Ancorabolina, GEORGE, 2006

Gheerardyn, Hendrik & George, Kai Horst, 2010, New representatives of the genus Ancorabolina George, 2006 (Copepoda, Harpacticoida, Ancorabolidae) including remarks on ancorabolid phylogeny, Zoological Journal of the Linnean Society 158 (1), pp. 16-55 : 17-18

GENUS ANCORABOLINA GEORGE, 2006

Ancorabolidae Sars, 1909 , Ancorabolinae Sars, 1909

Type species: Ancorabolina chimaera George, 2006

Other species: Ancorabolina belgicae sp. nov.; Ancorabolina anaximenesi sp. nov.; Ancorabolina galeata sp. nov.; Ancorabolina divasecunda sp. nov.

Generic diagnosis: Ancorabolinae . Body cylindrical, slightly tapering posteriorly, without clear demarcation between prosome and urosome. Prosomites and urosomites with a number of small projections along their posterior margins. Body somites bearing P2–P6 (genital half of double-somite in female, except in A. divasecunda ) with a single tube pore dorsally. Cephalothorax anteriorly slightly constricted, forming a ‘peak’ as described by George (2006b). Cephalothorax with one pair of lateral processes at the posterior margin, processes slightly curved backwards and each with two sensilla along anterior margin. Telson broader than long, trapezoid in lateral view. Anal operculum bearing row of spinules. Furcal rami elongate and cylindrical, inserted at outer corners of telson and directed upwards, not or only slightly divergent. Furcal rami with seven setae; setae I and II inserted closely together at posterior third of lateral margin; seta III inserted subapically; setae IV, V, and VI inserted apically; setae IV and V fused; seta V longest; seta VII tri-articulate at base. Sexual dimorphism in body size, antennule, P3 endopod, P4 endopod, P5, P6, and genital somites.

Rostrum variable in shape, from small and triangular to strongly elongate and ventrally curved; basally constricted; fused to cephalic shield; with paired sensilla subapically and paired membranous projections laterally. Antennule five-segmented in female, sevensegmented and subchirocer in male (with two segments distal to geniculation); aesthetasc arising from segments 3 and 5 in female, segments 5 and 7 in male; first segment two to five times as long as wide. Antenna with allobasis, abexopodal margin with one slender seta in distal quarter (except in A. divasecunda ); exopod entirely absent; endopod with two lateral and six distal elements (three geniculate, one small and slender). Mandibular palp one-segmented, with two inner, one outer, one subapical, and two apical setae. Maxillule with one or two setae on coxal endite; basis, endopod, and exopod fused, bearing seven to nine setae. Maxillary syncoxa with two well developed endites, each with three elements (two in A. divasecunda ); allobasis drawn out into a claw with two or three accessory setae; endopod reduced and represented by two setae. Maxilliped long and slender, prehensile; syncoxa with one apical seta; endopod drawn out into a long, narrow curved claw, with one accessory seta at base (not discernible in A. chimaera ).

P1. Coxa cylindrical and slightly elongate. Basis as long as coxa, or distinctly more elongate; slightly to strongly prolonged transversely. Endopod twosegmented, exopod two- or three-segmented. Enp-1 slender, about twice as long as exopod. Enp-2 much smaller, with minute seta along inner margin (not discernible in A. belgicae ), apically with one anterior claw-like seta and one posterior geniculate seta (two geniculate setae in A. divasecunda , two nongeniculate setae in A. chimaera ). Exp-1 with one outer spine. In the case of a two-segmented exopod: exp-2 with three outer and two apical geniculate setae closely set together near the distal margin. In the case of a three-segmented exopod: exp-2 with one outer geniculate seta; exp-3 with two outer and two apical geniculate setae closely set together near the distal margin.

P2–P4. Coxa small, trapezoid. Basis transversely elongate. Exopods three-segmented, endopods twosegmented. Enp-1 small. Exp-1 and enp-1 without inner setae; exp-3 with three outer spines. Male P3 endopod three-segmented; enp-2 elongate, apically with pointed apophysis; enp-3 with two apical setae. Enp-2 of male P4 additionally with one outer, subapical seta.

P5 with basal setophore; baseoendopod cylindrical, elongate; endopodal lobe vestigial, represented by two minute setae and one or two tube pores; exopod distinct in both sexes and elongate, with one inner, two apical, and two (in female) or one (in male) outer setae. Female genital field located in anterior half of double-somite. P6 represented by two small cuticular plates. Male P6 absent.