Fiersiphontina sensillata ( Wells & Rao, 1987 ) Wells & Rao, 1987

Bruno, Maria Cristina & Cottarelli, Vezio, 2011, Proposal of Fiersiphontina gen. nov., redescription of Fiersiphontina sensillata comb. nov., and new data on the distribution of Spiniferaphonte (Copepoda, Harpacticoida, Laophontidae), Zootaxa 2809, pp. 1-19 : 3-13

publication ID	https://doi.org/ 10.5281/zenodo.277103
DOI	https://doi.org/10.5281/zenodo.5694742
persistent identifier	https://treatment.plazi.org/id/03DD6331-FF8A-FF99-259E-95386676FCB9
treatment provided by	Plazi
scientific name	Fiersiphontina sensillata ( Wells & Rao, 1987 )
status	comb. nov.

Treatment

Fiersiphontina sensillata ( Wells & Rao, 1987) comb. nov.

( Figs 1–7 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Synonymy. Laophontina sensillata n. sp. — Wells & Rao, 1987: pp. 184–186, figs 149–150. Laophontina sensillata Wells & Rao—Mielke, 1997 : pp. 227–228, fig. 4; Wells, 2007; pp. 62, 433, 456. Laophonte sensillata Mielke, 1997 : p 228.

Material examined. Ten females ( NHMUK 2011.696, 2011.697, 2011.698, DSAUT 101-107), eleven males ( NHMUK 2011.699, 2011.700, DSAUT 108-116), one C3 ( DSAUT 117) and one C4 copepodid ( DSAUT 118), each mounted on one slide, from the interstitial habitat of a coral sandy beach near Sabang Village, Eastern Mindoro Province, Philippines, 13° 31’ 17” N; 120° 58’ 23” E, 20 March 1998.

One male ( NHMUK 2011.701) mounted on slide, from the interstitial habitat of a coral sandy beach on the southern shore of North Pandan Island, Western Mindoro Province, Philippines, 12° 51’ 24” N; 120° 45’ 12” E, 26 January 2006.

Two males ( NHMUK 2011.702, DSAUT 119) each mounted on one slide, from the interstitial habitat of a coral sandy beach in Sumilon Island, Visayas Archipelago, Philippines, 13° 33’ 22” N; 121° 03’ 23” E, 13 January 1985.

One male ( DSAUT 120) and two C4 copepodids ( DSAUT 121, 122), each mounted on one slide, from the interstitial habitat of a coral sandy beach in Verde Island, Batangas Province, Philippines, 9° 251’ 45” N; 123° 23’ 35” E, 14 February 2004.

Two males ( NHMUK 2011.703, DSAUT 123) and one female ( NHMUK 2011.704), each mounted on one slide, from the interstitial habitat of a coral sandy beach in Salag Do-Ong beach, Visayas Archipelago, Siquijor Island, Philippines, 9° 12’ 47” N; 123° 40’ 59” E, 5 April 1998.

One C 5 female copepodid ( DSAUT 124), mounted on one slide, from the interstitial habitat of a coral sandy beach in Gaspar Island, Marinduque Island, Philippines, 13° 15’ 13” N; 121° 52’ 03” E, 24 August 1992.

One C 5 male copepodid ( DSAUT 125), mounted on one slide, from the interstitial habitat of a coral sandy beach south of Nouméa, New Caledonia, 22° 18’ 2” N; 166° 26’ 17” E, 20 October 1982.

All material collected by V. Cottarelli.

