Mexicophria cenoticola
Creators: name: Boxshall, Geoff A.
name: Zylinski, Sarah
name: Jaume, Damià
name: Iliffe, Thomas M.
name: Suárez-Morales, Eduardo
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Maxillopoda
Misophrioida
Speleophriidae
Mexicophria
Mexicophria cenoticola

description: 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 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 A, 3A). Prosomal pedigerous somites with evenly rounded posterolateral corners. Urosome 5-segmented (Fig.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 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 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 D).
Antennule (Fig. 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 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 C) and biramous palp (Fig. 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 B) with large praecoxal arthrite bearing 12 elements, including pair of setae on posterior surface (Fig. 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 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 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 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 A).
Members of fifth leg pair (Fig. 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 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 E). Sixth legs each with 2 distal setae; posterior margin of somite with tooth-like protuberance just lateral to gonopore.
Antennules (Fig. 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 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
description: Published as part of 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, pp. 321-336 in Zootaxa 3821 (3) on pages 325-332, DOI: 10.11646/zootaxa.3821.3.2, http://zenodo.org/record/225854