03253nas a2200217 4500008004100000022001400041245016400055210006900219260001500288300000900303490000700312520249800319653001502817653001402832653002602846653001402872653001902886100001702905700002802922856008502950 2021 eng d a1742-999400aWhen SEM becomes a deceptive tool of analysis: the unexpected discovery of epidermal glands with stalked ducts on the ultimate legs of geophilomorph centipedes0 aWhen SEM becomes a deceptive tool of analysis the unexpected dis c20/04/2021 a1-190 v183 a

Background: The jointed appendage is a key novelty in arthropod evolution and arthropod legs are known to vary enormously in relation to function. Among centipedes, the ultimate legs always are distinctly different from locomotory legs, and different centipede taxa evolved different structural and functional modifications. In Geophilomorpha (soil centipedes), ultimate legs do not participate in locomotion and were interpret to serve a sensory function. They can be sexually dimorphic and in some species, male ultimate legs notably appear “hairy”. It can be assumed that the high abundance of sensilla indicates a pronounced sensory function. This study seeks for assessing the sensory diversity, however, documents the surprising and unique case of an extensive glandular epithelium in the ultimate legs of three phylogenetically distant species.
Results: The tightly aggregated epidermal glands with stalked ducts – mistakenly thought to be sensilla – were scrutinized using a multimodal microscopic approach comprising histology as well as scanning and transmission electron microscopy in Haplophilus subterraneus. Hence, this is the first detailed account on centipede ultimate legs demonstrating an evolutionary transformation into a “secretory leg”. Additionally, we investigated sensory structures as well as anatomical features using microCT analysis. Contrary to its nomination as a tarsus, tarsus 1 possesses intrinsic musculature, which is an indication that this podomere might be a derivate of the tibia.
Discussion: The presence and identity of ultimate leg associated epidermal glands with stalked ducts is a new discovery for myriapods. A pronounced secretory as well as moderate sensory function in Haplophilus subterraneus can be concluded. The set of characters will improve future taxonomic studies, to test the hypotheses whether the presence of these specialized glands is a common feature in Geophilomorpha, and that tarsus 1 may be a derivate of the tibia. As the number of epidermal glands with stalked ducts is sexually dimorphic, their function might be connected to reproduction or a sex-specific defensive role. Our results, in particular the unexpected discovery of ‘glandular hairs’, may account for a striking example for how deceptive morphological descriptions of epidermal organs may be, if based on non-invasive techniques alone.

10acentipedes10aEvolution10aFunctional morphology10aHistology10aUltrastructure1 aSombke, Andy1 aMüller, Carsten, H. G. uhttps://frontiersinzoology.biomedcentral.com/articles/10.1186/s12983-021-00402-302468nas a2200289 4500008004100000022001400041245016100055210006900216260001500285300001400300490000700314520151200321653001301833653001401846653002301860653001901883653001401902653002501916100002601941700003101967700003001998700002202028700002502050700002002075700002702095856005602122 2019 eng d a0944-134400aHistopatology and HSP70 analysis of the midgut of Rhinocricus padbergi (Diplopoda) in the evaluation of the toxicity of two new metallic-insecticides0 aHistopatology and HSP70 analysis of the midgut of iRhinocricus p c14/12/2019 a3023-30330 v273 a

Millipedes are organisms of the edaphic fauna and have been used as bioindicators for the evaluation of pollutants in the environment, as they are in constant contact with the soil. This study used the millipede Rhinocricus padbergi as surrogate to evaluate the toxicity of two metallic-insecticides that has been developed for leaf-cutting ants management. Millipedes were exposed in terrariums containing different concentrations of the metallic-insecticides and, after periods of 21 and 90 days, three individuals from each terrarium were dissected in order to remove the midgut, the organ where absorption of nutrients and, consequently, toxic substances occurs. The toxic action of the metallic-insecticides was analyzed through qualitative and semi-quantitative analysis of morphophysiological alterations and by quantitative analysis of the HSP70 stress protein. The results showed that the metallic-insecticides may increase HSP70 labeling, although not at all concentrations and periods of exposure. Histopathological alterations were not significant at any concentration, indicating that the cytoprotective action of HSP70 is able to prevent severe damage to the midgut. It is therefore suggested that the metallic-insecticides are not toxic to the species studied here as no toxicity was observed under the conditions tested. In addition, stress protein localization in midgut helps understand how morphophysiological processes can potentially be affected by pesticide exposure.