Description of female. Total body length, measured from anterior margin of rostrum to posterior margin of caudal rami = 405–480 μm (n = 9; mean = 437 μm). Largest width measured at posterior margin of cephalothorax: 92 µm. Body distinctly cylindrical, habitus as in Fig. 1 View FIGURE 1 A. Cephalothorax with parallel margins. Free prosomites as wide as cephalothorax. Urosome slightly tapering posteriorly. Second and third urosomites fused only ventrally to form genital double-somite. Integument of cephalothorax densely pitted in the median and anterolateral areas but with symmetrical pattern of smooth areas; in the anterodistal areas pits less dense and progressively substituted by striae intersecting and creating irregular polygons ( Fig. 2 View FIGURE 2 A). Distal margin of cephalothorax with one band of short, straight setules ( Fig. 2 View FIGURE 2 A). Cephalothorax with 31 sensilla, and eight sensilla along distal margin, slightly expanded into several lobes. Distodorsal margins of free somites ( Fig. 2 View FIGURE 2 B) (except penultimate urosomite) carrying the following number of small sensilla: first and second prosomites: ten sensilla; third prosomite and first urosomite: eight sensilla; genital double-somite and following urosomite: six sensilla. One pair of sensilla flanking each pair of swimming legs, and one pair of sensilla on distoventral margin of genital double-somite ( Figs 1 View FIGURE 1 A, 2C). All somites densely hairy on dorsal ( Fig. 2 View FIGURE 2 B) and ventral surface ( Fig. 1 View FIGURE 1 A), the latter with less dense hairs; free prosomites and first urosomite hairy also on lateral surface ( Fig. 1 View FIGURE 1 A). Dorsal and lateral distal margin of cephalothorax smooth, those of free prosomites and following four urosomites serrate, serration and sensilla present also along the separated portions of genital double-somite. Genital double-somite subdivided dorsally and laterally, ventral suture marked by chitin patches ( Fig. 2 View FIGURE 2 C), row of spinules only along the midventral distal margin, between the two medialmost sensilla ( Fig. 2 View FIGURE 2 C). Fourth and fifth urosomites with row of spinules along the ventral distal margin ( Fig. 1 View FIGURE 1 A). Genital field with one thin seta on each vestigial P6 and circular copulatory pore forming posterior margin of an elongated receptaculus seminis, and opening posteriorly to transversal ridge ( Fig. 2 View FIGURE 2 C). Anal somite with four ventral pores; lateral distal margin from end of operculum to insertion of caudal ramus projecting and serrate ( Fig. 2 View FIGURE 2 D). Anal operculum ( Figs 2 View FIGURE 2 D, 2E) distinctly posteriorly produced, semilunar, flanked by two sensilla, and with strongly incised margin forming ten large, tooth-like processes; a characteristic tuft of long hairlike setules increasing in length towards middle present below operculum.

Caudal rami ( Figs 2 View FIGURE 2 D, 2E): conical, shorter than anal somite, slightly wider than long (length measured to insertion of seta V, width measured at ramus insertion); ventral and outer sides hairy. Seven hook-like processes: three anterior to seta VII (the largest one flanking seta VII) (1–3, Figs 2 View FIGURE 2 D, 2E), one small process anterior to seta I (4, Figs 2 View FIGURE 2 D, 2E), one larger process on distal outer distal corner (5, Figs 2 View FIGURE 2 D, 2E), two ventral distal processes (6, 7, Figs 1 View FIGURE 1 A, 2E). Seven setae inserted distally; seta I, II, and III of different lengths: seta III smallest, seta II longest; seta IV plumose; seta V robust, dorsally bent, strongly sclerotised; seta VI short and slender; seta VII as long as seta IV, naked.

Rostrum ( Fig. 2 View FIGURE 2 F): large and prominent, broadly triangular, not fused to cephalothorax, with pair of sensilla anteriorly, dorsal surface pitted.

Antennule ( Fig. 2 View FIGURE 2 G): six-segmented; first and second segments wider than following ones; first segment with blunt process on outer margin and longitudinal spinule row along inner margin; second segment with large, posteriorly directed hook along outer margin; fourth segment with distal tubercle carrying very long aesthetasc and two setae of same length; sixth segment with acrothek carrying one short aethetasc and one seta. All setae naked; armature formula: 1-[1], 2-[9], 3-[6], 4-[2 + ae], 5-[1], 6-[8 + acrothek].

