taxonID	type	description	language	source
275E12F454C257C19EA6C92C85F31A14.taxon	description	Figs 9, 10, 11, 12, 13, 14, 15, 16, 17, 18	en	Novikov, Aleksandr, Sharafutdinova, Dayana, Abramova, Ekaterina, Mayor, Tatyana, Chertoprud, Elena (2025): An integrative approach to the delimitation of pseudocryptic species in the Eucyclops speratus complex (Copepoda, Cyclopoida) with a description of a new species. ZooKeys 1226: 217-260, DOI: 10.3897/zookeys.1226.138389
275E12F454C257C19EA6C92C85F31A14.taxon	etymology	Etymology. The species was first discovered and has its main range in Siberia. The word sibiricus is an adjective in the masculine gender.	en	Novikov, Aleksandr, Sharafutdinova, Dayana, Abramova, Ekaterina, Mayor, Tatyana, Chertoprud, Elena (2025): An integrative approach to the delimitation of pseudocryptic species in the Eucyclops speratus complex (Copepoda, Cyclopoida) with a description of a new species. ZooKeys 1226: 217-260, DOI: 10.3897/zookeys.1226.138389
275E12F454C257C19EA6C92C85F31A14.taxon	diagnosis	Diagnosis. Proctodeum with rows of setules. Caudal ramus with serra and dorsal pore. Length / width ratio of caudal rami 5.2 – 7.0. Ratio of lengths of caudal seta VI to seta III 1.07 – 1.47. Antennule 12 - segmented, with hyaline membrane on three distal segments. Hyaline membrane finely serrated. Antennal coxobasis with groups of spinules 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16. Maxillular basis with group of spinules. P 1 – P 4 Exp 1 without spinules / setules on outer side. P 1 – P 4 Exp 2 with setules on outer side. P 4 Exp 1 with 8 – 17 inner setules. P 4 Exp 2 with 6 – 10 inner setules.	en	Novikov, Aleksandr, Sharafutdinova, Dayana, Abramova, Ekaterina, Mayor, Tatyana, Chertoprud, Elena (2025): An integrative approach to the delimitation of pseudocryptic species in the Eucyclops speratus complex (Copepoda, Cyclopoida) with a description of a new species. ZooKeys 1226: 217-260, DOI: 10.3897/zookeys.1226.138389
275E12F454C257C19EA6C92C85F31A14.taxon	description	Description. Female. Body elongated (Fig. 9 A – C). Total body length from anterior margin of rostrum to posterior margin of caudal rami: mean 1279 µm (n = 3). Cephalothorax wider than first and second free somites, largest width 408 µm (n = 1), surface with 251 pores and sensilla, with all groups, except group 36 (Fig. 8 A – D). Naupliar eye present, color red or orange (Fig. 9 D). Rostrum fused with cephalothorax. Posterior margin of cephalothorax and all pedigerous somites smooth. Body color yellowish, except second pedigerous somite, this somite white (Fig. 9 D). Abdomen (Figs 10 A – C, 11 A) consisting of genital double-somite, two free abdominal somites, and anal somite with caudal rami. Genital, second, and third abdominal somites on posterior margin serrated. Genital double-somite consists of last thoracic somite and first abdominal somite; longer than wide; anterior part with two dorsal pairs of sensilla, dorsal unpaired pore, lateral and ventral pairs of pores; posterior part with three pairs of sensilla, two pairs of pores and dorsal unpaired pore. P 6 (Fig. 10 A, B) lateral, formed plate, partially fused with somite; with one long plumose seta, one short spine and small spiniform process. Genital field (Fig. 10 C) wide, bean-shaped. Copulatory pore medial, located on notable suture cord. Copulatory duct short, chitinised. Anterior and posterior chambers of seminal receptacle equal in wide, narrow. Two egg sacks attached to gonopore area. Second abdominal somite (Fig. 10 A – C) with three pairs of sensilla, two pairs of pores, and dorsal unpaired pore. Third abdominal somite (Fig. 10 A – C) with dorsal unpaired pore, pairs of lateral and ventral pores. Anal somite with one dorsal pair of sensilla: one dorsal, one anterolateral, one lateral, and one ventral pairs of pores; with or without small posterior spinules near sides of proctodeum; with ventro-lateral