taxonID	type	description	language	source
03E487C4B22DFFA818B2F919FC21FBF7.taxon	description	urn: lsid: zoobank. org: act: 00 C 6 B 95 A- 52 FD- 4 D 28 - 9 A 6 B- 6333 FD 7 A 51 E 3 Figs 4 – 5	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B22DFFA818B2F919FC21FBF7.taxon	diagnosis	Diagnosis Shell ovate-conic, large, with an inflated body whorl; upper region of shell aperture slightly pointed; protoconch microsculpture pitted; periostracum yellowish; central radular tooth formula 4 - C- 4 / 1 - 1; bursa copulatrix pyriform, U-shaped fold; seminal receptacle elongate with short peduncle; penis gradually tapering, with a patch of black pigment in distal region and a narrow base; nervous system pigmented, moderately concentrated (mean RPG ratio = 0.47); cerebral ganglia approximately equal in size.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B22DFFA818B2F919FC21FBF7.taxon	etymology	Etymology This species is named after Irene Ballesta, in recognition of her diligent collection of freshwater molluscs from numerous Andalusian localities, including specimens of this species.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B22DFFA818B2F919FC21FBF7.taxon	materials_examined	Type material Holotype SPAIN • sex unknown (dry preserved, ESEM preparation); Granada, Gordo Spring near Játar; 36.9308 ° N, 3.9166 ° W; MNCN 15.05 / 63703 H. Paratypes SPAIN – Granada Province • 10 specs (preserved in ethanol 96 % and 3 processed for DNA sequencing); same collection data as for holotype; 1 Jun. 2009; I. Ballesta and J. M Barea-Azcón leg.; MNCN 15.05 / 63703 P • 40 specs (preserved in ethanol 70 % and 100 %, 8 dissected); a pond connected to Gordo Spring; 36.9308 ° N, 3.9166 ° W; 1 Jun. 2009; I. Ballesta and J. M Barea-Azcón leg.; MNCN 15.05 / 63704 • 60 specs (preserved in ethanol 70 %); a second pond connected to Gordo Spring; 36.9308 ° N, 3.9166 ° W; 1 Jun. 2009; I. Ballesta and J. M Barea-Azcón leg.; MNCN 15.05 / 63705.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B22DFFA818B2F919FC21FBF7.taxon	description	Description SHELL. Ovate-conic, whorls about 5, height 4.25 – 5.50 mm (Fig. 4 A – E); periostracum yellowish, often eroded, especially on early whorls; protoconch 1.5 whorls, diameter ca 450 µm, nucleus ca 150 µm wide (Fig. 4 F); protoconch microsculpture pitted (Fig. 4 G – H); teleoconch whorls convex, separated by a deep suture; last body whorl about ⅔ of total length; peristome orthocline, slightly pointed at upper region; inner lip thicker than outer lip, partially hiding the umbilicus; aperture margin simple, straight (Fig. 4 E). OPERCULUM. Corneous, yellowish, thin, pliable, ellipsoidal, paucispiral with submarginal nucleus, 2.75 whorls; muscle attachment oval, located near nucleus (Fig. 5 A – B). RADULA. Length intermediate (20 % of total shell length), approximately 8 times as long as wide; having ca 55 rows of teeth. Central tooth formula 4 - C- 4 / 1 - 1, central cusp U or V-shaped, cutting edge slightly concave (Fig. 5 C – D). Lateral tooth formula 3 - C- 3, central cusp U-shaped. Inner marginal teeth with 18 – 20 cusps; outer marginal teeth with 20 – 22 cusps (Fig. 5 E). PIGMENTATION AND ANATOMY. Head dark brown, pigmented from snout to neck (Fig. 5 K); neck paler; tentacles with central brown stripe; ocular lobes unpigmented; snout as long as wide, with pronounced distal lobation; foot of intermediate length, dorsal surface pigmented. Ctenidium located in the anterior region of the pallial cavity; 20 – 24 gill filaments, taller than wide. Osphradium intermediate in width, positioned opposite middle of ctenidium (Fig. 5 F). Stomach slightly longer than wide; posterior chamber slightly larger than anterior (Fig. 5 G); style sac longer than wide, encircled by intestine with a small brown patch. NERVOUS SYSTEM. Dark brown pigmentation, moderately concentrated (mean RPG ratio = 0.47); cerebral ganglia equal in size, darker than other ganglia and connectives; supraoesophageal connective ca 6 times as long as pleurosuboesophageal one (Fig. 5 H). FEMALE GENITALIA. Capsule gland longer than albumen gland (Fig. 5 I); bursa copulatrix pyriform with U-shaped fold; bursal duct shorter than bursa, partly or fully embedded in bursa copulatrix; renal oviduct black-pigmented to above seminal receptacle insertion, coiled; seminal receptacle elongate, with short duct, positioned slightly above the junction of bursal duct and renal oviduct (Fig. 5 J). MALE GENITALIA. Prostate gland about 3 times as long as wide. Penis slightly pigmented distally, gradually tapering, attached to neck behind right eye; weak folds along inner edge; penial duct runs straight along outer side (Fig. 5 K).	