Sexually Dimorphic Morphological Characters in Five North Atlantic Deepwater Skates (Chondrichthyes: Rajiformes)

Table 4

Morphometrics and meristics of male and female Bigelow’s ray Rajella bigelowi from different areas of the North Atlantic (significant differences are given in bold, number of specimens examined are shown in parentheses, m = standard error, na = not available).

	Females (4)						Males (8)
Character	Absolute			% TL			Absolute			% TL
	Min	Max	Mean	Min	Max	Mean ±m	Min	Max	Mean	Min	Max	Mean ±m
TL, mm	102.0	453.0	283.8				101.0	436.0	231.0
Disc width	57.0	234.0	144.3	47.9	55.9	51.3 ± 0.87	54.0	215.0	116.1	47.8	54.3	50.6 ± 0.70
length	43.0	209.0	128.9	40.6	47.1	44.8 ± 0.82	46.0	196.0	102.8	41.3	49.0	44.5 ± 0.72
Snout length, preorbital	10.5	55.3	31.5	9.4	13.4	11.0 ± 0.44	8.0	41.0	23.1	7.9	12.7	10.2 ± 0.45
preoral	10.5	56.4	33.5	10.3	14.4	11.7 ± 0.48	11.0	44.5	26.6	10.2	14.8	11.8 ± 0.44
prenasal	8.5	46.0	28.5	8.3	12.7	10.0 ± 0.46	8.0	37.0	21.8	7.9	11.8	9.5 ± 0.35
Orbit, horizontal diameter	4.2	19.0	11.8	3.8	4.7	4.2 ± 0.12	4.0	17.0	9.4	3.1	5.3	4.1 ± 0.19
Interorbital width	5.0	16.5	10.5	3.4	4.9	3.8 ± 0.17	5.0	16.0	9.3	3.2	5.3	4.3 ± 0.21
Spiracle length	2.2	12.6	6.7	2.0	2.8	2.3 ± 0.10	2.0	11.5	5.7	2.0	3.0	2.4 ± 0.10
Interspiracular width	7.2	29.9	19.5	6.6	7.1	6.9 ± 0.06	8.0	30.0	14.9	6.4	8.0	7.1 ± 0.19
Orbit + spiracle length	5.0	21.5	13.1	4.1	5.2	4.7 ± 0.11	5.5	21.5	11.4	4.1	9.1	5.3 ± 0.45
D1, height	1.4	12.0	6.5	1.4	2.6	2.1 ± 0.18	2.0	12.0	5.4	1.7	3.2	2.2 ± 0.15
base length	7.7	23.8	15.3	4.1	7.5	5.5 ± 0.36	5.0	24.0	12.4	4.1	6.1	5.1 ± 0.19
D2, height	1.6	12.1	6.3	1.4	2.7	2.1 ± 0.19	2.0	13.0	5.4	1.7	3.0	2.2 ± 0.15
base length	6.2	21.0	13.9	3.5	6.2	5.0 ± 0.34	5.5	22.0	12.4	4.7	5.9	5.4 ± 0.15
Interdorsal space	0.0	5.0	1.1	0.0	2.8	0.6 ± 0.37	0.0	3.0	0.7	0.0	1.9	0.5±0.20
C, base length	3.9	12.0	8.9	1.9	5.9	3.4 ± 0.57	3.0	14.0	6.7	1.6	3.6	2.9 ± 0.21
Tail, postdorsal length	4.0	12.0	8.6	1.9	5.9	3.4 ± 0.50	3.0	14.0	7.0	2.1	3.9	3.1 ± 0.18
height at V-tips	3.2	12.5	8.2	2.6	3.1	2.9 ± 0.07	3.5	11.5	6.4	2.3	3.5	2.8 ± 0.10
width at V-tips	4.5	18.7	11.4	3.2	4.6	4.0 ± 0.15	4.0	19.5	9.3	3.1	4.5	4.0 ± 0.14
height at D1 origin	1.4	4.8	3.0	1.0	1.4	1.1 ± 0.04	1.5	5.0	2.7	1.0	1.8	1.2 ± 0.09
width at D1 origin	1.8	8.0	4.4	1.1	1.8	1.5 ± 0.12	1.8	8.3	3.6	1.1	2.0	1.6 ± 0.09
