Stoloteuthis maoria ( Dell, 1959 )

Reid, Amanda L., 2021, Two new species of Iridoteuthis (Cephalopoda: Sepiolidae: Heteroteuthinae) from the southwest Pacific, with a redescription of Stoloteuthis maoria (Dell, 1959), Zootaxa 5005 (4), pp. 503-537 : 519-524

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.

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 ).

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.

Figures

FIGURE 3. Iridoteuthis lophia, n. sp. a, SEM sucker, arm 2, male paratype, NMNZ M.330459, 14.2 mm ML. b, SEM, portion of sucker rim arm 3 (specimen as in a). c, SEM, sucker rim arm 3, female paratype, NMNZ M.67238, 24.6 mm ML. d, SEM, sucker rim arm 4 (specimen as in a). e, SEM, sucker rim arm 4 (specimen as in c). f, tentacular club (specimen as in a), arrow indicates tentacle organ. g, SEM, portion of tentacular club (specimen as in a). h, club sucker rim (specimen as in a). Scale bars: a = 100 µm; b, e, h = 10 µm; c, d = 20 µm; f = 1 mm; g = 50 µm.

FIGURE 4. Iridoteuthis lophia, n. sp. a, upper beak, lateral view, NMNZ M.330459, 14.4 mm ML. b, lower beak, lateral view (specimen as in a). c, SEM, radula, male paratype, NMNZ M.330459, 14.2 mm ML. d, reproductive tract (specimen as in c), anterior accessory gland (aag), accessory gland (ag), ciliated canal (cc), distal deferent canal (ddc), genital opening (go), mucilaginous gland (mg), spermatophoric gland (sg), spermatophore storage sac (sss), testis (t). Scale bars: a, b, 1 mm; c = 100 µm; d = 1 mm.

FIGURE 5. Iridoteuthis merlini, n. sp. a, lateral view, male holotype, NMNZ M.67223, 16.5 mm ML. b, ventral view, same specimen. c, funnel, ventral view, male paratype, NMNZ M.330463, 12.5 mm ML; flc, funnel-locking cartilage. d, mantlelocking cartilage (specimen as in a). e, funnel organ (fo), and funnel valve (fv), ventral view (specimen as in b). f, visceral photophore (vp), ventral view, (pt) photophore tubes (specimen as in a). g, mantle cavity, antero-ventral view (specimen as in b), arrow indicates renal papilla. Scale bars: a, b = 5 mm; c, e, f, g = 2 mm; d = 1.0 mm.

FIGURE 6. Iridoteuthis merlini, n. sp. a, left arm 2 (arrow), ventro-lateral view, male paratype NMNZ, M.330463, 12.5 mm ML. b, distal tip of right arm 1 (specimen as in a; note some suckers missing from distal arm tip in this specimen). c, SEM, sucker rim, left arm 1 (specimen as in a). d, SEM, sucker rim, arm 1, female paratype, NMNZ M.330463, 10.9 mm ML. e, SEM, sucker rim, right arm 1 (specimen as in a). f, tentacular club, ventro-lateral view (specimen as in a), tentacle organ (to). g, SEM club sucker rim (specimen as in a). h, SEM, enlargement of club sucker rim as in g. Scale bars: a, b = 1 mm; c, g = 20 µm; d, e = 50 µm; f = 0.5 mm; h = 10 µm.

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.

FIGURE 10. Stoloteuthis maoria (Dell, 1959). a, upper beak, lateral view, male, NMNZ M.91475, 14.4 mm ML. b, lower beak, oblique lateral view (specimen as in a). c, SEM, radula (specimen as in a). d, reproductive tract, male, NIWA 84789, 20.1 mm ML, anterior accessory gland (aag), accessory gland (ag), distal deferent canal (ddc), genital opening (go), mucilaginous gland (mg), spermatophoric gland (sg), spermatophore storage sac (sss), testis (t), vas deferens (vd). e, spermatophore ejaculatory apparatus, NMNZ M.91475, 11.6 mm ML. Scale bars: a = 2 mm; b, d = 50 µm; c, g = 10 µm; e = 0.5 mm.

FIGURE 11. Distribution of Iridoteuthis merlini, n. sp. (solid circles); I. lophia, n. sp. (crosses) and S. maoria (open circles) examined in this study. Black arrow indicates the type locality for I. merlini, n. sp. and I. lophia, n. sp.