New representatives of the genus Ancorabolina George, 2006 (Copepoda, Harpacticoida, Ancorabolidae) including remarks on ancorabolid phylogeny Author Gheerardyn, Hendrik Author George, Kai Horst text Zoological Journal of the Linnean Society 2010 2010-01-31 158 1 16 55 http://dx.doi.org/10.1111/j.1096-3642.2009.00567.x journal article 10.1111/j.1096-3642.2009.00567.x 0024-4082 5447784 ANCORABOLINA DIVASECUNDA SP. NOV. Type locality: South-east Atlantic Ocean , Guinea Basin , multiple corer, station 61/10 during DIVA 2 , 0.0°0.0′S, 2.0°24.9′W, depth 5066 m , collected on 15.iii.2005 . Figure 16. Ancorabolina galeata sp. nov. , female holotype. A, habitus, dorsal; B, furcal setae IV and V; C, habitus, lateral. Material examined: (1) From type locality: Male holotype (coll. no. SMF 34160/1–12) dissected on 12 slides; (2) Female allotype (coll. no. SMF 34161) on one slide, collected in Cape Basin (south-east Atlantic Ocean) with multiple corer at station 35/7 during DIVA 2 , 28.0°6.8′S, 7.0°20.7′W, depth 5033 m , on 3.iii.2005 ; (3) Female paratype 1 (coll. no. SMF 34162) on one slide, collected in Guinea Basin (south-east Atlantic Ocean) with multiple corer at station 56/1 during DIVA 2 , 0.0°0.0′S, 2.0°25.0′W, depth 5064 m , on 14.iii.2005 . Etymology: The specific name divasecunda refers to the second cruise of the DIVA project, DIVA 2. Description: Male: Habitus ( Fig. 25A ) long and slender. Total body length: 374 Mm (measured from tip of rostrum to posterior end of furcal rami). Urosome six-segmented, one spermatophore. Rostrum ( Fig. 26C ) fused to cephalothorax and considerably elongate, with paired sensilla subapically. Cephalothorax anteriorly slightly constricted, forming a ‘peak’, and with sensilla and pores as figured. Dorsally with pair of small cuticular projections. Lateral processes ( Fig. 26D ) strongly cuticularized and curved backwards, subapically with one small cuticular projection each, anteriorly with a few long and fine spinules. Posterior margin of cephalothorax with small sensillate processes. Cephalothorax and all body somites except telson with fine hair-like structures dorsally at posterior margins. Free body somites 1–5 with a single mediodorsal tube pore. Posterior margins of free body somites 1–2 with inner pair of sensillate processes and outer pair of sensilla between small processes. Free body somites 3–4 with a pair of sensilla and a row of small processes along posterior margins. First and second urosomites dorsally with a pair of tube pores and small sensillate processes. Telson ( Fig. 25B ) broader than long. Margin of anal operculum with small spinules. Furcal rami ( Fig. 25B ) long and slender, about six times as long as wide, with seven setae: I and II inserted closely together near middle of lateral margin, II being slightly longer than I; III inserted subapically, accom- panied by short tube pore; IV , V , and VI inserted apically, IV longer than VI , V longest; VII inserted dorsally at distal margin. Outer margin proximally with tube pore. Furcal rami inserted at outer corners of telson and directed upwards (cf. Fig. 31B ), covered with spinules along two thirds of length. Figure 17. Ancorabolina galeata sp. nov. , female holotype. A, antennule, dorsal; B, antenna; C, mandible. Figure 18. Ancorabolina galeata sp. nov. , female holotype. A, first thoracopod (P1) [armature of endopod-3 (enp-3) omitted]; B, P1 enp-3; C, maxilliped; D, syncoxa of maxilliped; E, maxilla; F, maxillule. Antennule ( Fig. 26A ) seven-segmented, subchirocer, with geniculation between segments 5 and 6. Armature formula: 1, 9, 7, 2, 11 + (1 + aes), 0, 7 + (2 + aes). First segment nearly 3.5 times as long as wide. Second segment slightly longer than first segment. First segment with long spinules along inner surface, second segment with some long spinules on a small, round bump near middle of outer margin. Third segment much smaller than preceding ones, fourth segment smallest. Fifth segment slightly swollen, with one long aesthetasc and 12 bare setae. Sixth segment without setae. Seventh segment with one aesthetasc and nine setae. Figure 19. Ancorabolina galeata sp. nov. , female holotype. A, second thoracopod (P2); B, endopod of right P2; C, P3. Antenna ( Fig. 26B ) with allobasis; exopod absent; abexopodal margin of allobasis with spinules, without setae. Endopod with several rows of spinules, laterally with two pinnate spines. Apical armature consisting of two pinnate spines, three long geniculate setae, and one small bare seta (fused basally to seta next to it). Subapically with one cuticular spinular frill. Mandible ( Fig. 27A ) with strong gnathobase bearing several incised blades and one additional bare seta. Mandibular palp one-segmented, with two inner bipinnate, one outer, one subapical, and two apical setae. Maxillule ( Fig. 27B, B′ ). Praecoxal arthrite with two setae on anterior surface, and several spinules on posterior surface. Armature consisting of five bare apical spines and one slender subapical seta. Subapically with two spines (one broken). Coxal endite with one well-developed pinnate spine