Two new species of Iridoteuthis (Cephalopoda: Sepiolidae: Heteroteuthinae) from the southwest Pacific, with a redescription of Stoloteuthis maoria (Dell, 1959)
Author
Reid, Amanda L.
text
Zootaxa
2021
2021-07-28
5005
4
503
537
journal article
10.11646/zootaxa.5005.4.3
1175-5326
5142011
A06EDB00-575C-4F6A-B47F-A9CFB4CF50B4
Stoloteuthis maoria
(
Dell, 1959
)
Figures 8–11
;
Table 5
; Appendices 5, 6
Iridoteuthis maoria
Dell, 1959
(in part:
holotype
and male
paratype
from Cook Strait): 3,
Figures 3–6
.
Iridoteuthis merlini
Dell, 1959
(in part: female
paratypes
from the
Bay of Plenty
).
Type material.
Holotype
:
New Zealand
:
♂
(
16.1 mm
ML),
North Island
, N of
Wellington
,
Paraparaumi
,
40°53.00´S
,
174°59.00´E
, washed ashore after frosty night,
9 Aug.1954
(
NMNZ
M.11179).
Paratype
.
New Zealand
:
♂
(12.0 mm ML),
North Island
, off
Palliser Bay
,
41°31´S
,
174°58´E
,
457 m
, FV ‘
Regina’
,
Stn
VUZ17,
13 May 1955
(
NMNZ
M.11177).
Other material.
New Zealand
:
♂
(
8.7 mm
ML)
,
36°38´46.79´´S
,
176°10´58.19´´E
,
288 m
, coll. Minister of Fisheries, NIWA,
24 Jan. 1988
(
NIWA 156131
);
♀
(
13.7 mm
ML), SE of
Cape Palliser
,
41°50.36´S
,
175°38.54´E
,
300 m
over
2000 m
, RV ‘
James Cook’
,
Stn J
10/01/75,
27 Jun.1975
(
NMNZ
M.67900);
2♂
(
14.6 mm
ML,
17.2 mm
ML)
,
42°43´37.2´´S
, 178°62´1.6´´E–
42°43´4.8´´S
, 178°59.6´´E, 1002–
996 m
,
18 Aug. 2015
(
NIWA 106152
);
♂
(
8.9 mm
ML),
western Chatham Rise
,
42°50.2´S
,
177°32.3´W
,
821–863 m
, RV ‘
James Cook’
,
Stn J
12/42/84,
29 Jul.1984
(
NMNZ
M.287522);
♂
(
16.5 mm
ML),
♀
(
14.3 mm
ML), 43°32´16´´8 S
,
174°34´22.8´´E
–
43°33´0 S
,
174°33´57.6´´E
,
500–515 m
,
9 Dec. 2015
(
NIWA 128488
);
♀
(
9.4 mm
ML),
western Chatham Rise
,
43°34.08´S
,
176°17´E
,
62 m
over
352 m
, RV ‘
James Cook’
,
Stn J
01/17/75,
28 Jun.1975
(
NMNZ
M.287545);
♂
(
14.7 mm
ML),
4 juveniles
(6.0–
9.3 mm
ML),
western Chatham Rise
,
43°36´S
,
176°14.54´E
,
196 m
over
355 m
, RV ‘
James Cook’
,
Stn J
10/15/75,
28 Jun.1975
(
NMNZ
M.287540);
♂
(
11.1 mm
ML),
N of Jackson Head
,
43°53.4´S
,
168°39.5´E
,
173–194 m
, RV ‘
James Cook’
,
Stn J
07/43/85,
13 May 1985
(
NMNZ
M.91475);
♂
(
13.9 mm
ML),
Chatham Rise
,
44°42.7´S
,
176°31.6´E
,
150–230 m
, RV ‘
James Cook’
,
Stn J
15/28/90,
24 Sep.1990
(
NMNZ
M.287525);
♂
(16.0 mm ML),
Chatham Rise
,
44°45.05´S
,
177°49.50´E
,
800 m
,
4 Dec.1993
(
NMNZ
M.287528),
♂
(
20.1 mm
ML)
,
51°28´58.20´´S
,
167°49´36.58´´E
,
644 m
,
1 Dec. 2001
(
NIWA 84789
).
Australia
:
Tasmania
:
♀
(
9.2 mm
ML)
,
42°48´31.68´´S
,
148°28´45.84´´E
,
0–1000 m
,
19 Apr. 2015
(
AM
C.581915)
.
Diagnosis.
Occipital band wide. Dorsal arms in males with swollen glands on ventro-lateral sides. Males with enlarged suckers on second arm pair, approximately halfway along arms. Females with enlarged suckers on distal ends of arms 2. All arm suckers biserial in both sexes (sometimes crowded on dorsal arm pair of males, appearing as if in three series). Male arms 4 with a greater number of suckers (56–70) than on remaining arms.
