Arthropod Structure & Development最新文献

{"title":"Anatomy of the light organ of the glow-worm Arachnocampa flava (Diptera; Keroplatidae)","authors":"Hamish R. Charlton,&nbsp;David J. Merritt","doi":"10.1016/j.asd.2025.101488","DOIUrl":"10.1016/j.asd.2025.101488","url":null,"abstract":"<div><div>In dipteran glow-worms (genus <em>Arachnocampa</em>) bioluminescence is produced by cells of the Malpighian tubules. Light is used to lure prey into sticky webs secreted by the larvae. Larvae can regulate the intensity of the emitted light so neural control of the glow is likely, either acting directly on the light-emitting cells or through regulation of oxygen access to the light organ. Here we describe the innervation, musculature, and tracheal supply in relation to the three-dimensional structure of the light organ, cryptonephridial complex and hindgut using serial section light microscopy and micro computed tomography (μCT). We also use video macrophotography to observe light emission in live larvae. Tracing of trachea in serial sections showed no structures that could actively restrict air supply to the mass of trachea termed the reflector. A bilateral pair of nerves lie alongside the Malpighian tubules and give rise to branches that innervate the hindgut and musculature. A network of muscles surround the light organ. A cryptonephridial complex anterior to the light organ is surrounded by a connective tissue sheath. The fact that the cryptonephridial complex is a plesiomorphic trait in Keroplatidae, the majority of which are not bioluminescent, suggests that the light organ is evolutionarily derived from the complex. We also propose that the cryptonephridial complex has a water conservation function in <em>Arachnocampa</em> because the larvae are potentially water-restricted. The three-dimensional reconstruction of the light organ provides morphological context for ongoing investigations of the biochemistry of light production and the physiological regulation of light output.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"89 ","pages":"Article 101488"},"PeriodicalIF":1.3,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An overview of campaniform sensilla arrangement and location on hexapod legs","authors":"Ruben G.F. Eich,&nbsp;Jane I. Lemmen,&nbsp;Brian Saltin,&nbsp;Alexander Blanke","doi":"10.1016/j.asd.2025.101477","DOIUrl":"10.1016/j.asd.2025.101477","url":null,"abstract":"<div><div>Campaniform sensilla (CS) are mechano-sensors in the cuticle of insects which are able to detect cuticle deformation. On insect legs, CS play a role in the modulation of locomotion behavior because they provide feedback on cuticle bending. The presence and location of these sensors on the legs across insects is virtually unknown except for a few classical model species such as <em>Drosophila melanogaster</em> (Diptera), <em>Periplaneta americana</em> (Blattodea), <em>Carausius morosus</em> (Phasmatodea) and a few others. We studied representatives of all insect orders, except Strepsiptera, regarding the morphology, location, and arrangement of CS on their legs to infer whether (i) CS location and arrangement is phylogenetically structured, (ii) there is any variation in CS morphology in relation to leg function, and (iii) CS morphology and arrangement is fundamentally different between holo- and hemimetabolous insects. We found enormous variation in all three aspects studied here - CS morphology, location, and arrangement - with no tangible phylogenetic structure or any distinction between holo- and hemimetabolous insects. Moreover, species from orders which are commonly considered to walk only for very short distances such as Odonata or Raphidioptera showed high quantities of CS on their legs compared to orders which are commonly considered to have “good” walking abilities such as Coleoptera or Diptera. We could also find putative CS on the coxa in Odonata, Dermaptera, Plecoptera, Orthoptera, Mantophasmatodea, Grylloblattodea, Embioptera, Blattodea, Hymenoptera, Raphidioptera, Neuroptera, Coleoptera, and Mecoptera which contradicts a common paradigm that CS occur only from the trochanter towards more distal leg segments. With its high variability, it appears that CS location and arrangement evolves according to the particular ecological and neurophysiological niche of each species with no phylogenetic constraints and a rather high adaptivity instead. Our study provides a baseline for future studies on CS function in insects with different ecological niches.