Phyllognathopus viguieri (Maupas, 1892)

Galassi, Diana M. P., Laurentiis, Paola De & Fiasca, Barbara, 2011, Systematics of the Phyllognathopodidae (Copepoda, Harpacticoida): re-examination of Phyllognathopus viguieri (Maupas, 1892) and Parbatocamptus jochenmartensi Dumont and Maas, 1988, proposal of a new genus for hyllognathopus bassoti Rouch, 1972, and description of a new species of Phyllognathopus, ZooKeys 104, pp. 1-65 : 3-9

Phyllognathopus viguieri (Maupas, 1892) Figs 19

Material examined.

11 ♀♀ and 2 ♂♂,completely dissected and mounted in polyvinyl lactophenol, S. Anna D’Alfaedo, Progno di Valpantena (Verona, Italy), hyporheic habitat, 25.06.2002, E. Gattone coll.; 1 ♀, karstic spring in the hydrogeological basin of Rio Biondo, Progno di Valpantena (Verona, Italy), karstic habitat, 7. 07. 2003, B. Fiasca coll.; 3 ♀♀, Lake Bracciano (Latium, Italy), interstitial habitat, 27.05.02, V. Cottarelli coll.; 10 ♀♀ and 5 ♂♂, Avisio floodplain (Trento, northern Italy), hyporheic habitat, 30.05.2006, T. Di Lorenzo coll.; 3 ♀♀ and 1 ♂, Oignin stream (French Jura Mountains), hyporheic habitat, 30.07.2002, M.-J. Dole-Olivier coll.; 2 ♀♀ and 1 ♂, Ariège floodplain (France), P. Dumas coll.; 1 ♀, Lac Léman (France), slide code MNHN - Cp922, Paris; 2 ♂♂, S. Pierre, (France), slide code MNHN - Cp456, Paris; 3 ♂♂ and 2 ♀♀, Ruhr floodplain (Germany), T. Glatzel coll.; 6 ♀♀ and 1 ♂, R. Krishna, India, Y. Ranga Reddy coll.; 1 ♀, in pitcher of Nepenthes mirabilis (Hong Kong), B. Coker det., slide code 1982.329, Natural History Museum, London; 2 ♀♀ deposited at the Smithsonian Institution, Washington D.C., code USMN 251806, 204501; 1 ♂, code USMN 204500; 1 ♂ (juvenile), code USMN 204501.

Phyllognathopus cf. viguieri A. 2 ♂♂, 2 ♀♀, Madagascar, vial code, MNHN - Cp910, Paris, B. Dussart coll..

Phyllognathopus cf. viguieri B. 1 ♀, slide code 66/52, freshwater well, Mindoro Island, Philippines, 17.8.1992, V. Cottarelli coll.

Phyllognathopus viguieri ?. 10 ♀♀ and 5 ♂♂, Andhra Loyola College Campus, Vijaya-Woda, Andhra Pradesh, India, Y. Ranga Reddy coll..

Phyllognathopus viguieri menzeli . 1♀, vial code USNM 150192, labelled: Pacific Ocean, Mariana Islands, Guam, 19 November 1970, Watkins R.L. coll. (remaining material in the vial: 17 ♀♀).

Phyllognathopus viguieri menzeli 2. ♂♂, vial code USNM 150193, labelled: Pacific Ocean, Mariana Islands, Guam, 1 April 1971, Belk and Watkins R.L. coll. (remaining material in the vial: 8 specimens, of which several copepodids).

Supplementary description.

FEMALE. Body length, measured from tip of rostrum to posterior margin of caudal rami, from 400 to 600 µm (mean = 439 µm; n = 27). Habitus slender, no clear demarcation between prosome and urosome. Integument with surface pits, moderately sclerotized as in Fig. 1A. Cephalosome sub-quadrate, with a dorsal rounded protuberance, hardly observable, plausibly referable to a dorsal integumental window. Setule pattern as in Fig. 1A. Rostrum elongate, subrectangular in shape, clearly articulated to the cephalosome; two dorsal sensilla laterally inserted on its distal third, and one pore apically. Cephalosome and both thoracic and abdominal somites with cuticular ornamentation apparently represented by reduced number of paired sensilla (Fig. 1A). First pedigerous somite free. Hyaline frills of cephalosome, somites bearing P1-P4 and urosome dorsally smooth. Urosomites with smooth hyaline frill ventrally, except third urosomite (Figs 1B, 2A). Last three urosomites with spinular fringe on proximal third ventrally; anal somite with distal continuous spinule row. Anal somite with paired sensilla on dorsal side only (Fig. 1C), and two short spinule rows close to the anal operculum. Anal operculum rounded, only slightly protruding beyond insertion line of caudal rami (Figs 1C, 2B). P5-bearing somite with large paired pores laterodorsally and paired spinule rows laterally inserted on distal third of somite (Fig. 1A). Genital double-somite with three lateral spinule rows. Female genital field located between first and second third of genital double-somite. Genital apparatus apparently simplified; copulatory pore located halfway of genital double-somite (Figs 1B, 3A). Seminal receptacles located laterally and condensed close to the lamellar P6 (Fig. 3B).