and one slender pinnate seta. Basis, endopod, and exopod fused, bearing seven setae. Maxilla ( Fig. 27C ). Syncoxa bearing two endites, with long outer spinules. Proximal endite with one seta and one bipinnate spine. Distal endite with two bare setae. Basis drawn out into a claw (broken in Fig. 27C ), accessory armature consisting of three bare setae. Endopod reduced and represented by two bare setae. Maxilliped ( Fig. 27D ) long and prehensile. Syncoxa without spinules, apically with a plumose seta. Basis with two rows of long spinules along inner, and a row of long spinules along outer margin. Endopod drawn out into long, curved, pinnate claw with one accessory seta at base. Figure 20. Ancorabolina galeata sp. nov. , female holotype. A, fourth thoracopod (P4); B, P5. P1 ( Fig. 28A ) with two-segmented endopod and three-segmented exopod. Praecoxa triangular, without spinules. Coxa about 1.5 times as long as wide. Basis prolonged transversely, with inner and outer seta, with spinules along inner margin. Exp-1 with outer spine, exp-2 with one geniculate outer seta, exp-3 with four geniculate setae. Exp-2 slightly longer than exp-1 and exp-3. Enp-1 approximately 1.7 times as long as exopod, with a row of long spinules along inner and outer margin. Enp-2 much smaller, subapically with a small, slender inner seta, apically with two bare geniculate setae. P2–P4 ( Figs 28B , 29A , 30A ). Coxa short, nearly quadrangular. Basis transversely elongate, with several long spinules and one tube pore near middle of anterior surface. Natatory legs with threesegmented exopods, with outer spines elongate. Outer basal seta of P2 ( Fig. 29A ) longest and bipinnate, of P3 ( Fig. 30A ) and P4 ( Fig. 28B ) bare. Endopods of P2 and P4 two-segmented with enp-1 very small, without ornamentation; enp-2 long, with long inner and outer spinules. Enp-2 apically with two setae, P4 enp-2 additionally with an inner and an outer seta. P4 exp-3 subapically with a tube pore. P3 endopod threesegmented; enp-1 very small, without ornamentation; enp-2 long, with long inner and outer spinules, apically with apophysis; enp-3 as long as apophysis, apically with two bipinnate setae. P3 exp-3 with two tube pores. Armature formula as in Table 1. P5 ( Fig. 27E ). Baseoendopod with a few long, outer spinules. Endopodal lobe vestigial, with two small setae and two tube pores. One additional tube pore close to the setophore. Exopod distinct and elongate, with long inner spinules, and with one inner, two apical and one outer bipinnate setae; one tube pore on anterior surface. The innermost apical seta shows a coarser ornamentation than the remaining ones. Figure 21. Ancorabolina galeata sp. nov. , female holotype. A, urosome, ventral; B, telson and furcal ramus, dorsal; C, telson and furcal ramus, lateral. Female: The female differs from the male in the following characters: body remarkably longer, genital double somite present, shape of antennule, endopods of P3 and P4, P5. Habitus ( Fig. 31A, B ) long and slender. Total body length: 494–526 Mm (mean = 510 Mm; N = 2; measured from tip of rostrum to posterior end of furcal rami). Genital double-somite with only partial fusion of second and third urosomites; former separation represented by dorsal suture. Genital double-somite and following urosomites dorsally without tube pores. Penultimate body somite without fine hair-like spinules at posterior margin. Coverage with spinules on furcal rami more dense than in male. Figure 22. Ancorabolina galeata sp. nov. , male allotype. A, habitus, dorsal; B, first to third urosomite, ventral; C, fifth thoracopod. Antennule ( Fig. 32A ) five-segmented. Armature formula: 1, 6, 4 + (1 + aes), 1, 9 + (2 + aes). First segment about twice as long as wide, with spinules along inner surface. Second segment with several long spinules on a small, round bump near middle of outer margin. First to third segments nearly equal in length. Fourth segment shortest, nearly square in shape. Fifth segment as long as each of the first three segments. P3 and P4 endopods ( Fig. 29B, C ) two-segmented, enp-1 very small, without ornamentation; enp-2 long, with long inner and outer spinules, and with two apical and one inner seta, the latter being smaller in P4 than in P3. P5 ( Fig. 30B ). Baseoendopod with a few long, outer spinules. Endopodal lobe vestigial, with two small setae and two tube pores. One additional tube pore close to the setophore. Exopod distinct and elongate, with one inner, two apical, and two outer bare setae, with one tube pore on anterior surface and with some spinules. As in the male, the innermost apical seta shows a coarser ornamentation than the remaining ones. Figure 23. Ancorabolina galeata sp. nov. , male allotype. A, antennule (armature of segments 3 to 7 omitted), ventral; B, segments 3 and 4 of antennule, ventral; C, segment 5 of antennule, ventral; D, segments 6 and 7 of antennule (armature of segment 7 omitted), dorsal; E, segment 7 of right antennule, dorsal; F, segment 1 of right antennule, ventral. Genital field ( Fig. 30C ). P6 represented by two small cuticular plates.