[Copepoda] P1-5: swimming legs 1-5. In the keys, P1-P4 segmentation is denoted as, e.g., 3/3 (number of Exp segments/number of Enp segments). The spine (Roman numerals) and seta (Arabic numerals) formula for the swimming legs is given in the mode of Sewell (1949) (Fig. Co.2). The outer elements are given first and are separated by a hyphen from the inner elements. The terminal segment of each ramus has 3 components, separated by commas, with the sequence: outer, terminal, inner.

P5 of Euchaetidae males (Fig. Co.6.7M): the following abbreviations are used, dp: digitiform process, dpsl: distal poorly sclerotized lobe, ht: hairy tubercle, ppsl: proximal poorly sclerotized lobe, sl: serrate lamella.

(Fig. Co.1a , Structure of Calanoid body),
(Fig. Co.2 , Swimming leg).

Alternative forms for P1 : P2, P3, P4, P5.