Mexicophria cenoticola

Boxshall, Geoff A., Zylinski, Sarah, Jaume, Damià, Iliffe, Thomas M. & Suárez-Morales, Eduardo, 2014, A new genus of speleophriid copepod (Copepoda: Misophrioida) from a cenote in the Yucatan, Mexico with a phylogenetic analysis at the species level, Zootaxa 3821 (3), pp. 321-336 : 325-332

publication ID	https://doi.org/ 10.11646/zootaxa.3821.3.2
publication LSID	lsid:zoobank.org:pub:13AD493F-8B71-4F1E-9887-CBDB9A2FAA45
DOI	https://doi.org/10.5281/zenodo.5667159
persistent identifier	https://treatment.plazi.org/id/8A338442-8732-FFD7-47FA-FDEF182A045A
treatment provided by	Plazi
scientific name	Mexicophria cenoticola
status

Treatment

Mexicophria cenoticola gen. et sp. nov.

Type locality. Cenote Carwash (also known as Cenote Aktun Ha) near Tulum, Quintana Roo, Mexico; (location: 20°16' 26" N; 87° 29' 11"W).

Type material. Undissected holotype female (ECO-CHZ-07538) and 2 undissected paratype females (ECO- CHZ-07539) stored in the collections of ECOSUR, Chetumal, partly dissected male and 2 undissected female paratypes stored in collections of the Natural History Museum, London, Reg. Nos. NHMUK 2014.10-12.

Adult female. Body ( Fig. 1 View FIGURE 1 A) cyclopiform, compressed laterally, colourless. Body length about 0.480 to 0.534 mm [varying with degree of telescoping of urosomites and degree of dorsal flexure of body]. Nauplius eye absent. Prosome 5-segmented, with first pedigerous somite not incorporated into cephalothorax. Dorsal shield of cephalosome lacking carapace-like extension on posterior margin. Rostrum sickle-shaped, powerfully developed, not fused to dorsal shield; ornamented with paired sensilla near middle of lateral margin ( Figs 1 View FIGURE 1 A, 3A). Prosomal pedigerous somites with evenly rounded posterolateral corners. Urosome 5-segmented ( Fig.1 View FIGURE 1 B); genital and first abdominal somites completely fused to form elongate double-somite. Fifth pedigerous somite carrying fifth legs ventrally, adjacent to midline; posterior margin ornamented with smooth hyaline frill ventrally. Genital doublesomite ( Fig. 1 View FIGURE 1 B) with genital field located in anterior third; gonopores separate, in form of narrow sigmoid slits, each closed off by unarmed vestigial leg 6, located latero-ventrally on each side of single copulatory pore located in ventral midline; genital double-somite with conspicuous swelling midventrally in posterior third ( Fig. 1 View FIGURE 1 A–B); posterior margin with continuous hyaline frill varying in width. Second, third and fourth (= anal) abdominal somites, with extensive arthrodial membrane anteriorly, allowing telescoping inside posterior end of preceding somite. Anal somite with 2 dorsolateral sensilla, on either side of smooth anal operculum. Caudal rami short, just longer than wide; armed with 6 setae; anterolateral accessory seta (seta I of Huys & Boxshall 1991) absent, as in male ( Fig. 1 View FIGURE 1 D).

Antennule ( Fig. 2 View FIGURE 2 A) 27-segmented: segment 1 with dorsolateral margin swollen, forming ovoid protuberance distally; segments 2 to 10 densely packed, perhaps not completely separate posteriorly; segments 11 and 12 not completely separate posteriorly; apical segment double. Segmental armature as follows: segment 1, 3 setae; segments 2 to 10, 2 setae each; segment 11, 2 setae + long aesthetasc; segment 12, 1 seta, segments 13 to 15, 2 setae each; segment 16, 2 setae (1 very long) + long aesthetasc; segments 17 to 20, 2 setae each; segment 21, 2 setae + aesthetasc; segments 22 and 23, 1 seta each; segments 24 to 26, 2 setae (1 posterior) each; apical segment 27 (fused ancestral segments XXVII and XXVIII), 5 setae + aesthetasc.

Antenna ( Fig. 2 View FIGURE 2 B) biramous: coxa unarmed, ornamented with distal spinule row; basis separate, armed with 1 inner distal seta. Endopod indistinctly 3-segmented; first segment with 2 unequal setae near mid distance along medial margin; second and third segments incompletely separated; second segment with 5 inner and distal setae; third segment with 7 setae on tip and ornamented with longitudinal row of setules along outer margin. Exopod distinctly 7-segmented; second segment longer than first and third, possibly compound; distal segment double; setal formula 1, 1, 1, 1, 1, 1, 4.

Labrum an undivided muscular lobe.

Mandible comprising stout coxal gnathobase ( Fig. 2 View FIGURE 2 C) and biramous palp ( Fig. 2 View FIGURE 2 D); gnathobase with large ventral tooth, separated by small gap from slender curved tooth, and row of 5 simple teeth; dorsal seta present; spinule row present near base of teeth. Mandibular palp with basis markedly longer than wide, bearing 2 unequal setae on inner margin, curved proximal seta longer than endopod; exopod indistinctly 4-segmented, apical segment double; setal formula 1, 1, 1, 3: endopod 2-segmented, proximal segment elongate with convex medial margin; setal formula 4, 7.