Description.
Counts and indices for individual specimens are given in Appendices 5 and 6.
Species relatively small: ML males examined 11.6–
16.0
–20.1 (SD, 2.7), females 7.6–
11.1
–
14.3 mm
ML (SD, 3.2). Mantle short, broad, dome-shaped posteriorly (
Figures 8a–d
), MWI males 64.2–
88.0
–104.2 (SD, 12.0), females 74.1–
90.0
–110.1 (SD, 16.8). Body not markedly deep dorso-ventrally. Dorsal mantle contiguous with head, joined by wide occipital band, OBLI males 59.7–
88.9
–112.1 (SD, 14.9), females 78.9–
97.5
–108.7 (SD, 16.2). Ventral mantle extends anteriorly to base of funnel, anterior margin with shallow m-shaped indentation ventral to funnel (
Figure 8d
). VMLI males 82.5–
93.8
–135.0 (SD, 15.8), females 105.3–
109.1
–113.0 (SD, 4.3). Ventral shield clearly demarcated, with densely packed chromatophores and darker outline; covers almost entire ventral surface of body VSLI males 66.9–
85.4
–105.8 (SD, 9.6), females 87.0–
94.2
–99.3 (SD, 5.2). Fins oval, rounded anteriorly and posteriorly; positioned anteriorly, extend anteriorly beyond ventral mantle margin; FIIa males 14.9–
23.5
–33.3 (SD, 5.9), females 13.2–
20.3
–26.1 (SD, 5.5); fin width ~50% ML; FWI males 42.3–
56.5
–82.5 (SD, 12.6), females 48.5–
54.1
–59.8 (SD, 6.2); attached dorso-laterally; FII males 14.9–
23.5
–33.3 (SD, 5.9), females 26.6–
39.4
–54.3 (SD, 11.4).
Funnel conical, projects anteriorly well beyond ventral mantle margin FuLI males 48.2–
54.4
–66.7 (SD, 6.8), females 54.5–
58.3
–63.2 (SD, 3.9); free for most of its length, FFuI males 27.1–
37.0
–52.9 (SD, 7.3), females 31.5–
36.9
–46.1 (SD, 6.6). Tip of funnel not swollen on dorsal side. Funnel-locking cartilage long, narrow, straight, uniform width. Mantle cartilage a straight ridge (
Figure 8e
). Funnel valve a small flap. Funnel organ (
Figure 8f
) dorsal element broad, inverted V-shape, with ridge mid-anteriorly; ventral elements elongate oval.
Head broader than long, HLI males 78.6–
101.9
–130.8 (SD, 18.5), females 92.1–
101.4
–108.7 (SD, 7.2); HWI males 65.0–
82.4
–97.5 (SD, 10.3), females 82.9–
104.4
–127.2 (SD, 22.2). Eyes large, EDI males 39.7–
50.4
–69.0 (SD, 8.9), females 31.5–
42.9
–59.2 (SD, 11.9); ventral eyelids absent. Olfactory pore on latero-posterior surface of head, posterior and ventral to eyes.
Visceral photophore rounded, divided medially by septum that is joined to ventral mantle, ventral to ink sac and dorsal to, and associated with, anus (
Figure
8g
). Paired openings slitlike, teardrop-shaped, without protruding pores. Both sexes with large pads of glandular tissue on each side of mantle cavity between gills and funnel organ.
Arms 2 and 3 slightly longer than other arms in both sexes (
Table 5
). Arm length index of longest arms in males (ALI3) 59.4–
69.4
–81.9 (SD, 8.0); females (ALI3) 59.7–
78.3
–111.8 (SD, 23.0). Arms 1–3 connected by very deep webs extending almost to arm tips. Aboral keels gelatinous on arms 3; arms 4 with lateral keels.
Arms 1 of males hectocotylised with swollen and glandular ventral margins. Hectocotylus suckers uniform in size, sometimes crowded into three series. Remaining arm suckers biserial. Males with enlarged suckers midway along arms 2 (
Figure 9a
). Females with enlarged suckers on distal end of arms 2.
FIGURE 8.
Stoloteuthis maoria
(
Dell, 1959
)
.
a,
dorsal view, male holotype, NMNZ M.11179, 17.8 mm ML.
b,
ventral view, same specimen.
c,
dorsal view, male, NMNZ M.287525, 14.1 mm ML.
d,
ventral view, same specimen.
e,
funnel, male holotype (as in a); flc, funnel-locking cartilage; mlc, mantle-locking cartilage.
f,
funnel organ, male paratype, NMNZ M.11177, 12.0 mm ML.
g,
visceral photophore (vp), photophore opening (po), anus (a) (specimen as in c). Scale bars: a–d = 5 mm, e = 4 mm, f = 1 mm, g = 2 mm.