Antenna ( Fig. 3 View FIGURE 3 A): coxa bare; allobasis with pinnate abexopodal seta inserted in distal third. Exopod one-segmented and small, carrying four subequal bipinnate setae. Endopod with two subapical spinules along outer margin; two bipinnate subapical inner spines; apically from inner to outer: one plain spine, one bipinnate spine, one unipinnate spine, three geniculate spines.

Mandible ( Fig. 3 View FIGURE 3 B): with well-developed, strongly sclerotised gnathobase carrying four blunt teeth and one bipinnate seta. Palp uniramous, with three long setae and a short one (vestige of endopod?).

Maxillule ( Fig. 3 View FIGURE 3 C): praecoxal arthrite well developed; with transverse row of long spinules on posterior surface; distal margin with four setae of same length and a shorter one, and four strong, curved and unidenticulate spines. Coxal endite with two naked setae of same length. Basal endite with four naked setae, two of which geniculate. Endopod small, partially fused to basis, with three apical and one subapical naked setae; exopod one-segmented, completely fused to basis, with two apical setae.

Maxilla ( Fig. 3 View FIGURE 3 D): syncoxa with row of long spinules along outer margin, increasing in length towards the middle of row, transverse rows of short spinules on posterior surface, and row of short spinules along inner margin. Two endites, each with one strong unipinnate spine and two slender and long setae. Allobasis drawn out into strong, slightly curved, armed claw carrying two setae. Endopod very reduced, fused to allobasis, carrying two naked setae of same length.

Maxilliped ( Fig. 3 View FIGURE 3 E): syncoxa elongate with short outer subdistal naked seta. Basis long and slender, slightly enlarged in middle part, naked. Endopod drawn out into long unipinnate claw, as long as basis, with short accessory seta anteriorly.

P1-P4: intercoxal sclerite separated from coxa.

P1 ( Fig. 3 View FIGURE 3 F): coxa cylindrical with row of long spinules along inner margin and two setae at about 2/3 of same margin. Basis slightly shorter than coxa, with one short distal seta and hair-like setules along inner and outer margins. Exopod one-segmented, hair-like spinules on inner margin, three subequal naked setae along outer margin, one seta on outer distal corner, one normal and one geniculate apical setae of different length. Endopod two-segmented, first segment very long and 3.8 times as long as second segment, bare; second segment apically with armed claw, one minute, naked accessory seta and one smaller spine.

P2 ( Fig. 3 View FIGURE 3 G): coxa bare, slightly longer than wide. Basis with outer tubercle carrying seta; exopod fused to basis, represented by lobe carrying one inner sparsely plumose seta and one apical strong spiniform bipinnate spine. Endopod represented by one sparsely plumose seta.

P3 ( Fig. 4 View FIGURE 4 A): coxa and basis completely fused, outer basipodal tubercle carrying one seta. Exopod one-segmented, with one sparsely plumose seta on distal inner corner, one sparsely plumose seta and two strong bipinnate spines apically. Endopod fused to coxobasis represented by one tubercle carrying one sparsely plumose seta.

P4 ( Fig. 4 View FIGURE 4 B): coxa and basis completely fused, outer basipodal tubercle carrying one seta. Exopod two-segmented, first segment with one strong, long, bipinnate spine on outer distal corner; second segment with two sparsely plumose setae on distal inner corner, one sparsely plumose seta and one strong bipinnate spine apically. Endopod fused to coxobasis represented by tubercle carrying one naked seta.

P5 ( Fig. 4 View FIGURE 4 C): baseoendopod separate from exopod, with spinules along inner margin and outer basal seta arising from long peduncle. Endopodal lobe carrying two pinnate setae. Exopod rectangular, longer than wide, with spinules along outer and inner margins, carrying three apical pinnate setae, innermost seta longest.

