Table 3.

Variation in morphometric traits for three species of Spinoncaea (both sexes, including form variants of female S. ivlevi) from three locations in the Pacific Ocean (WP = western equatorial Pacific; EP = eastern equatorial Pacific; KS = Korea Strait; n = number of specimens examined) Abbreviations: A2 = antenna; AS = anal somite; CR = caudal ramus, for numbering of setae see Fig. 2C; DES = distal endopod segment; DS = distal spine; G(D)S = genital (double-)somite; in = inner margin; out = outer margin; L = length; PGS = postgenital somites; Pro = prosome; Uro = urosome; W = width.

		S. ivlevi								S. tenuis				S. humesi
		female					male			female		male		female	male
		WP		EP		KS	WP	EP	KS	EP	KS	EP	KS	EP	WP	KS
		robust	elongate	robust	elongate	robust
n		11	1	6	4	3	4	4	1	8	1	3	1	3	2	1
Total length (μm)		327–360	305	318–373	330–345	343–344	306–329	307–331	298	320–355	329	310–325	292	344–348	285/295	292
Pro:Uro including CR		1.5–1.7	1.4	1.5–1.7	1.3	1.5–1.6	1.3–1.5	1.5–1.6	1.4	1.5–1.7	1.3	1.5	1.4	1.3–1.4	1.1/1.2	1.3
AS L:W		1.0–1.1	1.3	1.0–1.1	1.2–1.4	1.0–1.1	0.9–1.1	0.9–1.0	0.9	1.1–1.3	1.2	1.0	1.2	1.2–1.3	1.2	1.2
CR	L:W (in)	1.9–2.2	2.0	1.9–2.2	2.0–2.1	2.1	1.8–1.9	1.7–2.0	1.8	1.8–2.5	2.5	1.9–2.2	2.4	2.3–2.5	2.1/2.2	2.5
	L:W (out)	2.4–2.9	2.5	2.4–2.6	2.6–2.8	2.4	2.3–2.7	2.3–2.5	2.4	2.3–2.9	3.0	2.2–2.6	2.8	2.8–3.1	2.6/2.9	3.2
	Setae III:II	1.5–1.9	2.0	1.3–1.7	1.6–2.0	1.3–1.6	1.6–1.9	1.2–1.9	1.4	1.0–1.5	1.1	1.2–1.5	1.2	1.6–1.7	1.6/1.8	1.3
	Setae IV:III	1.2–1.8	1.7	1.5–1.7	1.2–1.3	1.8–1.9	1.3–1.5	1.2–2.0	1.8	1.4–2.3	2.2	1.7–1.9	2.0	1.2–1.6	1.4/1.5	1.6
G(D)S (dorsal view)	L:W	1.8–2.0	2.0	1.6–1.9	1.9–2.2	1.8	1.8–1.9	1.8–1.9	1.8	1.8–2.3	2.2	1.8–1.9	2.0	1.9–2.0	1.7/1.9	2.1
G(D)S L : PGS L		1.4–1.5	1.7	1.7	1.4–1.5	1.6	2.3–2.5	2.0	2.1	1.5–2.1	1.9	2.6–2.7	2.4	1.4–1.5	2.1/2.2	2.3
G(D)S Max W: Min W (posterior portion)		1.2–1.5	1.5	1.4–1.5	1.4–1.6	1.3–1.5	-	-	-	1.5–2.1	1.8	-	-	1.7–2.0	-	-
A2DES L:W		3.4–3.9	2.2	3.0–3.8	3.4–3.9	3.2–3.9	3.2–3.9	3.6–3.8	-	3.3–4.1	4.1	3.6–4.0	3.8	3.7–4.3	3.8–4.1	3.5