taxonID	type	description	language	source
A83E8983ECE05D1D8A65931E969678BE.taxon	type_taxon	Type species. Helobdella stagnalis (Linnaeus, 1758).	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
9FD084D88D7A50789F172A2E967956C1.taxon	description	Figs 8, 9	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
9FD084D88D7A50789F172A2E967956C1.taxon	diagnosis	Diagnosis. Small leech, 4.5 – 8 length and 2 – 2.5 maximum width at somite XIX (n = 6). Dorsum with ~ 37 longitudinal brown stripes. A pair of midline brown stripes originates near the eyespots until XVI, then fusing forming a single, broad stripe that reach XXI. Beyond this somite, the stripe is interrupted by square white spots, from XXI a 3 to the posterior end. Three longitudinal rows of black-tipped papillae present; additional, incomplete rows occasionally observed near the body margins. Papillae slightly wider than individual annuli. Eyespots semi-oval. Whole body with total of 69 annuli. Esophagus short, extending one or two annuli in length. Crop with five pairs of caeca, last pair forming post-caeca. Intestine with four caeca. Testisacs in four intersegmental pairs.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
9FD084D88D7A50789F172A2E967956C1.taxon	description	Description. Description based on holotype (stained), 9.6 length and 2.3 maximum width at somite XIX a 2, and six paratypes, five stained and one processed for SEM. External morphology. Body slightly lanceolate, 4.5 – 8 length and 2 – 2.5 maximum width at somite XIX. Ground color pale yellow or cream; dorsal preocular zone unpigmented (I + II to Va 2) except for the anterior end of the dorsal midline stripes that extend to reach the eyespots (Fig. 8 A). Dorsal surface with the characteristic brown longitudinal striping pattern of species of the “ triserialis ” series, with ~ 37 brown stripes visible in stained specimens. A pair of longitudinal midline stripes from IVa 3 and fuse into a single, broad stripe from XVI to the anus; this band is interrupted by square-shaped white spots located at each a 3 / a 1 from XXII to the posterior end. The remaining pairs of dorsal brown stripes extend from IVa 3 to the anus. Three rows of dorsal papillae heavily pigmented on a 2. Additional lateral may occur though these are typically incomplete. Papillae slightly exceed the width of individual annulus. Midline row of papillae extends from X, with conspicuous papillae evident from XII or XIII to XXVI (Fig. 8 C). Lateral rows of papillae begin at XIV to XXV. White spots conspicuous, square to circular in shape, and smaller than the width of individual annulus; arranged in two paired rows on each side of the body, located on a 2, flanking each papilla. White spots flanking central papillae begin at V or VI, and extend to XXVI, lateral rows of white spots extend from XII to XXVII. Eyespots semioval, at IVa 1 + a 2, well-separated. Anus on XVII, typically surrounded by black pigment. Ventral surface ground cream-colored, with faint, thin longitudinal brown stripes (Fig. 8 B). Oral sucker white; mouth located at the anterior margin. Gonopores separated by a single annulus (XII a 2). Whole body with 69 annuli. Annulation: I and II fused; III and IV bi-annulate; V – XXIV tri-annulate; XXV bi-annulate, and XXVI, XXVII uni-annulate (Fig. 8 C). Internal morphology. Proboscis straight, not recurved, 1.52 length, extending from X to XIV. Salivary glands diffuse into parenchyma between XII and XV; ductules not forming bundle, insert independently into base of proboscis. Esophagus short, from at XVa 1 to XV a 2. Crop with five pairs of caeca; first four pairs digitiform and laterally directed; last pair with descending sinuous path or post-caeca, from XIX to XXII (Fig. 9 A). Intestine with four pairs of digitiform caeca, the first three pairs directed anteriorly and last pair directed posteriorly. Testisacs in four intersegmental pairs, the first pair between XV / XVI, last pair XVIII / XIX. Ejaculatory ducts reaching the first pair of testisacs or XV / XVI (Fig. 9 B). Ovisacs saccular, reaching XIX when it is filled (Fig. 9 C). Reproductive information. No specimens were observed with spermatophores attached to the body wall, nor were any specimens found carrying eggs or young leeches on the ventral surface.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
9FD084D88D7A50789F172A2E967956C1.taxon	etymology	Etymology. The species is named in honor of the Argentinian biologist Dr. Betina Sandra Gullo, in recognition of her significant contributions to the knowledge of South American leeches, in particular those within the genus Helobdella.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
350992B645705AE8AE41F237A8B92167.taxon	description	Figs 5, 6, 7	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