Maxillule ( Fig. 3 View FIGURE 3 B) with large praecoxal arthrite bearing 12 elements, including pair of setae on posterior surface ( Fig. 3 View FIGURE 3 C); coxa with single endite bearing 5 setae, and vestigial epipodite incorporated into segment margin, represented by 7 setae; basis with unarmed outer margin; 2 widely separated basal endites present, proximal endite discrete, armed with 3 setae; distal endite incorporated into segment, represented by 4 setae; exopod 1-segmented, lamella-like, with 8 setae, medial and lateral margins with setule rows; endopod with 2 free segments, proximal segment representing double segment subdivided by partial suture line; setal formula (4, 2), 5.

Maxilla ( Fig. 3 View FIGURE 3 D) powerfully developed, 6-segmented. Praecoxa and coxa discrete; each with 2 endites, setal formula 5, 3, 3, 3. Allobasis with proximal (= basal) endite powerfully developed, drawn out distally into stout, non-articulating curved medial claw with 3 setae implanted around base; distal (= endopodal) endite weakly developed, represented by 2 unequal setae. Free endopod 3-segmented, with setal formula 2, 2, 4.

Maxilliped 8-segmented ( Fig. 3 View FIGURE 3 E), comprising syncoxa with 3 defined endites, basis and slender 6-segmented endopod, with proximal endopodal segment free: praecoxal seta lacking, syncoxal endites with setal formula 0, 2, 4, 3; basis with 2 setae, distal setae bilaterally spinulate; endopodal setal formula 2, 2, 2, 2, 2+1, 4; distal segment longest.

Swimming legs 1 to 4 biramous ( Fig. 4 View FIGURE 4 A–D), with 3-segmented rami except 2-segmented endopod of leg 1, due to failure of second and third segments to separate; members of each leg pair joined by intercoxal sclerite; incomplete hoop-like praecoxa remnant retained laterally on each leg; distolateral corners of endopodal segments 1 and 2 of legs 2 to 4 typically produced into conspicuous spinous processes, bifid on second segment of leg 2. Inner margin of first exopodal segment of legs 1 to 4 and outer margins of all endopodal segments of legs 2 to 4 ornamented with setules. Outer margins of exopod segments of leg 1 with scale-like ornamentation. Spine and seta formula for legs 1 to 4 as follows:

Outer margin spines and terminal spine on exopod of leg 1 each with flagellate tip ( Fig. 4 View FIGURE 4 A).

Members of fifth leg pair ( Fig. 1 View FIGURE 1 C) located immediately adjacent to ventral midline, intercoxal sclerite lacking. Fifth leg slender, uniramous, 2-segmented; proximal segment representing undivided protopod, slightly wider than and shorter than distal segment, bearing outer basal seta; distal segment 3.5 times longer than wide, representing exopod, bearing 2 spiniform elements on distal margin; outer spine slightly longer than inner.

Adult male. Body ( Fig. 1 View FIGURE 1 D) cyclopiform as in female, sexually dimorphic in antennules, legs 5 and 6, and in genital segmentation. Body length 0.476 mm. Urosome 6-segmented, with genital somite just longer than wide, and markedly larger than all other urosomites; free posterior margins of genital and first to third free abdominal somites with narrow strips of hyaline frill; segments not showing extreme telescoping as in females. Genital somite with paired ventral gonopores located close to posterior margin, closed off by opercular plates formed by sixth legs ( Fig. 1 View FIGURE 1 E). Sixth legs each with 2 distal setae; posterior margin of somite with tooth-like protuberance just lateral to gonopore.

Antennules ( Fig. 3 View FIGURE 3 F) bilaterally symmetrical, similar to those of female in general aspect, but indistinctly 23- segmented with articulations between densely packed segments 2 to 11 less complete than in female; segment 1 with dorsolateral margin swollen, forming ovoid protuberance distally, as in female; segments 2 to 11 partly fused, separated by incomplete articulations; segments 12 to 18 separate, with segment 15 (XV) forming sheath around proximal part of segment 16 (XVI); geniculate between segments 19 (XIX–XX) and 20 (XXI–XXIII); segment 21 (XXIV) free, segment 22 (XXV–XXVI) and apical segment (XXVII–XXVIII) double. Segmental armature as in female except as follows: segments 4, 7 and 8 each with 1 seta; double segment 19 (XIX–XX) bearing 1 seta, 1 modified plate-like element; triple segment 20 (XXI–XXIII) with 2 modified, plate-like elements plus 1 distal seta.

Members of fifth leg pair located immediately adjacent to ventral midline, intercoxal sclerite lacking. Fifth leg slender, uniramous, 3-segmented ( Fig. 1 View FIGURE 1 F), comprising coxa, basis and 1-segmented exopod: coxa short, unarmed; basis slightly longer than coxa, bearing outer basal seta; distal (exopodal) segment 4.2 times longer than wide; narrower than coxa and basis, bearing 4 setal elements on distal margin, inner spine slightly more than half as long as segment, ornamented with minute pinnules bilaterally, adjacent spine minute, 2 outer spines about equal in length.

Species Characters 1-56