Morphological Similarity and Taxonomic Confusion Between Neoscona (Araneidae) Species: Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876)

Morphological Similarity and Taxonomic Confusion Between Neoscona (Araneidae) Species: Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876) | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Morphological Similarity and Taxonomic Confusion Between Neoscona (Araneidae) Species: Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876) Adile Akpınar, Şuheda Ay, Asiye Seçkin, Derya Arslan Talapov This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9402334/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract This study presents a comparative morphological analysis of the closely related species Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876) (Araneidae). A total of 100 specimens representing these two species were examined, and 83 morphological characters were identified. A dataset was constructed and scored based on these characters, including morphological features of the prosoma, opisthosoma, spinnerets, as well as male and female genital structures. Principal Coordinate Analysis (PCoA) and the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) were applied to the dataset to generate scatter plots and dendrograms illustrating morphological relationships among the specimens. The results indicated that specimens of N. adianta and N. byzanthina could not be reliably distinguished based on habitus-related morphological characters or genital morphology. Analyses based solely on female genital characters allowed partial separation of the species, whereas male genital characters exhibited limited discriminatory power. Overall, the findings suggest that these taxa are not fully differentiated and that N. byzanthina may represent a subspecies of N. adianta . However, further integrative and comprehensive comparative studies are required to clarify the taxonomic relationship between these taxa. Araneidae morphological features Neoscona adianta Neoscona byzanthina spider Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Neoscona Simon, 1864, belongs to the family Araneidae and can be readily distinguished from other genera by the characteristic oval shape of the opisthosoma and its distinctive zigzag pattern (Nentwig et al., 2026). The genus comprises 124 species worldwide, ranking fifth in species richness within the family (World Spider Catalog, 2026). Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876) are among the most taxonomically controversial species within the genus (Geci and Naumova, 2021). The species identified as N. byzanthina is a poorly studied orb-weaving spider and was only relatively recently recognized as a valid species by Ledoux (2008). This species was originally described by Pavesi (1876) as Epeira byzanthina and was later described by Simon (1879) as Epeira turcica , based on specimens collected from Istanbul, Turkey. Simon (1884) subsequently acknowledged the priority of E. byzanthina when he reported this species for the first time from Greece (Euboea Island). Subsequently, both names were treated as synonyms of the widespread European species Neoscona adianta (Walckenaer, 1802) by Simon (1929). However, Ledoux (2008) re-established Neoscona byzanthina as a distinct species from the closely related N. adianta , based on a series of morphological characters, including genital structures. These two species have been primarily evaluated based on their external morphology, with N. byzanthina generally distinguished from N. adianta by its larger body size, opisthosomal pattern (in which the first lateral extensions of the opisthosomal bands are slightly smaller and the overall opisthosomal pattern is more variable than in N. adianta ), and femora that are typically darker apically (Mora-Rubio et al., 2019). To date, studies addressing these two species have been presented mainly as new records or checklist contributions rather than detailed morphological descriptions and comparative analyses (Danısman et al, 2025; Demircan Aksan N, Topçu A (2022c), Pintilioaie A-M, Urák I, (2022a); Bolognin et al, 2021; Maro Rubio et al, 2019; Blick 2018; Bosman et al, 2013; Ivanov,2013; Rozwałka R, Stanska M (2008); Bosman and Chatzaki, 2005; Kronestedt 2001; Gajdoš et al, 1999). The aim of this study was to compare N. adianta and N. byzanthina based on 83 morphological characters identified from their specimens in order to elucidate their similarities and differences. Materials and Methods Specimens were collected from the provinces of Çorum, Samsun, Sinop, and Amasya, located in the Black Sea Region of Türkiye, using an aspirator, hand collecting, and sweep-netting from vegetation. A total of 100 specimens belonging to N. adianta and N. byzanthina were examined, and 83 morphological characters were identified. Morphological characters were determined through direct examination using an Olympus SZX12E trinocular stereomicroscope. For specimens of both species, the following morphological features were examined: eye shapes; dorsal and lateral patterning of the prosoma; sternum shape; dorsal, lateral, and ventral patterning of the opisthosoma; structure and positioning of the spinnerets; and