10adiplopod10aFormicide10aHeat shock protein10aHistochemistry10aHistology10aImmunohistochemistry1 ade Souza, Raphael, B.1 aMoreira-de-Sousa, Cristina1 aAnsoar-Rodríguez, Yadira1 aCoelho, Maria, PM1 ade Souza, Cleiton, P1 aBueno, Odair, C1 aFontanetti, Carmem, S. uhttp://link.springer.com/10.1007/s11356-019-07203-602661nas a2200253 4500008004100000022001300041245013500054210006900189260001500258490000800273520183100281653001402112653002202126653002102148653001402169653001402183100002102197700001802218700003502236700002102271700002302292700002502315856006702340 2019 eng d a1096495900aEnzymatic activities in the digestive tract of spirostreptid and spirobolid millipedes (Diplopoda: Spirostreptida and Spirobolida)0 aEnzymatic activities in the digestive tract of spirostreptid and c18/11/20190 v2413 a

Millipedes represent a model for the study of organic matter transformation, animal-microbial interactions, and compartmentalisation of digestion. The activity of saccharidases (amylase, laminarinase, cellulase, xylanase, chitinase, maltase, cellobiase, and trehalase) and protease were measured in the midgut and hindgut contents and walls of the millipedes Archispirostreptus gigas and Epibolus pulchripes. Assays done at pH 4 and 7 confirmed activities of all enzymes except xylanase. Hydrolysing of starch and laminarin prevailed. The hindgut of E. pulchripes was shorter, less differentiated. Micro-apocrine secretion was observed only in the midgut of A. gigas. Merocrine secretion was present in midgut and hindgut of E. pulchripes, and in the pyloric valve and anterior hindgut of A. gigas. Alpha-polysaccharidases were mostly active in the midgut content and walls, with higher activity at pH 4. The low activity of amylase (A. gigas) and laminarinase (E. pulchripes) in midgut tissue may indicate their synthesis in salivary glands. Cellulases were found in midgut. Chitinases, found in midgut content and tissue (E. pulchripes) or concentrated in the midgut wall (A. gigas), were more active at an acidic pH. Polysaccharidases were low in hindguts. Protease shows midgut origin and alkaline activity extending to the hindgut in E. pulchripes, whereas in A. gigas it is of salivary gland origin and acid activity restricted to the midgut. Some disaccharidases, with more alkaline activity, showed less apparent midgut-hindgut differences. It may indicate an axial separating of the primary and secondary digestion along the intestinal pH gradient or the presence of enzymes of hindgut parasites.

10aCellulase10aDigestive enzymes10aGut compartments10aHistology10aMyriapoda1 aŠustr, Vladimir1 aSemanová, S.1 aRost-Roszkowska, Magdalena, M.1 aTajovský, Karel1 aSosinka, Agnieszka1 aFlorentyna, Kaszuba. uhttps://linkinghub.elsevier.com/retrieve/pii/S109649591930347103249nas a2200217 4500008004100000022001400041245007700055210007200132260001500204300001200219490000800231520262600239653001202865653001402877653003002891653001502921653001402936100001702950700001702967856004702984 2020 eng d a1313-298900aNo Tömösváry organ in flat backed millipedes (Diplopoda, Polydesmida)0 aNo Tömösváry organ in flat backed millipedes Diplopoda Polydesmi c28/04/2020 a103-1150 v9303 a

The Tömösváry organ is a sensory structure of the head in myriapods and some other terrestrial arthropods. Due to its variable shape, size, and position in millipedes (Diplopoda) the Tömösváry organ is commonly used as diagnostic character in taxonomic descriptions and often included in phylogenetic analyses. For the Polydesmida, the largest millipede order, the Tömösváry organ is inconsistently stated as being either absent or present as a pear-shaped pit covered by a membrane or cuticular disc. In order to resolve this inconsistency, we investigated the morphology of the presumable Tömösváry organ in four polydesmidan species based on paraffin-histology, semi-thin sections and micro-computed tomography. Our results unambiguously favor the view that the articulation of the cephalic tentorium with the head capsule was misidentified as the Tömösváry organ in previous studies, and thus that the Tömösváry organ indeed is absent in the Polydesmida. The pear-shaped pit proved to represent the distal roundish expansion of the incisura lateralis, to which – similarly as in julidan millipedes – the tentorial transverse bar is articulated. The absence of the Tömösváry organ in the Polydesmida does not affect the topology of the interrelationships among the millipede orders retrieved in previous cladistic analyses based on morphology. As a character shared by Colobognatha and Juliformia, however, absence of a Tömösváry organ in Polydesmida favors the optimization of its presence in nematophoran millipedes as a reversal. Further studies are needed to clarify whether among chilognathan millipedes a Tömösváry organ really exists in taxa such as Stemmiulida, and whether the Tömösváry organs are homologous across millipedes.

 

10aanatomy10aHistology10aMicro-Computed Tomography10amorphology10atentorium1 aMoritz, Leif1 aKoch, Markus uhttps://zookeys.pensoft.net/article/48438/