Pseudochirella Sars, 1920
Taxonomic description:
Female. Total length 3.6-9.2 mm. Cephalothorax 3.0-4.6 times longer than abdomen. Cephalon and Th1 distinctly, or indistinctly separated, Th4 and Th5 separated (except P. hirsuta ). Crest absent. Rostrum present, well visible laterally, one-pointed. Posterior Th5 corners rounded, rarely with spines, may be prolonged into rounded, or triangular lobes, symmetrical, slightly or clear asymmetrical. Genital segment symmetrical, slightly or abruptly asymmetrical, may be close to barrel in shape, or with different projections; its length and width may be nearly equal, rarely length twice the width (P. divaricata ). Ventral swelling is developed in different degree: smooth (P. hirsuta ), or strongly prominent (P. dubia ). Genital field arranged in about the middle of genital segment (ventral view), but sometimes removed laterally (P. fallax , P. mariana ). Genital segment - Abd3 in the majority of species with minute spinules along posterior border. A1 24-segmented (rarely 23-segmented), usually longer than cephalothorax, may be slightly longer than body. Re A2 usually 1.5-1.8 times longer than Ri. A2 coxopodite with 1 setae, basipodite with 2 setae (rarely with 1 setae: P. mariana ); Ri1 with 1-2, Ri2 with 6 long posterior setae and 1 short on external lobe, and 6-7 (5 in P. mariana ) long and 1-2 (rarely 3) shorter posterior setae on internal lobe; Re1 without setae, or with rudiment of seta, sometimes (P. dubia , P. hirsuta ) with well developed seta, in the latter species in addition to 1 distal seta, there are 2 well developed setae on Re2; in other species of the genus these setae absent; Re3-Re6 with 1 seta each, Re7 with 1 medial and 3 terminal setae. Md palp base with 3 setae, Ri1 Md with 2 setae, rarely with third additional small seta; Ri2 Md with 9 long and 1-2 short posterior setae. Mx1 gnathobase with 9 claw-like and 1 short terminal setae and 4 setae on posterior surface (in P. mariana with 3 posterior setae). Second Mx1 internal lobe with 5 setae, third with 4 setae (in P. mariana and P. fallax with 5 setae); on protopodite near Ri base 5 setae, Ri with 15-16 setae, Re with 11 setae, external lobe with 7 long and 2 shorter setae. 1 setae on the fourth and fifth Mx2 endites transformed into claw-like spine, Mx2 structure typical of Aetideidae. Mxp protopodite 1.6-1.9 times shorter than Ri1 Mxp, 1 seta present in proximal part of segment, with 3 setae groups: proximally with 1-2 setae, medially with 3 and distally with 3 setae and sensitive knob. P1 with 3-segmented Re, separation between Re1 and Re2 may be incomplete, each segment with external spine, spine on Re1 is long, exceeding the base of spine on Re2; Ri one-segmented. Ri P2 2-segmented, sometimes separation between segments incomplete; other rami of swimming legs 3-segmented. P4 coxopodite with group of spines. They are in different degree sclerotized, vary in size and number, from 5 to 30.
Male. Total length 3.20-7.20 mm. Cephalon and Th1, as well as Th4 and Th5 usually fused, rarely separated. Cephalothorax about 3 times longer than abdomen. Rostrum developed poorer than in females. Posterior Th5 corners symmetrical, sometimes slightly asymmetrical, rounded, rarely with spines, or teeth. A1 22-24-segmented. Sometimes shorter, sometimes longer than body. Setation of A2 in comparison with female diminished. Md palp base usually with 1 seta, Ri1 Md with 1, Ri2 with 8-9 setae. Mx1, Mx2 and Mxp strongly reduced, setation weaker than in female. P1-P4 like in female, but usually segmentation of limb more complete; spines on P4 coxopodite absent. Often external spines on Re1 P1 and Re2 P1 shorter than in females of corresponding species. P5 powerful, of complex structure, usually longer than abdomen, biramous. Coxopodites not big, right and left basipodites strongly sclerotized, large, wide; Ri P5 one-segmented; right Re 2-segmented, left 3-segmented.
Type species: Pseudochirella obesa Sars, 1920 (designated in Markhaseva, 1996).
The genus Pseudochirella includes 27 species described from adult and 2 species: P. calcarata Sars, 1920 and P. cryptospina (Sars, 1920) described from fifth copepodid stage. Their descriptions are given below except of P. semispina Vervoort, 1949 and 2 species described from juveniles.
Pseudochirella accepta Zvereva, 1976 (male unknown)
Pseudochirella batillipa Park, 1978
Pseudochirella bilobata Vervoort, 1949 (male unknown)
Pseudochirella bowmani Markhaseva, 1986 (male unknown)
Pseudochirella dentata (A. Scott, 1909) (male unknown)
Pseudochirella divaricata (Sars, 1905) (male unknown)
Pseudochirella dubia Sars, 1925
Pseudochirella fallax Sars, 1920
Pseudochirella formosa Markhaseva, 1989 (male unknown)
Pseudochirella gibbera Vervoort, 1949 (male unknown)
Pseudochirella hirsuta (Wolfenden, 1911)
Pseudochirella limata Grice and Hulsemann, 1968 (male unknown)
Pseudochirella lobata (Sars, 1907) (male unknown)
Pseudochirella mariana Markhaseva, 1989 (male unknown)
Pseudochirella mawsoni Vervoort, 1957
Pseudochirella notacantha (Sars, 1905)
Pseudochirella obesa Sars, 1920
Pseudochirella obtusa (Sars, 1905)
Pseudochirella pacifica Brodsky, 1950
Pseudochirella palliata (Sars, 1907) (male unknown)
Pseudochirella pustulifera (Sars, 1903)
Pseudochirella scopularis (Sars, 1905) ( male unknown)
Pseudochirella spectabilis (Sars, 1900)
Pseudochirella spinosa (Wolfenden, 1911)
Pseudochirella tanakai Markhaseva, 1989 (male unknown)
Pseudochirella vervoorti Tanaka and Omori, 1969 (male unknown)