350992B645705AE8AE41F237A8B92167.taxon	diagnosis	Diagnosis. Small leech, 5 – 9 length and 2.5 – 3.8 maximum width at somite XIX (n = 14). Dorsal surface with ~ 40 longitudinal brown stripes. Brown coloration present or fade in larger specimens. Midline paired stripes not joining. Three longitudinal rows of black-tipped papillae, one median and two lateral rows, with additional incomplete marginal rows in all specimens. Papillae larger than the width of annuli. A pair of dorsal papillae located beside the anus. Eyespots oval, well separated. Whole body with a total of 67 annuli. Esophagus short. Crop with five pairs of caeca, the last pair forming post-caeca. Testisacs in five intersegmental pairs.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
350992B645705AE8AE41F237A8B92167.taxon	description	Description. Based on adult specimen (holotype), CNHE 12295 (stained), 7 length and 3.7 maximum width at somite XIX a 3. Twenty-eight paratypes, CNHE 11132, include 15 adult alcohol-preserved specimens, 10 flattened and stained specimens, and 3 specimens prepared for SEM. External morphology. Body lanceolate to ovoid, 5 – 9 length and 2.5 – 3.8 maximum width at XIX. Ground color pale yellow or cream; dorsal preocular zone unpigmented. Dorsal surface with ~ 40 longitudinal stripes (visible in stained organisms). Patterns of metameric brown pigmentation and pigmented papillae, features otherwise characteristic of species in the “ triserialis ” series, are visible in some specimens. However, this pigmentation tends to fade in larger specimens (Fig. 5 A, B). Paired midline stripes extend from annulus 5 (Va 1) to the anus at XXVII and remain not joined. Additional brown stripes extend from annulus 6 or 7 (Va 2 or Va 3) to the anus. Dorsal surface with three longitudinal rows of pigmented papillae, one median and two lateral rows; an additional pair of incomplete paramedial rows present in all specimens. Median row of papillae from XII to XXVI, smaller additional paired papillae may be present in somite XXI and continue posteriorly (Fig. 5 D). Lateral rows from XIV and continue posteriorly. Papillae generally wider than the width of individual annuli. A pair of prominent papillae located adjacent the anus (Fig. 5 D). White dorsal spots faint, circular and larger than the length of an annuli, arranged in two pairs of rows per side, located at each a 2 adjacent to the papillae. White spots beside median papillae beginning at X and reaching XXVII, lateral white spots at XIV and reaching XIV. Eyespots cup-like at IVa 2, well separated. Ventral surface white (Fig. 5 C). Mouth pore located at the anterior margin of the anterior sucker. Gonopores separated by a single annulus (XII a 2). Whole body with 67 annuli. Anus on XVII. Annulation: I – II fused; III uni-annulate; IV and V bi-annulate; VI to XXIV tri-annulate; XXV biannulate; XXVI and XXVII uni-annulate (Fig. 5 D). Internal morphology. Proboscis straight, not recurved, 1.8 length, extending from IX to XIV, or reaching XV when retracted. Salivary glands diffuse into parenchyma from XI to XVII; ductules not forming bundle, insert independently into base of proboscis. Esophagus short, located at XV a 1. Crop with five pairs of digitiform caeca; the first four pairs laterally directed, fifth pair with a posterior sinuous path or post-caeca, from XIX to XXIII (Fig. 6 A). Intestine with four pairs of digitiform caeca, the first three slightly oriented anteriorly, and last pair directed posteriorly. Five pairs of testisacs, first pair between XIV / XV (Fig. 6 B), last pair between XVIII / XIX. Ejaculatory ducts with a short posterior loop reaching XIV and then with an anterior trajectory to XIII. Ovisacs simple, elongated, extending posteriorly to XVII or XVIII (Fig. 6 C). Reproductive and ecological information. Specimens were found attached to the shells of the invasive Asian clam Corbicula fluminea (Müller, 1774). Eight of 21 collected leeches with eggs or young leeches attached to the ventral surface, carrying between 21 to 36 eggs or 51 young leeches (Figs 5 C, 7 A). Brooding area spans ~ 15 annuli, from XVIII a 3 to XXIII (Fig. 7 A). Egg diameter 238 – 428 μm (322, n = 7). Spermatophores observed in three of 21 leeches, attached to the body wall, between annuli 24 – 27 (Fig. 7 B, C). Each spermatophore ~ 350 μm length and 40 μm width. Spermatophores with a broad proximal portion attached on body wall of the recipient specimen, a narrow middle region or neck and distal portion with two horn-like tubes. Almost all leech specimens with epibionts (ciliates) attached to the body wall (Fig. 7 B).	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
350992B645705AE8AE41F237A8B92167.taxon	etymology	Etymology. The specific epithet refers to the presence of a distinctive pair of papillae located adjacent to the anus.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
