the endemic rhinocricid, Anadenobolus putealis , from Mexico, is redescribed. This species was originally described from the spirobolid Hiltonius carpinus from Morelos State, Mexico. A redescription is presented and a neotype proposed due to the loss of the type material. Ransomnema bravoae can be distinguished from all other described species of Ransomnema by the presence of a cervical expansion extending from the base of the buccal cone to approximately the last one-third of the muscular pharynx and is offset by a slight constriction at the termination point, the presence of broad lateral alae beginning at the cervical expansion termination and terminating at the phasmids, the size and distribution of the male caudal papillae, and the size of the spicules, the right spicule being 3-4 times longer than the left. Ransomnema bravoae resembles R. alatum and R. bursatum in the presence of lateral alae but differs markedly in their distribution along the body. The right spicule is within the size range of that of R. longispiculum. Males of R. bravoae possess the usual papillal composition of the genus and are very similar to that of R. christiei in that the last pair of papillae is arranged in tandem. It is similar to species where males possess three precloacal papillae placed on lateral protuberances, showing morphological affinities to Caribbean species R. artigasi and R. habanense from Cuba. [ABSTRACT FROM AUTHOR]

A molecular hypothesis of the Infraorder Rhigonematomorpha is presented. The phylogeny recovered using combined SSU and LSU markers suggests that the Rhigonematomorpha is nested within a larger clade that includes Ascaridomorpha, Spiruromorpha and Oxyuridomorpha and is strongly supported by maximum likelihood (ML) bootstrap support values (BS) and Bayesian posterior probabilities (BPP). SSU and LSU ML and Bayesian analyses recovered Rhigonematomorpha as a paraphyletic clade. In the ML and Bayesian analyses of a combined matrix of complete to partial sequences of SSU and LSU, respectively, Rhigonematomorpha is recovered as a monophyletic clade with moderate BPP but low BS. Highly supported BS and BPP of a combined SSU and LSU matrix support a hypothesis of a monophyletic Superfamily Ransomnematoidea that includes the families Carnoyidae, Hethidae, Ransomnematidae plus a Brumptaemilius, Cattiena, Insulanema clade, and a monophyletic Superfamily Rhigonematoidea that probably includes the paraphyletic families Rhigonematidae and Ichthyocephalidae. It is suggested that the future inclusion of more families and genera might help resolve the monophyly of the Infraorder Rhigonematomorpha as advanced here. [ABSTRACT FROM AUTHOR]

Carnoya cepacapitatus n. sp. and C. mexicana n. sp. from the intestine of Anadenobolus putealis from Mexico are described herein. Specific characters like the number of collars and spines set these species apart from those previously described from the Caribbean and South American regions. Males of C. cepacapitatus n. sp. can be differentiated from those of all other described species of Carnoya from the Americas by the presence of a broader cephalic annule two annules posterior to the lip region, eight transverse rows of spines linearly arranged on cervical region, finely striated regions at the midventral body section and in the region posterior to cloacal aperture, and a pair of double postcloacal papillae, females by a spherical, knob-like annule posterior to lip region, annulated neck region with fourth annule wider than the other six, and 15 spined cervical collars. Males of C. mexicana n. sp. can be differentiated from other described species by the presence of minute and irregularly distributed cervical spines placed on 11 annules, plus an elevated lip region; females bear 15 cervical collars with leaf-like spines. Carnoya cepacapitatus n. sp. closely resembles C. caputbulla, whereas C. mexicana n. sp. resembles several species of Caribbean distribution, mainly C. haiti, but differs from all of them primarily in the number, distribution and size of the cervical spined collars. Females of C. cepacapitatus n. sp. resemble Asian species that possess a knob-like cephalic region. Carnoya mexicana n. sp. resembles more closely the American species of this genus based on the form of the cephalic region in both sexes, but especially the number and distribution of the spined collars in the male. Partial sequences of SSU and LSU are presented for females of both species. [ABSTRACT FROM AUTHOR]

Heth gordae n. sp., H. xarochae n. sp. and H. tuxtlensis n. sp. from the intestine of spiroboloids from Mexico are described herein. Females of H. gordae n. sp. and H. xarochae n. sp. can be differentiated from all other described species of Heth from the Americas by the presence of two sets of lateral spines with multiple cusps with a common broad base arranged in a semilunar shape pattern. Heth gordae n. sp. exhibits a narrower pattern that resembles more a comb-like structure, whereas H. xarochae n. sp. exhibits a broader pattern. Both aforementioned species resemble H. hexaspinosum from Panamá, but the latter possesses fewer spines without a common base. Lateral spines with multiple cusps have never been previously described in the genus Heth. Females of H. tuxtlensis n. sp. resemble Asian collar lappet-species but differ from them in possessing a complete uninterrupted collar with indented single lateral lappets. Specific characters described herein set these species apart from the Caribbean Heth species, most South American, and those previously described from Mexico. The present descriptions increase the number of Heth species recorded from Mexico from three to six. [ABSTRACT FROM AUTHOR]