the morphology of male and female genital structures. The identified characters were scored as present (1) or absent (0) through manual entry in Microsoft Excel, and a data matrix was subsequently constructed (Appendix1 and Supplementary Table 1). The resulting data matrix was analyzed using the Dice similarity coefficient in PAST version 4.05, and an UPGMA dendrogram and PCoA scatter plots were generated. The collected specimens are preserved in 96% ethanol at − 20°C in the Zoology Laboratory of the Department of Biology, Faculty of Arts and Sciences, Gaziantep University. Results UPGMA and PCoA analyses were performed based on the morphological characters identified for N. adianta and N. byzanthina (excluding characters related to genital structures). According to the results of these analyses, no clear separation between the species was observed, and the dendrograms revealed mixed clustering of the two species (Figs. 1 and 2 ). UPGMA and PCoA analyses were performed based solely on the morphological characters of male sexual structures (Figs. 3 and 4 ). Examination of the results indicated that no clear separation could be observed among the male specimens (n = 20) of N. adianta and N. byzanthina . This suggests that the male sexual characters of both species are insufficient for reliably distinguishing between them. Data for UPGMA and PCoA analyses were obtained using only the morphological characters of female sexual organs based on the Dice coefficient (Figs. 5 and 6 ). The results indicated that partial separation could be observed among the female specimens (n = 80) of N. adianta and N. byzanthina. Discussion The main focus of this study was the morphological similarity between Neoscona adianta and Neoscona byzanthina . Previous studies have also highlighted their close resemblance. Simon (1929) treated N. byzanthina as a synonym of N. adianta , a species widely distributed in Europe. Later, Ledoux (2008) revalidated N. byzanthina as a distinct species, separate from the morphologically similar N. adianta . Comparative analyses of external morphology by Mora-Rubio et al. (2019) indicated that N. byzanthina differs from N. adianta by its larger overall size, the pattern of the opisthosoma (with the initial extensions of the opisthosomal bands being slightly smaller and the pattern more variable than in N. adianta ), and generally darker apical femora. Geci and Naumava (2021) further reported that males of N. byzanthina are notably larger and more robust, whereas no significant morphological differences were observed among females. These findings are further supported by the UPGMA and PCoA analyses presented in Figs. 3 – 6 . While sexual characters of male specimens were found to be insufficient for reliably distinguishing the species, partial separation could be achieved among female specimens. Ledoux (2008) reported that N. byzanthina is generally larger than N. adianta and does not typically occur in highly humid habitats. He also observed that adult N. adianta are usually active in June and July, whereas adult N. byzanthina are primarily observed in August and September. In contrast, in the present study, specimens of both species were collected in June and July, including adult individuals of both species. Contrary to Ledoux (2008), no consistent size differences were detected between N. byzanthina and N. adianta . Although Ledoux (2008) was the first to revalidate N. byzanthina , the morphological distinctions reported in his study were insufficient to provide clear diagnostic criteria for differentiating the two species. In this study, morphological differences reported in the literature were taken as references, and examinations were conducted using characters determined excluding genital structures to distinguish between N. adianta and N. byzanthina . In female specimens, distinct differences were observed particularly in the opisthosomal patterning, whereas such differences were not detected in male individuals. These variations observed in females, which were considered to be associated with geographic location, were found to be insufficient for reliable species discrimination. Based on this outcome, both male and female specimens were re-examined with genital structures included in the analyses. According to the evaluated characters, female specimens exhibited a partial clustering pattern distinguishing the two species; however, similarities in the epigynal structures created difficulties in species separation. Similarly, analyses conducted by including the pedipalp structures of male individuals did not reveal a species-level separation comparable to that observed in females. The overall morphological similarities observed in male specimens, together with the resemblance in pedipalp structures, were found to be inadequate for distinguishing the two species. Indeed, analyses based solely on habitus characteristics are generally considered insufficient for clear species-level discrimination in spiders, particularly within diverse groups such as Araneae, where morphological variation is often high. Furthermore, examinations performed at the genital level may also present relative challenges in morphologically similar species such as N. adianta