6196F8F3009D5BCD8E7830F03ECAD9AB.taxon	description	Figs 2, 3, 4	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
6196F8F3009D5BCD8E7830F03ECAD9AB.taxon	diagnosis	Diagnosis. Small leeches, 4 – 16 length and 1.5 – 9 width (n = 115). Dorsal surface with ~ 34 brown stripes. Midline longitudinal paired stripes of solid color extend from Va 2 to the anus, separated by a distance approximately equal to that between eyespots; the stripes join each other at a 2 of each somite, creating a chain-like appearance. Three dorsal rows of longitudinal, dark brown-tipped papillae on a 2: one median and two lateral rows. In some specimens, an additional pair of marginal rows more prominent in the posterior third of the body. Papillae smaller than the width of individual annuli. Eyespots punctiform and well separated. Full body with 68 annuli. Esophagus slightly globular, spanning six annuli. Crop with five pairs of digitiform caeca, the last pair forming post-caeca. Testisacs in five intersegmental pairs.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
6196F8F3009D5BCD8E7830F03ECAD9AB.taxon	description	Description. External morphology. Body lanceolate, 3 – 16 length and 1.5 – 9 maximum width at somite XIX (n = 115). Ground color pale yellow or cream; dorsal preocular zone unpigmented (Fig. 2 A – C). Dorsal surface with ~ 34 stripes of longitudinal brown stripes (visible in stained specimens). A pair of solid midline stripes, separated by a distance equivalent to the distance between eyespots, extends from Va 2 to the anus at XXVII. The stripes join each other at a 2 of each somite, creating a chain-like appearance. The remaining 32 stripes (16 pairs) are slender extend from Va 2 or Va 3 (annuli 6 or 7) and continue to the anus (Fig. 2 A). Dorsum with three longitudinal rows of dark brown-tipped papillae located in a 2 of each somite, one row median and two laterals. In some specimens, an additional pair of incomplete marginal rows may be present, papillae more prominent in the posterior third of the body, some papillae unpigmented (Fig. 2 A). Median papillae row extends from X – XI to XXV – XXVI; lateral rows from XIII to XXVI (Fig. 2 C). Papillae smaller than the width of an annulus. Dorsal white spots conspicuous, in three longitudinal rows metamerically arranged: one central and two laterals. White spots somewhat circular, approximately the size of an annulus and located in a 2, beside lateral rows of papillae. Median row of white spots from VIII to XXVI; lateral rows from XII or XIII. Eyespots punctiform at IV a 1 / a 2, well-separated. Anus dorsal, at XVII. Ventral surface whitish, without papillae. Mouth pore located at the anterior margin of the anterior sucker. Gonopores separated by a single annulus, male gonopore in XII a 1 / a 2, female gonopore in XII a 2 / a 3. In total, 68 annuli along the body. Annulation: I – II fused; III uni-annulate; IV bi-annulate; V – XXIV tri-annulate; XXV bi-annulate; XXVI and XXVII uni-annulate (Fig. 2 C). Internal morphology. Proboscis straight, not curved. 1.95 total length, extending from IX to XIV when retracted. Salivary glands diffuse in the parenchyma, extending from XI to XVII. Salivary ducts connect to the base of the proboscis at XIV. Esophagus enlarged, slightly globular, chamber-like, from XIIIa 3 to XV a 1. Crop with five pairs of digitiform caeca, the first four pairs laterally directed, with the first pair at XV; the fifth pair forming sinuous post-caeca from XIX to XXIII (Fig. 3 A). Intestine with four pairs of caeca, the first three pairs directed slightly anteriorly and last pair directed posteriorly. Male atrial cornua laterally directed. Vas deferens with a short descending loop, reaching the first pair of testisacs or XIV (Fig. 3 B, C). Five pairs of testisacs present, first pair between XIV and XV. Ovisacs simple, elongate, and not folded, extending to XVII or XVIII (Fig. 3 C). Reproductive information. No specimens with spermatophores attached to the body wall were observed at any time. In total, 18 of 116 specimens were found with five or six thin-walled cocoons attached to the ventral surface. The total number of eggs ranges from 20 to 100. The brooding area extended from XVIIa 2 to XXa 3 or XVIa 3 to XXI (Fig. 4). Egg diameter 306 – 479 μm (373, n = 29). Some specimens carried up to 69 embryos attached to ventral surface (Fig. 2 B), easily lost during manipulation and fixation. The highest proportion of gravid or brooding individuals were collected between May and July.	en	Torres-Carrera, Gerardo, Duarte-De Lima, Lucas, Oceguera-Figueroa, Alejandro (2025): Description of two new species of freshwater leeches of the genus Helobdella (Hirudinea, Glossiphoniidae) from Mexico, with a redescription of Helobdella socimulcensis (Caballero, 1931). ZooKeys 1261: 141-164, DOI: 10.3897/zookeys.1261.162279