FIGURE 9.
Stoloteuthis maoria
(
Dell, 1959
)
.
a,
arm crown, ventral view, male, NIWA 84789, 20.1 mm ML.
b,
SEM, sucker rim, arm 2, male, NMNZ M.91475, 11.6 mm ML.
c,
SEM, sucker rim enlargement, arm 2 (specimen as in a).
d,
SEM, sucker rim, arm 4, female, NMNZ M.67900, 13.4 mm ML.
e,
tentacular club (specimen as in d), arrow indicates tentacle organ;
f,
SEM, portion of tentacular club (specimen as in d).
g,
SEM, club sucker rim (specimen as in d).
h,
SEM, club sucker rim (specimen as in d). Scale bars: a, c, d = 50 µm; b, f = 10 µm; e = 0.5 mm; g = 10 µm.
Sucker counts range from 20–54 on arms
1–3 in
males; Arms 4 with a greater number of suckers than other arms (56–70). Females with a similar number of suckers on all arms, ranging from 28–46.
Chitinous arm sucker rims: infundibulum with 3–4 rows of pavement-like processes (
Figure 9b–d
), peripheral sucker rim processes small, tightly packed, rest irregular oval. Chitinous inner ring of normal arm suckers with teeth on one side only in males, very slightly crenulated on opposite side (
Figure 9b, c
). Sucker rings smooth in females.
Tentacles slender, stalks naked, semicircular in cross section. Club relatively short; ClLI males 19.7–
25.0
–35.5 (SD, 5.8), females 32.6–
38.7
–44.8 (SD, 8.6), straight, tapers to rounded end distally; sucker-bearing face curved (
Figure 9e, f
). Suckers approximately
0.5–1.5 mm
in diameter in centre of club. ClRC 10–17 (usually 15); suckers enlarged slightly at base of club. Aboral keel absent; tentacle organ extends from proximal end of sucker-bearing portion of club, along tentacle stalk well beyond club sucker-bearing portion (
Figure 9e
); shallow median groove extends along length of club. Club sucker dentition (
Figure
9g
, h
): inner ring without teeth, and bearing ring of widely-spaced pegs; infundibulum with three rows of pavement-like processes; inner two rows hexagonal or pentagonal basally; pegs narrower than bases of processes; outer row wedge-shaped without pegs (
Figure
9g
); pegs with regular pitted surfaces (
Figure 9h
).
TABLE 5.
Stoloteuthis maoria
(
Dell, 1959
)
ranges of arm length indices (ALI), arm sucker diameter indices (ASIn) and arm sucker counts (ASC) of ten mature males and four mature females. min. = minimum, max. = maximum, SD = standard deviation.
Males |
Females |
min. |
mean |
max. |
SD |
min. |
mean |
max. |
SD |
ALI1 |
42.7 |
53.3
|
68.8 |
8.6 |
41.0 |
54.0
|
72.4 |
13.7 |
ALI2 |
56.7 |
68.9
|
87.5 |
10.0 |
48.5 |
63.4
|
81.6 |
14.4 |
ALI3 |
59.4 |
69.4
|
81.9 |
8.0 |
59.7 |
78.3
|
111.8 |
22.9 |
ALI4 |
45.5 |
55.7
|
69.7 |
8.0 |
48.5 |
58.3
|
72.4 |
10.0 |
ASIn1 |
3.4 |
4.4
|
5.2 |
0.6 |
3.5 |
3.9
|
4.6 |
0.5 |
ASIn2 |
5.2 |
7.7
|
10.8 |
1.7 |
3.5 |
3.9
|
4.6 |
0.5 |
ASIn3 |
4.2 |
5.1
|
6.3 |
0.8 |
3.5 |
4.0
|
4.9 |
0.6 |
ASIn4 |
2.2 |
4.2
|
5.4 |
0.9 |
3.1 |
4.0
|
4.6 |
0.7 |
ASC1 |
26 |
32
|
43 |
5 |
30 |
36
|
42 |
5 |
ASC2 |
20 |
30
|
37 |
6 |
28 |
37
|
42 |
6 |
ASC3 |
41 |
46
|
54 |
5 |
34 |
40
|
46 |
5 |
ASC4 |
56 |
63
|
70 |
6 |
36 |
39
|
42 |
2 |
Gills with 16–29 lamellae per demibranch; GLI males 32.8–
41.5
–56.0 (SD, 7), females 31.5–
38.9
–52.6 (SD, 9.5). Buccal membrane with six lappets; suckers absent.
