Eucyclops estherae Mercado-Salas & Suárez-Morales & Silva-Briano 2015, sp. nov.
Creators: name: Mercado-Salas, Nancy F.
name: Suárez-Morales, Eduardo
name: Silva-Briano, Marcelo
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Hexanauplia
Cyclopoida
Cyclopidae
Eucyclops
Eucyclops estherae

description: Eucyclops estherae sp. nov. Mercado-Salas and Suárez-Morales (Figures 61 – 66)
Material examined
Holotype. Adult ♀ specimen dissected, mounted in glycerin, slides sealed with Entellan (ECO-CH-Z-04636).
Allotype. Adult ♂, dissected, mounted in glycerin, slides sealed with Entellan (ECO-CH- Z-04637).
Paratypes. Twelve adult ♀♀ undissected ethanol-preserved (90%) (ECO-CH-Z-04638). Samples from type locality collected 15 October 2006 by Marcelo Silva-Briano and Nancy F. Mercado-Salas.
Type locality
San Francisco Pond, San Francisco, San Luis Potosí, Mexico (22°03´13.8´´ N; 99°50´50.3´´ W).
Etymology
This species is warmly dedicated to the late Mrs. Esther Ruiz Jiménez, the beloved grandmother of the first author (NFM-S).
Distribution
Central and Northern Mexico (San Luis Potosí, Durango, Coahuila).
Description
Female. Habitus as Figure 63A – B. Average length excluding caudal setae = 770 µm. Prosome widest at end of cephalosome and second pediger, representing 57% of total body length, symmetrical in dorsal view (Figure 63C). Prosomal fringes slightly serrate dorsally (Figure 63C). Urosomal fringes strongly serrate. Genital double somite symmetrical (Figure 63D), representing 8% of total body length; anterior third of genital double somite expanded laterally. Seminal receptacle with rounded lateral arms, posterior margin with sinuous sac (Figure 61A). Length/ratio of caudal rami = 5.5; inner margin of caudal ramus naked; strong spines covering 67% with respect to the total length of ramus. Dorsal seta (VII) 0.5 times as long as caudal ramus and as long as outermost caudal seta (III). Ratio of innermost caudal seta (VI)/outermost caudal seta (III) = 1.5. Lateral caudal seta (II) inserted at 80% of caudal ramus.
Antennule (Figures 61B, 64A–D). Tip reaching posterior margin of third pediger. Armature per segment as follows: 1(8s), 2(4s), 3(2s), 4(6s), 5(4s), 6(1s+1sp), 7(2s), 8(3s), 9(2s+1ae), 10(2s), 11(3s), 12(7s). First segment with two rows of spinules, proximal row
bearing minute spinules, second row with stronger, slightly longer spinules. Spine on sixth segment not reaching medial margin of seventh segment.
Antenna (Figures 61C–D, 64E). Coxa (unarmed), basis (2s+Exp), plus three-segmented Enp (1s, 9s, 7s, respectively). Basis with row of spinules on frontal surface: N1(V), N2(4), N3(4), N4(5), N5(6), N15(4), N17(11), N18(4); on frontal surface: N7(6), N8(6), N9+10(9), N11(6), N12(7), N13(5), N14(5), N22(8). Caudal surface of first Enp with B1(7) and B2(6). Leg 1 (Figures 62A–B, 64F, 65A–B). Intercoxal sclerite with row I bearing small hairs arranged in circular pattern on each side of frontal surface; caudal row II armed with long hair – setules on middle margin, medial setules slightly shorter, distal margin with two rounded, chitinised projections. Inner coxal seta biserially setulated, caudal coxal surface with spinule formula = A-B-C. Inner basal seta (basipodal spine) not reaching middle margin of Enp3, 0.6 times as long as Enp. Length/width ratio Enp3 = 1.5, apical spine of Enp3 being 1.2 times as long as Enp3.
Leg 2 (Figures 62C–D, 65C–D). Frontal surface of intercoxal sclerite with row I bearing hairs arranged in circular pattern on each side; caudal row II bearing 7 – 8 long hair – spinules on each side (gap in middle margin), row I absent. Distal margin of sclerite with two rounded, chitinised projections. Inner coxal seta biserially setulated, caudal coxal surface with spinule formula = A-B-C. Small spinules along insertion of basipode (frontal surface). Length/width ratio of Enp3 = 2, apical spine of Enp3 being 1.4 times as long as segment (Enp3). No modified setae present.
Leg 3 (Figures 62E–F, 65F, 66A–B). Intercoxal sclerite with frontal row I bearing hairs arranged in a circular pattern on each side; caudal surface with row I bearing nine long hairs on each side (small gap in the middle section); row II continuous, bearing long hairs (about 16); row III continuous, bearing slightly shorter hairs setules (about 18). Distal margin with two rounded, chitinised projections. Coxa with strong, biserially setulated coxal seta. Caudal coxal surface with spinule formula = A-B-C. Length/width ratio of Enp3 = 2.1; apical spine of Enp3 being 1.2 times longer than Enp3. No modified setae present.