Caudal rami rectangular, parallel, distinctly longer than wide (length/width ratio about 1.7), with incomplete setal pattern (6 setae) (Fig. 1 B–C). Anterolateral accessory seta (I) absent, anterolateral seta (II) smooth, inserted at half of caudal ramus; posterolateral seta (III) inserted on distal third of ramus, transformed in a large and stout spiniform element. Outer terminal seta (IV) very short, thin, and naked, shorter than caudal ramus, inner terminal seta (V) unipinnate and relatively short, without articulation at base, with very enlarged proximal part tapering in a subtle tip; terminal accessory seta (VI) slightly shorter than outer terminal seta, thin and naked; dorsal seta (VII) inserted on distal third of caudal ramus, about as long as caudal ramus. Three spinule rows inserted dorsolaterally and two spinule rows inserted at distal margin of caudal ramus ventrally. Two pores located close to the insertion of setae II and IV, ventrally.

Antennule (Fig. 4A): short, 8-segmented. Segment 1 with 1 spinule row. Both segments 1 and 2 bearing long and flaccid tube-pores. Armature formula: 1-[1], 2-[8], 3-[5], 4-[1 + (1+ae)], 5-[1], 6-[3], 7-[4], 8-[6 + (1+ae)]. Aesthetasc on segment 4 large, reaching about the proximal part of the penultimate antennulary segm ent.

Antenna (Fig. 4B): coxa unarmed; basis with 1 transverse spinule row on surface, a spinule row inserted on inner margin; exopod 1-segmented, well-defined at base, with surface spinule row, bearing 3 lateral and 2 apical setae; free endopod 2-segmented; both segments robust, of about the same length; segment 1 with inner spinule row; segment 2 with two inner spinule rows; armature consisting of 2 inner spines and 1 seta, 1 unipinnate apical spine, 4 geniculate setae, 1 apical slender seta and 1 subapical slender seta; a row of spinules at outer corner.

Labrum (Fig. 1D): trapezoidal, with two spinule rows on free distal margin. Paired rows of hair-like elements on medioventral surface.

Mandible (Fig. 4C): coxal gnathobase elongate, cutting edge with 2 large and coarse teeth, three smaller teeth and row of fringed teeth; naked seta at dorsal corner. Mandibular palp biramous, basis with inner spinule row, exopod with 1 apical and 1 inner bipinnate setae; endopod with 1 inner, 1 subapical and 2 apical bipinnate setae.

Maxillule (Fig. 4D): well developed arthrite incorporated into praecoxa, with 7 strong curved spines inserted on free distal margin and 1 short seta inserted on a sort of surface peduncle and 2 anterior surface setae. Coxal epipodite represented by 2 setae; coxo-endite with 2 plumose setae. Exopod and endopod incorporated into basis, with a total of 7 plumose setae.

Maxilla (Fig. 4E): syncoxa with 3 endites. Proximal endite with 6 setae; medial and distal endites, each with 3 plumose setae. Allobasis drawn out into a strong claw, distally spinulose, accompanied by 2 robust and 1 thin setae; endopod 3-segmented; segment 1 with 1 robust curved seta; segment 2 with 2 robust curved setae; segment 3 with 2 robust curved and 2 slender setae.

Maxilliped (Fig. 4F): phyllopodial, lamelliform, and 1-segmented. Trace of ancestral 2-segmented condition marked by the presence of outer incision, representing original segmentation boundary between former segments 1 and 2. Armature consisting of 10 elements, of which 5 bipinnate setae in apical position, 1 unipinnate seta inserted along inner margin together with 4 strong unipinnate stout spines. No trace of incision along inner margin.

P1-P3 with 3-segmented exopods and endopods. P4 with 3-segmented exopod and 2-segmented endopod. Intercoxal sclerites: boundary between intercoxa and basis not well defined at posterior surface of P2-P4 (Fig. 5 B–D). P1-P3 praecoxa well developed, with outer spinule row. P4 praecoxa absent.

P1 (Fig. 5A): praecoxa and coxa with outer spinule row on anterior surface; one posterior row of thin spinules inserted close to coxo-basis boundary. Basis with 1 outer spiniform seta and 1 inner spine, with spinule rows along outer margin, between exopod and endopod and at the insertion of inner spine, respectively. Exopod about as long as endopod; exp-1 and -2 with 1 outer unipinnate spine; exp-3 with 2 unipinnate spines in apical position, and 1 apical and 1 subapical inner setae. Endopod: enp-1 unarmed, about as long as enp-2 and enp-3, wider than enp-2 and enp-3. Enp-2 cylindrical, with short inner seta inserted at the middle of segment. Enp-3 with 1 inner spine, 1 apical seta and 1 curved apical spine. Ornamentation as in Fig. 5A.