Upper beak (
Figure 10a
) with pointed rostrum, hood convex, high above crest posteriorly; jaw curved, not sharply angled. Lower beak (
Figure 10b
) with pointed, short rostrum, rostral edge obtuse, curved; hood notch absent, wings straight. Distinct dark pigmentation restricted to rostrum and hood.
Radula with seven series of teeth (
Figure 10c
). Rhachidian simple, without cusps, triangular, sides straight, with narrow bases. First lateral teeth with pointed cusps, strongly displaced laterally, directed towards midline of radula. Second and third laterals, curved. Third laterals scythe-like, longer than second lateral teeth.
Gladius absent.
Male reproductive tract (
Figure 10d
) with large, ovoid accessory gland; spermatophore storage sac in one section; vas deferens prominent. Spermatophores approximately 1/5 mantle length SpLI 11.3–
16.1
–21.6 (SD, 3.5), SPWI 0.7–
0.9
–1.3 (SD, 0.2), very densely packed in spermatophore storage sac in high numbers. Spermatophore cement body unipartite; cylindrical, approximately uniform width, connects to sperm reservoir via a broad duct (
Figure 10e
). Oral end of ejaculatory apparatus with 3–4 simple coils.
Female reproductive tract: Ovary occupies large proportion of posterior end of mantle cavity. Nidamental glands paired, broad, located ventral to ovary. Large, cream-coloured accessory nidamental glands located toward distal end of nidamental glands. Bursa copulatrix absent. EgDI 14.0–
14.8
–15.7 (SD, 1.2).
Colour.
Alcohol preserved specimens with rich coloration: maroon with large deep purple chromatophores on dorsal head and mantle; spots small and animal darker on ventral surface; ventral shield bordered by dark U-shaped margin (
Figure 8c, d
); chromatophores on arms, arm webs, tentacles and clubs. Funnel with scattered chromatophores in a band covering the funnel tube on dorsal and ventral side; distal tip and base of funnel unpigmented. Fins with scattering of chromatophores close to junction with mantle.
Type
locality.
New Zealand
:
North Island
, N of
Wellington
,
Paraparaumi
,
40°53.00´S
,
174°59.00´E
(
Type
lo- cality approximate: washed ashore after frosty night.)
Distribution.
New Zealand
. Southern and southeastern
Australia
.
Comments.
An excellent detailed account of
S. maoria
, including additional details regarding colouration is provided in
Young
et al.
(2007b)
.
The
two female
specimens in the type series from the
Bay of Plenty
(
NMNZ
M.91591 and NMNZM.11178) are not conspecific with the type males and are identified here as
I. merlini
(described above).
Thus
, the diagnostic characters for females of this species are likely misreported if they refer to the original species description or the type material.
It
is difficult, however, to ascertain from the original description to which gender some of the traits refer.
However
,
Dell (1959)
mentions that, ‘in some specimens the tip [
of the funnel
] is swollen’ (p. 3).
This
likely refers to the misidentified female
paratypes
as this trait is not seen in females now known as
S. maoria
.
The rest of the original description is not very detailed, but the measurement data (albeit including only a few characters) provided for the
two specimens
from the
Bay of Plenty
(
Dell 1959: 6
) refer to the two misidentified female
paratypes
.
It has been mentioned in some works that
S. maoria
has ‘pointed fins’ (
Harman & Seki 1990: 179
), or pointed posterior lobes (
Young
et al.
2007b
). However, this is not the case based on the material examined here and likely refers to misidentified specimens.
It is also likely that records of
Stoloteuthis
from east of
Tasmania
, as reported in
Villanueva & Sánchez (1993
: NMV F.51921 and NMV F.52327) are
S. maoria
, but these specimens are yet to be examined. Future examination of additional material held in Australian repositories will provide additional information regarding the distribution of
S. maoria
.
Stoloteuthis maoria
is most similar to
S. leucoptera
and
S. cthulhui
Fernandez-Álvarez
et al.,
2021
.
Stoloteuthis maoria
differs in that the occipital band is narrow in
S. leucoptera
and
S. cthulhui
rather than broad as in
S. maoria
, the dorsal and ventral sides of the dorsal arm pair are swollen in
S. leucoptera
and
S. cthulhui
, rather than just the ventral side in
S. maoria
, and the suckers on the distal tips of the ventral arms are biserial in
S. maoria
, rather than tri- or tetraserial as in
S. leucoptera
and (possibly)
S. cthulhui
.
Stoloteuthis weberi
and
Stoloteuthis
sp. A
of
Young
et al.
(2014)
differ (among other traits) in that the mantle is not fused to the head in these two species.