Eucyclops wixarica, Mercado-Salas & Suárez-Morales & Silva-Briano, 2015

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, Journal of Natural History 50, pp. 25-147 : 93-102

publication ID	https://doi.org/ 10.1080/00222933.2015.1061715
publication LSID	lsid:zoobank.org:pub:2F320DE0-FF96-4E5F-8520-586303082E09
DOI	https://doi.org/10.5281/zenodo.4332569
persistent identifier	https://treatment.plazi.org/id/397AD47D-FFB4-FFBE-A656-FC3BFDBE77FE
treatment provided by	Carolina
scientific name	Eucyclops wixarica
status	sp. nov.

Treatment

Eucyclops wixarica sp. nov. Mercado-Salas and Suárez-Morales ( Figures 40 – 47 View Figure 40 View Figure 41 View Figure 42 View Figure 43 View Figure 44 View Figure 45 View Figure 46 View Figure 47 )

Material examined

Holotype. Adult ♀ specimen dissected, mounted in glycerin sealed with Entellan (ECO- CH-Z-04633).

Allotype. Adult ♂, dissected, mounted in glycerin sealed with Entellan (ECO-CH- Z-04634).

Paratypes. Ten adult ♀♀ undissected ethanol-preserved (90%) (ECO-CH-Z-04635). 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) GoogleMaps .

Etymology

This species is warmly dedicated to one of the most important indigenous ethnic groups from Mexico, the Wixaricas or Huicholes. One of their main ceremonial sites is located in the state of San Luis Potosí, where the type specimens were collected .

Distribution

Bordo San Francisco, San Luis Potosí, Mexico.

Description

Female. Habitus as in Figure 42A View Figure 42 . Average length excluding caudal setae = 850 µm. Prosome representing 62% of total body length, symmetrical in dorsal view. Prosomal fringes finely serrate in dorsal view ( Figure 42B View Figure 42 ). Urosomal fringes strongly serrate. Genital double somite symmetrical ( Figure 42C View Figure 42 ), representing 10% of total body length; anterior third of genital double somite expanded. Seminal receptacle with rounded lateral arms on posterior margin, typical of the serrulatus -complex. Anal operculum slightly rounded, smooth ( Figure 42D View Figure 42 ). Length/width of caudal ramus = 5.1; inner margin of caudal ramus naked; strong spinules covering 61% with respect to the total length of ramus. Dorsal seta (VII) 0.4 times as long as caudal ramus and 0.9 times as long as outermost caudal seta (III). Ratio of innermost caudal seta (VI)/outermost caudal seta (III) = 0.9. Lateral caudal seta (II) inserted at 77% of caudal ramus.

Antennule ( Figures 40B View Figure 40 , 43A–C View Figure 43 ). Tip reaching posterior margin of cephalosome. 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(2s+1ae), 12(8s). Two transverse rows of spinules on first segment, first row with strong spinules (outer spinules slightly smaller than medial one), adjacent second row with minute spinules. Spine on sixth segment reaching midlength of seventh antennular segment.

Antenna ( Figures 40C–D View Figure 40 , 43D–F View Figure 43 , 44A View Figure 44 ). Coxa (unarmed), basis (2s+Exp), plus threesegmented Enp (1s, 9s, 7s, respectively). Basis with rows of spinules on frontal surface:

N1(IV), N2(IV), N3(6), N4(7), N5(6), N15(4), N17(14), N18(3); on caudal surface: N7(16), N8(5), N9(6), 10(3), N11(9), N12(9), N13(12) N14(7), N16(11). Caudal surface of Enp1 with B2(5).

Leg 1 ( Figures 41A–B View Figure 41 , 44B–C View Figure 44 ). Frontal surface of intercoxal sclerite with a row of strong spinules arranged in a semicircular pattern on each side; caudal surface with row I continuous, bearing 18 short hair spinules; row II continuous, with 17 short hair spinules. Inner coxal seta biserially setulated, caudal coxal surface with spinule formula = A-B-C. Inner basal seta (basipodal spine) not reaching midlength of Enp3, 0.6 times as long as Enp. Length/width ratio Enp3 = 1.6, apical spine of Enp3 being 1.1 times as long as Enp3.

Leg 2 ( Figures 41C–D View Figure 41 , 44D–E View Figure 44 ). Frontal surface of intercoxal sclerite with row I bearing hairs arranged in circular pattern; caudal surface with row I divided into two groups bearing long hairs and arranged in a semicircular pattern on each side and close to the posterior margin. Row II continuous, with small hairs. Distal margin of intercoxal sclerite with two rounded, chitinised projections. Inner coxal seta biserially setulated, caudal

coxal surface with spinule formula = A-B-C-D. Length/width ratio of Enp3 = 2.0, apical spine of Enp3 being 1.4 times as long as Enp3. No modified setae present.

Leg 3 ( Figures 41E–G View Figure 41 , 44F View Figure 44 , 45A View Figure 45 ). Frontal surface of intercoxal sclerite with hairs arranged in circular pattern on each side; caudal surface with row I bearing long hairs (gap in the middle section), rows II and III continuous, bearing long hairs. Distal margin with two rounded, chitinised projections. Coxa with strong, biserially setulated inner coxal seta, proximally with long hairs and distally with strong spinules along both margins. Caudal coxal surface with spinule formula = A-B-C. Length/width ratio of Enp = 2.2, apical spine of Enp3 being 1.2 times as long as Enp3. No modified setae present.

