Table 9 Comparison of the Arctic and northern North Atlantic species of Muusoctopus Gleadall, 2004 [20]. Immature individuals are not used (except for Muusoctopus sp. 1, where only immature individuals are known, and M. leioderma (Berry, 1911) [64], where it is impossible to separate them from the rest in Akimushkin (1965) [66], Hochberg (1998) [67] and Ibanez et al. (2016) [92]). Values are minimum to maximum (mean ± SE), where applicable (except for M. leioderma (Berry, 1911) [64], where values from Akimushkin (1965) [66], Hochberg (1998) [67] and Ibanez et al. (2016) [92] are impossible to recalculate due to lack of individuals’ details). ML, mantle length

Habitat depth, m

Original data

86–2442

(579.4 ± 52.4)

540–1957

(1470.6 ± 230.4)

No data

101–450.5

(314.8 ± 108.2)^a

No data

29–255

(58.2 ± 16.6)

Literature data

86–2000^b

797–2540^c

38–1760^d

No data

500–1843^f

30–220 ^g

Habitat temperature,

° C

Original data

-1.31 to 6.90

(0.41 ± 0.30)

2.34–5.50

(3.18 ± 0.48)

No data

1.97–2.00^e

No data

-1.74 to 0.28

(-1.23 ± 0.18)

Literature data

-0.9^b

No data

-1.0 to 4.9^d

No data

No data

-1.4 to 1.6 ^g

Sources of information on morphology

This study (n = 25);

Nesis (2001) (n = 2)

This study (n = 3);

Allcock et al. (2006)

(n = 3);

Gleadall (2013) (n = 1)

Kondakov (1941)

(n = 3; 2 = juv.);

Akimushkin (1965)

(n not stated);

Nesis (1987)

(n not stated);

Hochberg (1998)

(n not stated);

Ibanez et al. (2016)

(n not stated)

This study (n = 3);

A. L. Allcock (unpubl. data)

(n = 1)

Allcock et al. (2006)

(n = 16);

Barrat et al. (2007)

(n = 5);

Gleadall (2013) (n = 1)

This study (n = 2);

Løyning (1930) (n = 1);

MacGinitie GE (1955) + 

MacGinitie N (1959)

(n = 1);

Kondakov et al

(1981) (n = 2);

Nesis (2001) (n = 1)

ML, mm

20–52 (32.3 ± 1.8)

47–113 (78.6 ± 10.2)

42–100

22–31 (26.5 ± 2.3)

50–107 (73.1 ± 3.2)

26–59 (43.4 ± 6.0)

TL, mm

96–235 (141.6 ± 7.8)

255–510 (354.2 ± 49.8)

Up to 210

99–148 (121.7 ± 14.3)

320–648 (431.6 ± 21.8)

94–253 (187.6 ± 27.8)

Ventral ML, mm

17–49 (27.8 ± 1.9)

40–89 (64.7 ± 8.5)

No data

17–26 (20.7 ± 2.7)

43–61 (50.5 ± 2.1)

36–37^e

Mantle width, % ML

87.5–140.0 (111.3 ± 3.4)

83.1–100.0 (91.0 ± 2.4)

63.0–89.0

87.8–109.7 (102.0 ± 5.1)

43.3–78.8 (69.7 ± 2.2)

54.0–105.3 (85.8 ± 11.1)

Head width

% ML

50.0–100.0 (78.7 ± 2.6)

63.7–106.1 (81.0 ± 6.1)

No data

74.2–86.7 (80.2 ± 2.8)

36.4–69.4 (56.4 ± 2.0)

54.0–78.9 (62.3 ± 5.7)

% mantle width

48.0–85.7 (71.3 ± 2.2)

75.8–106.1 (88.4 ± 4.8)

78.1–105.0

67.6–95.0 (79.5 ± 5.9)

67.7–127.6 (81.8 ± 3.3)

62.9–75.0 (68.9 ± 6.1)

Eye diameter, % ML

26.4–40.7 (32.5 ± 0.8)

32.6–55.1 (47.0 ± 7.2)

No data

27.3–30.4 (28.7 ± 0.9)

No data

21.1–23.1^e

Lens diameter, % eye diameter

20.0–38.9 (28.8 ± 1.3)

28.0–31.0 (29.6 ± 0.9)

No data

28.6–35.3 (32.4 ± 2.0)

No data

25.0–26.7^e

Funnel length, % ML

28.8–56.7 (42.1 ± 1.6)

39.8–55.3 (46.8 ± 2.2)

30.0–58.0

39.1–45.2 (42.1 ± 1.3)

20.9–46.3 (35.1 ± 1.5)

53.8–63.2^e

Free funnel length,

% funnel length

45.5–57.1 (52.9 ± 0.7)

50.0–75.0 (64.3 ± 3.5)

No data

53.8–78.6 (65.0 ± 5.2)

19.2–66.7 (40.2 ± 2.9)

45.8–52.4^e

Funnel organ shape

W; medial and marginal limbs of same length, or medial can be slightly longer; marginal limbs broad

W; medial and marginal limbs of same length, or marginal can be slightly longer; marginal limbs moderately broad

W; medial limbs longer than marginal limbs; marginal limbs broad

VV; medial limbs slightly longer than marginal limbs; marginal limbs relatively narrow

VV; medial and marginal limbs of same length, or medial can be slightly longer; marginal limbs relatively narrow

