Zosime eliasi, Pointner, 2017

Pointner, Karin, 2017, Description of two new species of Zosime (Copepoda: Harpacticoida: Zosimeidae), including remarks on its phylogeny and distribution on the Great Meteor Seamount plateau (North-east Atlantic Ocean), Journal of Natural History (J. Nat. Hist.) 51 (37 - 38), pp. 2283-2330 : 2302-2315

Zosime eliasi sp. nov.

( Figures 12 – 20 )

Type locality

Plateau of the GMS, subtropical north-eastern Atlantic (30.0°N, 28.5°W); sediment type: biogenic carbonate sediment, water depth: 284 – 339 m.

Type material

Holotype: female, #1-91-5, undissected, 1 slide, coll. no. SMF 37089/1 . Paratype 1: male from station #1-91-5, undissected, 1 slide, coll. no. SMF 37090/1 . Paratype 2: female #1- 91-8, dissected, mounted on 13 slides, coll. nos. SMF 37091/1 – 13 . Paratype 3: male, #1- 91-5, dissected, mounted on 8 slides, coll. nos. SMF 37092/1 – 8 . Paratype 4: female, #1- 91-5, dissected, mounted on 6 slides, coll. nos. SMF 37093/1 – 6 . Paratype 5: female, #1- 91-8, not dissected, 1 slide, coll. no. SMF 37094/1 . Paratype 6: female, #1-91-5, dissected, mounted on 4 slides, coll. nos. SMF 37095/1 – 4 .

Etymology

Zosime eliasi sp. nov. is dedicated to Elias Campano Pointner, Wolfratshausen, Germany.

Description of female

Habitus ( Figure 12 (a,b)). Fusiform, slightly compressed dorso-ventrally. Body length measured in dorsal view, from tip of rostrum to end of the caudal rami, without setae, 667.0 – 767.1 µm (average: 718.1 µm, n = 12). Rostrum fused to cephalothorax, triangular in shape ( Figure 12 (a,b)). P1-bearing somite fused with cephalosome to form cephalothorax. Surface of cephalothorax covered with several sensilla. Postero-dorsal margins of all somites except for anal somite with differently shaped cuticular frills: cephalothorax and following two free prosomites with square-like frills, last prosomite and urosomites one and two with thorn-like frills, urosomites three and four with smaller cuticular frills on postero-dorsal margin; prosomites one to three and urosomite one with additional cuticular frill having one sensillum and one row of minute spinules (except for urosomite one) on lateral surface. Each somite with small number of sensilla and covered with scales except for anal somite. Urosomites two and three not fused in dorsal or lateral view, but in ventral view ( Figure 13 (c)) forming genital double-somite. Penultimate abdominal segment with pseudoperculum composed of four large cuticular extensions, each with three tips. Posterior margin of anal somite with small, spinules laterally and two sensilla dorso-laterally; anal operculum absent.

Caudal ramus ( Figure 13 (a)). Cylindrical, about 3.0 – 4.3 times longer than maximum width (average: 3.8×, n = 12). Surface covered with scales and inner margin with several setules proximally. Seven setae: seta I minute bare, ventrally placed at proximal third of outer margin; seta II bipinnate, lateral, located at distal third of outer margin; seta III bare, apical, smaller than seta II, located at outer distal corner; terminal seta IV multipinnate, second longest; terminal seta V multipinnate longest; seta VI bipinnate, located at inner distal corner, as long as seta III; seta VII bare, but bi-articulated at base and rising from pedestal, near inner distal corner, as long as seta III.

Antennule ( Figure 14 ). Eight-segmented; first segment with one long, slender and bipinnate seta and several spinules on anterior margin; second segment longest with narrowing, proximal part possessing nine setae and distal part with seven setae; third segment with one aesthetasc and three setae, all of different sizes, aesthetasc fused at basis with large spinous seta; fourth segment with two setae; fifth segment with five setae; sixth segment with three small, bare setae; seventh segment with one bipinnate seta; eighth segment with one aesthetasc and seven setae, all of different sizes, longest seta flexible, aesthetasc fused at basis with bipinnate seta. Setal formula: 1-1; 2-16; 3-2 + (1 + aesthetasc); 4-2; 5-5; 6-3; 7-1; 8-6 + (1 + aesthetasc).

