Copepoda
Use of the Key

The key starts at Page 451: Copepoda. Keys are given to orders, families, genera, and species although, in a few cases, keys cover more than one of these taxonomic levels where there is only one or a few species in the group. These keys have been constructed from sometimes inadequate information on the morphology of each species and its variability. Also it is likely that the fauna of the South Atlantic is incompletely known and that not all species have been included in the keys. Only those families which have been recorded from the South Atlantic have been included here. There are bound to be cases where the keys do not appear to work. In these instances where a particular character appears to be at fault or is ambiguous to interpret, take the alternative of a couplet to see if this brings you to a credible identification. The size of species (see the Family Tables in Co.12 Tables. Morphometric and distributional data for the species treated) is often a useful additional check. If this fails then we refer you to the revisions mentioned in the text and original descriptions.

Abbreviations used in the figures and keys

(Fig. Co.1a , Structure of Calanoid body)
(Fig. Co.1b , A1 antennule)
(Fig. Co.1c , A2 antenna)
(Fig. Co.1d , Md mandible)
(Fig. Co.1e , Mxp maxilliped)
(Fig. Co.1f , Mx1 maxillule)
(Fig. Co.1g , Mx2 maxilla)

Abbrevations[/textfile][/l]

[l][m]Glossary[/m][r]A1[/r]A1: antennule
A2: antenna
Ba: basis
Co: coxa
Ce: cephalosome (the head region when this includes only the somite of the maxillipeds)
CR: caudal rami
Enp: endopod; Enp1-3 - endopod segments 1-3
Exp: exopod; Exp 1-3 - exopod segments 1-3
Gn: gnathobase
Gns: genital somite
Md: mandible
Mdp: mandibular palp
Mx1: maxillule
Le 1: coxal epipodite - first external lobe
Le 2: basal exite - second external lobe
Li 1: praecoxal arthrite - first internal lobe
Li 2: coxal endite - second internal lobe
Li 3, 4: basal endites - third and fourth internal lobes
Mx 2: maxilla
Li 1, 2: praecoxal endites - first and second lobes
Li 3, 4: coxal endites - third and fourth lobes
Li 5: basal endite - fifth lobe
Li 6: (if present) - sixth lobe
Mxp: maxilliped
Li 1: praecoxal endite (not figured)
Li 2-4: syncoxal endites (not figured)
P1-5: swimming legs 1-5. (Fig. Co.1a). 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. For the 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.
Pc: praecoxa
Pcs: praecoxal sclerite (not figured)
Pd1-5: pedigerous somites 1-5
Pr: prosome (the anterior region of the body limited by a major articulation)
Sc: syncoxa (fused praecoxa and coxa)
Ur1-5: urosomites 1-5, last somite being the anal somite
ven.: ventral view.