W; medial limbs much longer than marginal limbs; marginal limbs very broad

Web depth, % longest arm

10.4–35.6 (25.5 ± 1.1)

17.9–32.4 (25.1 ± 1.3)

14.0–24.0

14.0–25.7 (20.1 ± 2.2)

10.8–25.0 (17.7 ± 0.6)

20.0–34.4 (27.3 ± 1.1)

Web formula

b > c > a > d > e

b > c > d > a > e

b > a = c > d > e or

c > b > d > a > e or

a > b > c > d > e

c > b > d > a > e

c > b > a > d > e

b > c > a > d > e

Arm length, % ML

234.6–376.2

(313.7 ± 6.8)

271.9–456.9

(351.3 ± 14.4)

224.0–374.0

245.5–373.9

(293.2 ± 17.7)

328.1–541.6

(417.5 ± 12.6)

230.0–350.0

(303.6 ± 28.4)

Arm formula

1 > 2 > 3 > 4

2 > 1 > 3 > 4

1 > 2 > 3 > 4

1 > 2 > 3 > 4

1 > 2 > 3 > 4

2 > 1 > 4 > 3

Sucker count

84–120 (95.5 ± 1.5)

128–164 (140.3 ± 3.3)

80–102

81–118 (99.9 ± 5.3)

134–199 (170.0 ± 4.8)

84–104 (88.1 ± 1.4)

Sucker diameter, % ML

6.3–11.7 (8.9 ± 0.3)

7.1– 9.0 (8.4 ± 0.3)

7.0–11.0

8.7–10.0 (9.4 ± 0.3)

4.5–10.6 (7.0 ± 0.4)

7.8–16.7 (11.3 ± 1.9)

Enlarged suckers, diameter

(% ML) and location

Enlarged suckers absent

Enlarged suckers absent

Enlarged suckers absent

No data (as only immature individuals are known)

Enlarged suckers absent

7–12 pairs; 20.5–25.0

(23.1 ± 1.3)

Gill length, % ML

21.9–44.0 (34.4 ± 1.3)

25.8–31.9 (29.4 ± 0.8)

27.0

39.1–45.0 (41.9 ± 1.7)

20.9–32.0 (25.3 ± 0.7)

42.1–48.7^e

Gill lamellae, outer/inner

8–9 (mode 8)/

7–8 (mode 7)

8–11 (mode 10)/

8–11 (mode 9)

11–12/?

(whole gill 16–20)

8–10 (mode 10)/

8–9 (mode 9)

7–10 (mode 9)/

6–9 (mode 8)

10–11 (mode 10)/10

Stylets

Absent

Present

Present

(vestigial?)

No data

Present

Vestigial

Vestigial ink duct

Absent

Present

Present

No data

Present

Present

Hectocotylized arm length

% ML

177.8–282.6

(233.8 ± 6.5)

208.0–299.0

(268.6 ± 12.9)

127.0–139.0

246.7–256.5^e

189.0–261.2

(220.3 ± 6.3)

287.2–323.7^e

% opposite arm

55.2–80.7 (71.5 ± 2.2)

65.3–88.4 (78.5 ± 4.2)

69.0–89.0

79.7–93.7^e

51.0–63.7 (58.0 ± 1.7)

91.1–123.4 (102.6 ± 7.2)

Hectocotylized arm

sucker count

46–56 (52.0 ± 1.1)

67–71 (68.3 ± 0.6)

47–61

56–66^e

61–72 (65.8 ± 1.3)

60–64 (62.7 ± 1.3)

Ligula length, % hectocotylized

arm length

8.0–14.1 (10.3 ± 0.5)

3.9–10.6 (6.3 ± 1.0)

11.0–18.0

4.6–6.5^e

6.3–11.1 (8.6 ± 0.4)

9.0–13.4 (11.5 ± 0.9)

Ligula width, % ligula length

45.0–63.3 (55.4 ± 2.1)

48.0–57.1^e

No data

55.6–62.5^e

No data

20.0–24.1^e

Calamus length, % ligula length

27.5–43.3 (36.8 ± 1.4)

28.0–43.5 (36.9 ± 2.8)

12.0–20.0

37.5–66.7^e

26.7–60.0 (42.3 ± 2.9)

14.3–17.2 (15.6 ± 0.9)

Number of spermatophores

5–22 (12.5 ± 2.4)

4–19^e

No data

No data

3–25 (13.1 ± 2.3)

49–52^e

Spermatophore length

mm

27.9–48.0 (39.8 ± 0.5)

104.0–120.0^e

No data

No data

75.0–119.0 (92.8 ± 4.4)

46.3–63.5 (57.9 ± 1.1)

% ML

78.0–135.9 (108.1 ± 1.8)

92.0–114.3^e

No data

No data

97.5–142.2 (121.0 ± 5.9)

118.7–167.1 (150.6 ± 3.3)

Fecundity of females

65–168 (99.5 ± 6.8)

227–300 (259.0 ± 21.5)

No data

No data

70–342 (218.9 ± 34.2)

136

Ripe oocyte length

mm

12.5–13.0^e

No data; large vitellogenic oocytes are 17.0–22.0

(mean 20.0) mm

14.0–17.0

No data

15.0–22.0 (18.0 ± 0.7)

No data

% ML

52.1–54.2^e

No data; large vitellogenic oocytes 19.1–24.7

(mean 22.5)

No data

No data

21.1–40.7 (27.8 ± 2.3)

No data