and N. byzanthina , and the findings obtained from such analyses may vary among researchers. According to the PCoA and UPGMA analyses performed based on all morphological data obtained in this study, a clear species-level separation could not be achieved due to the high morphological similarity between the two species; however, location-dependent variations were observed. In conclusion, no morphological characters capable of reliably distinguishing the two species were identified. Although the opisthosomal characteristics of both taxa exhibited variation depending on seasonal conditions and sampling localities, these variations were not sufficient to permit clear species-level discrimination. The high degree of morphological similarity observed between the two taxa, supported by multivariate analyses such as PCoA and UPGMA, further indicates the absence of consistent diagnostic differences. In light of these findings, Neoscona byzanthina does not appear to be fully distinct from Neoscona adianta , and it may represent a subspecies of N. adianta . However, additional integrative studies incorporating molecular, ecological, and broader geographic sampling are recommended to clarify the taxonomic status of these taxa and to confirm the extent of their differentiation. Declarations Author Contribution AA: Identifying examples, interpreting analyses, and writing the manuscript textSA:Identifying examples,writing the manuscript textAS:conducting and interpreting analysesDAT: conducting and interpreting analyses,writing the manuscript text Acknowledgement We would like to thank the Gaziantep University Scientific Research Projects Unit for providing financial support for this study (Project Nos. FEF.YLT.23.11 and FEF.YLT.23.12). References Blick T (2018) A small collection of spiders (Arachnida: Araneae) from the River Vjosa, Albania – with an updated spider checklist of Albania. Acta ZooBot Austria 155: 213-232 Bolognin L, Moretto E, Devincenzo U, Guariento L A (2021) First record of Neoscona byzanthina (Pavesi, 1876) (Arachnida Araneae) from Italy. Biodiversity Journal 12: 17-19 Bosmans R, Chatzaki M (2005) A catalogue of the spiders of Greece – a critical review of all spider species cited from Greece with their localities. Nieuwsbrief van de Belgische arachnologische Vereniging 20 (2, suppl.): 1-124 Bosmans R, Van Keer J, Russell-Smith A, Kronestedt T, Alderweireldt M, Bosselaers J, De Koninck H (2013) Spiders of Crete (Araneae). A catalogue of all currently known species from the Greek island of Crete. Nieuwsbrief van de Belgische Arachnologische Vereniging 28 (Suppl. 1): 1-147 Danışman T, Kunt K B, Özkütük R S, Coşar İ (2025a) The checklist of the spiders of Turkey. Version 2025 [last updated 22 July 2025], online at http://www.spidersofturkey.info Demircan Aksan N, Topçu A (2022c) A preliminary checklist of the spider fauna of European Türkiye. Serket 19: 39-56 Gajdoš P, Svatoň J, Sloboda J (1999) Katalóg pavúkov Slovenska. Catalogue of Slovakian spiders. Ústav kr. ekol. SAV, Bratislava, 337 pp. Geci D, Naumova M (2021a) The spotted orb-weaver Neoscona byzanthina (Pavesi, 1876) – an enigmatic but common species on the Balkans (Araneae: Araneidae). Ecologia Balkanica, Special Edition 4: 1-9 Ivanov V V (2013) The checklist of Belarusian spiders (Arachnida, Araneae). Zoology and Ecology 4: 293-311 Kronestedt T (2001) Checklist of Spiders (Araneae) in Sweden [Preliminary version February 2001] Ledoux J-C (2008a) Réhabilitation de Neoscona byzanthina (Pavesi, 1876) espèce voisine de Neoscona adianta (Araneae, Araneidae). Revue Arachnologique 17: 49-53 Mora-Rubio C, Morano E, Pérez-Bote J L (2019) First record of Neoscona byzanthina (Pavesi, 1876) (Araneae, Araneidae) from the Iberian Peninsula. Graellsia 75(e092): 1-3 Nentwig W, Blick T, Bosmans R, Kropf C, Stäubli A (2026) Spiders of Europe. Version 02.2026. Online at https://www.araneae.nmbe.ch, accessed on 20.02.2026. https://doi.org/10.24436/1 Pavesi P (1876) Gli aracnidi Turchi. Atti della Società Italiana di Scienze Naturali, 19: 1-27 Pintilioaie A-M, Urák I (2022a) First record of Neoscona byzanthina (Araneae: Araneidae) in Romania. Arachnologische Mitteilungen 63: 1-3 Rozwałka R, Stanska M (2008) Check-list of spiders (Araneae) of Poland. 1. December 2008. online at http://www.arachnologia.edu.pl/en/species/8-spiders-of-poland.html Simon E (1879) Liste d’arachnides de Constantinople et description d’une espèce nouvelle Epeira turcica. Annales de la Société Entomologique de France, (5), 9(Bull.): 36-37. Simon E (1884) Matériaux pour servir à la faune des Arachnides de la Grèce. Etudes arachnologiques, 16ème mémoire, n° XXIII. Annales de la Société ento¬mologique de France, (6), 4: 305-356. Simon E (1929) Arachnides de France, t. 6, fasc. 3. Roret. Paris. pp. 533-772 World Spider Catalog (20269 World Spider Catalog. Version 27. Natural History Museum Bern, online at http://wsc.nmbe.ch, accessed on {20.02.2026}. doi: 10.24436/2 Additional Declarations No competing interests reported. Supplementary Files SupplementaryTable1.xlsx Appendix1.