Ultra Structural Comparison of Trophi in Species of the Genus &amp;lt;i&amp;gt;Brachionus&amp;lt;/i&amp;gt; Pallas, 1766 in Aguascalientes State, Mexico

Guerrero-Jiménez, Gerardo; Silva-Briano, Marcelo; Adabache-Ortíz, Araceli; Hernandez-Rodriguez, S

doi:10.4236/ns.2015.79045

Cited by 2 publications

(2 citation statements)

References 15 publications

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“…This distal end often displays small cavities or small to very large holes (e.g., in Brachionus Guerrero‐Jiménez et al. ); in Brachionus plicatilis , the fulcrum even takes the form of a hollow, truncated cone with single large distal opening (Kleinow et al. ).…”

Section: Discussionmentioning

confidence: 99%

Ontogeny of the jaws of monogonont rotifers: the malleate trophi of Rhinoglena and Proalides (Ploima, Epiphanidae)

Smet

Segers

2017

Invertebrate Biology

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Information on the embryonic development of the malleate trophi in Epiphanidae (Rotifera, Monogononta, Ploima) is presented, based on scanning electron microscopy observations in Rhinoglena fertoeensis, R. frontalis, R. kutikovae, R. tokioensis, and Proalides tentaculatus, to contribute to the understanding of this structure of high evolutionary and functional relevance in Rotifera. The first observable and distinctly sclerotized structures were a double row of median transversal sclerites along the longitudinal axis, wherein the future unci, rostellar scleropili, cristae rami, and basal apophyses became recognizable. Fulcrum and manubria arose subsequently; the fulcrum sclerites were longitudinally ordered in a double layer. The rami chambers developed last as lamellar structures. Unci appeared as separate thin, elongate elements, the primary uncini, developing to uncus plates by transversal growth and apposition of sclerite material on the shafts of the uncini. The heads of the uncini showed their greatest development after fusion of their shafts into uncus plates. The interjacent spaces between the heads functioned as a mold, organizing bundles of sclerites which developed into the uniseriate, zigzag‐shaped cristae rami. The fulcrum attained its definite shape by elongation of the double layer of rod‐shaped sclerites into appressed sclerofibrillae. Manubria became visible as a proximal ridge of sclerites, whereupon a triangular lamella composed of crisscross‐oriented sclerites developed distally, growing out to the manubrial chambers. Ramus chambers originated from two longitudinal amorphous lamellae incorporating the median rami sclerites and closing from distal to proximal; subbasal chambers were formed before the basal chambers.

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Section: Discussionmentioning

confidence: 99%

Ontogeny of the jaws of monogonont rotifers: the malleate trophi of Rhinoglena and Proalides (Ploima, Epiphanidae)

Smet

Segers

2017

Invertebrate Biology

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“…In Brachionus (e.g. Guerrero-Jiménez et al 2015) with a maleate trophi, the manubrium, the unci with connected teeth, and the ramus form some sort of surface . In Adineta, with a ramate trophi , there is no such membrane, although uncus teeth are quite numerous and can give an impression of membrane, this last structure is not continuous (e.g.…”

Section: Jaw Apparatus Forming a Ventral Membrane (Removed)mentioning

confidence: 99%

Careful amendment of morphological data sets improves phylogenetic frameworks: re-evaluating placement of the fossil Amiskwia sagittiformis

Bekkouche

Gąsiorowski

2022

Journal of Systematic Palaeontology

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The Cambrian fossil Amiskwia sagittiformis has puzzled palaeontologists for more than a century, but recent reinvestigation of its morphology suggested a close relationship with the bilaterian clade Gnathifera, comprising Rotifera, Gnathostomulida and Micrognathozoa. Since Amiskwia has already been considered closely related to Chaetognatha, this new interpretation of its morphology supports recent molecular and developmental studies finding a close phylogenetic relationship between Chaetognatha and Gnathifera. The recent redescription of the jaw apparatus of Amiskwia with the first phylogenetic analysis by Vinther and Parry (2019) found a rather surprising topology with Amiskwia and Chaetognatha being sister groups and nested inside Gnathifera. Furthermore, a following paper from Caron and Cheung (2019) redescribed the jaws of Amiskwia as very similar to the 2 configuration found in Gnathostomulida, but did not carry any phylogenetic analysis.Here we test the topology of Vinther and Parry with various parsimony and Bayesian analyses, taking into account the new description of Caron and Cheung with careful re-amendment of the matrix of Vinther and Parry. According to our results and the recent findings on the molecular phylogeny of their extant members, we suggest a new systematization of these taxa. We recovered Amiskwia as a stem group chaetognath within a clade Cucullophora nov., rejecting the Caron and Cheung hypothesis of its close affinity to Gnathostomulida, and found a more consensual topology with monophyletic Gnathifera sister group to Cucullophora, altogether forming the clade Chaetognathifera. Furthermore the clade Rotifera + Micrognathozoa form a clade named Gynognathifera nov.. We discuss the characters supporting each clade and the reasons that account for the topology found by Vinther and Parry. Finally, we hope that this carefully amended matrix focused on Gnathifera, Amiskwia and Chaetognatha, together with a formal classification and robust phylogeny, will be of use for future studies on the palaeontology and morphology of these clades.

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Ultra Structural Comparison of Trophi in Species of the Genus <i>Brachionus</i> Pallas, 1766 in Aguascalientes State, Mexico

Cited by 2 publications

References 15 publications

Ontogeny of the jaws of monogonont rotifers: the malleate trophi of Rhinoglena and Proalides (Ploima, Epiphanidae)

Ontogeny of the jaws of monogonont rotifers: the malleate trophi of Rhinoglena and Proalides (Ploima, Epiphanidae)

Careful amendment of morphological data sets improves phylogenetic frameworks: re-evaluating placement of the fossil Amiskwia sagittiformis

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