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B22DFFA818B2F919FC21FBF7.taxon	biology_ecology	Ecology and distribution The species is restricted to a single spring and two connected ponds in the Granada Province, southern Spain. Specimens were found on submerged stones. Co-occurring gastropod species included Ancylus fluviatilis O. F. Müller, 1774 in the spring, with both A. fluviatilis and Potamopyrgus antipodarum (J. E. Gray, 1843) present in the ponds. The Gordo Spring was last visited in 2024 according to the Catálogo de Manantiales y Fuentes de Andalucía (www. conocetusfuentes. com) and remains in good ecological condition (J. M. Barea Azcón pers. com.), suggesting that C. ballestae sp. nov. likely faces no significant habitat threats.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B22DFFA818B2F919FC21FBF7.taxon	discussion	Remarks Corrosella ballestae sp. nov. is among the largest species within this group, comparable in size to C. luisi. It can be distinguished from other taxa in the same clade by its more tubular penis shape, a longer seminal receptacle (with most other species averaging under 0.30 mm in length, except for C. luisi, which has a similarly sized receptacle; Delicado et al. 2012), and the longest prostate gland recorded among species of Corrosella, mean length of approximately 2.20 mm. Although C. ballestae shares more morphological characteristics with C. luisi, it is phylogenetically closer to C. andalusica (Fig. 1), exhibiting an average sequence divergence of 7.1 % from C. luisi and 7 % from C. andalusica for the COI gene (Supp. file 1: Table S 3). Species of Corrosella from northern Iberia can be differentiated from C. ballestae sp. nov. by several traits: smaller shell size, a greater number of cusps on radular teeth, a cylindrical bursa copulatrix, a shorter seminal receptacle, a more triangular penis that is centrally positioned on the head, and a more strongly pigmented renal oviduct extending to the seminal receptacle.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B229FFB71B16FBB1FDF1F91C.taxon	description	Figs 6 – 7	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B229FFB71B16FBB1FDF1F91C.taxon	materials_examined	Type material Holotype SPAIN • 1 spec. (sex unknown); Zaragoza, Bulbuente, Balsa de Vargas (at Borja according to Delicado et al. 2010: 101); SMF 257406; designated by Boeters (1986). Paratypes SPAIN • numerous specs; Zaragoza, Bulbuente; SMF 257407 / 5 • numerous specs; same data as for preceding; BOE 599, 600 and 1240. Material examined SPAIN – Teruel Province • 8 specs; spring of river park in Calamocha; 40.9261 ° N, 1.2989 ° W; 10 Dec. 2009; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63701 • 3 specs; Caminreal, Prado Spring; 40.8452 ° N, 1.3343 ° W; 10 Dec. 2009; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63702. – Zaragoza Province • 18 specs; Borja, Balsa de Vargas; 41.8253 ° N, 1.5525 ° W; 7 Oct. 2009; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63698 • 17 specs; Borja, Cazuelas Spring; 41.8225 ° N, 1.5502 ° W; 14 July 2009; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63699.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B229FFB71B16FBB1FDF1F91C.taxon	description	Description SHELL. Ovate-conic, whorls 4, height 2.75 – 3.50 mm (Fig. 6 A – F); periostracum yellowish, strongly eroded, especially on early whorls; protoconch 1.5 whorls, diameter ca 425 µm, nucleus ca 150 µm wide (Fig. 6 G); protoconch microsculpture pitted (Fig. 6 H – I); teleoconch whorls convex, separated by deep sutures; peristome orthocline; inner lip thicker than outer lip, partially covering umbilicus; aperture margin slightly sinuate adapically (Fig. 6 F). OPERCULUM. Corneous, yellowish, thin, pliable, ellipsoidal, paucispiral with submarginal nucleus, 2.75 whorls; muscle attachment oval, located near nucleus (Fig. 7 A – B). RADULA. Length intermediate (20 % of total shell length), approximately 8 times as long as wide; having