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 30 Apr, 2026 Editor assigned by journal 29 Apr, 2026 Submission checks completed at journal 29 Apr, 2026 First submitted to journal 13 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9402334","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":622763169,"identity":"d4ba11b8-a9b0-4a5f-9fac-886b98a5a1a8","order_by":0,"name":"Adile Akpınar","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYJACCRDiR/ATiNQi2QBkHYBpOUBYCwODwQFitfC3tz+88THHIt/4/OJnjz9U3GHgZ88xYP64B48NZw4kW87cJmG57cYzc4MDZ54xSPa8MWA48AyPNTcSjknzbpMwMLtxwEziYNthBoMbOUAteFwmfyOxTfovUIvxjOPfJA7+O8xgT0iLwY1kNmlGoBYD/h6gLQ1AWyQIaDE8c4zZsheoReIGT5nEmWPPeCTOPCs4cAaPFrnjwBD7ua3OgL//+DaJipo7cvztyRsfVODRggASCSDyAA+YJEYDMIYOkKB4FIyCUTAKRhQAADZ/W4x0aJwtAAAAAElFTkSuQmCC","orcid":"","institution":"Gaziantep University","correspondingAuthor":true,"prefix":"","firstName":"Adile","middleName":"","lastName":"Akpınar","suffix":""},{"id":622763170,"identity":"c70c8744-5dbc-4787-afea-4eea879a5367","order_by":1,"name":"Şuheda Ay","email":"","orcid":"","institution":"Gaziantep University","correspondingAuthor":false,"prefix":"","firstName":"Şuheda","middleName":"","lastName":"Ay","suffix":""},{"id":622763171,"identity":"9f67d2eb-eae7-4bed-832f-692d7922f19f","order_by":2,"name":"Asiye Seçkin","email":"","orcid":"","institution":"Gaziantep University","correspondingAuthor":false,"prefix":"","firstName":"Asiye","middleName":"","lastName":"Seçkin","suffix":""},{"id":622763172,"identity":"abede678-3e9a-4b73-b0d4-4b49ac5299eb","order_by":3,"name":"Derya Arslan Talapov","email":"","orcid":"","institution":"Gaziantep University","correspondingAuthor":false,"prefix":"","firstName":"Derya","middleName":"Arslan","lastName":"Talapov","suffix":""}],"badges":[],"createdAt":"2026-04-13 10:09:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9402334/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9402334/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107481102,"identity":"adc508ee-23c7-4d9f-910f-3e4a37c9e8ca","added_by":"auto","created_at":"2026-04-22 02:15:49","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":315604,"visible":true,"origin":"","legend":"\u003cp\u003eUPGMA dendrogram of 100 Neoscona specimens based on the Dice coefficient of morphological characters, excluding sexual organs. Black symbols represent \u003cem\u003eN. adianta\u003c/em\u003e, and blue symbols represent \u003cem\u003eN. byzanthina.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/8792f7230d7e058d6cdb93a7.png"},{"id":107036014,"identity":"e1833a07-0a12-49f7-b17e-c691182edf9e","added_by":"auto","created_at":"2026-04-16 04:33:16","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":61633,"visible":true,"origin":"","legend":"\u003cp\u003ePCoA plot of 100 Neoscona specimens based on the Dice coefficient of morphological characters (excluding sexual organs), with “+” \u003cem\u003eN. adianta\u003c/em\u003e and “●”\u003cem\u003eN. byzanthina\u003c/em\u003e.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/d0463f0d71e4a24a3ea3656c.png"},{"id":107036008,"identity":"a55308ec-076f-46bc-9a18-4c9781ea8e16","added_by":"auto","created_at":"2026-04-16 04:33:16","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":186679,"visible":true,"origin":"","legend":"\u003cp\u003eUPGMA dendrogram of 20 male Neoscona specimens based on the Dice coefficient of morphological characters, including male sexual organs. Black symbols indicate \u003cem\u003eN. adianta\u003c/em\u003e, and blue symbols indicate \u003cem\u003eN. byzanthina\u003c/em\u003e.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/9f92ba0e941bca6a8a4db50b.png"},{"id":107036010,"identity":"0af79e6b-9341-47ff-926a-5fc898b3e5fb","added_by":"auto","created_at":"2026-04-16 04:33:16","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":21411,"visible":true,"origin":"","legend":"\u003cp\u003ePCoA plot of 20 male Neoscona specimens based on the Dice coefficient of morphological characters, including male sexual organs. \u003cem\u003eN. adianta\u003c/em\u003e are indicated by “+” symbols, and \u003cem\u003eN. byzanthina\u003c/em\u003e are indicated by “●” symbols.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/f0b397b5e5dfd67464d08d2e.png"},{"id":107481108,"identity":"a69a2d1b-1a3e-42cc-8eb8-e13f9f01c610","added_by":"auto","created_at":"2026-04-22 02:15:51","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":320192,"visible":true,"origin":"","legend":"\u003cp\u003eUPGMA dendrogram of 80 female Neoscona specimens based on the Dice coefficient of morphological characters, including female sexual organs. Black symbols represent \u003cem\u003eN. adianta\u003c/em\u003e, and blue symbols represent \u003cem\u003eN. byzanthina\u003c/em\u003e.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/b7f2f8af3d298a58e83ead08.png"},{"id":107481041,"identity":"b2b3a153-0674-43f2-9afc-cbc4c9ee76a5","added_by":"auto","created_at":"2026-04-22 02:15:30","extension":"jpeg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":217249,"visible":true,"origin":"","legend":"\u003cp\u003ePCoA plot of 80 female Neoscona specimens based on the Dice coefficient of morphological characters, including female sexual organs. Specimens of \u003cem\u003eN. adianta\u003c/em\u003e are indicated by “+” symbols, and specimens of \u003cem\u003eN. byzanthina\u003c/em\u003e are indicated by “●” symbols.\u003c/p\u003e","description":"","filename":"floatimage6.