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101477"},"PeriodicalIF":1.3,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144852253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Complete cycle of receptacle development in parasitic barnacle, Parasacculina pilosella (Van Kampen and Boschma, 1925) (Rhizocephala: Polyascidae)","authors":"Olga V. Yurchenko,&nbsp;Darya D. Golubinskaya,&nbsp;Alexander V. Kalachev,&nbsp;Olga M. Korn","doi":"10.1016/j.asd.2025.101476","DOIUrl":"10.1016/j.asd.2025.101476","url":null,"abstract":"<div><div>The complete cycle of receptacle development in the parasitic barnacle <em>Parasacculina pilosella</em> (Van Kampen and Boschma, 1925) (Rhizocephala: Polyascidae) was studied by light and electron microscopy. This rhizocephalan has two globular receptacles located outside the visceral sac. Two variants of development of the receptacles from the same externa were observed: (1) with both receptacles fertile and (2) with one of them (usually larger one) fertile and the other sterile. The presence of the second fertile receptacle probably extends the breeding season in <em>P. pilosella</em>. The following stages in the development of the fertile receptacle were identified: trichogon-free, trichogon-containing, early, middle, late, and degenerating. The sterile receptacle that has not received a trichogon, continued to develop and, after reaching the middle stage, atrophied. The cell types composing the receptacle wall (accessory, large female, polygonal, small-sized, and sheath cells) and the meshwork formed by the intercellular matrix were examined in detail. The accessory cells that separated spermatogenic and large female cells were probably derived from the trichogon which implanted cells of both germ and somatic lines. Globular and tubular receptacles had different fine organizations. Globular receptacles, as well as tubular ones, lacked morphological structures separating female and male organisms. Further studies, involving a larger number of other rhizocephalan species, are needed to clarify whether the receptacle ultrastructure can be useful in resolving taxonomic issues.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101476"},"PeriodicalIF":1.3,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144842022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Sp6-9 ortholog is expressed in developing legs in the tardigrade Hypsibius exemplaris","authors":"Mandy Game ,&nbsp;Frank W. Smith","doi":"10.1016/j.asd.2025.101471","DOIUrl":"10.1016/j.asd.2025.101471","url":null,"abstract":"<div><div>Orthologs of the zinc finger transcription factor-coding gene <em>Sp6-9</em> are expressed in developing appendages across Arthropoda and in Onychophora. Sp6-9 regulates appendage outgrowth in some arthropods by activating <em>Distal-less</em> (<em>Dll</em>) expression. This function has been proposed to represent an ancestral function of <em>Sp6-9</em> for Arthropoda. Expression patterns of <em>Sp6-9</em> and <em>Dll</em> in the onychophoran <em>Euperapotoides kanangrensis</em> suggest the conservation of this function in Onychophora. Here, we investigate <em>Sp6-9</em> in the tardigrade <em>Hypsibius exemplaris</em>. We identified two <em>Sp6-9</em> orthologs in this species. One ortholog, <em>He-Sp6-9A</em>, was expressed in the lateral ectoderm where legs develop before <em>He-Dll.</em> Later, both genes were expressed in limb buds at the earliest stages of outgrowth and were broadly expressed in developing legs throughout the remainder of development. Our results present the possibility that an ortholog of <em>Sp6-9</em> regulates appendage outgrowth in Tardigrada, possibly by activating or maintaining expression of <em>He-Dll</em>. These results raise the possibility that this function was already present in the last common ancestor of Panarthropoda.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101471"},"PeriodicalIF":1.3,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144827307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of hydraulic pressure in spider cheliceral function","authors":"Hannah M. Wood ,&nbsp;Jeffrey W. Shultz","doi":"10.1016/j.asd.2025.101475","DOIUrl":"10.1016/j.asd.2025.101475","url":null,"abstract":"<div><div>Recent μCT-based surveys of spider chelicerae highlight a problematic aspect of skeletomuscular function, that is, the absence of extrinsic muscles capable of projecting the chelicerae outward or forward. Instead, all appear to generate an inward or rearward force. Previous work by comparative anatomists assigned antagonistic functions to sets of extrinsic muscles, but no anatomically distinct pivot points within a lever-based system were specified and do not appear to exist. These observations led us to revisit the problem and to propose a significant role for internal hydraulic pressure in cheliceral movement. The hydraulic hypothesis predicts that unimpeded increase in internal fluid pressure should result in inflation of basal membranes resulting in movement that could be resisted and manipulated by extrinsic cheliceral muscles. Experiments on freshly killed spiders showed that increased hydraulic pressure causes both rotational (adduction, levation, etc.) and translational (projection) movements at the cheliceral bases, movements that are synergistic with predatory strikes. This suggests that the co-option of hydraulics into cheliceral function may have increased cheliceral biting forces. Hydraulic function also allows for the basal cheliceral articulation to simultaneously produce both rotational and translational movement, a challenge for a lever-based fixed articulation. The co-option of hydraulics into additional tasks may have contributed to the evolutionary success of spiders, compared to their arachnid relatives that use hydraulics solely for locomotion.