Description of male. Total body length, measured from anterior margin of rostrum to posterior margin of caudal rami = 402–467 μm (n = 10; mean = 429 μm). Largest width measured at posterior margin of cephalothorax: 74 µm. Habitus ( Fig. 1 View FIGURE 1 B) similar to female, but proportionally thinner, with fully separated second and third urosomites. Body surface ornamentation as in female, second urosomite ornamented as first one. Caudal rami similar to those of female in shape and ornamentation, seta I longer (both absolutely and relative to setae II–III), seta II shorter (about as long as seta III), seta V proportionally longer and thinner ( Fig. 4 View FIGURE 4 D) than in female ( Fig 1 View FIGURE 1 B). Anal operculum ( Fig. 4 View FIGURE 4 D), similar to that of female but with 11 tooth-like processes.

A2, mouth parts, P1, P3, P4 ( Figs 4 View FIGURE 4 F, 4G) similar to those of female except small differences in the length of some setae and spines. Spermatophore as in Fig. 5 View FIGURE 5 A.

Antennule ( Figs 5 View FIGURE 5 D, 5E): seven-segmented; sub-chirocer. First segment as in female but with additional distal row of spinules; setules along outer margin longer, less numerous and with more restricted distribution than in female. Second segment as in female but with transformed seta (asterisked in figure); fifth segment strongly enlarged with distal tubercle carrying very long aesthetasc and two setae of same length, and seven setae, one of which (ventral) is unipinnate; seventh segment with acrothek carrying one thin and long aethetasc, and one seta. Armature formula: 1-[1], 2-[9], 3-[6], 4-[2], 5-[9 + ae], 6-[0], 7-[8+ ae].

P2 ( Fig. 4 View FIGURE 4 E): similar to that of female but vestigial exopod carrying one additional inner sparsely plumose seta.

P5 ( Fig. 5 View FIGURE 5 B): baseoendopods fused, very reduced naked endopodal lobe: exopod with three subequal pinnate setae.

P6 ( Figs 1 View FIGURE 1 B, 5C): vestigial, asymmetrical, right P6 with reduced, non-functional plate, left P6 with large internal plate articulated with the somite, each P6 with a process carrying two setae of different thickness.

Description of third copepodid (C3). Seven somites, habitus as in fig. 6A; length, measured from anterior margin of rostrum to posterior margin of caudal rami, 305 µm. Distal margin of cephalotorax smooth, distal margin of all somites and of anal operculum denticulate as in the adult. Anal operculum ( Fig. 6 View FIGURE 6 B) with some denticles (not present in the adult) transversely aligned dorso-laterally near sensilla.

Caudal rami ( Fig. 6 View FIGURE 6 B): seta V transformed and fused with the caudal ramus, dorsal process not completely developed. Armature incomplete: two lateral setae (setae I and II) missing.

Antennule four-segmented; first segment similar to that of adult, second segment with a small posteriorly directed hook.

P1 ( Fig. 6 View FIGURE 6 C): similar to that of adults, all exopodal setae not geniculate.

P2 ( Fig. 6 View FIGURE 6 D): protopodite still fused to somite; exopod represented by one lobe fused with the protopodite and carrying three setae, one of which enlarged and spiniform. Endopod represented by one seta.

P3 (fig. 6E): protopodite still fused to somite; exopod represented by one lobe fused with the protopodite and carrying two normal setae and one laminate seta with finely extruded apex; endopod represented by one tubercle with one seta.

P4 ( Fig. 6 View FIGURE 6 F): protopod still fused to somite; exopod represented by one lobe fused with the protopodite and carrying four setae, one enlarged and spiniform; endopod represented by one tubercle with one seta.

P5 (fig. 6G): two small adjacent tubercles, each with one seta.

P6 ( Fig. 6 View FIGURE 6 H): one small bare lobe.