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/c010f6e4eb36570880656014.jpeg"},{"id":108180870,"identity":"8a5bde4c-7bb3-467a-87b5-eeb7c44eea00","added_by":"auto","created_at":"2026-04-30 08:54:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1118942,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/3a72c9fd-18ea-4823-85cf-2d708085fecc.pdf"},{"id":107036007,"identity":"fd1b436e-81a1-4d93-afa5-43cb1097143f","added_by":"auto","created_at":"2026-04-16 04:33:15","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":37301,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTable1.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/c9081bb9418125861f2ed963.xlsx"},{"id":107036013,"identity":"4e202a80-c496-46c7-885e-de6030ac07f1","added_by":"auto","created_at":"2026-04-16 04:33:16","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":18214,"visible":true,"origin":"","legend":"","description":"","filename":"Appendix1.docx","url":"https://assets-eu.researchsquare.com/files/rs-9402334/v1/904ee33d74d1d63195c073d0.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological Similarity and Taxonomic Confusion Between Neoscona (Araneidae) Species: Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876)","fulltext":[{"header":"Introduction","content":"\u003cp\u003eNeoscona Simon, 1864, belongs to the family Araneidae and can be readily distinguished from other genera by the characteristic oval shape of the opisthosoma and its distinctive zigzag pattern (Nentwig et al., 2026). The genus comprises 124 species worldwide, ranking fifth in species richness within the family (World Spider Catalog, 2026). \u003cem\u003eNeoscona adianta\u003c/em\u003e (Walckenaer, 1802) and \u003cem\u003eNeoscona byzanthina\u003c/em\u003e (Pavesi, 1876) are among the most taxonomically controversial species within the genus (Geci and Naumova, 2021). The species identified as \u003cem\u003eN. byzanthina\u003c/em\u003e is a poorly studied orb-weaving spider and was only relatively recently recognized as a valid species by Ledoux (2008). This species was originally described by Pavesi (1876) as \u003cem\u003eEpeira byzanthina\u003c/em\u003e and was later described by Simon (1879) as \u003cem\u003eEpeira turcica\u003c/em\u003e, based on specimens collected from Istanbul, Turkey. Simon (1884) subsequently acknowledged the priority of \u003cem\u003eE. byzanthina\u003c/em\u003e when he reported this species for the first time from Greece (Euboea Island). Subsequently, both names were treated as synonyms of the widespread European species Neoscona adianta (Walckenaer, 1802) by Simon (1929). However, Ledoux (2008) re-established \u003cem\u003eNeoscona byzanthina\u003c/em\u003e as a distinct species from the closely related \u003cem\u003eN. adianta\u003c/em\u003e, based on a series of morphological characters, including genital structures. These two species have been primarily evaluated based on their external morphology, with \u003cem\u003eN. byzanthina\u003c/em\u003e generally distinguished from \u003cem\u003eN. adianta\u003c/em\u003e by its larger body size, opisthosomal pattern (in which the first lateral extensions of the opisthosomal bands are slightly smaller and the overall opisthosomal pattern is more variable than in \u003cem\u003eN. adianta\u003c/em\u003e), and femora that are typically darker apically (Mora-Rubio et al., 2019). To date, studies addressing these two species have been presented mainly as new records or checklist contributions rather than detailed morphological descriptions and comparative analyses (Danısman et al, 2025; Demircan Aksan N, Top\u0026ccedil;u A (2022c), Pintilioaie A-M, Ur\u0026aacute;k I, (2022a); Bolognin et al, 2021; Maro Rubio et al, 2019; Blick 2018; Bosman et al, 2013; Ivanov,2013; Rozwałka R, Stanska M (2008); Bosman and Chatzaki, 2005; Kronestedt 2001; Gajdoš et al, 1999).\u003c/p\u003e \u003cp\u003eThe aim of this study was to compare \u003cem\u003eN. adianta\u003c/em\u003e and N. \u003cem\u003ebyzanthina\u003c/em\u003e based on 83 morphological characters identified from their specimens in order to elucidate their similarities and differences.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eSpecimens were collected from the provinces of \u0026Ccedil;orum, Samsun, Sinop, and Amasya, located in the Black Sea Region of T\u0026uuml;rkiye, using an aspirator, hand collecting, and sweep-netting from vegetation. A total of 100 specimens belonging to \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina\u003c/em\u003e were examined, and 83 morphological characters were identified. Morphological characters were determined through direct examination using an Olympus SZX12E trinocular stereomicroscope. For specimens of both species, the following morphological features were examined: eye shapes; dorsal and lateral patterning of the prosoma; sternum shape; dorsal, lateral, and ventral patterning of the opisthosoma; structure and positioning of the spinnerets; and the morphology of male and female genital structures. The identified characters were scored as present (1) or absent (0) through manual entry in Microsoft Excel, and a data matrix was subsequently constructed (Appendix1 and Supplementary Table\u0026nbsp;1). The resulting data matrix was analyzed using the Dice similarity coefficient in PAST version 4.05, and an UPGMA dendrogram and PCoA scatter plots were generated. The collected specimens are preserved in 96% ethanol at \u0026minus;\u0026thinsp;20\u0026deg;C in the Zoology Laboratory of the Department of Biology, Faculty of Arts and Sciences, Gaziantep University.