Leg 4 ( Figures 41H–I View Figure 41 , 45B–F View Figure 45 ). Distal margin of intercoxal sclerite with two low, rounded, chitinised projections. Frontal surface of sclerite with row I bearing long hairs arranged in circle, caudal surface of intercoxal sclerite with row I bearing very long hairs, row II with long hairs on outer margins; row III with long hairs close to outer margins. Frontal surface of coxa with row of small spinules at insertion of Bsp. Inner coxal spine with heterogeneous ornamentation; inner margin with long hairs on proximal section and with strong spinules distally; outer margin with one distal spinule and setulated along proximal section, gap in middle margin. Spinule formula on caudal surface = A-B-C + D-E-F-H-J. Length/width ratio Enp3 = 2.5, length ratio inner spine of Enp3/length Enp3 = 1.3; length ratio outer spine of Enp3/length Enp3 = 0.9; length ratio inner/outer spines Enp3 = 1.5. Lateral seta of Enp3 inserted at 65% of segment. No modified setae in Enp and Exp.

Leg 5. Free segment subrectangular, 1.4 times longer than wide, bearing one strong inner spine and two setae; medial seta 2.4 times longer than outer seta and 1.5 times longer than inner spine. Inner spine 2.6 times longer than segment.

Male. Urosome slightly elongated, urosomal fringes serrated. Caudal ramus smooth along both inner and outer margins, only with strong spinules at insertion of lateral seta. Length/width ratio of caudal ramus = 3.8, dorsal seta (VII) 0.5 times as long as caudal ramus and 0.9 times as long as outermost caudal seta (III). Innermost caudal seta (VI)/outermost caudal seta (III) ratio = 1.8. Lateral caudal seta (II) inserted at 71% of caudal ramus length.

Antennule ( Figure 43A View Figure 43 ). Armature as follows: 1(5s+4ms), 2(4s), 3(1s+1ms), 4(1ms) 5(1ms), 6(1s) 7(1s), 8(1s), 9(0), 10(3s), 11(1s), 12(1sp+1s), 13(0), 14(0), 15(3s), 16(8s).

Legs 1–4. Enp and Exp of all swimming legs three-segmented, armed as in females.

Leg 5 ( Figure 43B View Figure 43 ). Free segment subrectangular, 1.5 times longer than wide, bearing inner spine and two setae; medial seta longer than outer seta (about 2.8 times) and inner spine (1.5 times).

Leg 6 ( Figure 43B View Figure 43 ). Represented by small, low plate adjacent to lateral margin of genital somite armed with strong inner spine and two unequal setae. Inner spine reaching posterior margin of third urosomite, inner spine 1.5 times longer than medial seta and 1.6 longer than outer seta. Strong spinules at insertion of inner spine.

Remarks. Eucyclops wixarica sp. nov. can be easily distinguished from most of its congeners distributed in the Americas by the presence of long hair-like elements on the frontal surface of the antennal basipodite; this character is shared with the American E. elegans , E. defayeae sp. nov. and E. mittmanni sp. nov., and also with some other members of the serrulatus -group such as E. serrulatus s. str., E. romaniensis , E. albuferensis , E. miracleae , E. agiloides roseus , E. paci fi cus and E. vandouwei ; these species are known from Europe, Africa and Asia ( Ishida 2000; Dussart and Defaye 2006; Alekseev 2008, 2010; Alekseev and Defaye 2011). Eucyclops wixarica sp. nov. differs from E. elegans and E. mittmanni sp. nov. because of its total body length. The two latter species are – together with E. neumani s. str. and E. titicacae – the largest Eucyclops in the Americas; their size is> 1050 µm, whereas E. wixarica sp. nov. is clearly a smaller species (810 µm). Also, the new species can be distinguished from those species by the length/width ratio of the caudal ramus; it is about 5.1 in the new species vs more than 6.0 in both E. elegans and E. mittmanni sp. nov. The ornamentation of the antennal basis is more complex in E. elegans and E. mittmanni sp. nov. than in E. wixarica sp. nov. In addition, the caudal surface of the P3 and P4 coxal plates differs among these species. In E. wixarica all rows of both P3 and P4 are long hairs, whereas some rows with spinules are present in the other species. Eucyclops wixarica sp. nov. seems to be closely related to E. serrulatus because of the presence of long hairs on row N2 of the antennal basis and the similar length/width ratio of the caudal ramus (about 5.0 in both species), and also in most morphometric values. These species can be separated by a combination of characters. Row N6 is absent in E. wixarica sp. nov. and is present in E. serrulatus . The new species shows a more complex ornamentation on the caudal surface of the antennal Bsp; it has rows N8, N10, N13, N16 and N18, all of them absent in E. serrulatus . The ornamentation of the caudal surface of P2 intercoxal sclerite diverges in these species; in E. wixarica sp. nov. row I is present but it is absent in E. serrulatus . Also, the P3 and P4 sclerites have rows with strong spinules in E. serrulatus , thus differing from E. wirxarica sp. nov., in which all rows bear long hair-like elements. The P4 coxa of E. wixarica sp. nov. has row F; this row is absent in E. serrulatus .