Description of fourth copepodid (C4). Eight somites; habitus and ornamentation of cephalotorax and somites as in C3. Total body length, measured from anterior margin of rostrum to posterior margin of caudal rami = 355 μm.

Anal somite ( Fig. 6 View FIGURE 6 I): dorsolateral row of denticles more marked. Anal operculum ( Fig. 6 View FIGURE 6 I): distal denticles ornamentation almost identical to that of the adult; the characteristic tuft of long hair-like setules increasing in length towards the middle is already present below the operculum.

Caudal rami ( Fig. 6 View FIGURE 6 I): seta IV and V as in the adult, ramus quadrangular in lateral view (not yet conical as it is in the adult) with a strong dorsal hook-like process anteriorly to seta VII, which is strongly similar to that of the copepodid and adult of Spiniferaphonte (see Fiers 1991 and Gheerardyn et al. 2007).

Antennule ( Fig. 6 View FIGURE 6 J): four-segmented; first and second segment very similar to those of adult; projection of second segment larger and more pointed than in adult.

P2 ( Fig. 6 View FIGURE 6 K): protopodite still fused to somite; exopod represented by one lobe fused with the protopodite and carrying two setae, one enlarged and spiniform. Endopod represented by one tubercle with one small seta.

P3 (fig. 6L): protopodite still fused to somite; exopod represented by one lobe fused with the protopodite and carrying yhree setae, two enlarged and spiniform. Endopod represented by one tubercle with one small seta.

P4 ( Fig. 6 View FIGURE 6 M): exopod one-segmented with five setae (same number as those present in the two-segmented exopod of the adult), three enlarged and spiniform. Endopod represented by one seta.

P5 (fig. 6N): distinct expodal lobe with three setae. Endopodal lobe not recognizable.

P6 (fig. 6O): two small lobes, each one with one seta.

Decription of female fifth copepodid (C5). Nine somites, total body length, measured from anterior margin of rostrum to posterior margin of caudal rami = 450 μm. Anal somite ( Fig. 7 View FIGURE 7 A): with dorso-lateral row of denticles. Anal operculum ( Fig. 7 View FIGURE 7 A): distal denticles ornamentation almost identical to those of adult. Caudal rami ( Fig. 7 View FIGURE 7 A): almost completely developed: each carrying six normal and one transformed setae, two dorsal hook-like processes anterior to seta VII still inserted on large protrusion (see figure in lateral view for male C5 as described below). Hooks and protrusion shrunk in the adult to form conical shape of ramus.

A1 as in Fig. 7 View FIGURE 7 C.

P1 ( Fig. 7 View FIGURE 7 D): with one seta at midlength of the inner margin of basis, apical seta of exopod geniculate.

P2-P4 ( Figs 7 View FIGURE 7 E, 7F, 7G): as in C4, but proportionally larger.

P5 ( Fig 7 View FIGURE 7 H): exopodal lobe with three setae, endopodal lobe with two small setae.

P6 ( Fig. 7 View FIGURE 7 I): two adjacent lobes, each one with one seta.

Description of male fifth copepodid (C5). Nine somites, total body length, measured from anterior margin of rostrum to posterior margin of caudal rami = 419 μm. Anal somite ( Fig. 7 View FIGURE 7 B), anal operculum ( Fig. 7 View FIGURE 7 B), A1, A2, mouth parts, P1-P4 and P6 as in the female C5. Caudal rami ( Fig. 7 View FIGURE 7 B) sexually dimorphic: transformed seta V is longer than in female C5.

P5 ( Fig. 7 View FIGURE 7 J): setae on the exopodal lobe shorter than those of female C5, baseoendopodal lobe bare.

Variability. In adult specimens, the number of tooth-like processes on the anal operculum ranges from 9 to 12 in females, and from 9 to 14 in males. In one male paratype from Siqujior the second segment of exp-P4 is longer than wide ( Fig. 5 View FIGURE 5 F).