Giesbrecht, 1892
Females
Total length 2-4 mm. Body relatively robust, anterior Ce rectangular in dorsal view with conspicuous lateral constriction anteriorly. Many species possess dark pigment which gives dark brown or black colour to some parts of body. Ce and Pd1 separated, Pd4 and 5 fused and extended into pointed, often asymmetrical, processes, rarely rounded. R atrophied. Ur of 3 somites; Gns often spinose or asymmetrically swollen; Ur2 is sometimes asymmetrical. CR short with 6 setae. A1 symmetrical 24-segmented, segments 24 and 25 fused. A2 Coxa with 1 seta; Basis and Enp1 fused; Enp1 with with 1 distal seta, Enp2 with 8+7 setae; Exp 6-segmented, separated from Basis, narrow and short, with Exp2 long and distal segments short with 0, 2, 1, 1, 1, 2 setae respectively; Md gnathobase narrow with few teeth, basal tooth usually divided into one or more pointed cusps or may be simple; Basis large; Enp 2-segmented with 0 and 6 setae respectively; Exp 4-segmented with 1, 1, 1, 2 setae respectively. Mx1 with most lobes small except for very elongate Li2; Li1 with 6-10 spines and setae; Li2 and 3 with 3 setae each; Li4 with 2 setae; Enp 2-segmented, with 0 and 5 setae respectively; Exp small, with 7 setae; Le1 and 2 without setae. Mx2 very large; Li1 and 2 rudimentary with 3 and 2 setae respectively; Li3 and 4 with 2 setae each; Li5 with 2 stout spines of variable length and thickness and very small spinule or proximal spine may be one-half length and considerably thinner than distal spine; Enp with 3 stout spines and 4 small setae. Mxp small, Coxa with 1 medial and 2 terminal setae; Basis with patches of setules and 3 setae medially; Enp 6-segmented, segment 1 almost fully incorporated into Basis, with 1, 2, 2, 2, 2, 2, setae respectively. P1-4 with 3-segmented exopods with serrated outer margins, especially Exp2 and 3, and 2-segmented Enp (segments 1 and 2 fused).
Spine and seta formula: Spine and seta Candaciidae.
P5 uniramous, not natatory, usually symmetrical; Coxa and intercoxal sclerite fused; Basis and 1-segmented Exp separate, Basis with 1 distolateral spinule; terminal segment longest, either may end in one or more spine-like processes, finger-like process, or single long seta; setae may or may not be present on inner margins.
Males
Body similar to female, but Ur of 5 somites; posterior corners of Pr always asymmetrical; Gns is almost always asymmetrical, bearing process on right side sometimes with complex apex. Right A1 geniculate, 23-segmented, segments 17-18 and 19-20 fused, with or without denticulate segments at bend. Mouthparts and P1-4 similar to the female. P5 not natatory, 4-segmented on left and 3-segmented on right; may be chelate on right or ending in a long feather-like seta; Coxa, not counted in segmental complement, are small and fused with intercoxal sclerite.
This family was revised by Grice (1963) and contains only two genera, both known from the South Atlantic:
Genus Candacia Dana, 1846
Genus Paracandacia Grice, 1963