ca 65 rows of teeth. Central tooth formula 6 - C- 6 / 1 - 1, central cusp V-shaped, cutting edge slightly concave (Fig. 7 C – D). Lateral tooth formula 4 - C- 4, central cusp V-shaped, slightly shorter than that central tooth. Inner marginal teeth with 22 – 24 cusps; outer marginal teeth with 27 – 29 cusps (Fig. 7 E). PIGMENTATION AND ANATOMY. Head dark brown, pigmented from snout to neck (Fig. 7 L); lighter pigmentation on neck and tip of the snout; tentacles with medial brown stripe; ocular lobes unpigmented; snout as long as wide, with a strong distal lobation; foot intermediate in length, pigmented dorsally. Ctenidium located anterior in pallial cavity; 14 – 18 gill filaments, taller than wide. Osphradium intermediate in width, positioned opposite middle of ctenidium (Fig. 7 F). Stomach slightly longer than wide; posterior chamber slightly larger than anterior chamber (Fig. 7 G); large gastric caecum; style sac longer than wide, encircled by intestine with a small patch of brown pigment. NERVOUS SYSTEM. Dark brown pigmentation, elongated (mean RPG ratio = 0.58); cerebral ganglia equal in size, darker than other ganglia and connectives; supraoesophageal connective ca 6 times as long as pleurosuboesophageal one (Fig. 7 H). FEMALE GENITALIA. Capsule gland one-third longer than albumen gland (Fig. 7 I); bursa copulatrix pyriform to elongate, folded in U-shaped; bursal duct slightly shorter than bursa; renal oviduct coiled, with 2 – 3 loops, pigmented to last loop; seminal receptacle pyriform with short duct, positioned slightly above junction of bursal duct and renal oviduct (Fig. 7 J – K). MALE GENITALIA. Prostate gland about 3 times as long as wide. Penis gradually tapering, slightly pigmented centrally, with folds along inner edge, attached to the central area of head (Fig. 7 L – N).	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B229FFB71B16FBB1FDF1F91C.taxon	biology_ecology	Ecology and distribution The species has been recorded from four spring systems in the Zaragoza and Teruel provinces, northeast Spain. These springs are characterised by clean, well-oxygenated water with low temperatures (15 – 19 ° C), conductivity below 1 mS / cm ² and a continuous but moderate flow. Specimens occur in high densities on stones, rocks, sandy or gravelly substrates and the submerged parts of aquatic vegetation. Potamopyrgus antipodarum was found co-occurring at all localities except in the River Park Spring in Calamocha, where the species was found alongside Theodoxus sp.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B229FFB71B16FBB1FDF1F91C.taxon	discussion	Remarks Molecular and morphological studies (Delicado et al. 2013; Boeters et al. 2015), based on specimens collected from the type locality, indicate that C. hinzi does not occur in Pozo Azul (Burgos Province) as previously declared by Boeters (1988). Instead, our study revealed that this population, along with those from nearby areas, belongs to C. navasiana, thereby restricting the distribution of C. hinzi to a few localities in the northeastern Iberian Peninsula. Despite its limited range, anatomical differences exist within C. hinzi: populations from Teruel Province exhibit longer shells and penises (Fig. 7 M – N) compared to those from Zaragoza Province, although they share similar female genitalia, nervous systems, and stomach structures.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B236FFBE1B0AF906FC86FD7A.taxon	description	Figs 8 – 11	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B236FFBE1B0AF906FC86FD7A.taxon	materials_examined	Type material Unknown. Type locality Spain, Zaragoza, Bulbuente. Material examined SPAIN – Burgos Province • 16 specs; Covanera, Pozo Azul Spring; 42.7396 ° N, 3.7976 ° W; 1 May 2008; D. Delicado leg.; MNCN 15.05 / 63675 • 11 specs; a stream in Tubilleja; 42.8535 ° N, 3.7149 ° W; 3 May 2008; D. Delicado leg.; MNCN 15.05 / 63677 • 11 specs; Tubilla del Agua, La Toba Spring; 42.7087 ° N, 3.8046 ° W; 1 May 2008; D. Delicado leg.; MNCN 15.05 / 63673 • 1 spec.; Sedano, Valdeménez Stream; 42.7163 ° N, 3.8007 ° W; 1 May 2008; D. Delicado leg.; MNCN 15.05 / 63679 • 15 specs; a stream in Valtubilla; 42.7268 ° N, 3.7529 ° W; 1 May 2008; D. Delicado leg.; MNCN 15.05 / 63678. – Cuenca Province • 22 specs; El Hosquillo, Tía Perra Spring; 40.3709 ° N, 2.0054 ° W; 9 Mar. 2008; D. Delicado leg.; MNCN 15.05 / 63695. – Guadalajara Province • 11 specs; Somolinos, Canalejas Spring; 41.2577 ° N, 3.0710 ° W; 5 Apr. 2008; D. Delicado leg.; MNCN 15.05 / 63660 • 11 specs; Somolinos, Manadero River; 41.2570 ° N, 3.0741 ° W; 5 Apr. 2008; D. Delicado leg.; MNCN 15.05 / 63654 • 10 specs; Cabrera, Dulce River; 41.0077 ° N, 2.6763 ° W; 6 Apr. 2008; D. Delicado leg.; MNCN 15.05 / 63656 • 16 specs; a spring in Peralejos de las Truchas; 40.6113 ° N, 1.9615 ° W; 6 Apr. 2008; D. Delicado leg.; MNCN 15.05 / 63653. – Segovia Province • 32 specs; a spring next to the Sanctuary Virgen de la Fuencisla; 40.9562 ° N, 4.1319 ° W; 6 Jul. 2019; J. P. Miller and M. Carrillo leg.; MNCN 15.05 / 97257. – Soria Province • 11 specs; Medinaceli, Tinte Spring; 41.1592 ° N, 2.4271 ° W; 25 May 2010; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63643 • 17 specs; a spring in Arbujuelo; 41.1361 ° N, 2.3790 ° W; 25 May 2010; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63625. – Toledo Province • 18 specs; Ontígola, María Spring; 39.9979 ° N, 3.5774 ° W; 21 Oct. 2007; D. Delicado leg.; MNCN 15.05 / 63670 • 28 specs; a ditch in Borox; 40.0571 ° N, 3.7388 ° W; 9 Jun. 2007; D. Delicado leg.; MNCN 15.05 / 63668. – Valladolid Province • 10 specs; Quintanilla de Onésimo, Aceña Spring; 41.6279 ° N, 4.3623 ° W; 3 Sep. 2016; J. P. Miller and M. Carrillo leg.; MNCN 15.05 / 97200. – Zaragoza Province • 33 specs; Bulbuente, Fonnueva Spring; 41.8183 ° N, 1.3873 ° W; 1 May 2007; D. Delicado and R. M. Álvarez-Halcón leg.; MNCN 15.05 / 53718 • 16 specs; Ojos de Cimballa Wetland; 41.6381 ° N, 1.2876 ° W; 24 Feb. 2005; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63617 • 1 spec.; a spring in Mesones; 41.5517 ° N, 1.5362 ° W; 10 Feb. 2009; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63635 • 13 specs; Navalos, Espejo Lake; 41.1975 ° N, 1.7881 ° W; 27 May 2010; R. M. Álvarez-Halcón leg.; MNCN 15.05 / 63624.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B236FFBE1B0AF906FC86FD7A.taxon	description	Description SHELL. Ovate-conic, whorls 4, height 2.50 – 4.50 mm (Fig. 8); periostracum greyish or yellowish, often eroded, especially on early whorls; protoconch with 1.5 whorls, diameter ca 425 µm, nucleus ca 125 µm wide (Fig. 9 A); protoconch microsculpture grooved or pitted (Fig. 9 B – C); teleoconch whorls convex, separated by deep sutures; last body whorl about ⅔ of total length; peristome orthocline; inner lip thicker than outer lip, partially hiding umbilicus; aperture margin simple, straight. OPERCULUM. Corneous, yellowish, thin, pliable, ellipsoidal, paucispiral with submarginal nucleus, 2.75 whorls; muscle attachment oval, located near nucleus. RADULA. Length intermediate (25 % of shell length), approximately 8 times as long as wide; having ca 55 rows of teeth. Central tooth formula 4 - C- 4 / 1 - 1, central cusp U- or V-shaped (Fig. 9 D – E, G – H, J – K), cutting edge slightly concave. Lateral tooth formula (3) 4 - C- 4 (3), central cusp U-shaped. Inner marginal teeth with 18 – 22 cusps; outer marginal teeth with 20 – 24 cusps (Fig. 9 F, I, L). PIGMENTATION AND ANATOMY. Head dark brown, pigmented from snout to neck (Fig. 10 A, F, K, M, O – R); lighter pigmentation on neck; tentacles with central brown stripe; ocular lobes unpigmented; snout as long as wide, with pronounced distal lobation; foot intermediate in length, dorsally pigmented. Ctenidium located anterior in pallial cavity; 15 – 20 gill filaments, taller than wide. Osphradium intermediate in width, positioned opposite middle of ctenidium. Stomach slightly longer than wide; posterior chamber slightly larger than anterior; style sac longer than wide, surrounded by intestine with small brown patch. NERVOUS SYSTEM. Dark brown pigmentation, moderately concentrated (mean RPG ratio = 0.48); cerebral ganglia equal in size and darker than other ganglia and connectives; supraoesophageal connective ca 6 times as long as pleurosuboesophageal one. MALE GENITALIA. Prostate gland about 3 times as long as wide. Penis gradually tapering, slightly pigmented centrally, with folds along inner edge; attached at central head area; penial duct straight or undulating along outer side of penis (Fig. 10). FEMALE GENITALIA. Capsule gland longer than albumen gland; bursa copulatrix pyriform to elongate, U-shaped fold; bursal duct shorter than bursa, partly or fully embedded in bursa copulatrix; renal oviduct coiled, with 2 – 3 loops, pigmented up to bursal duct insertion; seminal receptacle small, pyriform, with short duct, positioned slightly above junction of bursal duct and renal oviduct; seminal receptacle and bursa copulatrix broadly separated, occasionally nearly touching (Fig. 11).	