lateral fold length	21.3	122.0	66.1	12.1	29.0	20.5 ± 2.59	17.0	106.0	55.7	14.0	27.0	20.6 ± 1.72
Head length, ventrally	21.5	109.2	67.0	21.1	25.6	23.4 ± 0.47	22.0	91.0	50.7	20.4	25.6	22.3 ± 0.53
Mouth width	8.3	28.3	17.0	4.9	8.1	6.3 ± 0.32	7.0	35.0	15.4	5.9	8.0	6.7 ± 0.22
Internasal width	7.2	33.2	19.0	5.8	7.3	6.7 ± 0.17	8.0	29.0	14.5	5.5	7.9	6.9 ± 0.23
Nasal curtain, length	3.1	15.3	8.7	2.6	3.7	3.0 ± 0.16	2.0	13.0	6.0	2.0	3.3	2.5 ± 0.14
width each lobe	1.6	7.7	4.6	1.4	1.9	1.7 ± 0.06	1.0	6.5	3.2	0.8	2.0	1.4 ± 0.11
space between lobes	5.2	13.0	9.8	2.9	5.7	4.1 ± 0.49	4.8	16.0	9.6	3.0	5.9	4.6 ± 0.44
Gill slit length, first	1.0	8.8	4.2	1.0	1.9	1.4 ± 0.11	1.5	5.0	2.8	0.9	1.6	1.3 ± 0.07
third	0.7	9.3	4.4	0.7	2.1	1.5 ± 0.14	1.0	6.0	3.0	0.9	1.6	1.2 ± 0.08
fifth	1.0	7.1	3.3	1.0	1.6	1.1 ± 0.07	1.0	4.8	2.3	0.7	1.6	0.9 ± 0.09
Space between first gill slits	13.8	62.9	37.6	12.4	14.0	13.2 ± 0.21	14.0	58.0	30.5	12.3	14.2	13.3± 0.19
fifth gill slits	9.7	38.6	24.3	7.7	9.5	8.6 ± 0.21	9.0	35.0	18.4	6.8	9.1	8.2 ± 0.23
V-length, anterior lobe	11.0	62.3	36.2	10.7	13.8	12.5 ± 0.42	13.0	56.0	29.7	11.5	13.8	12.8 ± 0.25
posterior lobe	14.5	81.2	43.0	12.8	17.9	14.7 ± 0.55	13.0	61.0	32.6	11.9	16.0	13.8 ± 0.42
Clasper, postanus length	na	na	na	na	na	na	7.0	45.0	17.7	5.4	10.3	7.2 ± 0.43
Snout tip to center of anus	38.0	195.0	116.1	37.3	43.4	40.3 ± 0.85	39.0	180.0	91.3	36.0	41.3	39.4 ± 0.49
to max. disc width	31.5	125.0	73.1	12.5	32.8	27.2 ± 2.23	23.3	130.0	56.5	10.2	30.1	24.5 ± 2.30
Center of anus to D1	40.0	199.0	128.9	39.2	48.5	45.2 ± 0.99	47.0	190.0	106.5	43.0	48.9	46.1 ± 0.61
to D2	46.0	222.0	144.5	45.1	53.6	50.9 ± 1.00	53.0	215.0	119.5	49.3	54.5	51.9 ± 0.43
to tail tip	62.0	254.0	166.2	56.1	63.2	59.2 ± 0.82	59.0	249.0	137.4	57.1	61.7	59.5 ± 0.50
Snout angle	106.0	111.0	108.5 ± 2.50				107.0	110.0	108.3 ± 0.88
No. preorbital thorns	2	6	3.1 ± 0.52				1	5	2.1 ± 0.39
No. postorbital thorns	2	4	2.4 ± 0.26				1	4	2.1 ± 0.26
No. interspiracular thorns	0	4	1.3 ± 0.53				0	3	0.8 ± 0.42
No. scapular thorns	2	8	4.6 ± 0.75				2	10	3.6 ± 0.79
No. nuchal thorns	2	4	2.6 ± 0.32				2	4	2.4 ± 0.22
No. interscapular thorns	1	1	1.0 ± na				1	1	1.0 ± na
No. median thorns	25	33	29.4 ± 0.96				26	33	28.6 ± 0.69
No. middorsal thorns	0	1	0.1 ± 0.13				0	1	0.1 ± 0.10
Tooth rows upper jaw	22	38	30.7 ± 2.35				22	40	32.3 ± 2.63
lower jaw	24	36	29.2 ± 2.15				22	38	30.3 ± 2.60