posterior rows of spinules; proctodeum with rows of setules. Anal operculum slightly protruding. Caudal rami (Figs 10 A – C, 11 A). Length / width ratio 6, 5 in holotype (5.2 – 7.0, median 5.91, n = 19). Ramus with one ventral and two dorsal pores; with longitudinal row of small spinules (serra); with spinules at base of seta III. Serra extending from base of seta II to anterior 8 % of ramus in holotype (8 % – 30 %, median 16 %, n = 19). Seta I absent. Seta II dorsolateral, small. Seta III spiniform, with spinules on outer side and long setules on inner side. Apical setae IV and V (Fig. 10 D) long; bipinnate; with fracture planes; proximal part bare, medial part with rare long spinules, distal part with dense long spinules; length ratios 1 and 1.63, respectively. Seta VI with several inner setules and with or without outer setules; longer than seta III (ratio of lengths of seta VI to seta III 1.07 – 1.47, median 1.26, n = 19). Seta VII biarticulate. Antennule (Fig. 11 B, C) 12 - segmented; extending to second pedigerous somite. Armature formula as follows: 1 - [8], 2 - [4], 3 - [2], 4 - [6], 5 - [4], 6 - [2], 7 - [2], 8 - [3], 9 - [2 + ae], 10 - [2], 11 - [2 + ae], 12 - [7 + ae]. Segment 1 with four rows of spinules. Segment 4 with one pore. Three distal segments with finely serrate hyaline membrane (Fig. 11 C); proximal part of membrane of distal segment with 90 small denticles. Aesthetascs located on segments 9, 11, and 12. One seta on segment 6 spiniform. One apical seta on segment 12 fused basally to aesthetasc. Antenna (Fig. 12 A – D) four-segmented include coxobasis and three-segmented endopod. Coxobasis rectangular; with three setae, one of these exopodal long pinnate seta; with groups of spinules 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16. Number of spinules of group 7: 1 – 6 (median 3, n = 19). Number of spinules of group 8: 0 – 5 (median 1, n = 19). First endopodal segment with one naked seta; one postero-lateral and postero-medial rows of spinules. Second endopodal segment with nine naked setae on inner margin, these setae longer from proximal to distal; with row of spinules along outer margin. Third endopodal segment cylindrical, same length as second segment; with seven naked apical setae with claw-like tips; with two spinular rows on outer margin. Labrum (Fig. 11 D) trapezoidal. Anterior surface with two groups of long spinules. Distal margin with lateral outgrowths with small denticles and 11 medial teeth. Mandible (Fig. 12 E) composed of coxa and small palp. Coxal gnathobase with 14 distal elements: one serrate seta; eight strong teeth; five slender teeth, three of these fused in base; gnathobase distally with row of long spinules. Palp with three apical setae: two long and plumose and one short and naked. Paragnaths (Fig. 11 E) with paired lateral lobes. Distal parts of lobes with folded outgrowths. Proximal part of lobes on posterior side with three transverse group of spinules; medial part on posterior side with two longitudinal rows of spinules; distal part with one dense longitudinal posterior, one longitudinal anterior and distal rows of spinules. Ventral surface of cephalothorax posteriorly to paragnaths with groups of long hairs. Maxillule (Fig. 13 A, B) composed of syncoxa and two-segmented palp: one-segmented basis and one-segmented endopod. Praecoxal arthrite medially with three distal strong teeth, distal pinnate seta, two strong medial spines, three medial setae, one short plumose proximal seta and one long pilose robust proximal seta. Basis with anterior group of spinules; distally with two setae and one spine. Exopod represented by one plumose seta on proximal part of basis. Endopod with three plumose setae. Maxilla (Fig. 13 C) five-segmented, composed of syncoxa, basis and three-segmented endopod. Syncoxa with two rows of spinules on anterior side; with endite with two long pinnate setae. Basis with