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B236FFBE1B0AF906FC86FD7A.taxon	biology_ecology	Ecology and distribution The species is widely distributed across the Ebro, Tajo and Duero River basins in central and northeastern Spain. It inhabits springs and streams with clean, well-oxygenated waters and typically abundant vegetation. Populations are often found in high densities, with specimens attached to stones and submerged vegetation. The species co-occurs with several other gastropods, including Alzoniella cantabrica (Boeters, 1983), Spathogyna fezi Arconada & Ramos, 2002, Galba truncatula (O. F. Müller, 1774), Potamopyrgus antipodarum and Theodoxus sp.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
03E487C4B236FFBE1B0AF906FC86FD7A.taxon	discussion	Remarks Delicado et al. (2013) identified three subclades within Corrosella navasiana: one including populations from Burgos, Cuenca, Guadalajara, Soria and Zaragoza (with the type locality near Bulbuente, Zaragoza), a second from Burgos and a third from Toledo. Later, Boeters et al. (2015) reinterpreted these molecular clades as representing distinct species, assigning the first to C. navasiana s. str., the Burgos clade to C. collingi, and the Toledo clade to C. tajoensis. Boeters et al. (2015) noted that specimens from the type locality of C. navasiana (i. e., Fonnueva Spring near Bulbuente, Zaragoza) differ from those of C. collingi, C. tajoensis and C. valladolensis in several diagnostic traits: deeper sutures between shell whorls, a shoulder on the body whorl, a separate bursal duct from the bursa copulatrix, absence of contact between the seminal receptacle and bursa and a straight penial duct. These features were proposed as distinguishing characteristics for C. navasiana relative to the other species of Clade 1 (Boeters et al. 2015). However, these traits are inconsistently observed in other populations from Burgos, Cuenca, Guadalajara, Soria and Zaragoza, which were recognised as part of the C. navasiana clade by Boeters et al. (2015: 111). Our geometric morphometric analysis revealed no significant differences in suture depth or whorl edge shapes among members of Clade 1 (Fig. 2 A). Additionally, variations in the degree of bursal duct embedding were noted, with specimens from Fonnueva and Tía Perra Springs showing complete embedding within the bursa copulatrix (Fig. 11 A, D) and those from the Dulce River displaying partial embedding (Fig. 11 B – C). The distance between the seminal receptacle and the bursa – a noninfluential trait in the CVA of female genitalia – and the outer edge undulation of the penial duct vary among C. navasiana populations (Figs 10 A – E, 11 A – D) and may also vary in C. collingi (Figs 10 F – J, 11 E – H). While these traits may appear to distinguish the species of Clade 1 when only the C. navasiana specimens from the type locality are considered (Boeters et al. 2015), they do not hold when individuals from the entire range are examined. The expanded morphospace of C. navasiana encompasses all species of Clade 1 described by Boeters et al. (2015). Furthermore, molecular delimitation methods did not distinguish these populations as separate taxa. Thus, all analysed populations are best interpreted as belonging to a single, morphologically variable species, C. navasiana, which is widely distributed across the Ebro, Tajo and Duero River basins in central and northeastern Iberia and exhibits notable morphological variation within and between subclades.	en	Delicado, Diana, Miller, Jonathan P., Boulaassafer, Khadija, Ramos, Marian A., Hauffe, Torsten (2026): Taxonomic assessment of 24 hydrobiid species (Caenogastropoda, Truncatelloidea) of conservation concern in springs of Iberia and Maghreb. European Journal of Taxonomy 1043: 1-32, DOI: 10.5852/ejt.2026.1043.3203, URL: https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/3203/14221
