Heteropsyllus celticus, Nam & Lee, 2006

Nam, Eun-Jung & Lee, Wonchoel, 2006, Two new species of the genus Heteropsyllus (Crustacea, Copepoda, Harpacticoida) from Jeju Island, Korea and Devon, England, Journal of Natural History 40 (29 - 31), pp. 1719-1745 : 1732-1741

publication ID

https://doi.org/ 10.1080/00222930600909428

persistent identifier

https://treatment.plazi.org/id/2D1BA542-6613-FF99-FE0D-A13F306A4A99

treatment provided by

Carolina

scientific name

Heteropsyllus celticus
status

sp. nov.

Heteropsyllus celticus sp. nov.

( Figures 9–14 View Figure 9 View Figure 10 View Figure 11 View Figure 12 View Figure 13 View Figure 14 )

Type locality

Salcombe, Devon, UK.

Material examined

Holotype: 1♀ dissected on 10 slides (NHM 1911.11.8.45151). Paratypes: 1 „ dissected on three slides (NHM 1911.11.8.45152), and 3♀♀ dissected on slides and 1♀ in 70% ethanol.

Etymology

The species name, celticus , refers its type locality, close to the Celtic Sea.

Description Female. Total body length 418 Mm measured from anterior margin of cephalic shield to

posterior margin of caudal rami. Body subcylindrical. Largest width 105 Mm, measured at posterior margin of cephalic shield. Body surface covered with tiny denticles as illustrated in Figure 9A, B View Figure 9 , except for cephalothorax and some parts of body.

Prosome ( Figure 9A, B View Figure 9 ) four-segmented, comprising cephalothorax (bearing first pedigerous somite) and three free pedigerous somites. Cephalothorax with ornamentations consisting of reticulation and few sensilla as illustrated in Figure 9A, B View Figure 9 , smooth posterior margin and posterolateral pleural areas rounded and well developed. From second to fourth prosomites without defined hyaline frills, and with serrulated hind margin.

Rostrum well developed, defined at base ( Figures 9A, B View Figure 9 , 11A View Figure 11 ) and dorsal surface with reticulation as in cephalothorax and pair of sensilla near anterior margin.

Urosome ( Figures 9A View Figure 9 , 10A, B View Figure 10 ) five-segmented, comprising P5-bearing somite, genital double-somite and three free abdominal somites. Urosomites with surface ornamentation consisting of dense denticles and some reticulated area; urosomites 2–4 with ventral row of spinules on posterior margin and denticulate hyaline frills.

Genital double-somite completely fused dorso-ventrally. Genital field ( Figure 10A View Figure 10 ) located rather proximally and with large copulatory pore located in median depression. Gonopores fused medially forming single genital slit covered on both sides by opercula derived from sixth legs. P6 with small protuberance bearing one short naked seta. Ventral surface of genital double somite covered with reticulation or dense denticles.

Anal somite ( Figure 10B View Figure 10 ) with well-developed operculum with spinulous posterior margin and flanked by pair of sensillae.

Caudal rami ( Figure 10A, B View Figure 10 ) 1.5 times as long as broad, with seven setae; seta I minute and ventral to seta II, and situated more distally than latter; seta II about 1.5 times longer than seta I and located laterally; seta III 1.5 times longer than seta II and located ventrally; seta IV and V bare proximally and bipinnate distally, and seta V 1.5 times longer than seta IV; seta VI as long as seta III and located on inner distal corner; seta VII bare, close to outer margin on middle and tri-articulated.

Antennule ( Figure 11A, B View Figure 11 ) five-segmented, segment 1 with inner margin ornamented with few spinules. Armature formula: 1-[1 plumose], 2-[2 bare+6 plumose+1 spinulose], 3- [1 bare+4 plumose+(1+ae)], 4-[1 plumose], 5-[6 bare+3 large spinulose+1 acrothek]. Aesthetasc on segment 3 large and geniculate fused to long spinulose seta; apical acrothek consisting of well-developed asesthetasc fused basally to one slender and one strong bipinnate seta.

Antenna ( Figure 10E View Figure 10 ) comprising coxa, allobasis, free one-segmented endopod, and two-segmented exopod. Allobasis with two setae; one bare seta proximally close to coxa and one plumose seta on mid-lateral margin, and with groove along insertion of exopod. Exopod two-segmented; exp-1 with one plumose seta posterodistally, exp-2 with one plumose seta posteromedially and two plumose setae distally. Free endopodal segment with strong spinules along inner proximal margin and with two lateral spines, and five apical setae and spines.

Mandible ( Figure 11C View Figure 11 ) with large coxa bearing well-developed gnathobase; cutting edge with six major blunt teeth overlapping each other; accessory seta spinulose. Mandibular palp well developed. Basis with one plumose seta. Endopod with one lateral and three apical plumose setae. Exopod small and one-segmented with one plumose seta.

Maxillule ( Figure 11D View Figure 11 ); arthrite with one posterior seta, six strong spine-like claws with spinules medially and two slender setae at posterior corner. Coxa with cylindrical endite bearing one plumose seta. Basis with three plumose setae laterally, and one strong pinnate and two slender setae terminally. Endopod with two setae apically. Exopod absent.