P2 (Fig. 5B): ornamentation of praecoxa and coxa as in P1. Basis with 1 outer spine, with spinule rows along outer margin, and between exopod and endopod. Exopod slightly longer than endopod; exopodal segments of about the same length; exp-1 and -2 with 1 outer unipinnate spine; exp-3 with 2 outer unipinnate spines, 1 apical unipinnate seta and 1 subapical long inner seta. Endopod: enp-1 unarmed; enp-2 wit h 1 naked inner seta; enp-3 with 1 spine and 1 long bipinnate seta in apical position, and 1 short bipinnate subapical seta. Ornamentation as in Fig. 5B.

P3 (Fig. 5C): ornamentation of praecoxa and coxa as in P2. Basis with short outer seta and spinule rows along outer margin and at the insertion of the endopod. Exopod distinctly longer than endopod. Exp-1 and -2 with 1 unipinnate outer spine; exp-3 with 2 unipinnate outer spines, 1 bipinnate apical seta and 1 long bipinnate subapical seta. Endopod: enp-1 and -2 unarmed; enp-3 with 1 spine and 2 bipinnate setae in apical position. Ornamentation as in Fig. 5C.

P4 (Fig. 5D): reduced in size, praecoxa absent, coxa and basis without ornamentation; basis with long outer naked seta; exopod and endopod about as long as half of remaining legs; the exopod only slightly longer than endopod. Exp-1 with 1 unipinnate outer spine; exp-2 unarmed; exp-3 with 1 bipinnate outer spine and 2 apical setae of different length. Endopod: enp-1 unarmed; enp-2 with 3 apical setae. Ornamentation as in Fig. 5D.

P5 (Figs 3A, 5E): free, with clear articulation to P5-bearing somite; right and left legs distinct; baseoendopod and exopod coalescent, incision marked original segmentation between them still present; basipodal outer seta present, exopodal armature consisting of 3 bipinnate setae and 1 stout spine: all elements in apical position; baseoendopod armed with 2 robust bipinnate setae, the outermost the longest.

P6 (Figs 3B, 5F): rudimentary, consisting of paired small chitinous lamellar plates not coalescent along medial margin, partially covering seminal receptacles. Armature consisting of 1 short naked spine with rounded tip on each leg.

Male.

Body length, measured from tip of rostrum to posterior margin of caudal rami, from 370 to 541 µm, with mean of 424 µm based on 8 individuals. Sexual dimorphism in antennule, abdominal segmentation, P5, P6 and caudal setae morphology. Habitus, cephalosome (Figs 6A, 7 A–B), sensilla and pore patterns as in female. Integument with surface pits. Urosome as in Figs 6B, 7C. Caudal rami with 6 setae (Fig. 6B). Anterolateral seta (II) as in female, posterolateral seta (III) setiform, not transformed (length seta/length caudal ramus: about 2) and bipinnate. Outer terminal seta (IV) as in female, inner terminal seta (V) not transformed, plumose and long, not articulated at base; terminal accessory seta (VI) and dorsal seta (VII) as in female (Fig. 6). Ornamentation and pore patterns as in female. Anal operculum as in female.

Antennule (Figs 6C, 7 D–F): elongate, basically 10-segmented, last segment still showing a surface suture line only on anterior surface, indicating an incipient 11-segmented condition. Segment 1 with 1 ventral spinule row and 1 tube-pore (Fig. 8A). Segment 2 with tube-pore. Segment 4 represented by small U-shaped sclerite. Segment 6 the largest, sclerotized. Segment 8 elongate and transformed, moderately sclerotized, segment 9 distinct, not incorporated into segment 8, segment 10 derived by incomplete fusion between former segments 10 and 11 (Fig. 7 D–F). Armature formula: 1-[1], 2-[9], 3-[8], 4-[2], 5-[7+(1 + ae)], 6-[2], 7-[2], 8-[0], 9-[1], 10-[10 + (1 + ae)]. Aesthetasc on segment 5 very large. Segment 8 with medial pointed protrusions as in Fig. 6C.

P 1-P4 as in female; for morphological details of P1-P4 see Fig. 8B. P5 (Figs 6D, 9A): free, with clear articulation to P5-bearing somite; right and left legs coalescent; exopod clearly discernible but incorporated to basis: no trace of articulation between them observable, bearing 2 inner, 2 apical and 2 outer bipinnate setae; endopod discrete, distinctly 1-segmented, bearing 1 large leaf-like transformed seta and a spinule row along its free outer margin. Basipodal outer seta slender and naked, one pore near its insertion.

P6 (Figs 6E, 9B): right and left legs coalescent, forming a single linear lamellar plate, with no trace of incision between right and left P6; armature consisting of 2 spines and 1 outer seta.