postero-lateral row of spinules and group of small spinules on posterior side; with two endites: proximal with one plumose seta; distal with one plumose and one bare setae. First endopodal segment with slender seta, strong subdistal plumose seta and strong claw with longitudinal row of spinules. Second endopodal segment with one strong serrate and one strong plumose setae. Third endopodal segment with one seta with small spinules, one bare and one strong serrate seta. Maxilliped (Fig. 13 D) four-segmented, composed of syncoxa, basis and two-segmented endopod. Syncoxa elongated; on anterior side with proximal row of spinules, medial flap-like structure and medial group of small spinules; with three plumose setae. Basis with two outer rows of spinules; two rows of spinules on anterior side; with two plumose setae. First endopodal segment with row of spinules on anterior side and long plumose seta. Second endopodal segment with one plumose and two serrulate setae. Setae / spine armature of P 1 – P 4 presented in Table 7. P 1 (Fig. 14 A) with three-segmented rami. Praecoxa with two rows of long spinules. Coxa rectangular; with two posterolateral, one anterolateral and one posteromedial rows of spinules; distal anterior margin with small spinules; anterior side with one pore and seven rows of tiny spinules; with long pinnate inner seta. Intercoxal sclerite almost square, with anterior distal paired and posterior medial continuous rows of spinules. Basis with pore; spinulose rows at base of endopod and inner seta; inner row of setules; outer row of small spinules; large number ungrouped tiny spinules on anterior side; with outer plumose and inner thick pinnate setae. All exopodal and endopodal setae plumose; all exopodal and endopodal spines spinulose. First exopodal segment with outer spine and inner seta; distal posterior, distal anterior rows of spinules, inner row of setules, spinules at base of outer spine. Second exopodal segment with inner seta and outer spine; with anterior pore, distal posterior, distal anterior rows of spinules; inner and outer rows of setules, spinules at base of seta and spine. Third exopodal segment with three outer spines, two apical and three inner setae; with inner setules and spinules at base of setae and spines. First endopodal segment with inner seta; with anterior distal rows of spinules and outer setules. Second endopodal segment with two inner setae; with one pore, distal anterior and distal posterior rows of spinules, outer and inner row of setules. Third endopodal segment with outer seta, apical spine, apical seta, three inner setae; with outer row of setules and spinules at base of spine and setae. P 2 (Fig. 15 A) with three-segmented rami. Praecoxa with group of long spinules. Coxa rectangular; with two posterolateral, two anterolateral and one posteromedial row of spinules; distal anterior margin with small spinules; anterior side with one pore and six rows of tiny spinules; with pinnate inner seta. Intercoxal sclerite almost square, with anterior distal paired and posterior medial continuous rows of spinules. Basis with pore; spinulose rows at base of endopod and on outer side; inner row of setules; several ungrouped tiny spinules on anterior side; with outer plumose seta. All exopodal and endopodal setae plumose; all exopodal and endopodal spines spinulose. Segments with small spinules near base of all spines and setae, except inner seta of first exopodal segment. First exopodal segment with outer spine and inner seta; distal posterior, distal anterior rows of spinules, inner row of setules. Second exopodal segment with inner seta and outer spine; with anterior pore, distal posterior, distal anterior rows of spinules; inner and outer rows of setules. Third exopodal segment with three outer spines, one apical spine, one apical seta and four inner setae; with one pore and inner setules. First endopodal segment with inner