Antenna as in male (see below).

Mandible ( Figure 15 (b)). Gnathobase with well-developed teeth and with one plumose seta. Basis with three plumose setae distally. Exopod and endopod one-segmented.

Exopod with two apical and one lateral setae proximally plumose, distally bipinnate. Endopod with three apical and one lateral plumose setae. All setae of basis, exopod and endopod similar in size.

Maxillule, maxilla and maxilliped. As in male (see below).

P1–P4 ( Figures 16 (a,b,bʹ) and 17(a,aʹ,b)). For setal formula see Table 3. Unless otherwise specified, all setae plumose and flexible.

P1 ( Figure 16 (a)). Coxa with one row of setules on outer margin and one row of spinules on inner anterior surface. Basis with one plumose outer and one inner setae (broken), and with long setules on inner margin. Exopod three-segmented, with spinules on outer margins of exp1 – 3: exp1 with one outer spine and long setules on inner margin; exp2 with one outer spine and one inner seta; exp3 with three outer spines, one apical spine, one apical seta and one inner short seta. Endopod two-segmented, with spinules on outer margin, inner margin without ornamentation: enp1 with one inner seta; enp2 with one apical spine, one apical seta and one inner seta. All spines similar in shape: proximal part slightly plumose, then pinnate, distal part with pinnae of increasing size; apical spines with additional apical setule. Intercoxal sclerite shown in Figure 16 (a).

P2–P4 ( Figures 16 (b,bʹ) and 17(a,aʹ,b)). Coxa with two groups of spinules, coxa of P4 with one additional row of minute setules. Basis with one outer seta, long and plumose in P4 (broken in P2 and P3), with minute spinules around seta basally; inner margin with row of setules, very long in P3 and P4, shorter in P2; P2 with additional spinules and setules. Exopod and endopod three-segmented, each segment longer than wide: exp1 – 2 with one outer spine and one inner seta; exp3 with three outer spines, two apical setae and two inner setae, apical outer seta. Exp1 – 3, outer margins pinnate with strong spinules and inner margins plumose. Inner margins of P2 – P4 exp1 and P3 exp2 with long setules; inner margins of P3 – P4 exp3 and P4 exp2 with several setules. All outer spines more or less similar in shape: stout, with rounded or hooked tip. Enp1 – 2 with one inner seta and with long setules along outer margin; inner margins of P3 – P4 enp2 with setules; enp3 with three apical setae and one inner seta, inner margin with spinules, P3 enp3 with additional row of setules. Outer apical seta of P2 and P3 enp3 plumose proximally and pinnate distally.

P5 ( Figure 13 (b)). Outer basal seta long, slender and plumose, arising from setophore. Exopod fused to baseoendopod, with three plumose apical setae (two very long, with the outer one smallest) and one plumose seta arising from pedestal on the surface. Baseoendopod with four very long, plumose setae; surface with one row of scales.

P6 and genital field ( Figure 13 (c)). P6 consisting of one plate with three setae on each side; outer one long and plumose and inner two setae shorter and bare. Copulatory pore covered by cuticular ridge with two sensilla.

Description of male

Habitus ( Figure 18 (a,b)) and most other characters as in female. Sexual dimorphism observed in the body length, antennule, P2, P5 and P6. Body length 573.6 – 693.7 µm (average: 619.8 µm, n = 12).

Antennule ( Figure 19 ). Subchirocer, seven-segmented: first segment with one flexible seta (broken) and several spinules along inner margin; second segment with one long bipinnate flexible seta; third segment with eight setae, five located on inner margin (one broken) and three arising from posterior; fourth segment with nine setae; fifth segment with one aesthetasc and nine setae, one of which spine-like and multipinnate, three setae located proximally on pedestal-like part of segment, aesthetasc fused at basis with long and spinous seta; sixth segment with one bare setae; seventh segment with one small aesthetasc and 11 setae, three of which broken, two apical setae very small, aesthetasc fused at basis with bare and slender seta. Setal formula: 1-1; 2-1; 3-8; 4-9; 5-8 + (1+ aesthetasc); 6-1; 7-10 + (1 + aesthetasc).

