Tapholeon ornatus Wells, 1967
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publication ID |
https://doi.org/ 10.1080/00222930701695629 |
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persistent identifier |
https://treatment.plazi.org/id/D34587E1-FFB0-FFD2-FE09-FF4654A5FE4C |
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treatment provided by |
Felipe |
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scientific name |
Tapholeon ornatus Wells, 1967 |
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( Figures 1–4 View Figure 1 View Figure 2 View Figure 3 View Figure 4 )
Type locality
Mozambique, Inhaca Island : Ilha dos Portuguesos, Barriera Vermelha beach (clean sand) and Saco da Inhaca (detritus sand) ( Wells 1967) .
Type material
Type specimens are deposited in the British Museum of Natural History , London ( Wells 1967) .
Material examined
Type material. One female holotype dissected on one slide ( NHM 1967.8.4.106), one male paratype in one slide ( NHM 1967.8.4.107), one female paratype in one slide ( NHM 1967.8.4.108), one male and three female paratypes in 70% alcohol ( NHM 1967.8.4.109), one female paratype dissected on five slides ( NHM 2006.1492 ), one female paratype dissected on four slides ( NHM 2006.1493 ), and one male paratype in one slide ( NHM 2006.1494 ); all from the type locality .
Additional material. One female dissected on one slide ( COP 1991 View Materials ), nine females and 13 males in 70% alcohol ( COP 1990 View Materials ); all from Comoros, southeast coast of Grande Comore, Ouroveni (11 ° 549S, 43 ° 299E), small protected creek with mangrove, fine sand sample; collected 3 August 1984 by Groupe Plongée de l’Expedition Karthala .
Redescription of female Total body length 448–514 Mm (n 54; average5484 Mm; measured from anterior margin of rostrum to posterior margin of caudal rami). Largest width measured at posterior margin of cephalothorax: 103 Mm. Measurements by Wells (1967): average length 443 Mm (range 364–507 Mm) (measured from base of rostrum to distal edge of last somite, thus excluding caudal rami).
Rostrum ( Figure 2A View Figure 2 ) well-developed, broad at base; fused to cephalothorax; with pair of sensilla anteriorly.
Habitus ( Figure 1A, B View Figure 1 ) elongate and slender, slightly dorso-ventrally depressed; with distinct convex curvature in lateral aspect; without demarcation between prosome and urosome. Cephalothorax slightly longer than wide, with parallel margins. Free prosomites and following urosomite equally wide; genital double-somite and following urosomite slightly extended laterally, resulting in posteriorly directed lateral process; urosome scarcely tapering posteriorly. Second and third urosomite fused to form genital double-somite. Genital doublesomite with transverse surface ridge dorsally and laterally, indicating original segmentation; fused ventrally. Anal operculum convex with slightly serrate margin, not distinctly protruding.
Integument of cephalothorax with pattern of slight depressions; regularly ornamented with small sensilla. Pleurotergites of prosomites and urosomites and dorsal surface of anal somite densely clothed irregularly with small denticles, some of which organized in transversal rows. Posterodorsal margin of cephalothorax smooth, of all free somites serrate. Posterodorsal margins of cephalothorax and free somites clothed with slender hairs, all bearing number of sensilla (not in penultimate urosomite).
Ventral surface ( Figure 4A View Figure 4 ) of genital double-somite smooth. Copulatory pore minute, situated in middle of anterior somite. Ventral surface of following somites clothed with transversely arranged small denticles and spinules. Genital double-somite and following two urosomites laterally with spinules. Ventral surface of caudal rami smooth, with few small spinules laterally and two spinular rows apically. Posteroventral margins of genital double-somite and of following two urosomites slightly serrate, bearing row of slender spinules.
Caudal rami ( Figure 5G View Figure 5 ) slightly flattened; as long as broad. Dorsal surface depressed beyond implantation of seta VII. Dorsal surface covered with small denticles; inner margin bearing transversal rows of spinules along proximal half, with transversal row of strong denticles medially from seta VII. Seta I, II, and III inserted near middle of outer margin; seta VII near middle of ramus. Seta IV and V not fused, both unipinnate; all other setae naked. Seta I rudimentary.
Antennule ( Figure 2A View Figure 2 ) six-segmented; suture between fourth and fifth segment faint. First segment with small spinules along anterior margin. Second segment bearing small blunt process along posterior margin. Majority of setae long and slender; second segment with strong, armed spine along outer margin; ultimate segment bearing two stout setae, one fused basally to slender seta. Armature formula: 1-[1], 2-[8], 3-[7], 4-[1+(1+ae)], 5-[1], 6- [11]. Apical aesthetasc could not be discerned.
Antenna ( Figure 2E View Figure 2 ): allobasis with spinular row along abexopodal side; with one minute abexopodal seta. Exp unisegmented and small, bearing one long plumose seta, two short bipinnate setae, and one small naked seta. Enp with spinular rows and two subapical frills; with following armature: subapically, two spines and one small seta; apically, two strong spines, three geniculate, pinnate setae, and one slender seta.
Mandible ( Figure 2F View Figure 2 ): gnathobase formed by several blunt teeth and one seta. Palp uniramous; endopod and exopod represented by three and one smooth seta(e), respectively. Basal seta plumose.