seta; with distal anterior and distal posterior rows of spinules and outer row of setules. Second segment with two inner setae; with one pore, distal anterior and distal posterior rows of spinules, and outer and inner rows of setules. Third segment with one outer seta, one apical spine, one apical seta, and three inner setae; with one pore; with outer and inner row of setules. P 3 (Fig. 15 B) similar to P 2. Intercoxal sclerite on posterior side with two rows of spinules. P 4 (Fig. 16 A, B) with three-segmented rami. Praecoxa with group of long spinules. Coxa rectangular; with pinnate inner seta. Posterior side of coxa with three proximal straight rows, three medial groups, several lateral groups and rows, and one distal row of large spinules. Anterior side with one pore and six rows of tiny spinules; with spinules on distal margin. Intercoxal sclerite on posterior side with continuous distal row of setules and discontinuous medial and proximal rows of long spinules / setules. Basis with pore; spinulose rows at base of endopod and on outer side; inner row of setules; several ungrouped tiny spinules on anterior side; with outer plumose seta. All exopodal and endopodal setae plumose; all exopodal and endopodal spines spinulose. Segments with small spinules near base of all spines and setae, except inner seta of first exopodal segment. First exopodal segment with outer spine and inner seta; distal posterior, distal anterior rows of spinules; inner row of setules; number of inner setules 8 – 17 (median 12, n = 13). Second exopodal segment with inner seta and outer spine; with anterior pore, distal posterior, distal anterior rows of spinules; inner and outer rows of setules; number of inner setules 6 – 10 (median 7, n = 13). Third exopodal segment with two outer spines, one apical spine, apical seta, and four inner setae; with one pore, outer and inner setules; three distal setae with hyaline frill. First endopodal segment with inner seta; with distal anterior and distal posterior rows of spinules and outer row of setules. Second segment with two inner setae; with one pore, distal anterior and distal posterior rows of spinules, outer row of setules. Third segment with one outer and one apical seta, one apical spine, and three inner setae; with one pore; with outer and inner row of setules; with small proximal outgrowth; all setae with weakly expressed hyaline frill. P 5 (Fig. 14 B) one-segmented, without intercoxal sclerite. Segment with large robust inner spine, one apical pinnate and outer pinnate setae; with row of spinules near base of inner spine and with or without outer row of spinules. Male. Significantly smaller than female (Fig. 9 E – G). Total body length from anterior margin of rostrum to posterior margin of caudal rami: 870 µm (n = 1), largest width of cephalothorax 255 µm (n = 1). Sexual dimorphism expressed in the antennule, ornamentation of A 2, P 2 – P 4, genital segmentation and ornamentation, P 6, caudal rami. Pore pattern of cephalothorax and abdominal somites as in female. Genital somite (Fig. 17 A, B) free; with two spermatophores visible inside; with P 6. Spermatophores (Fig. 17 B) bean-shaped. P 6 (Fig. 17 B) marked by two large flaps fused to the somite; with ventral pores; with outer and middle pinnate setae and inner long spinulose spine. Antennule (Fig. 18 A – C) 16 - segmented, haplocer with two geniculations: first one between segments 7, 8, and 9; second one between segments 14 and 15. Segment 1 long; with three spinulose rows; one long setiform aesthetasc, six unmodified setae and two modified “ blowball-setae ” with abruptly breaking tip with dense bunch of setules. Segment 2 with three unmodified setae and one “ blowball-seta ”. Segment 3 with one unmodified seta and one “ blowball-seta ”. Segment 4 with one long setiform aesthetasc, one unmodified seta and one “ blowball-seta ”. Segment 5 with one unmodified seta and one “ blowball-seta ”. Segments 6, 7, 8 similar, short, each with two setae. Segment 9 with two unmodified setae and one aesthetasc. Segments 10 and 11 widened, each with two setae. Segment 12 with one small and one spiniform robust seta. Segment 13 with one robust serrate seta, one small seta and one aesthetasc. Segment 14 elongated, with one modified flattened laminar seta and three small finger-like modified setae. Segment 15 elongate; with two modified flattened setae; one long unmodified seta; one modified spiniform seta and one aesthetasc. Segment 16 with two aesthetascs, eleven setae, one of which fused in base with aesthetasc. Armature formula: 1 - [8 + ae], 2 - [4], 3 - [2], 4 - [2 + ae], 5 - [2], 6 - [2], 7 - [2], 8 - [2], 9 - [2 + ae], 10 - [2], 11 - [2], 12 - [2], 13 - [2 + ae], 14 - [4], 15 - [4 + ae], 16 - [10 + ae + (1 + ae)]. Antenna (Fig. 18 D, E). Endopod similar to that in female. Coxobasis rectangular; with three setae, one of these exopodal long pinnate seta; with groups of spinules 1, 3, 4, 5, 6, 7, 9, 10, 11, 12, 15, 16. P 2 – P 4 (Fig. 17 C) similar to this in female, differences in relative length and shape of segments; smaller ornamentation; spines longer with strong spinules; setae shorter, with well-expressed hyaline frills.	en	Novikov, Aleksandr, Sharafutdinova, Dayana, Abramova, Ekaterina, Mayor, Tatyana, Chertoprud, Elena (2025): An integrative approach to the delimitation of pseudocryptic species in the Eucyclops speratus complex (Copepoda, Cyclopoida) with a description of a new species. ZooKeys 1226: 217-260, DOI: 10.3897/zookeys.1226.138389
97A5F10FC10A5745A0CF9C0733A6F3A7.taxon	description	Figs 19, 20, 21	en	Novikov, Aleksandr, Sharafutdinova, Dayana, Abramova, Ekaterina, Mayor, Tatyana, Chertoprud, Elena (2025): An integrative approach to the delimitation of pseudocryptic species in the Eucyclops speratus complex (Copepoda, Cyclopoida) with a description of a new species. ZooKeys 1226: 217-260, DOI: 10.3897/zookeys.1226.138389
97A5F10FC10A5745A0CF9C0733A6F3A7.taxon	description	Description. Female. Body elongated (Fig. 19 A – C). Total body length from anterior margin of rostrum to posterior margin of caudal rami: mean 1310 µm (n = 1). Cephalothorax pitted (Fig. 19 E), wider than first and second free somites, largest width 395 µm (n = 1), surface with 253 pores and sensilla, with all groups (Fig. 8 A – D). Naupliar eye not observed. Posterior margin of cephalothorax and all pedigerous somites smooth. Pedigerous and abdominal somites pitted, with “ sutures ” (Figs 19 D, 20 A, B). Abdomen and P 6 similar to that in E. sibiricus sp. nov. (Fig. 20 A). Caudal rami similar to that in E. sibiricus sp. nov. (Fig. 20 A, B). Length / width ratio 5.4 – 6.3 (median 6.04, n = 13). Serra extending from base of seta II to anterior 20 % of ramus (10 % – 36 %, median 20 %, n = 13). Ratio of length of seta VI to seta III 1.07 – 1.28 (median 1.18, n = 13). Antennules, antennae, mouthparts, labrum, and paragnaths similar to that in E. sibiricus sp. nov. Antenna (Fig. 20 C – E). Coxobasis with groups of spinules 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16. Number of spinules of group 7: 3 – 10 (median 5, n = 13). Number of spinules of group 8: 0 – 10 (median 4, n = 13). P 1 – P 4 similar to that in E. sibiricus sp. nov., but with shorter segments (Fig. 21 A – C). Number of inner setules of P 4 Exp 1 (Fig. 21 B): 1 – 6 (median 1, n = 13). Number of inner setules of P 4 Exp 2: 1 – 3 (median 0, n = 13). P 5 (Fig. 20 F) similar to that in E. sibiricus sp. nov., but without outer row of spinules. Male. Not studied.	en	Novikov, Aleksandr, Sharafutdinova, Dayana, Abramova, Ekaterina, Mayor, Tatyana, Chertoprud, Elena (2025): An integrative approach to the delimitation of pseudocryptic species in the Eucyclops speratus complex (Copepoda, Cyclopoida) with a description of a new species. ZooKeys 1226: 217-260, DOI: 10.3897/zookeys.1226.138389