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eUPGMA and PCoA analyses were performed based on the morphological characters identified for \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina\u003c/em\u003e (excluding characters related to genital structures). According to the results of these analyses, no clear separation between the species was observed, and the dendrograms revealed mixed clustering of the two species (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eUPGMA and PCoA analyses were performed based solely on the morphological characters of male sexual structures (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Examination of the results indicated that no clear separation could be observed among the male specimens (n\u0026thinsp;=\u0026thinsp;20) of \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina\u003c/em\u003e. This suggests that the male sexual characters of both species are insufficient for reliably distinguishing between them.\u003c/p\u003e \u003cp\u003eData for UPGMA and PCoA analyses were obtained using only the morphological characters of female sexual organs based on the Dice coefficient (Figs.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). The results indicated that partial separation could be observed among the female specimens (n\u0026thinsp;=\u0026thinsp;80) of \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina.\u003c/em\u003e\u003c/p\u003e "},{"header":"Discussion","content":"\u003cp\u003eThe main focus of this study was the morphological similarity between \u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003eNeoscona adianta\u003c/span\u003e and \u003cem\u003eNeoscona byzanthina\u003c/em\u003e. Previous studies have also highlighted their close resemblance. Simon (1929) treated \u003cem\u003eN. byzanthina\u003c/em\u003e as a synonym of \u003cem\u003eN. adianta\u003c/em\u003e, a species widely distributed in Europe. Later, Ledoux (2008) revalidated \u003cem\u003eN. byzanthina\u003c/em\u003e as a distinct species, separate from the morphologically similar \u003cem\u003eN. adianta\u003c/em\u003e. Comparative analyses of external morphology by Mora-Rubio et al. (2019) indicated that \u003cem\u003eN. byzanthina\u003c/em\u003e differs \u003cem\u003efrom N. adianta\u003c/em\u003e by its larger overall size, the pattern of the opisthosoma (with the initial extensions of the opisthosomal bands being slightly smaller and the pattern more variable than in \u003cem\u003eN. adianta\u003c/em\u003e), and generally darker apical femora. Geci and Naumava (2021) further reported that males of \u003cem\u003eN. byzanthina\u003c/em\u003e are notably larger and more robust, whereas no significant morphological differences were observed among females. These findings are further supported by the UPGMA and PCoA analyses presented in Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e. While sexual characters of male specimens were found to be insufficient for reliably distinguishing the species, partial separation could be achieved among female specimens.\u003c/p\u003e \u003cp\u003eLedoux (2008) reported that \u003cem\u003eN. byzanthina\u003c/em\u003e is generally larger than \u003cem\u003eN. adianta\u003c/em\u003e and does not typically occur in highly humid habitats. He also observed that adult \u003cem\u003eN. adianta\u003c/em\u003e are usually active in June and July, whereas adult \u003cem\u003eN. byzanthina\u003c/em\u003e are primarily observed in August and September. In contrast, in the present study, specimens of both species were collected in June and July, including adult individuals of both species. Contrary to Ledoux (2008), no consistent size differences were detected between \u003cem\u003eN. byzanthina\u003c/em\u003e and \u003cem\u003eN. adianta\u003c/em\u003e. Although Ledoux (2008) was the first to revalidate \u003cem\u003eN. byzanthina\u003c/em\u003e, the morphological distinctions reported in his study were insufficient to provide clear diagnostic criteria for differentiating the two species.\u003c/p\u003e \u003cp\u003eIn this study, morphological differences reported in the literature were taken as references, and examinations were conducted using characters determined excluding genital structures to distinguish between \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina\u003c/em\u003e. In female specimens, distinct differences were observed particularly in the opisthosomal patterning, whereas such differences were not detected in male individuals. These variations observed in females, which were considered to be associated with geographic location, were found to be insufficient for reliable species discrimination. Based on this outcome, both male and female specimens were re-examined with genital structures included in the analyses. According to the evaluated characters, female specimens exhibited a partial clustering