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101475"},"PeriodicalIF":1.3,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144826808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights for the subtribal-level phylogenetic reconstructions in Paederinae (Coleoptera: Staphylinidae): a study on mesoventral plate with elements of comparative morphology","authors":"Alexandra Tokareva ,&nbsp;Dagmara Żyła","doi":"10.1016/j.asd.2025.101473","DOIUrl":"10.1016/j.asd.2025.101473","url":null,"abstract":"<div><div>Morphological characters are one of the bases for describing any organismal group and comparative morphology plays an important role in taxonomy, systematics, and evolutionary research. Yet, in many groups, especially highly diverse, the terminology and homology of morphological structures are poorly understood. One of such examples is the mega-diverse group of animals, rove beetles (Staphylinidae), where comparative studies are very rare, both across the subfamilies and within them. In this paper, we present our results of morphological examination of mesoventral sclerotisation across different subtribes and genera of Paederinae, which is one of the most diverse rove beetle subfamily. Additionally, we compare them with several representatives of Staphylininae and Xantholininae. We revise morphological terminology for the mesoventral area in Paederinae and propose a hypothesis for character homologisation within Paederinae and across the listed subfamilies. Our results are based on examination of representatives of 157 Paederinae genera and the major groups are illustrated by schematic drawings and SEM scans. Additionally, we introduce new characters with potential importance for subtribal level phylogenetic reconstruction of Paederinae relationships. This is the first comprehensive review of the mesoventral area for the subfamily.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101473"},"PeriodicalIF":1.3,"publicationDate":"2025-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144763917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An evo-devo perspective on terrestrial isopod respiratory organs","authors":"Kian Long Tan,&nbsp;Antónia Monteiro","doi":"10.1016/j.asd.2025.101470","DOIUrl":"10.1016/j.asd.2025.101470","url":null,"abstract":"<div><div>The evolution and diversification of respiratory structures enabled arthropods to colonize terrestrial habitats multiple times independently. One such group of ancestrally marine arthropods, the Isopods, successfully colonized freshwater and terrestrial habitats. The transition to land was facilitated by the evolution of novel respiratory organs on the abdomen, the pleopodal lungs, which either complemented or replaced the ancestral pleopodal gills. Here, we review the current understanding of terrestrial isopod respiratory structure evolution and development and explore its potential molecular basis. We hypothesize how pleopodal gills and lungs may share common developmental features and propose candidate genes for respiratory structure development. We propose that work in this area holds significant implications for our understanding of breathing structure evolution and physiology across the Arthropoda.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101470"},"PeriodicalIF":1.7,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of light spectra emitted by two firefly species: Luciola italica and Luciola pedemontana","authors":"Tito Sacchi ,&nbsp;Matteo Galli ,&nbsp;Giuseppe Camerini","doi":"10.1016/j.asd.2025.101472","DOIUrl":"10.1016/j.asd.2025.101472","url":null,"abstract":"<div><div>Light plays an important role in fireflies (Coleptera, Lampyridae) and emission spectra and signalling patterns are usually species specific. In Italy there are two species of fireflies belonging to the genus <em>Luciola: Luciola italica</em> and <em>L. pedemontana</em>. No information was available on the light spectrum emitted by <em>L. italica</em> in vivo; moreover, the only data obtained on <em>L. pedemontana</em> dated back more than 50 years and were obtained using outdated measurement equipment. To fill this gap, we studied the spectra of adult males and females of both species. Samples