Maxilla ( Figure 12A View Figure 12 ): syncoxa with three endites; proximal praecoxal endite with one well-developed pinnate seta; middle and distal praecoxal endite with three setae (innermost seta pinnate and outermost seta wide proximally). Allobasis produced into strong claw with one pinnate and two bare setae on anterior surface, and one bare seta on posterior surface.

Maxilliped ( Figure 12B View Figure 12 ) comprising syncoxa, basis, and one-segmented endopod. Syncoxa and basis with setules and spinules on outer lateral and inner margin. Endopodal segment produced into strong claw with two additional setae.

Swimming legs 1–4 biramous, P1 with three-segmented exopod and endopod. P2–P4 with three-segmented exopod and two-segmented endopod, and each ramus ornamented with setules and spinules on inner and outer margins as figured. Armature formulae as in H. coreanus sp. nov.

P1 ( Figure 12C View Figure 12 ): praecoxa with spinules on distal margin. Coxa wider than long. Basis with one short bare outer seta and one strong spinulose seta on inner distal corner. Endopod three-segmented and each segment subequal in length; enp-1 with one small seta on middle of inner margin; enp-2 with one inner pinnate seta; enp-3 with one pinnate inner seta, one plumose distal seta and one spinulose outer spine. Exopod three-segmented and reaching almost end of enp-2; exp-3 with two geniculate distal setae and two spinulose outer spines; innermost distal seta longest.

P2–P3 ( Figures 12D View Figure 12 , 13A View Figure 13 ): praecoxa small. Coxa with row of spinules proximally. Basis with small (P2) or long (P3) naked outer seta and hair-like setules on inner margin. Endopod two-segmented, enp-2 about 1.5 times longer than enp-1, reaching almost to end of exp-2 and with hair-like setules on inner margin; enp-1 with one bare seta; enp-2 with two plumose inner setae (distal inner seta of P2 much longer than exp and that of P3 as long as exp), two distal setae (innermost distal seta reduced and bare) and one spinulose outer spine. Exopod three-segmented, first two segments with hair-like setules and hyaline frills on inner distal margin, and exp-3 longest; exp-2 with one plumose inner seta; exp-3 with one plumose inner seta (P2) or two plumose inner setae (P3), two plumose distal setae and three spinulose outer spines.

P4 ( Figure 13C View Figure 13 ): praecoxa with spinules on distal margin. Coxa with row of spinules proximally. Basis with one short outer seta and spinules on inner margin. Endopod twosegmented and each segment subequal in length; enp-1 with one bare inner seta; enp-2 with two plumose inner and two distal setae (innermoset seta reduced and bare). Exopod same as that of P3.

P5 ( Figure 10C View Figure 10 ): both legs separated; exopod and baseoendopod defined. Baseoendopod as long as broad, with wrinkled circular area near proximal margin of exopod, and with five pinnate setae; innermost seta unipinnate and outermost seta longest. Exopod twice as long as wide and with five setae; distal outer seta pinnate.

Male. Body smaller and more slender than in female ( Figure 9C View Figure 9 ). Body length 297 Mm measured from anterior margin of cephalic shield to posterior margin of caudal rami. Greatest width 78 Mm, measured at posterior margin of cephalic shield. Sexual dimorphism in A1, P3 enp, P5, and genital field. Whole body surface covered with tiny denticles except for reticulated cephalothorax.

Prosome ( Figure 9C View Figure 9 ) four-segmented, comprising cephalothorax (bearing first pedigerous somite) and three free pedigerous somites. Cephalothorax narrower than in female and with smooth posterior margin. Second and third prosomites with posterior hyaline frills. Last prosomite without defined hyaline frill and with serrulated hind margin. Rostrum same as in female.

Urosome ( Figures 9C View Figure 9 , 14A, B View Figure 14 ) six-segmented, comprising P5-bearing somite, genital somite, and four free abdominal somites. All urosomites with surface ornamentation consisting of dense denticles dorsally and ventrally. First two urosomites with serrulated hind margin and others with hyaline frills.

Antennule nine-segmented (not figured) and subchirocer with geniculation between segments 7 and 8. Segment 2 largest. Segment 3 represented by small sclerite. Segment 7 with spinules on dorsal surface. Modified setae on segments 7 and 8 swollen and split into two folds proximally. Apical acrothek consisting of minute aesthetasc and two naked setae. Armature formula same as in H. coreanus sp. nov.

P3 enp ( Figure 13B View Figure 13 ) two-segmented and enp-2 longer than enp-1; enp-1 with one short bare seta on inner margin; enp-2 with two plumose inner, two distal setae (outer distal seta wide proximally) and one apophysis on anterior side.

P5 ( Figure 14A, B View Figure 14 ): both legs fused medially; baseoendopod and exopod defined. Baseoendopod with three pinnate setae and circular wrinkled area near proximal margin of exopod. Exopod with four bare setae. Outer basal seta bare.

Sixth legs ( Figure 14A, B View Figure 14 ) asymmetrical, each represented by small plate with two setae; outer seta bare and inner seta pinnate.

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