Leg 4 (Figures 62G–I, 66C–D). Distal margin of intercoxal sclerite with two low, rounded, chitinised projections. Frontal surface with row I bearing hairs arranged in a semicircular pattern on each side; caudal surface of intercoxal sclerite with row I bearing long hairs, about 13 on each side (small gap between them), row II bearing 7 – 9 hairs on each side (adjacent to outer margins); row III bearing 3 – 7 hairs on each side. Frontal surface of coxa with spinules at insertion of Bsp. Inner coxal seta with heterogeneous ornamentation; proximal inner margin with long hairs and distally with strong spinules; outer margin basally with hairs and distally naked. Caudal coxal surface with spinule formula = A-B-C + D-E-G-H-J. Length/width ratio Enp3 = 2.6, length ratio inner spine of Enp3/length Enp3 = 1.3; length ratio outer spine of Enp3/length of Enp3 = 0.9; proportion inner/outer spine Enp3 = 1.4. Lateral seta of Enp3 inserted at 65% of segment. No modified setae in Enp and Exp.
Leg 5 (Figure 66F). Free segment subrectangular, 1.5 times longer than wide, bearing one strong inner spine and two setae; medial seta 3 times longer than outer seta and 1.4 times longer than inner spine. Inner spine 2.5 times longer than segment.
Male. Prosome symmetrical in dorsal view. Urosome slightly elongated. Caudal ramus smooth along both inner and outer margins, except for strong spinules at insertion of lateral seta. Length/width ratio of caudal ramus = 4.0, dorsal seta (VII) 0.6 times as caudal ramus and 1.1 times as long as outermost caudal seta (III). Innermost caudal seta (VI)/ outermost caudal seta (III) ratio = 2.0. Lateral caudal seta (II) inserted at 68% of ramus length.
Antennule. Armature as follows: 1(5s+3ms), 2(3s), 3(1s+2ms), 4(1s+1ms), 5(1s), 6(2s), 7(2s), 8(2s), 9(0), 10(2s), 11(1sp), 12(2s), 13(0), 14(0), 15(3s), 16(6s).
Antenna. Basis with spinule groups on frontal surface: N1(III), N2(3), N3(6), N4(6), N5(6), N15(4), N17(10), N18(4) and on caudal surface: N7(5), N8(5), N9+10(5), N115) N12(7), N13(4), N14(6).
Legs 1–4. Enp and Exp of all swimming legs three-segmented, armed as in females.
Leg 5. Free segment subrectangular, 2.1 times longer than wide, bearing one inner spine and two setae, medial seta longer than inner spine and outer seta (about 1.2 times), inner spine and outer seta equal in size.
Leg 6. Represented by a small, low plate adjacent to lateral margin of genital somite, armed with one strong spine and two unequal setae. Inner spine reaching posterior margin of fourth urosomite, inner spine 1.8 times longer than medial seta and 2.2 times as long as outer seta. Small and strong spinules presents at insertion of inner spine.
Remarks. Eucyclops estherae sp. nov. is closely related to both E. festivus and E. wixarica sp. nov. because they have similar morphometrical characters. The new species can be distinguished by a unique combination of characters. It differs from these two species by the presence of a sinuous lobe on posterior margin of seminal receptacle, which is present also in E. alekseevi sp. nov., E. angeli and E. prionophorus. The new species differs from E. festivus in details of the antennal basis ornamentation; in E. estherae sp. nov. rows N6 and N16 are absent while both rows are present in E. festivus. In E. estherae sp. nov. caudal row I of P1 intercoxal sclerite is absent, while this row is present in E. festivus; also, row II bears long hairs in the new species and in E. festivus it is formed by minute spinules. The P2 sclerite differs between these two species: in the caudal surface of E. estherae sp. nov. row I is absent and it is present in E. festivus; row II bears long hairs in the new species vs minute spinules in E. festivus. All caudal rows of the intercoxal sclerite of P3 differ between these species. In E. estherae sp. nov. all rows have long hairs whereas a different pattern is present in E. festivus; it has hairs only in row I and rows II and III bear strong spinules. The intercoxal sclerite of P4 shows differences in both surfaces; in the frontal surface E. estherae sp. nov. bears hairs arranged in a semicircle while in E. festivus this row is straight, armed with minute spinules. On the caudal surface all rows in E. estherae are armed with long hairs, thus diverging from E. festivus, in which these rows bear spinules. The medial seta of P5 is remarkably long in the new species when compared with the outer seta (3.0); other species with long medial setae are E. chihuahuensis (2.8) and E. wixarica sp. nov. (2.4); the rest of the Mexican species show values ranging between 1.0 and 2.0.
description: Published as part of Mercado-Salas, Nancy F., Suárez-Morales, Eduardo & Silva-Briano, Marcelo, 2015, Taxonomic revision of the Mexican Eucyclops (Copepoda: Cyclopoida) with comments on the biogeography of the genus, pp. 25-147 in Journal of Natural History 50 on pages 120-128, DOI: 10.1080/00222933.2015.1061715, http://zenodo.org/record/3983088