Antenna ( Figure 15 (a,aʹ)). Coxa small and bare. Basis with two rows of setules, some small spinules and one abexopodal seta. Exopod three-segmented ( Figure 15 (a ʹ )): exp1 and 2 small, with one lateral seta each; exp3 with one lateral seta proximally and three apical setae (one seta broken). Endopod two-segmented ( Figure 15 (a)): enp1 with one abexopodal seta; enp2 with some spinules proximally, two spines and some spinules subapically and two spines and four setae apically, two of which long, slender and flexible.

Maxillule ( Figure 15 (c,cʹ)). Praecoxal arthrite with eight pinnate stout spines, on anterior side with one minute bare seta amongst apical spines and two long

slender setae. Coxa ( Figure 15 (c ʹ )) with five setae (four long, bare and slender apically and one minute anteriorly); coxal epipodite with one plumose seta. Basis ( Figure 15 (c)) with seven setae of different sizes, one plumose, others bare. Exopod and endopod one-segmented, similar in size: exopod with three long plumose setae and with small spinules on inner margin; endopod with six plumose setae of same size.

Maxilla ( Figure 15 (d,dʹ)). Syncoxa with three endites. Proximal (praecoxal) endite bilobed, with three setae on each lobe, proximal lobe with additional minute spinules. Middle coxal endite with three setae (two long and slender, and one small and bare). Distal coxal endite with one pinnate claw and two setae. Basis ( Figure 15 (d ʹ )) with two serrated claws and three bare, slender setae, one of which arising apically, one subapically, and one close to endopod. Endopod two-segmented ( Figure 15 (d)), bearing two setae on the first endopodal segment and four on the second.

Maxilliped ( Figure 16 (c)). Syncoxa with one slender and bare seta. Basis with one spine and one row of stout spinules. Endopod with three setae, two apical and one lateral small, flexible.

P2 ( Figure 20 (a)). Coxa with several rows of spinules. Basis as in female, but armed with more spinules and setules. Exopod as in female. Enp1 as in female but with some scales on inner margin. Enp2 as in female but with spinules on outer margin and setules on inner margin. Enp3 with spinules on outer and inner margin, apical margin transformed into hook-like apophysis, with tube-pore.

P5 ( Figure 20 (b)). Reduced, proximal margin fused with somite, left and right leg of P5 confluent. Outer basal seta long, plumose and flexible, arising from setophore. Exopod with three apical plumose and flexible setae and one smaller and bare surface seta arising from short setophore between outer basal seta and outermost marginal seta. Endopodal lobe vestigial, with two bare setae.

P6 ( Figure 20 (c)). With one spinule and three setae; outer seta plumose and flexible; middle seta longest proximally plumose and distally bipinnate; innermost seta smallest and bare.

Updated key to female species of the genus Zosime Boeck, 1873 As two new species of Zosime are described and the anneae group was included into the typica group erected by Kim et al. (2016), their key is updated.

1. Caudal rami at least 1.5 as long as greatest width ............................... ( typica group) 2

– Caudal rami less than 1.5 as long as greatest width ..................( incrassata group) 16

2. A1 8-segmented ................................................................................................................................... 3

– A1 6- or 7-segmented........................................................................................................................ 4 3. P1 enp2 with 4 setae/spines...................................... Z. anneae Koller and George, 2011

– P1 enp2 with 3 setae/spines............................................................................. Z. eliasi sp. nov.

4. Caudal rami at least 2.5 times as long as greatest width.................................................. 5

– Caudal rami less than 2.5 times as long as greatest width............................................11

5. P1 enp2 with 3 setae/spines........................................................................................................... 6

– P1 enp2 with 4 setae/spines........................................................................................................... 8

6. P1 exp3 with 6 setae/spines; P5 endopodal lobe with 3 setae.......................................... ............................................................................................................. Z. bergensis Drzycimski, 1968

– P1 exp3 with 5 setae/spines; P5 endopodal lobe with 4 setae ...................................... 7

7. Caudal rami about 3 times as long as wide........................... Z. paramajor Bodin, 1968

– Caudal rami 4 times as long as wide................................................ Z. erythraea Por, 1967

8. A1 7-segmented......................... ......................... Z. paratypica Becker and Schriever, 1979

– A1 6-segmented ................................................................................................................................... 9

