Chorizococcus multiporus Gertsson & Hodgson

CHORIZOCOCCUS MULTIPORUS Gertsson & Hodgson spec. nov (Fig. 2)

(Described from 2 good, well­stained specimens plus another in fair condition)

Unmounted material: not known.

Mounted material. Oval in outline, 1175–1250 µm long and 575–675 µm wide; anal lobes moderately developed; antennae 7 or 8 segmented; legs of normal length; circulus present; with 3 pairs of distinct cerarii; oral rim ducts present.

Dorsum. Membranous, with frequent fine setae, each 7–22 µm long; setae absent medially on abdominal segment VIII. Trilocular pores relatively sparse and fairly evenly distributed. Simple (discoidal) pores possibly only present mesad to eyespots; also with 3–5 small convex pores dorsad to each scape. Cerarii clearly present on abdominal segments VI, VII, and VIII, each with two stout spinose setae (stoutest on VIII), length of cerarian setae on VIII 17–22 µm; with 11 or 12 auxiliary setae, longest about 33–40 µm; setae on segment V stouter than normal setae and set further apart than on other cerarii and without associated trilocular pores. Ostioles membranous, each lip with few trilocular pores plus 0 or 1 small setae. Oral rim ducts each 8 µm wide, present as follows (totals across segment): VIII 0; VII 5–13; VI 6–9; V 11–16; IV 10–14; III 6–10; II 5–9; I 6–12; metathorax 4–10; mesothorax 5–14; prothorax 2 or 3; head 1–7. Oral collar ducts absent. Multilocular disc­pores absent. Anal ring 70–74 µm wide, with six setae, each about 90– 107 µm long.

Venter. Membranous, with frequent fine setae, each 10–25 µm long, some obviously longer than those on dorsum, with some on head 40–50 µm long; suranal setae 35–40 µm long; long anal lobe setae each 100–118 µm long. Trilocular pores relatively sparse and fairly evenly distributed. Simple (discoidal) pores not detected. Oral rim ducts present: generally 1 or 2 (occasionally 0) on lateral margins of most segments. Oral collar ducts probably of two sizes, with larger ducts located along the posterior margin of each segment and near lateral margin of abdominal segments II –VIII; small ducts in transverse lines medially across all abdominal segments; large ducts absent anteriorly to abdomen but small ducts present on at least meso­ and metathorax. Multilocular disc­pores quite large, 8 µm wide, present on abdomen as follows (totals across segment): VIII 14–20; VII 13–22 along posterior margin and 9–12 along anterior margin; VI 18–22 post. + 10–12 ant.; V 22–26 post. + 3 or 4 ant.; IV 8–10 post. + 0 ant.; III & II 0; absent more anteriorly apart from an occasional disc­pore between procoxa and anterior spiracle. Circulus oval, 30– 34 µm long and 38–45 µm wide, probably without a transverse membrane medially. Eyespot about 33 µm wide. Antennae 7 or 8 segmented, 290–305 µm; non­apical segments each with 4 or 5 setae; preapical segment without a fleshy seta; apical segment with about 10 hair­like setae; 4 fleshy setae and 6 stiff setae near apex; apical seta about 31–35 µm long. Clypeolabral shield about 115–125 µm long; labrum about 100–120 µm long, with 11 pairs of setae. Spiracles: width of peritremes 20–24 µm. Metathoracic legs: lengths (µm): coxa 120–137; trochanter + femur 170–175; tibia 135–155; tarsus 77–90; claw 22– 25; number of setae: coxa 8 or 9; trochanter 5 or 6 (longest 65–80 µm); femur 9 or 10; tibia 7–9 (tibia with two spurs, each 20–24 µm long); tarsus 9; translucent pores quite abundant on lateral half of each metacoxa, with a few occasionally on distal end of femur and usually some on distal dorsal margin of tibia. Tarsal digitules with one slightly shorter and thinner than other, both capitate; claw digitules slightly longer than claw and also capitate; claw without a denticle. Vulva obvious, between segments VII and VIII.

Material examined: HOLOTYPE Ψ: GREENLAND: Zackenberg, stn 3 F, in water traps, 8.vii. 2000, Jens Böcher (ZMUC): 1 / 2 adΨΨ (holotype right hand specimen).

PARATYPE ΨΨ: GREENLAND: Zackenberg, stn 4 E, 29.vii. 2002, Jens Böcher (BMNH): 1 / 1 adΨ.

Other material: East Greenland, 1932; Angmagssalik (Thule­exp.), 1933; Vejrhøj, 13.i. 1934; Ulvesø, Ellaø, 14.v. 1934; no site, 18.viii. 1958; Qeqertasussuk (Disko Bugt), 12.viii. 1987; Lindhard Ø (Dove Bugt), 22.vii. 1989; Søndre Strømfjord, 2.viii. 1992; Jameson Land, 2.viii. 1994; Zackenberg, 22.vii. 2000 (ZMUC).

Comment. The adult females of C. multiporus from Greenland are significantly different from those of C. altoarcticus from Ellesmere Island, Canada, redescribed below. Female C. multiporus differ from C. altoarcticus particularly in the following (characterstates on Canadian material in brackets): (i) oral rim ducts abundant on dorsum, with a total of between 75 and 115 (total of between 10 and 30), and (ii) oral collar ducts absent on dorsum (a few present on all abdominal segments). The limbs of C. multiporus also tend to be slightly larger. The host plants of this species are unknown.

Etymology: the species name multiporus refers to the many oral rim ducts on the dorsum (Latin, multi ­ from multus, meaning more, and porus = pores).