Topic
Chaeta
About: Chaeta is a research topic. Over the lifetime, 144 publications have been published within this topic receiving 1764 citations.
Papers published on a yearly basis
Papers
TL;DR: Two new species of Tubificoides (subfamily Tubificinae) are described based on morphological analyses, one of which strongly resembles the north-west European, largely sublittoral species T. amplivasatus, but differs from this species in terms of body size, width of vas deferens, and the shape and size of both the ejaculatory duct and penial sac.
Abstract: Two new species of Tubificoides (subfamily Tubificinae), T. charlotteae n. sp. and T. mackiei n. sp., are described based on morphological analyses. Both species were flagged as potentially cryptic in a previous investigation, based on both mitochondrial and nuclear sequence data. Tubificoides charlotteae n. sp., known only from an intertidal site in southern Spain, is characterized by the lack of cuticular papillation, the possession of several needle-like hair chaetae in dorsal bundles, a cone-shaped penis sheath, and a rather large, muscular penial sac. It strongly resembles the north-west European, largely sublittoral species T. amplivasatus, but differs from this species in terms of body size, width of vas deferens, and the shape and size of both the ejaculatory duct and penial sac. Tubificoides mackiei n. sp., collected from the southeast coast of Norway and the west coast of Sweden, is characterized by the lack of cuticular papillae and hair chaetae, and the possession of a rather long penis sheath with a wide terminal opening. It shares several morphological features with the sympatric species Tubificoides pseudogaster, but is distinguished from the latter by the detailed morphology and length of the penis sheaths, the width of the atrium, and the lower maximal number of bifid chaetae in dorsal preclitellar bundles. The utility of an integrative comparative approach, combining molecules and morphology, for the identification and delineation of new taxa within Tubificoides is briefly discussed.
104 citations
TL;DR: Two new species of the genus Temeritas are described from Brazil: T. andreazzei sp.
Abstract: Temeritas Richards is a small genus of Sminthuridae with 40 species described worldwide, 10 of them from Neotropical Region. Herein we describe in detail two new species of the genus from Brazil: T. andreazzei sp. nov., similar to other neotropical taxa such T. amazonensis Arle & Oliveira and T. caatingae Arle & Oliveira in the presence of several long chaetae on body and appendages, absence of oval organs on tibiotarsi and presence of mucronal chaeta, but can be readily separate from both by its exclusive combination of fourth antennal segment articles and head, male’s parafurcal area and dorsal dens chaetotaxy; and T. paradoxalis sp. nov., unique in the genus by the combination of low number of fourth antennal segment articles, absence of remarkably long chaetae on third and second antennal segments and head, ungues with serrated dorsal and lateral margins, and mucronal chaeta absent. We also present an updated diagnosis, a comparison of neotropical Temeritas with an identification key to these species and notes on the genus.
98 citations
TL;DR: Pogonophora, also known as Siboglinidae, are tube-dwelling marine annelids that rely on endosymbiotic chemoautotrophic bacteria for nutrition and their anatomy and physiology are adapted to their need to obtain both oxygen and reduced sulphur compounds.
Abstract: Pogonophora, also known as Siboglinidae, are tube-dwelling marine annelids. They rely on endosymbiotic chemoautotrophic bacteria for nutrition and their anatomy and physiology are adapted to their need to obtain both oxygen and reduced sulphur compounds. Frenulate pogonophores are generally long and slender, sediment-living tubeworms; vestimentiferans are stouter, inhabitants of hydrothermal vents and cool seeps; and moniliferans or sclerolinids are very slender inhabitants of decaying wood and sulphidic sediments. The anatomy and ultrastructure of the three groups are compared and recent publications are reviewed. Annelid characters are the presence of chaetae and septa, concentrated at the hind end. The adaptations to a specialised way of life include, in particular, the chitinous tube; the anterior appendages that function as gills; the internal tissue called the trophosome, where the endosymbiotic bacteria live; and the blood vascular system that transports oxygen, sulphide and carbon dioxide to the trophosome.
96 citations
TL;DR: An updated diagnosis of Aethiopella based on current knowledge of Pseudachorutinae is presented, a table comparing all species, a key to Neotropical taxa and remarks on the genus are presented.
Abstract: Aethiopella Handschin, 1942 as other Pseudachorutinae (Neanuridae) presents a diagnosis with overlapping characters when compared to other similar genera, especially Halachorutes Arle, 1966, Ceratrimeria Borner, 1906 and Pseudachorutes Tullberg, 1871. This condition, combined to several gaps on the knowledge of described species and a wide range of morphological differences within the genus, reinforces the need of its revision, since it can be an artificial group. In spite of that, a new species, Aethiopella ricardoi sp. nov., is described and illustrated. It resembles the other five Neotropical taxa of Aethiopella but is unique by the combination of fourth antennal segment with trilobed apical bulb and 7 dorsal sensilla, lack of dorsolateral S-microchaeta (ms); postantennal organ with 13-19 vesicles; mandibles with 7-8 teeth; maxillae apically hooked; and tibiotarsi I-III with 19/19/18 chaetae, respectively, with M chaeta slightly basally displaced. We also present an updated diagnosis of Aethiopella based on current knowledge of Pseudachorutinae, a table comparing all species, a key to Neotropical taxa and remarks on the genus.
95 citations
TL;DR: The main emphasis is laid on the evaluation of the position of the taxon within the Clitellata, including a discussion of the Branchiobdellida, and the cladograms presented show the Acanthobdella peledina to be the sister group of the Euhirudinea.
Abstract: In recently collected specimens of Acanthobdella peledina the nervous system, the genital organs and the coelomic organisation were reinvestigated after complete serial sections. These anatomical results are schematically represented. In addition, the integument, the chaetae and the peripheral muscle layer were investigated by electron microscopy. In general, the results confirm Livanow's classic monograph (1906), with the exception of a few details. The body apparently possesses neither a prostomium nor an achaetous buccal region (peristomium). The number of 29 true segments is concluded from the number of segmental ganglia. The five anteriormost segments, each with four pairs of hookshaped chaetae arranged around the mouth opening, are considered to be functionally equivalent to an anterior sucker. The ultrastructure of the integument and the chaetae generally conforms to the typical annelidan pattern. The muscle cells are of the typical hirudinean type. The outer male genital pore is positioned in segment 10; the female organs open in segment 11 directly behind the septum between segments 10 and 11. The main emphasis is laid on the evaluation of the position of the taxon within the Clitellata, including a discussion of the Branchiobdellida, and the cladograms presented show the Acanthobdellida to be the sister group of the Euhirudinea. Characters shared by the Branchiobdellida and Hirudinea (including A. peledina) are considered to be convergently evolved.
87 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 55 |
| 2024 | 65 |
| 2023 | 52 |
| 2022 | 280 |
| 2021 | 217 |
| 2020 | 51 |