9. P5 endopodal lobe with 4 setae.......................... .......................... Z. major Sars G.O., 1919

– P5 endopodal lobe with 3 setae.................................................................................................10

10. Caudal rami about 3 times as long as wide; pseudoperculum on pre-anal somite ornamented with large protrusions...................................................... Z. gisleni Lang, 1948

– Caudal rami about 2.5 times as long as wide; pseudoperculum on pre-anal somite ornamented with small protrusions.................................................... Z. typica Boeck, 1873

11. P1 enp2 with 4 setae/spines.................................................................. Z. paci fi ca Fiers, 1991

– P1 enp2 with 3 setae/spines.........................................................................................................12

12. P5 endopodal lobe with 4 setae.................................................................................................13

– P5 endopodal lobe with 2 setae.................................................................................................15

13. P2 – P4, exp3 with 6 setae/spines; P4 enp3 with 3 setae/spines......................................... ............................................................................................................................ Z. bathyalis Por, 1967

– P2 – P4, exp3 with 7 setae/spines, respectively; P4 exp3 with 4 setae/spines.........14

14. A1 7-segmented...................................................................................... Z. atlantica Bodin, 1968

– A1 6-segmented.............................................................................. Z. mediterranea Lang, 1948

15. A1 7-segmented; P4 enp3 with 4 setae/spines.................................. Z. valida Sars, 1919

– A1 6-segmented; P4 enp3 with 3 setae/spines Z. destituta Kim, Jung and Yoon, 2016

16. A1 8-segmented................................................................................................ Z. carsteni sp. nov.

– A1 7-segmented.................................................................................................................................17

17. P5 endopodal lobe with 4 setae.............................. .............................. Z. reyssi Dinet, 1974

– P5 endopodal lobe with 3 setae.................................................................................................18

18. A2 exopod, terminal segment with 2 setae...................... Z. incrassata Sars G.O., 1910

– A2 exopod, terminal segment with 3 setae............... ............... Z. bathybia Bodin, 1968

Figures

Figure 12. Zosime eliasi sp. nov., female habitus (holotype): (a) dorsal view; (b) lateral view. Scale bar: 200 µm.

Figure 13. Zosime eliasi sp. nov., female: (a) pseudoperculum, anal somite and caudal rami, dorsal (paratype 5), caudal setae indicated by I–VII; (b) P5 (paratype 6), anterior; (c) P6 and genital field (paratype 4), ventral. Scale bar: 50 µm.

Figure 14. Zosime eliasi sp. nov., female antennule (paratype 4): general shape and setation of segments 1–8. Scale bar: 25 µm.

Figure 15. Zosime eliasi sp. nov.: (a) antenna (paratype 3, male), exopod omitted (origin indicated by dashed lines); (aʹ) antenna exopod (paratype 3, male; dashed setae reconstructed from second antenna of same paratype); (b) mandible (paratype 2, female); (c) maxillule; (cʹ) coxa of maxillule (paratype 3, male); (d) maxilla (paratype 3, male); (dʹ) basis of maxilla (paratype 3, male). Scale bar: 50 µm.

Figure 16. Zosime eliasi sp. nov.: (a) right P1 with intercoxal sclerite (paratype 2, female; outer basal seta and inner seta of enp2 reconstructed from left P1 of same paratype), posterior, * marks broken seta; (b) female P2 (paratype 2, female); (bʹ) female P2 exp2–3 (paratype 2, female); (c) maxilliped (paratype 1, male). Scale bar: 50 µm.

Figure 17. Zosime eliasi sp. nov.: (a) P3 (paratype 2, female), posterior; (aʹ), P3 enp3 (paratype 2, female), posterior; (b) P4 with intercoxal sclerite (paratype 3, male), anterior. Scale bar: 50 µm.

Figure 18. Zosime eliasi sp. nov., male habitus (paratype 1): (a) dorsal view; (b) lateral view. Scale bar: 200 µm.

Figure 19. Zosime eliasi sp. nov., male antennule (paratype 3): general shape and setation of segments 1–7. Scale bar: 50 µm.

Figure 20. Zosime eliasi sp. nov., male: (a) right P2 (paratype 3; outer basal seta reconstructed from left P2 of same paratype); (b) P5 (paratype 1); (c) P6 (paratype 1). Scale bar: 50 µm.