Maxillule ( Figure 2G View Figure 2 ): praecoxa with arthrite bearing spinular row on posterior surface, medial margin furnished with eight setae/spines. Coxal endite with one seta and one pinnate spine. Basal endite with two naked setae and one curved spine. Endopod obsolete, represented by three setae. Exopod one-segmented with two apical setae.
Maxilla ( Figure 2H View Figure 2 ): syncoxa with three endites; with row of spinules along outer margin. Praecoxal endite small, with one seta. Both coxal endites with one strong, pinnate spine, one slender, naked and one slender, pinnate seta. Allobasis drawn out into slightly curved, distally pinnate claw; bearing two slender setae. Endopod obsolete, represented by two setae.
Maxilliped ( Figure 2D View Figure 2 ): syncoxa with one pinnate seta and two rows of spinules. Endopod claw-shaped, naked; with short naked seta at base.
P1 ( Figure 3A View Figure 3 ): coxa with several spinular rows as figured. Basis with one pinnate seta along outer margin; medial seta arising on anterior surface; long spinules along inner and few, small spinules along outer margin and on anterior surface. Exopod two-segmented; exp-2 bearing four setae. Enp-1 4.5 times as long as exp; with few spinules along inner margin. Enp-2 with spinules along outer margin and distal inner corner; with one smooth claw and one minute, naked accessory seta.
P2–P4 ( Figure 3B, C, D View Figure 3 ): setal formula in Table I. Exopods three-segmented and endopods two-segmented. Praecoxae triangular with distal row of small spinules. Coxae with rows of spinules along outer margin. Bases with spinular row near insertion place of pinnate (P2) or naked (P3–P4) basal seta. Segments of endopods and exopods with pattern of spinules as figured.
P5 ( Figure 4C View Figure 4 ) with separate exopod and baseoendopod. Margins of rami furnished with spinules, surfaces smooth. Baseoendopod reaching to distal fourth of exopod. Basal seta arising from cylindrical setophore, with tube pore proximally and small, spinous process along outer distal margin. Proximal spines of endopodal lobe unipinnate; sub-apical and apical seta plumose. Exopod rhomboid; two times as long as wide; bearing five plumose setae.
P6 vestige ( Figure 4A View Figure 4 ) bearing one seta.
Redescription of male
Total body length 448–480 Mm (n 52; average5464 Mm; measured from anterior margin of rostrum to posterior margin of caudal rami). Largest width measured at posterior margin of cephalothorax: 84 Mm. Measurements by Wells (1967): average length 389 Mm (range 351– 468 Mm) (measured from base of rostrum to distal edge of last somite, thus excluding caudal rami).
Habitus as in female, except for fully separated second and third urosomites and lack of lateral extensions in second to fifth urosomites ( Figure 4B View Figure 4 ). Ventral surface of third urosomite with several rows of spinules and small denticles.
Antennule ( Figure 2B, C View Figure 2 ) seven-segmented; sub-chirocer. Shape of first and second segment as in female. Setae on ultimate segment all slender, i.e. without any stout setae as in female. Armature formula: 1-[1], 2-[9], 3-[7], 4-[2], 5-[11+(1+ae)], 6-[0], 7- [9+acrothek]. Apical acrothek consisting of small aesthetasc fused basally to two setae.
Antenna, mouthparts, and P1–P4 as in female.
P5 ( Figure 4D View Figure 4 ): endopodal lobe of P5 obsolete; with tube pore and without seta. Basal seta on setophore, with tube pore proximally. Exopod small; slightly wider than long; bearing three plumose setae. Anterior surface with spinules.
P6 vestiges ( Figure 4B View Figure 4 ) asymmetrical. One vestige functional; one vestige fused to somite. Both produced into cylindrical process bearing one pinnate, strong inner and one naked outer seta.
Amendments
The most important amendment undoubtedly is the presence of two inner setae on exp-3 of P4, instead of one seta as mentioned by Wells (1967). The preparations of the holotype only contained the left P4 (also drawn by Wells), which clearly shows two inner setae on exp-3. Furthermore, a small abexopodal seta is present on the allobasis of the antenna. Drawings were made, based on one female ( NHM 2006.1492 ) and one male paratype ( NHM 2006.1494 ) . All characteristics were carefully verified on the female holotype ( NHM 1967.8.4.106) and the male paratype ( NHM 1967.8.4.107) .
Variability
The specimens from the Comoro Islands agree in all aspects with the type specimens from Mozambique .
Differential diagnosis
Species discrimination within Tapholeon is mainly based on the chaetotaxy of the swimming legs. Tapholeon ornatus bears three outer spines on the ultimate segments of the exopods of P2–P4, lacks an inner seta on exp-2 of P4, and bears three, four and three setae on the second endopodal segments of P2–P4, respectively. Also, the pleurotergites of the body somites of this species are densely clothed with small denticles, some of which are organized in transversal rows.
Distribution
Inhaca Island, Mozambique ( Wells 1967); Grande Comore, Comoro Islands (present study).
| NHM |
University of Nottingham |
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