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

Table 1

Morphometrics and meristics of male and female Jensen’s ray Amblyraja jenseni from different areas of the North Atlantic (significant differences are given in bold, number of specimens examined are shown in parentheses, m = standard error).

	Females (7)						Males (6)
Character	Absolute			% TL			Absolute			% TL
	Min	Max	Mean	Min	Max	Mean ±m	Min	Max	Mean	Min	Max	Mean ±m
TL, mm	369.0	1065.0	686.6				223.0	1113.0	635.0
Disc width	264.0	795.0	510.4	69.5	81.3	74.2 ± 1.51	156.5	837.0	466.4	70.2	75.5	73.3 ± 0.91
length	207.0	593.0	390.5	55.7	60.0	57.1 ± 0.60	119.8	632.0	351.5	51.9	56.8	55.1 ± 0.79
Snout length, preorbital	61.2	157.0	103.3	14.0	16.6	15.2 ± 0.31	32.1	174.0	89.6	10.3	15.8	14.2 ±0.84
preoral	54.9	135.0	92.9	11.6	16.3	13.6 ± 0.71	37.1	149.0	88.7	12.6	16.9	14.5 ± 0.65
prenasal	38.7	80.3	65.0	7.5	10.6	9.7 ± 0.72	29.9	115.0	66.8	7.4	11.1	9.7 ± 0.81
Orbit, horizontal diameter	10.6	40.0	27.0	2.5	5.8	4.2 ± 0.52	9.2	22.0	16.1	1.8	4.7	3.1 ± 0.52
Interorbital width	27.8	68.1	46.1	6.0	7.8	6.8 ± 0.26	13.8	77.2	47.4	6.2	11.1	7.5 ± 0.75
Spiracle length	11.2	34.4	19.6	2.3	3.4	3.0 ± 0.16	5.6	37.3	20.4	2.5	3.8	3.1 ± 0.18
Interspiracular width	40.8	110.0	75.8	10.3	12.0	11.1 ± 0.19	23.6	115.0	74.4	10.2	15.8	11.7 ± 0.85
Orbit + spiracle length	20.9	56.3	42.2	5.3	6.9	6.2 ± 0.33	16.2	60.0	39.9	4.8	7.2	5.8 ± 0.41
D1, height	6.0	42.0	17.3	1.5	4.9	2.3 ± 0.46	3.8	25.6	13.2	1.7	2.3	2.0 ± 0.10
base length	17.8	47.0	30.7	4.3	5.4	4.7 ± 0.16	11.2	48.9	28.4	3.9	5.0	4.6 ± 0.16
D2, height	5.6	28.0	14.4	1.3	3.3	2.0 ± 0.25	3.3	30.4	13.8	1.5	2.7	2.0 ± 0.18
base length	19.7	44.6	32.3	4.2	5.8	5.0 ± 0.27	8.8	53.0	29.8	3.3	5.2	4.5 ± 0.29
Interdorsal space	0.0	29.0	6.3	0.0	3.4	0.9 ± 0.44	0.0	3.1	1.3	0.0	1.1	0.4 ± 0.20
C, base length	13.1	28.3	20.1	2.4	3.6	3.0 ± 0.28	10.9	25.0	18.0	2.2	4.0	2.7 ± 0.34
Tail, postdorsal length	14.1	45.0	23.9	2.4	5.3	3.5 ± 0.49	8.7	30.0	18.1	2.2	5.5	3.3 ± 0.51
height at V-tips	8.9	25.3	17.0	2.4	2.7	2.5 ± 0.06	6.8	23.0	15.9	2.0	2.5	2.3 ± 0.10
width at V-tips	11.4	30.3	21.1	2.7	3.6	3.1 ± 0.18	8.1	31.7	21.5	2.8	3.6	3.1 ± 0.14
height at D1 origin	4.2	9.8	7.0	0.9	1.2	1.0 ± 0.06	3.0	11.0	7.2	0.8	1.3	1.0 ± 0.07
width at D1 origin	4.9	13.5	8.5	0.9	1.6	1.3 ± 0.12	4.2	14.3	9.1	1.1	1.6	1.3 ± 0.08
lateral fold length	143.0	337.0	243.0	31.6	38.8	36.4 ± 1.62	107.0	345.0	235.6	30.5	39.6	34.2 ± 1.81