pattern distinguishing the two species; however, similarities in the epigynal structures created difficulties in species separation. Similarly, analyses conducted by including the pedipalp structures of male individuals did not reveal a species-level separation comparable to that observed in females. The overall morphological similarities observed in male specimens, together with the resemblance in pedipalp structures, were found to be inadequate for distinguishing the two species. Indeed, analyses based solely on habitus characteristics are generally considered insufficient for clear species-level discrimination in spiders, particularly within diverse groups such as Araneae, where morphological variation is often high. Furthermore, examinations performed at the genital level may also present relative challenges in morphologically similar species such as \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina\u003c/em\u003e, and the findings obtained from such analyses may vary among researchers.\u003c/p\u003e \u003cp\u003eAccording to the PCoA and UPGMA analyses performed based on all morphological data obtained in this study, a clear species-level separation could not be achieved due to the high morphological similarity between the two species; however, location-dependent variations were observed. In conclusion, no morphological characters capable of reliably distinguishing the two species were identified. Although the opisthosomal characteristics of both taxa exhibited variation depending on seasonal conditions and sampling localities, these variations were not sufficient to permit clear species-level discrimination. The high degree of morphological similarity observed between the two taxa, supported by multivariate analyses such as PCoA and UPGMA, further indicates the absence of consistent diagnostic differences.\u003c/p\u003e \u003cp\u003eIn light of these findings, \u003cem\u003eNeoscona byzanthina\u003c/em\u003e does not appear to be fully distinct from \u003cem\u003eNeoscona adianta\u003c/em\u003e, and it may represent a subspecies of \u003cem\u003eN. adianta\u003c/em\u003e. However, additional integrative studies incorporating molecular, ecological, and broader geographic sampling are recommended to clarify the taxonomic status of these taxa and to confirm the extent of their differentiation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAA: Identifying examples, interpreting analyses, and writing the manuscript textSA:Identifying examples,writing the manuscript textAS:conducting and interpreting analysesDAT: conducting and interpreting analyses,writing the manuscript text\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eWe would like to thank the Gaziantep University Scientific Research Projects Unit for providing financial support for this study (Project Nos. FEF.YLT.23.11 and FEF.YLT.23.12).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eBlick T (2018) A small collection of spiders (Arachnida: Araneae) from the River Vjosa, Albania \u0026ndash; with an updated spider checklist of Albania. Acta ZooBot Austria 155: 213-232\u003c/li\u003e\n\u003cli\u003eBolognin L, Moretto E, Devincenzo U, Guariento L A (2021) First record of Neoscona byzanthina (Pavesi, 1876) (Arachnida Araneae) from Italy. Biodiversity Journal 12: 17-19 \u003c/li\u003e\n\u003cli\u003eBosmans R, Chatzaki M (2005) A catalogue of the spiders of Greece \u0026ndash; a critical review of all spider species cited from Greece with their localities. Nieuwsbrief van de Belgische arachnologische Vereniging 20 (2, suppl.): 1-124\u003c/li\u003e\n\u003cli\u003eBosmans R, Van Keer J, Russell-Smith A, Kronestedt T, Alderweireldt M, Bosselaers J, De Koninck H (2013) Spiders of Crete (Araneae). A catalogue of all currently known species from the Greek island of Crete. Nieuwsbrief van de Belgische Arachnologische Vereniging 28 (Suppl. 1): 1-147\u003c/li\u003e\n\u003cli\u003eDanışman T, Kunt K B, \u0026Ouml;zk\u0026uuml;t\u0026uuml;k R S, Coşar İ (2025a) The checklist of the spiders of Turkey. Version 2025 [last updated 22 July 2025], online at http://www.spidersofturkey.info \u003c/li\u003e\n\u003cli\u003eDemircan Aksan N, Top\u0026ccedil;u A (2022c) A preliminary checklist of the spider fauna of European T\u0026uuml;rkiye. Serket 19: 39-56\u003c/li\u003e\n\u003cli\u003eGajdo\u0026scaron; P, Svatoň J, Sloboda J (1999) Katal\u0026oacute;g pav\u0026uacute;kov Slovenska. Catalogue of Slovakian spiders. \u0026Uacute;stav kr. ekol. SAV, Bratislava, 337 pp.