were collected from the western central Po floodplain. Adults were sampled in the early part of the night when they were engaged in mating activity. The next day they were brought to the laboratory and their light emission was analysed using a spectrometer. The maximum emission wavelength (λ max) ranged from 571.8 nm to 584.8 nm. The values of λ max emitted by females of <em>L. italica</em> (581.5±2.4) and <em>L. pedemontana</em> (575.9±2.6) were significantly different. The plots obtained from the light emission measurements show a clear asymmetry, with a shorter tail on the left and a positive skew on the right. As light spectra depend on the structure of luciferases, such differences may indicate ongoing changes in the molecular composition of these enzymes resulting from the genomic divergence of the two species. The spectra of <em>L. italica</em> and <em>L. pedemontana</em> fall in the yellow region and are comparable to those of other <em>Luciola</em> species living in eastern Asia.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101472"},"PeriodicalIF":1.7,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144672487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The first complete larval development of the parasitic barnacle from the genus Briarosaccus","authors":"Darya D. Golubinskaya,&nbsp;Olga M. Korn","doi":"10.1016/j.asd.2025.101469","DOIUrl":"10.1016/j.asd.2025.101469","url":null,"abstract":"<div><div>The complete larval development of <em>Briarosaccus hoegi</em> (Rhizocephala: Peltogastridae)<em>,</em> including five naupliar and one cypris stages, is described and illustrated using SEM. The present study confirms that all rhizocephalans have 5 naupliar stages during the larval development. The larvae of <em>B. hoegi</em> are almost twice as large as the larvae of other rhizocephalans. Male larvae are considerably larger than female ones, their sizes never overlap. Larvae of <em>B. hoegi</em> show the peltogastrid type of development. Late male nauplii have large frontal protrusions, absent in female larvae. The second antennular segment in male nauplii is definitely longer than that in female larvae. These two characters indicate a distinct sexual dimorphism between male and female nauplii of rhizocephalans. Nauplii and cyprid of <em>B. hoegi</em> have pigmented nauplius eyes and show positive phototaxis. There is no correlation between the presence of a flotation collar and a nauplius eye in rhizocephalan larvae. The attachment disc in the female cyprid has a flap-like extension at the posterior margin. The attachment disc in male and female cyprids possesses two sensory setae. The large aesthetasc in the male cyprid is unilobed. The subterminal aesthetasc in female cyprid terminates into a single long filamentous process. A short postaxial sensory seta on the second antennular segment is completely reduced in the male cyprid. The nauplii and cyprids of <em>B. hoegi</em> and <em>Briarosaccus tenellus</em> are very similar. Our study confirms that the genus <em>Briarosaccus</em> consists of two cryptic species.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"88 ","pages":"Article 101469"},"PeriodicalIF":1.7,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling the insect head: Segmentation and pancrustacean homologous","authors":"Patricia Nel ,&nbsp;Michael S. Engel ,&nbsp;Carmen Soriano ,&nbsp;Sylvain Pont ,&nbsp;Lauriane Jacquelin ,&nbsp;Laurence Dollinger ,&nbsp;Laure Desutter-Grandcolas ,&nbsp;Tony Robillard ,&nbsp;Romain Garrouste ,&nbsp;Dany Azar ,&nbsp;André Nel","doi":"10.1016/j.asd.2025.101462","DOIUrl":"10.1016/j.asd.2025.101462","url":null,"abstract":"<div><div>The segmental composition of the arthropodan head is a long-standing biological question. This is particularly controversial in insects where considerable fusion and modification obfuscate the postembryonic segmentation. Here we propose a reinterpretation of the insect head morphology and segmentation, which also accords with current genetic and embryological data. The new interpretation of a generalized insect head is based on the discovery of intercalary segment remnants (the intercalates), thanks to the use of 3D-reconstruction of a Cretaceous thripidan and to a reassessment of the ‘anterior tentorial arm’ as the anteriormost part of a lateral segmental suture from the contact of the head lobe and gnathal segments during development. We show that the two-jointed mandibular articulation is likely symplesiomorphic for Insecta, no longer supporting the clade ‘Dicondylia’, the most diverse lineage of all insects. We discuss new perspectives on the ‘labrum’ in Pancrustacea.</div></div>","PeriodicalId":55461,"journal":{"name":"Arthropod Structure & Development","volume":"87 ","pages":"Article 101462"},"PeriodicalIF":1.7,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}