Head length, ventrally	105.3	281.0	205.3	26.4	33.3	30.4 ± 1.32	77.9	309.0	212.4	27.8	34.5	30.2 ± 1.22
Mouth width	45.5	157.0	93.3	11.9	15.9	13.3 ± 0.58	27.9	150.0	84.7	12.3	14.5	13.0 ± 0.35
Internasal width	46.6	126.0	84.1	11.8	13.0	12.4 ± 0.22	28.5	133.0	76.5	11.1	13.7	12.3 ± 0.36
Nasal curtain, length	20.5	56.4	34.6	3.7	5.6	5.1 ± 0.35	18.0	65.3	36.3	3.4	6.7	5.4 ± 0.56
width each lobe	10.0	23.6	13.8	1.5	2.8	2.1 ± 0.24	6.8	29.0	18.5	1.9	4.2	2.6 ± 0.41
space between lobes	30.4	107.0	65.7	8.2	10.1	9.4 ± 0.34	21.8	115.0	70.5	7.8	12.1	9.7 ± 0.85
Gill slit length, first	5.2	14.2	8.7	1.3	1.4	1.3 ± 0.02	2.9	18.5	9.6	1.3	1.7	1.4 ± 0.09
third	5.4	16.8	9.9	1.3	1.6	1.5 ± 0.05	3.6	22.5	12.1	1.6	2.0	1.7 ± 0.07
fifth	4.4	14.9	7.3	0.9	1.4	1.1 ± 0.08	2.2	16.9	8.2	0.9	1.5	1.2 ± 0.12
Space btwn first gill slits	68.7	186.0	137.5	17.5	22.1	20.2 ± 0.62	42.1	225.0	135.1	16.3	24.8	20.4 ± 1.43
fifth gill slits	52.3	139.0	104.9	13.1	18.1	15.6 ± 0.74	31.2	170.0	87.2	10.5	16.4	13.4 ± 1.10
V-length, anterior lobe	55.7	123.0	81.0	11.5	15.1	12.5 ± 0.54	23.9	143.0	78.2	10.7	15.2	12.4 ± 0.63
posterior lobe	74.6	206.0	131.5	18.1	20.2	19.3 ± 0.36	54.0	229.0	138.3	16.7	20.6	19.0 ± 0.81
Clasper, postanus length	na	na	na	na	na	na	20.5	240.0	116.9	7.6	23.2	13.5 ± 3.51
Snout tip to center of anus	196.0	625.0	367.8	52.8	58.7	55.2 ± 1.02	114.8	678.0	359.1	51.1	60.9	54.8 ± 1.65
to max. disc width	142.0	358.0	259.2	33.6	42.6	38.6 ± 1.44	105.0	400.0	255.8	31.4	39.7	36.5 ± 1.63
Center of anus to D1	121.0	356.0	223.8	30.4	34.8	32.5 ± 0.52	74.9	349.0	180.8	17.1	33.6	29.3 ± 2.52
to D2	139.0	398.0	264.3	35.4	39.7	37.2 ± 0.59	104.0	390.0	246.4	30.2	38.5	34.9 ± 1.39
to tail tip	175.0	470.0	306.7	42.7	47.4	45.0 ± 0.81	108.2	475.0	270.5	38.1	48.5	43.7 ± 1.47
Snout angle	85	91	88.0 ± 3.00				89	103	94.0 ± 4.51
No. preorbital thorns	1	2	1.6 ± 0.24				1	3	2.0 ± 0.32
No. postorbital thorns	1	2	1.8 ± 0.20				1	2	1.8 ± 0.20
No. interspiracular thorns	1	2	1.6 ± 0.24				1	2	1.4 ± 0.24
No. scapular thorns	3	5	4.0 ± 0.45				3	6	4.0 ± 0.63
No. nuchal thorns	1	2	1.6 ± 0.24				0	2	1.6 ± 0.40
No. interscapular thorns	1	1	1.0 ± 0.00				1	3	1.4 ± 0.40
No. median thorns	23	28	25.0 ± 0.95				20	31	24.4 ± 1.91
No. middorsal thorns	0	1	0.2 ± 0.20				0	1	0.2 ± 0.20
Tooth rows upper jaw	52	63	58.5 ± 2.53				59	64	61.3 ± 1.11
lower jaw	54	61	57.3 ± 1.89				52	64	57.8 ± 2.53