\u003c/li\u003e\n\u003cli\u003eGeci D, Naumova M (2021a) The spotted orb-weaver Neoscona byzanthina (Pavesi, 1876) \u0026ndash; an enigmatic but common species on the Balkans (Araneae: Araneidae). Ecologia Balkanica, Special Edition 4: 1-9 \u003c/li\u003e\n\u003cli\u003eIvanov V V (2013) The checklist of Belarusian spiders (Arachnida, Araneae). Zoology and Ecology 4: 293-311\u003c/li\u003e\n\u003cli\u003eKronestedt T (2001) Checklist of Spiders (Araneae) in Sweden [Preliminary version February 2001]\u003c/li\u003e\n\u003cli\u003eLedoux J-C (2008a) R\u0026eacute;habilitation de Neoscona byzanthina (Pavesi, 1876) esp\u0026egrave;ce voisine de Neoscona adianta (Araneae, Araneidae). Revue Arachnologique 17: 49-53 \u003c/li\u003e\n\u003cli\u003eMora-Rubio C, Morano E, P\u0026eacute;rez-Bote J L (2019) First record of Neoscona byzanthina (Pavesi, 1876) (Araneae, Araneidae) from the Iberian Peninsula. Graellsia 75(e092): 1-3\u003c/li\u003e\n\u003cli\u003eNentwig W, Blick T, Bosmans R, Kropf C, St\u0026auml;ubli A (2026) Spiders of Europe. Version 02.2026. Online at https://www.araneae.nmbe.ch, accessed on 20.02.2026. https://doi.org/10.24436/1\u003c/li\u003e\n\u003cli\u003ePavesi P (1876) Gli aracnidi Turchi. Atti della Societ\u0026agrave; Italiana di Scienze Naturali, 19: 1-27\u003c/li\u003e\n\u003cli\u003ePintilioaie A-M, Ur\u0026aacute;k I (2022a) First record of Neoscona byzanthina (Araneae: Araneidae) in Romania. Arachnologische Mitteilungen 63: 1-3\u003c/li\u003e\n\u003cli\u003eRozwałka R, Stanska M (2008) Check-list of spiders (Araneae) of Poland. 1. December 2008. online at http://www.arachnologia.edu.pl/en/species/8-spiders-of-poland.html\u003c/li\u003e\n\u003cli\u003eSimon E (1879) Liste d\u0026rsquo;arachnides de Constantinople et description d\u0026rsquo;une esp\u0026egrave;ce nouvelle Epeira turcica. Annales de la Soci\u0026eacute;t\u0026eacute; Entomologique de France, (5), 9(Bull.): 36-37.\u003c/li\u003e\n\u003cli\u003eSimon E (1884) Mat\u0026eacute;riaux pour servir \u0026agrave; la faune des Arachnides de la Gr\u0026egrave;ce. Etudes arachnologiques, 16\u0026egrave;me m\u0026eacute;moire, n\u0026deg; XXIII. Annales de la Soci\u0026eacute;t\u0026eacute; ento\u0026not;mologique de France, (6), 4: 305-356.\u003c/li\u003e\n\u003cli\u003eSimon E (1929) Arachnides de France, t. 6, fasc. 3. Roret. Paris. pp. 533-772\u003c/li\u003e\n\u003cli\u003eWorld Spider Catalog (20269 World Spider Catalog. Version 27. Natural History Museum Bern, online at http://wsc.nmbe.ch, accessed on {20.02.2026}. doi: 10.24436/2\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-zoology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bzoo","sideBox":"Learn more about [BMC Zoology](http://bmczool.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bzoo/default.aspx","title":"BMC Zoology","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Araneidae, morphological features, Neoscona adianta, Neoscona byzanthina, spider","lastPublishedDoi":"10.21203/rs.3.rs-9402334/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9402334/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study presents a comparative morphological analysis of the closely related species \u003cem\u003eNeoscona adianta\u003c/em\u003e (Walckenaer, 1802) and \u003cem\u003eNeoscona byzanthina\u003c/em\u003e (Pavesi, 1876) (Araneidae). A total of 100 specimens representing these two species were examined, and 83 morphological characters were identified. A dataset was constructed and scored based on these characters, including morphological features of the prosoma, opisthosoma, spinnerets, as well as male and female genital structures. Principal Coordinate Analysis (PCoA) and the Unweighted Pair Group Method with Arithmetic Mean (UPGMA) were applied to the dataset to generate scatter plots and dendrograms illustrating morphological relationships among the specimens. The results indicated that specimens of \u003cem\u003eN. adianta\u003c/em\u003e and \u003cem\u003eN. byzanthina\u003c/em\u003e could not be reliably distinguished based on habitus-related morphological characters or genital morphology. Analyses based solely on female genital characters allowed partial separation of the species, whereas male genital characters exhibited limited discriminatory power. Overall, the findings suggest that these taxa are not fully differentiated and that \u003cem\u003eN. byzanthina\u003c/em\u003e may represent a subspecies of \u003cem\u003eN. adianta\u003c/em\u003e. However, further integrative and comprehensive comparative studies are required to clarify the taxonomic relationship between these taxa.\u003c/p\u003e","manuscriptTitle":"Morphological Similarity and Taxonomic Confusion Between Neoscona (Araneidae) Species: Neoscona adianta (Walckenaer, 1802) and Neoscona byzanthina (Pavesi, 1876)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-16 04:33:07","doi":"10.21203/rs.3.rs-9402334/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-30T11:52:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-29T06:08:32+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-29T06:08:22+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Zoology","date":"2026-04-13T09:52:57+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-zoology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bzoo","sideBox":"Learn more about [BMC Zoology](http://bmczool.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bzoo/default.aspx","title":"BMC Zoology","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"93633d5a-44ed-485e-a64e-23778ddff885","owner":[],"postedDate":"April 16th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-04-30T11:52:27+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-01T13:08:46+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-16 04:33:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9402334","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9402334","identity":"rs-9402334","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}